Smokers More Likely To Experience Impotence, Wake Forest Study Shows

Men with high blood pressure who smoke are 26 times more likely to have erectile dysfunction --impotence -- than nonsmokers, John Spangler, M.D., M.P.H., of Wake Forest University Baptist Medical Center told the American Society of Hypertension May 19 in San Francisco.

Erectile dysfunction, or impotence, is the inability of a man to achieve an erection or to complete intercourse, he said, and affects an estimated 30 million Americans.

"These data are the first to quantify a 26-fold increase in erectile dysfunction among primary care men with hypertension who also currently smoke, a rate that is also twice that of former smokers," said Spangler, associate professor of family and community medicine.

He said the study showed that former smokers among patients with high blood pressure are 11 times more likely to be impotent than non-smokers.

"Cigarette smoking, hypertension and erectile dysfunction are common disorders in primary care, and informing men who smoke of the exceptionally high possibility of developing erectile dysfunction may motivate many to quit their tobacco habit."

Spangler said that cigarette smoking and impotence had been linked previously by other investigators, including finding what doctors call a dose response relationship: the more cigarettes smoked per day the greater the chance of impotence.

But most of these earlier studies looked at a highly selective group of patients going to urology or cardiology clinics, he said. "This is the first study that looked at a primary care population and is more reflective of the general population."

Spangler said smoking has "both acute and chronic effects on erectile physiology." In both human and animal studies, smoking inhibits the ability to achieve a full erection.

Smoking also is known to accelerate atherosclerosis -- hardening of the arteries-- and when the blood vessels in the pelvis area are narrowed, that contributes to reduced penile blood flow.

"A smoking history should be obtained from all patients, especially those who report erectile dysfunction," Spangler recommended, "Informing men who smoke about the exceptionally high likelihood of developing erectile dysfunction should become a standard part of care of these patients." Spangler said the research team was surprised that there was no relationship between stress and impotence, but noted that the small size of the study -- 59 patients -- may have limited the chance to detect differences. The smoker versus nonsmoker difference, however, was dramatic.

"It may be that cigarette smoking and high blood pressure are such powerful risk factors for impotence that it just overshadows stress," he said.

The study was supported in part by a cooperative agreement from the Centers for Disease Control and Prevention. The team, in addition to Spangler, include John H. Summerson, M.S., Joseph C. Konen, M.D., M.S.P.H., and Ronny A. Bell, Ph.D. Konen is now at the Department of Family Medicine at Carolinas Medical Center in Charlotte.

Source: Science Daily

Study Pinpoints An Enzyme Key To Both Male And Female Sexual Dysfunction - Along With A Potential Treatment

Researchers at the University of Pennsylvania and other institutions have identified an enzyme that appears to play a key role in bringing on sexual dysfunction in both men and women – and a second molecule that can just as easily yank the offending enzyme out of commission. The findings, which carry the possibility of new treatments for sexual disorders, are scheduled to appear in two papers in the March 13 issue of Biochemistry, a peer-reviewed journal of the American Chemical Society, the world’s largest scientific society.

Led by Penn chemist David W. Christianson, the team found that the enzyme arginase can effectively short-circuit a biochemical pathway critical to male sexual arousal. But unlike remedies developed expressly for erectile dysfunction, which have proven disappointing in clinical trials with women, treatments that home in on arginase may offer hope for both sexes.

"There is intense interest in new targets for sexual dysfunction therapy," said Christianson, the Edmund and Louise Kahn Professor in the Natural Sciences. "Arginase should be a target in men and women alike, insofar as sexual dysfunction arises in both from circulation defects in the genitalia."

Offering the means to strike that target, Christianson and his co-authors pinpoint the amino acid derivative S-(2-boronoethyl)-L-cysteine, also known as BEC, as one of the tightest-binding arginase inhibitors ever identified. BEC joins another powerful arginase-blocking compound, (S)-2-amino-6-boronohexanoic acid, which was identified by Christianson in 1999.

In the chemical pathway that leads to sexual arousal in both sexes, arginase comes into play somewhat before phosphodiesterase V, the target molecule of Viagra – which could present a new solution for the roughly 3 in 10 men for whom that medication is ineffective. Viagra has shown even less success in preliminary studies of female sexual dysfunction.

Healthy sexual function in both genders relies on a biochemical cascade as carefully orchestrated as any courtship ritual. At one critical step in that pathway, nitric oxide synthase converts arginine, one of the 20 human amino acids, into citrulline and nitric oxide. The latter product is said to be the principal mediator of penile erection; it facilitates neurotransmission and causes rapid relaxation of smooth muscle in the penis’ spongy tissue, allowing the thousands of tiny vessels there to swell with blood.

Arginase can derail this reaction by sequestering arginine and breaking it down into compounds unrelated to those physiologically responsible for arousal, depriving the genitalia of the nitric oxide needed for sexual function.

"Both Viagra and BEC function by blocking enzymes that can degrade key chemical players in this pathway," Christianson said. "The difference is that Viagra works several steps later than arginase-inhibiting compounds."

