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Strong Social Ties Protect Men From Suicide

Being socially connected to others appears to protect men against suicide, according to a new study.

Social integration acts as a safety net to lower the risk of suicide among men.

We speculate that men who are more socially well integrated may have greater access to emotional support and have more opportunities for social engagement and reinforcement of meaningful social roles,” said Alexander Tsai, MD, PhD, Assistant Professor of Psychiatry at Harvard Medical School in Boston.

Suicide is one of the 10 leading causes of death among men in the United States, and suicides among middle-aged men are increasing.

Current trends in research and prevention efforts usually emphasize the psychiatric, psychological, or biological aspects of what drives suicidal thinking and suicidal behavior.

However, research has shown that a substantial proportion of suicides occur in the absence of a formally diagnosed mental disorder, suggesting that a deeper understanding of factors driving suicide is needed, he said.

SOCIAL INTEGRATION STUDY

Dr. Tsai and colleagues analyzed data from the Health Professionals Follow-up Study, an ongoing prospective cohort study of nearly 35,000 men aged 40 to 75 years, to examine the relationship between social integration and suicide mortality over 24 years of follow-up.

They measured social integration with a 7-item index that included marital status, social network size, frequency of contact, religious participation, and participation in other social groups.

Over more than 700,000 person-years of follow-up, there were nearly 150 suicides.

The incidence of suicide decreased with increasing social integration.

MARRIAGE, SOCIAL NETWORK, RELIGION

Three components — marital status, social network size, and religious service attendance — showed the strongest protective associations.

Social integration also was inversely associated with all-cause and cardiovascular-related mortality, but accounting for competing causes of death did not substantively alter the findings.

“Men who were socially well-integrated had a more than 2-fold reduced risk for suicide over 24 years of follow-up,” Dr. Tsai said.

The study lacked information on participants’ mental well-being.

Some suicides also could have been misclassified as accidental deaths, he noted.

Dr. Tsai added: “The seminal studies about social integration and suicide are based on macro-level data, for example, examining the level of social integration across counties or states and the correlations with suicide rates in those jurisdictions, but these are subject to the well-known ‘ecological fallacy’—just because there is an association at the county or state level does not necessarily imply that an individual with poor social integration is also more likely to commit suicide.”

A fuller understanding of the role of social interaction is important in understanding suicide.

“The bottom line is that we should be approaching suicide as a public health issue relevant to a broad range of medical practitioners and public health specialists, not just a narrow mental health issue relevant only to psychiatrists like myself,” Dr. Tsai said.

“It is important for primary care physicians to recognize that their most socially isolated patients are at elevated risk of committing suicide.”

The researchers published their results in the July 14, 2014, issue of Annals of Internal Medicine.

No Added Heart Attack Risk With Testosterone Therapy in Older Men

Testosterone therapy does not increase the risk of heart attack, or myocardial infarction (MI), among older men, according to a comprehensive new study.

“We believe this is a methodologically rigorous study and should be thoughtfully weighed, critiqued, and discussed alongside the other studies of testosterone therapy and cardiovascular outcomes,” said lead author Jacques Baillargeon, PhD, Director, Epidemiology Division and Associate Professor of Preventive Medicine & Community Health at the University of Texas Medical Branch in Galveston.

“Although recent observational studies have reported an increased risk of cardiovascular disease associated with testosterone use, there is a large body of evidence that is consistent with our finding of no increased risk of MI associated with testosterone use,” Dr. Baillargeon said.

He noted that there are cardiovascular risks associated with untreated hypogonadism (a condition in which the body doesn’t produce enough testosterone) and those should be factored into the risk-benefit assessment about testosterone therapy.

INCREASE IN TESTOSTERONE PRESCRIPTIONS

Testosterone prescriptions for older men in the United States have increased more than 3-fold over the past decade.

This trend has been driven by increases in direct-to-consumer marketing; rapid expansion of clinics specializing in the treatment of low testosterone; the development of new drugs and improved delivery mechanisms, particularly dermal gels; and greater diagnostic awareness of hypogonadism, stated Dr. Baillargeon.

The retrospective study used information from 25,000 Medicare beneficiaries aged 66 years and older.

It compared more than 6,300 men treated with testosterone for 8 years with more than 19,000 who were not treated with testosterone.

“We found that use of intramuscular testosterone therapy was not associated with an increased risk of MI,” Dr. Baillargeon said.

In fact, testosterone was associated with a possible protective effect — reduced risk of MI in patients with the highest prognostic risk index.

There were no differences in risk in patients in the lower prognostic risk groups.

HOW TESTOSTERONE AFFECTS THE HEART

There are a number of physiologic pathways whereby testosterone therapy may affect the risk of adverse cardiovascular events.

“Some have reported that testosterone therapy may improve cardiovascular health by way of decreasing fat mass, insulin sensitivity, and lipid profile,” said Dr. Baillargeon.

“Also, testosterone may possess anti-inflammatory and anticoagulant properties.”

He continued, “It is possible that our findings of a protective effect among men in the highest MI prognostic group reflect a process whereby testosterone reduces peripheral vascular resistance, thereby reducing stress on the heart among those who have some degree of coronary artery disease.

It is important to note that there are also postulated mechanisms through which testosterone may increase the risk of cardiovascular disease.

Given the broad range of proposed biologic pathways, it is important to conduct further research on this topic.”

CONCERNS ABOUT TESTOSTERONE THERAPY

Several recent studies have raised concerns about cardiovascular risks associated with testosterone therapy, in particular for older men.

On June 19, the FDA expanded labeling on testosterone products to include a general warning about the risk of blood clots in veins.

The FDA and European Medicines Agency also are further examining the safety of these products.

The researchers reported their results in the July 2, 2014 issue of the Annals of Pharmacotherapy.

Migraines Worsen During Menopausal Transition

The frequency of migraine attacks is higher in women during perimenopause and postmenopause than in premenopause, according to the first study to demonstrate that the frequency of migraine attacks increases during the menopausal transition.

“Fluctuating estrogen levels play an important role in initiating migraine in women,” said study co-author Richard B. Lipton, MD, Co-Director of the Montefiore Headache Center and Professor and Vice Chair of Neurology and the Edwin S. Lowe Chair in Neurology at the Albert Einstein College of Medicine.

“Migraine onset increases with the beginning of menstruation and is more common around the time of bleeding during the menstrual cycle,” he said.

“The trigger factor is thought to be declining estrogen levels.

As menopause approaches, estrogen levels fluctuate and likely trigger migraine.”

Dr. Lipton noted that estrogen and other sex hormones act on the brain and alter the excitability or sensitivity of the nervous system.

LARGE POPULATION STUDY

The research was conducted as part of the American Migraine Prevalence and Prevention (AMPP) Study, a longitudinal mailed questionnaire survey of 120,000 households selected to be representative of the US population.

Data from the 2006 AMPP Study survey were used.

Women with migraine aged 35 to 65 years were eligible for the analyses.

Women with migraine were classified based on headache frequency.

A high-frequency group experienced 10 or