Erectile dysfunction, which afflicts half of men older than 40 to some extent, occurs when this enzyme-mediated pathway goes awry, impeding blood flow in and out of the penis. Female sexual dysfunction can also result from impaired blood flow to the genitalia. Sexual difficulties in both genders often manifest themselves as side effects of heart disease, hypertension, diabetes and the use of certain medications such as antidepressants.

Working with tissue taken from men undergoing penile prosthetic implantation, Christianson and his colleagues verified for the first time that arginase is present in the human penis. The group also found that administering BEC enhanced smooth muscle relaxation in human penile tissue, which triggers erection by allowing the penis’ spongy tissue to fill with blood.

Christianson is corresponding author of the two Biochemistry papers. He was joined by J. David Cox, Ricky F. Baggio and Evis Cama of Penn and authors at Boston University, Temple University, the University of Pittsburgh, the Wistar Institute in Philadelphia and Université Paris. The work was supported by the National Institutes of Health.

Source: Science Daily

Beyond Viagra: Other Phosphodiesterase Inhibitors Are Candidates For Potential Therapies

The same basic process used by the popular pharmaceutical Viagra may someday help people suffering from a variety of conditions, from allergies to diabetes. Viagra’s success has raised interest in the growing study of phosphodiesterase (PDE) inhibitors, says Joseph Beavo, Ph.D., a professor of pharmacology at the University of Washington School of Medicine.

Viagra works by inhibiting one specific type of enzyme called a cyclic GMP phosphodiesterase. "There is not just one, but many phosphodiesterases. Different PDEs are expressed in different tissues and in different parts of the cell, and have different physiological functions. The challenge has been for the drug companies to find agents that are selective for specific phosphodiesterases so that they can treat the disease without causing toxic side effects," Beavo says.

Beavo discussed PDEs and their inhibitors during the "Signal Transduction" panel at the American Association for the Advancement of Science annual meeting here today.

The different PDEs make up a large class of enzymes. Beavo and his colleagues discovered many of the 11 families that are recognized so far. These enzymes are found throughout the body, where they modulate many important functions. For example, they play a key role in many sensory processes including vision and smell. They may even play a role in learning and memory. On the one hand, this means that drugs regulating PDEs may someday provide a treatment for people with vision or memory problems. But at the same time, any researcher wanting to use PDE inhibitors to treat one specific part of the body must make sure that the therapy does not interfere with other PDEs – such as the ones involved in vision or memory.

Most PDE inhibitors currently available as medication affect PDEs in multiple organs, and so their use is often limited by their toxic side effects. Viagra, introduced in 1999, became a poster child for PDE research in part because of its selectivity.

"Viagra was the first really successful PDE inhibitor, both mechanistically and commercially," Beavo says. Viagra has generated more than $1 billion in sales. It is among the most widely prescribed drugs.

Viagra is a very selective drug. It acts on one specific PDE found in the penis. In the presence of nitric oxide, a signaling molecule released from the nerves in the penis, inhibition of this PDE helps cause an erection.

Here is why inhibition of the PDE has that effect: nitric oxide causes the production of a secondary signaling chemical, cyclic GMP, which leads to erection. During sexual stimulation, men with erectile dysfunction may have trouble producing enough cGMP. Normally, the PDE breaks down the cGMP into molecules that cannot cause erection. By inhibiting the breakdown of cGMP, Viagra leads to more cGMP. In other words, PDEs cause reductions in the needed chemical in the penis, and Viagra blocks the PDE to prevent this from happening. Viagra generally does not have side effects caused by inhibition of other PDEs.

"We use Viagra's mechanism of action as a beautiful example of drug and physiological selectivity when we talk to students," Beavo says. Researchers are now seeking other PDE inhibitors that will also act selectively, without toxic side effects throughout the body. Since many PDEs have been discovered only within the past year, the search is just beginning.

Beavo’s lab recently characterized PDE7 and PDE8, which can be induced in certain kinds of immune cells -- particularly T-cells. These two families of PDE do not break down cGMP; instead, they reduce cAMP, a similar signaling molecule, found in those immune cells. Since these PDEs appear to be very important for immune system activity, researchers are studying whether inhibitors of these enzymes might have an effect on anti-immune and hyper-inflammatory diseases such as rheumatoid arthritis and allergies. Other PDEs are thought to mediate other processes. PDE3 affects insulin secretion (with potential involvement in diabetes) and leptin signaling (with dietary and fat implications). Researchers at drug companies and other universities are examining how PDE inhibitors may be used to improve memory, treat chronic obstructive pulmonary disease and blood clotting disorders. In all of these examples, considerable work and testing will be needed before there are clinical benefits, Beavo said.

Source: Science Daily

Study Appears To Suggest That Use Of Viagra May Have Adverse Cardiovascular Effects

A limited study conducted at Cedars-Sinai Medical Center in Los Angeles, and utilizing post-marketing adverse event reports made to the FDA, shows that there appears to be a high number of deaths and serious cardiovascular events associated with the use of Viagra, the most commonly prescribed therapy for erectile dysfunction in men. These findings will be presented March 14 at the meeting of the American College of Cardiologists in Anaheim, CA. Presenters will be Sanjay Kaul, M.D., and Babak Azarbal, M.D.

In an analysis of 1,473 major adverse events, 522 people died, the majority due to cardiovascular causes. According to the study's senior author, Dr. Kaul, the majority of deaths were associated with standard Viagra dosages (70 percent of the deaths were associated with the 50 mg dose), were due to cardiovascular causes and appeared to be clustered around the time of dosing (two thirds of deaths in which the time from ingestion to death was reported, occurred within 4-5 hours of taking Viagra). The majority of deaths occurred in patients who were less than 65 years of age, and who had no reported cardiac risk factors.

The study confirmed the well-documented increased risk with combined use of nitrates and Viagra. Of the 90 patients who were on nitrates and taking Viagra, death occurred in about 68 percent, and death or myocardial infarction occurred in 88 percent. However, the study showed that most deaths (88 percent) actually occurred in patients who were not taking nitrates, leading investigators to speculate whether there are some susceptible individuals who don't need nitrates to unmask the harmful effects of Viagra.

Source: Science Daily

Erectile Dysfunction Lower In Men Who Have Intercourse More Often

Having intercourse more often may help prevent the development of erectile dysfunction (ED). A new study reports that researchers have found that men who had intercourse more often were less likely to develop ED.

Analyzing a five-year study of 989 men aged 55 to 75 years from Pirkanmaa, Finland, the investigators observed that men reporting intercourse less than once per week at baseline had twice the incidence of erectile dysfunction compared with those reporting intercourse once per week. Further, the risk of erectile dysfunction was inversely related to the frequency of intercourse.

Other factors that may affect the incidence of ED, such as age, chronic medical conditions (diabetes, heart disease, hypertension, cerebrovascular disease and depression), body mass index and smoking were included in the analysis of the data.

Erectile dysfunction incidence was 79 cases per 1000 in men who had reported sexual intercourse less than once per week, dropping to 32 cases per 1000 in men reporting intercourse once per week and falling further to 16 per 1000 in those reporting intercourse 3 or more times per week.

In addition, the frequency of morning erections predicted the development of complete erectile dysfunction, with an approximate 2.5-fold risk among those with less than 1 morning erection per week compared with 2 to 3 morning erections per week

Writing in the article, Juha Koskimäki, MD, PhD, Tampere University Hospital, Department of Urology, Tampere, Finland, states; "Regular intercourse has an important role in preserving erectile function among elderly men, whereas morning erection does not exert a similar effect. Continued sexual activity decreases the incidence of erectile dysfunction in direct proportion to coital frequency."

The study clearly indicates that regular intercourse protects men from the development of erectile dysfunction, which may, in turn, impact general health and quality of life. The investigators advise clinicians to support the sexual activity of their patients.

Source: Science Daily

Smoking Increases Likelihood Of Impotency

Men who smoke are more likely to suffer from erectile dysfunction than nonsmokers, reports an international group of impotency experts in the November issue of the Journal of Urology.

Erectile dysfunction is the inability to achieve or maintain an erection suitable for sexual intercourse. It is estimated that over 30 million American men have some form of erectile dysfunction.

The research consortium, headed by Kevin T. McVary, associate professor of urology at Northwestern University Medical School, found strong parallels and shared risks among smoking, coronary artery disease, atherosclerosis and erectile dysfunction. Results of the group’s review showed that smoking exacerbates the well-known negative effects of coronary artery disease and hypertension on a man’s ability to achieve and maintain an erection.

In addition, prevalence of erectile dysfunction in former smokers was no different from that in men who had never smoked. McVary said that the vascular system in the penis is subject to the same degenerative diseases of blood vessels of the heart, kidneys, brain and major vascular systems. Smoking alters the ability of blood to coagulate and accelerates hypertension by promoting vasoconstriction and atherosclerosis. In turn, hypertension increases the need for drugs that induce or worsen erectile dysfunction.

The underlying cause of erectile dysfunction in smoking is poorly understood, but there is evidence that smoking may impair production of nitric oxide, the principal "chemical messenger" involved in penile erection, in the cells that line blood vessels. Nitric oxide also plays an important role in cardiovascular health and inhibition of apoptosis, or programmed cell death.

While the results of the group’s study indicated that erectile dysfunction is linked to smoking and its related health risks, additional basic and clinical science studies will be required to determine the exact mechanism of the smoking effect and establish clinical practice guidelines for men with erectile dysfunction.

Scientists from the University of Washington School of Medicine, Seattle, McGill University Medical School, Montreal, and other members of the Sexual Medicine Society of North America also contributed to this study.

Source: Science Daily

Research Links Erectile Dysfunction And Cardiovascular Disease

Preliminary findings from clinicians at the Research Institute of the McGill University Health Centre (MUHC), show that men with erectile dysfunction are more likely to have cardiovascular disease. Cardiovascular disease affects approximately 40 000 Canadian men annually.

"Our study suggests, that erectile dysfunction, particularly in young men, may be an early warning sign of heart disease and stroke," says MUHC Director of Clinical Epidemiology and lead investigator, Dr. Steven Grover.

Dr. Grover, who is also a professor in the Faculty of Medicine at McGill University, and his colleagues evaluated more than 4 000 men. They compared the risk of erectile dysfunction among patients with and without cardiovascular disease. "We found that the presence of cardiovascular disease was strongly associated with erectile dysfunction," says Dr. Grover."

Among men without diagnosed cardiovascular disease, cardiovascular risk factors such as diabetes, smoking, high blood pressure and low HDL cholesterol were more common among those who had erectile dysfunction. This suggests that the men who have erectile dysfunction and have no other symptoms of cardiovascular disease may be at increased risk for developing the disease.

Accordingly, a complete diagnostic evaluation of erectile dysfunction should include screening for cardiovascular risk factors."

This study was selected as the winner of the Yamanouchi Impotence Best Abstract Series Award by the American Urological Association (AUA) and the findings will be presented today, at the Annual Meeting of the AUA.

This study was funded by Pfizer Canada Inc.

Source: Science Daily

Erectile Dysfunction Gives Early Warning Of A Heart Attack, Warns Expert

Erectile dysfunction gives a two to three year early warning of a heart attack, warns an expert on the British Medical Journal website.

But the link between erectile dysfunction and the risk of heart disease is being ignored by doctors, writes Dr Geoffrey Hackett from the Good Hope Hospital in Birmingham.

Over many years Hackett reports regularly seeing patients referred with erectile dysfunction after a heart attack, only to hear that they had developed erectile dysfunction two to three years before—a warning sign ignored by their general practitioners.

It is well known that erectile dysfunction (a symptom of vascular disease in the smaller arteries) doubles the risk of heart disease, a risk equivalent to being a moderate smoker or having an immediate family history of heart disease. Erectile dysfunction in type 2 diabetes has been shown to be a better predictor of the risk of heart disease than high blood pressure or high cholesterol.

But despite this considerable evidence erectile dysfunction is still treated as a recreational or "lifestyle issue" rather than a predictor of a serious health problem, says Hackett.

The UK government has pledged to reduce the death rate from coronary heart disease and stroke and related diseases in people under 75 by at least 40% by 2010, yet there is no screening for erectile dysfunction in patients with diabetes or heart disease, he says.

"Continuing to ignore these issues on the basis that cardiologists feel uncomfortable mentioning the word 'erection' to their patients or that they may have to deal with the management of a positive response, is no longer acceptable and possibly, based on current evidence, clinically negligent", he concludes.

Source: Science Daily

Newest Hypertension Drugs May Improve Sexual Function

Sexual dysfunction in men with high blood pressure may be aided by the newest type of hypertension drug, reported Carlos Ferrario, M.D., of Wake Forest University Baptist Medical Center (WFUBMC), today at the American Heart Association's annual conference.

After 12 weeks of treatment with the new drug losartan, 88 percent of hypertensive males with sexual dysfunction reported improvement in at least one area of sexuality. The number of men reporting impotence dropped from 75.3 percent to 11.8 percent.

"These results suggest a possible solution for people who've stopped taking blood pressure medicines because they interfere with sexual function," said Ferrario director of WFUBMC's Hypertension and Vascular Disease Center. "In addition to controlling blood pressure as well or better than other medications, losartan seems to have a positive effect on sexuality."

The study was conducted in Spain by Ferrario and colleagues at the University of Valencia School of Medicine and Hospital Marina Alta. It used a self-administered questionnaire to screen 323 men and women with hypertension for sexual dysfunction, which includes decreased libido, impotence, and poor sexual satisfaction. Sexual dysfunction was diagnosed in 82 men, a prevalence of 42 percent.

These 82 men were compared to an equal number of men without sexual dysfunction. Both groups took 50 to 100 milligrams of losartan (sold under the brand name of Cozaar) daily for 12 weeks. They completed the questionnaire at both the beginning and end of the treatment period.

In the men with sexual dysfunction, 88 percent reported improvement in at least one area of sexual function after treatment with losartan. The number reporting overall sexual satisfaction increased from 7.3 percent to 58.5 percent. The number reporting a high frequency (at least once a week) of sexual activity improved from 40.5 percent to 62.3 percent. An improved quality of life was reported by 73.7 percent of the men with sexual dysfunction.

Similar results were reported in a small group of women treated with losartan. The sample size, however, was too small for the results to be statistically validated.

In the group of men without sexual dysfunction, the drug treatment produced no changes in sexual function or satisfaction.

Ferrario said the results are promising and point to the need for additional research.

"This study was performed in a non-random sample, so we must be careful in extrapolating the findings to the general hypertensive population," said Ferrario. "However, the consistent nature of the findings points out the need for larger clinical trials on this subject."

In the study, losartan was equal to or better than other drugs at controlling blood pressure. Losartan works by blocking angiotensin, a hormone that causes high blood pressure, and keeping it from binding to body tissues.

"Our finding that impotence improved in men taking losartan supports the theory that angiotensin contributes to sexual dysfunction," said Ferrario. "This helps debunk the myth that impotence is caused by hypertension drugs. In fact, it appears that sexual dysfunction is part of the hypertension disease process. Certain drugs, such as beta blockers and diuretics, can aggravate sexual dysfunction, but we don't believe they cause it."

Ferrario said losartan may improve sexual function and satisfaction in two ways: by acting on blood vessels in the penis that have been damaged by high blood pressure and by acting in the brain to improve well-being.

"Aside from its vascular effects, losartan may affect the central nervous system," said Ferrario. "This suggestion comes from findings that sexual satisfaction improved even in men who had reported having sex once a day."

The research was funded by an unrestricted educational grant from Merck Sharp & Dohme Spain to the Spanish investigators.

Source: Science Daily

Premature Ejaculation May Be A Genetic Disorder

Premature ejaculation can be embarrassing, but a new study suggests that it might be a genetic disorder.

Researchers from Turku, Finland, interviewed more than three thousand men - all pairs of male twins and their older or younger brothers - about the first time they had sex. Many participants in the study reported that they had suffered from erectile dysfunction and premature ejaculation at their first sexual encounter.

These common problems are often attributed to external factors, such as intoxication or nervousness due to peer pressure. This research confirms that such factors do cause erectile dysfunction. On the other hand, premature ejaculation appears to be strongly linked to genetic factors, and is not just psychological.

In an earlier study, researchers in The Netherlands linked premature ejaculation to a gene for serotonin regulation in a group of two hundred men. The new data from Finland independently show a genetic link to premature ejaculation in a much larger group, and rule out environmental factors.

Faculty of 1000 Medicine member David Goldmeier notes that the increasing evidence for a genetic cause of premature ejaculation opens the way for the development of new drug treatments - something that many men might benefit from. However, both Goldmeier and reviewer Taylor Segraves emphasize that drug therapy is not the only solution: psychotherapy will continue to be a valuable and useful form of treatment for sexual dysfunctions - even those with a genetic cause.

The study by Pekka Santtila, Kenneth Sandnabba and Patrick Jern was published in the Journal of Sex & Marital Therapy in March 2009.

Source: Science Daily

Sexual Competition Drives Evolution Of A Sex-related Gene

In what could be termed a truly seminal discovery, researchers have shown that when females are more promiscuous, males have to work harder -- at the genetic level, that is. More specifically, they determined that a protein controlling semen viscosity evolves more rapidly in primate species with promiscuous females than in monogamous species. The finding demonstrates that sexual competition among males is evident at the molecular level, as well as at behavioral and physiological levels.

The researchers, led by Howard Hughes Medical Institute investigator Bruce Lahn at the University of Chicago, published their findings in the November 7, 2004, issue of Nature Genetics.

Lahn's group studied semenogelin, a major protein in the seminal fluid that controls the viscosity of semen immediately following ejaculation. In some species of primates, it allows semen to remain quite liquid after ejaculation, but in others, semenogelin molecules chemically crosslink with one another, increasing the viscosity of semen. In some extreme cases, semenogelin's effects on viscosity are so strong that the semen becomes a solid plug in the vagina. According to Lahn, such plugs might serve as a sort of molecular "chastity belt" to prevent fertilization by the sperm of subsequent suitors, though they might also prevent semen backflow to increase the likelihood of fertilization.

Lahn and his colleagues compared the SEMG2 gene, which contains the blueprint for semenogelin, from a variety of primates. They began by sequencing the SEMG2 gene in humans, chimpanzees, pygmy chimpanzees, gorillas, orangutans, gibbons, macaques, colobus monkeys, and spider monkeys. These species were chosen because they represent all the major mating systems, including those in which one female copulates with one male in a fertile period (such as gorillas and gibbons); those in which females copulate highly promiscuously (such as chimpanzees and macaques); and those in which mating practices fall somewhere in between (such as orangutans where a female will copulate with the dominant male, but may also copulate with other males opportunistically).

"When we plotted data on the evolution rate of the semenogelin protein against the level of female promiscuity, we saw a clear correlation whereby species with more promiscuous females showed much higher rates of protein evolution than species with more monogamous females," said Lahn. The researchers measured protein evolution rates by counting the number of amino acid changes in the protein, then scaling it to the amount of evolutionary time taken to make those changes.

"The idea is that in species with promiscuous females, there's more selective pressure for the male to make his semen more competitive. It's similar to the pressures of a competitive marketplace. In such a marketplace, competitors have to constantly change their products to make them better, to give them an edge over their rivals -- whereas, in a monopoly, there's no incentive to change."

The finding constitutes the first specific evidence that different levels of sexual competition produce different genetic effects, said Lahn. It had been established previously that levels of polyandry -- the mating of one female with more than one male -- affected physiological traits. For example, more polyandrous species have larger testes capable of producing more sperm. There is a metabolic cost to such adaptation, Lahn said, and in species where there is no competition, the cost is not worth the effort.

"Now, for the first time, we show such competitive effects, not only at the level of physiology, but of individual genes," said Lahn. "The genes have to adapt faster for any given male to gain an edge over his competitors."

According to Lahn, while other studies have indicated that male reproductive genes in general tend to evolve more rapidly than other genes, "this study extends those observations to a more quantitative level, showing that the rate of evolution actually correlates with how intense the sexual selection is."

Source: Science Daily

Sex Really Does Get Better With Age (Just Ask A 70 Year Old)

An increasing number of 70 year olds are having good sex and more often, and women in this age group are particularly satisfied with their sex lives, according to a study published on the British Medical Journal website.

Knowledge about sexual behaviour in older people (70 year olds) is limited and mainly focuses on sexual problems, less is known about "normal" sexual behaviour in this age group.

Nils Beckman and colleagues from the University of Gothenburg in Sweden, studied attitudes to sex in later life among four representative population samples of 70 year olds in Sweden, who they interviewed in 1971-2, 1976-7, 1992-3, and 2000-1. In total, over 1 500 people aged 70 years were interviewed about different aspects of their sex lives including sexual dysfunctions, marital satisfaction and sexual activity.

The authors found that over the thirty year period the number of 70 year olds of both sexes reporting sexual intercourse increased: married men from 52% to 68%, married women from 38% to 56%, unmarried men from 30% to 54%, and unmarried women from 0.8% to 12%.

In addition, the number of women reporting high sexual satisfaction increased, more women reported having an orgasm during sex and fewer reported never having had an orgasm.

While the proportion of women reporting low satisfaction with their sex lives decreased, the proportion of men reporting low satisfaction increased. The authors suggest that this might be because it is now more acceptable for men to admit "failure" in sexual matters.

They also note that the number of men reporting erectile dysfunction deceased, whereas the proportion reporting ejaculation dysfunction increased, but the proportion reporting premature ejaculation did not change.

Interestingly, both men and women blame men when sexual intercourse stops between them. This finding replicates the results of other studies in the 1950s and 2005-06.

"Our study...shows that most elderly people consider sexual activity and associated feelings a natural part of later life", they conclude.

These findings emphasise the important and positive part sex plays in the lives of 70 year olds and is a welcome contribution to the limited literature about sexual behaviour in older people, writes Professor Peggy Kleinplatz from the University of Ottawa in Canada.

It will hopefully highlight the need for doctors to be trained to ask all patients, regardless of age, about their sexual concerns, she adds.

Source: Science Daily

Sperm Counts Unchanged Over 50 Years

Although many American men have at least one type of abnormality in their sperm, they are just as virile as their grandfathers, researchers at the Keck School of Medicine of the University of Southern California have found. In fact, their sperm densities were no different from samples collected in major studies in the 1950s.

"Everything in our study indicates that the average man's sperm count is not changing," said study co-author Rebecca Sokol, M.D., of the Keck School of Medicine of USC. The results are published in the March issue of the journal Fertility and Sterility.

Sokol and her colleagues looked at semen samples collected from 1,385 men at LAC+USC Medical Center over a three-year period between 1994 and 1997. At the time samples were taken, the men were partners of women who were seeking infertility treatment.

Examining total sperm counts and semen abnormalities, the investigators found that of the half who showed some sperm abnormality, based on World Health Organization criteria, 52% had sperm that were borderline low in mortality; 18% had abnormal sperm concentration, and 14% had abnormally shaped sperm.

Previous studies popularized in the press claimed that male sperm counts were declining because of everything from pollution to sedentary jobs to tight underwear - and even spending too long in the car.

Sokol said this new study was both large and well designed, so that the results can be trusted to be an accurate reflection of sperm quality among American men. She noted that, coincidentally, the pool of men who provided semen samples primarily worked in blue-collar jobs that could have exposed them to significant environmental toxins - so if a drop was found and if pollutants were the cause, it would have been likely to be represented in the findings. Sokol and her colleagues nevertheless found that values for the average sperm count were identical to the count reported in the 1950s.

Source: Science Daily

Testosterone Deficiency Relatively Rare In Men

A new study reveals that relatively few men, only 5.6 percent of the male population, actually suffer from low testosterone accompanied by clinical symptoms. That percentage, however, rises substantially with age.

Low testosterone levels are typically defined as less than 300 ng/dL (nanograms per deciliter) of total testosterone and less than 5 ng/dL of free testosterone. Free testosterone is the amount of the hormone unbound to other proteins and is “free” to work inside the body. “Low levels of testosterone impact many aspects of male physiology,” said Andre B. Araujo, Ph.D., a research scientist at the New England Research Institutes in Watertown, Mass., and lead author of the study. “This is particularly significant because the ongoing aging of the U.S. male population is likely to cause the number of men suffering from androgen deficiency to increase appreciably.”

Consistent with a recently issued Clinical Practice Guideline from the Endocrine Society, symptomatic androgen deficiency in the study by Araujo and colleagues is defined as low total and free testosterone plus the presence of low libido, erectile dysfunction, osteoporosis or facture, or two or more of the following symptoms: sleep disturbance, depressed mood, lethargy, or diminished physical performance.

For this study, the researchers analyzed data on 1,475 randomly selected men enrolled in the Boston Area Community Health (BACH) Survey. The survey tracked subjects between the ages of 30-79 and compiled complete data on factors such as testosterone, symptoms of hormone deficiency, and medications that may impact sex hormone levels. Among all men in the study (mean age 47.3 plus-or-minus 12.5 years), approximately 24 percent had low total testosterone and 11 percent had low levels of free testosterone. Interestingly, while low testosterone levels were associated with symptoms, many men with low testosterone levels were asymptomatic (e.g., among men aged 50 years and older 47.6 percent were asymptomatic).

“Since these men would not likely come to clinical attention,” said Araujo, “it may be important to determine whether there are clinical risks to missing these asymptomatic men with low testosterone levels.” Overall, only 5.6 percent of men in the study had symptomatic androgen deficiency. For those men in the upper range of ages in the study (70 years or older), however, the percentage increased to 18.4 percent.

The researchers predicted that by the year 2025 there may be as many as 6.5 million American men 30-79 years of age with symptomatic androgen deficiency, an increase of 38 percent from year 2000 population estimates.

“This study did not assess whether men with symptomatic androgen deficiency are good candidates for testosterone therapy,” said Araujo. “Well designed randomized placebo-controlled trials would be needed to address the risks and benefits of testosterone therapy.”

The BACH Survey was supported by the National Institute of Diabetes and Digestive and Kidney Diseases (Grant DK 56842). Analyses for the current study were supported through an unrestricted educational grant from GlaxoSmithKline.

A rapid release version of this paper has been published on-line and will appear in the November 2007 issue of the Journal of Clinical Endocrinology & Metabolism, a publication of The Endocrine Society.

Source: Science Daily

Premature Ejaculation: It's Not All In Your Head

In a four-week study of 1,587 men, researchers report that men who suffer from premature ejaculation (PE) had an average intravaginal ejaculatory latency time (IELT) of 1.8 minutes, compared to 7.3 minutes in men who did not. Men with PE and their female partners also had higher ratings for personal distress, interpersonal difficulty with their partner, lack of ejaculation control, and dissatisfaction with sexual intercourse.

This scientific study, appearing in the May issue of The Journal of Sexual Medicine, is the first large epidemiologic study to define patient populations of those with (207) and without (1380) premature ejaculation by measuring average times to ejaculation with stopwatches. This average, or IELT, is defined as the time between the start of vaginal intromission and the start of intravaginal ejaculation.

This study is also one of the first data sets to address the concerns of female partners. Both members of the couples studied were asked to report on a variety of subjective factors. Significant overlap in IELT was observed between the groups who suffered from PE and those without. Thus, the study data suggest IELT may not be sufficient to diagnose PE, and that subjective factors, like lack of control, may also be valid indicators.

"Most people think uni-dimensionally about PE in terms of considering it a disorder of time," states Stanley E. Althof, Ph.D., corresponding author of the study. "This article demonstrates that subjective factors like sense of control, distress, and sexual satisfaction need to be considered when treating this highly prevalent disorder."

PE is the most common male sexual dysfunction affecting men and their partners. However, available data suggest that only 1-12% of males self-reporting receive treatment for their dysfunction. According to The Journal of Sexual Medicine editor Irwin Goldstein, most physicians do not inquire about the existence of premature ejaculation when the patient has other sexual complaints or when the partner has orgasmic dysfunction. As seen in this study, premature ejaculation adversely affects sexual satisfaction, and partner distress is a common motivation for afflicted men to seek treatment.

Source: Science Daily

Protein Translation In Sperm

A new paper in the February 15th issue of Genes & Development lends novel insight into the cellular changes that occur in sperm while they reside in the female reproductive tract -- providing a new understanding of the molecular genetics of successful fertilization.

It had been believed for decades that spermatozoa are translationally silent. However, Dr. Yael Gur and Haim Breitbart (Bar-Ilan University, Israel) now show that, in fact, protein translation does take place in mammalian sperm prior to fertilization.

Their paper has been released online ahead of print at www.genesdev.org.

After ejaculation, sperm reside in the female reproductive tract for several hours. During this time, a number of biochemical changes take place within sperm, collectively known as "capacitation," that render the sperm competent to penetrate and fertilize the female oocyte.

In their new report, Drs. Gur and Breitbart demonstrate that human, rat, bovine and mouse sperm all incorporate labeled amino acids into polypeptides during the capacitation phase. They identify that mitochondrial translation machinery (as opposed to cytoplasmic) directs translation of nuclear-encoded genes in sperm, and that its inhibition leads to a marked decrease in sperm motility, actin polymerization, the acrosome reaction and in vitro fertilization rates.

Thus, protein translation in sperm is essential for sperm functions that directly contribute to fertilization. Dr. Breitbart is confident that "The new findings would give us better understanding for treatment of male infertility and developing new male or female contraceptives."

Source: Science Daily

Daily Sex Helps Reduce Sperm DNA Damage And Improve Fertility

Daily sex (or ejaculating daily) for seven days improves men’s sperm quality by reducing the amount of DNA damage, according to an Australian study presented June 30 to the 25th annual meeting of the European Society of Human Reproduction and Embryology in Amsterdam.

Until now there has been no evidence-based consensus amongst fertility specialists as to whether or not men should refrain from sex for a few days before attempting to conceive with their partner, either spontaneously or via assisted reproduction.

Dr David Greening, an obstetrician and gynaecologist with sub specialist training in reproductive endocrinology and infertility at Sydney IVF, Wollongong, Australia, said: “All that we knew was that intercourse on the day of ovulation offered the highest chance of pregnancy, but we did not know what was the best advice for the period leading up to ovulation or egg retrieval for IVF.

“I thought that frequent ejaculation might be a physiological mechanism to improve sperm DNA damage, while maintaining semen levels within the normal, fertile range.”

To investigate this hypothesis, Dr Greening studied 118 men who had higher than normal sperm DNA damage as indicated by a DNA Fragmentation Index (DFI). Men who had a more than 15% of their sperm (DFI >15%) damaged were eligible for the trial. At Sydney IVF, sperm DNA damage is defined as less than 15% DFI for excellent quality sperm, 15-24% DFI for good, 25-29% DFI for fair and more than 29% DFI for poor quality; but other laboratories can have slightly different ranges.

The men were instructed to ejaculate daily for seven days, and no other treatment or lifestyle changes were suggested. Before they started, levels of DNA damage ranged between 15% and 98% DFI, with an average 34% DFI when measured after three days’ abstinence. When the men’s sperm was re-assessed on the seventh day, Dr Greening found that 96 men (81%) had an average 12% decrease in their sperm DNA damage, while 22 men (19%) and an average increase in damage of nearly 10%. The average for the whole group dropped to 26% DFI.

Dr Greening said: “Although the mean average was 26% which is in the ‘fair’ range for sperm quality, this included 18% of men whose sperm DNA damage increased as well as those whose DNA damage decreased. Amongst the men whose damage decreased, their average dropped by 12% to just under 23% DFI, which puts them in the ‘good’ range. Also, more men moved into the ‘good’ range and out of the ‘poor’ or ‘fair’ range. These changes were substantial and statistically highly significant.

“In addition, we found that although frequent ejaculation decreased semen volume and sperm concentrations, it did not compromise sperm motility and, in fact, this rose slightly but significantly.

“Further research is required to see whether the improvement in these men’s sperm quality translates into better pregnancy rates, but other, previous studies have shown the relationship between sperm DNA damage and pregnancy rates.

“The optimal number of days of ejaculation might be more or less than seven days, but a week appears manageable and favourable. It seems safe to conclude that couples with relatively normal semen parameters should have sex daily for up to a week before the ovulation date. In the context of assisted reproduction, this simple treatment may assist in improving sperm quality and ultimately achieving a pregnancy. In addition, these results may mean that men play a greater role in infertility than previously suspected, and that ejaculatory frequency is important for improving sperm quality, especially as men age and during assisted reproduction cycles.”

Dr Greening said he thought the reason why sperm quality improved with frequent ejaculation was because the sperm had a shorter exposure in the testicular ducts and epididymis to reactive oxygen species – very small molecules, high levels of which can damage cells. “The remainder of the men who had an increase in DFI might have a different explanation for their sperm DNA damage,” he concluded.

Source: Science Daily

Obese Men Have Less Semen, More Sperm Abnormalities

Obese men should consider losing weight if they want to have children, a scientist told the 24th annual conference of the European Society of Human Reproduction and Embryology July 9. Dr. A Ghiyath Shayeb, from the University of Aberdeen, Aberdeen, UK, said that his research had shown that men with a higher body mass index (BMI) had lower volumes of seminal fluid and a higher proportion of abnormal sperm.

Dr. Shayeb and colleagues looked at the results of seminal fluid analysis in 5316 men attending Aberdeen Fertility Centre with their partners for difficulties in conceiving. 2037 of these men had complete data on their BMIs. "We felt that it was possible that male overweight might contribute to fertility problems," he said, "particularly since it is a known risk factor for problems in conceiving among women."

The scientists divided the men into four groups according to their BMI, from being underweight to being considerably overweight. Taking into account other characteristics that could confound the analysis, such as smoking, alcohol intake, age, social deprivation, and the length of time of abstinence from sex prior to producing a semen sample for analysis, they looked for a relationship between BMI and semen quality. The analysis showed that the men in Group B, who had an optimal BMI (20-25, as classified by WHO), had higher levels of normal sperm than those in the other groups. They also had higher semen volume. There was no significant difference between the four BMI groups in sperm concentration or motility.

The researchers did not look at DNA damage in the sperm, preferring to look at the parameters of the routine semen analysis, which all men attending the fertility centre will have at least once. "Other studies have suggested an association between male obesity and increased DNA damage in the sperm, which can be associated with reduced fertility as well," said Dr. Shayeb.

"Our findings were quite independent of any other factors," he said, "and seem to suggest that men who are trying for a baby with their partners, should first try to achieve an ideal body weight. This is in addition to the benefit of a healthy BMI for their general well being.

"Adopting a healthy lifestyle, a balanced diet, and regular exercise will, in the vast majority of cases, lead to a normal BMI. We are pleased to be able to add improved semen quality to the long list of benefits that we know are the result of an optimal body weight."

The team intends to follow up their research by comparing male BMI in fertile and infertile couples to see if the poorer semen quality correlates with reduced fertility. "There has been a significant rise in the numbers of men with poorer semen parameters in the industrialised world," said Dr. Shayeb, "but this has not been reflected so far in male infertility. To compare male BMI in these two groups therefore seemed to us to be a logical next step."

Further research is also needed on exactly how obesity affects semen production, said Dr. Shayeb. "The mechanism for the relationship could be a number of things -- different hormone levels in obese men, simple overheating of the testicles caused by excessive fat in the area, or that the lifestyle and diet that leads to obesity could also lead to poorer semen quality. We just don't know the answer yet, but this is an important question that needs urgent attention."

Source: Science Daily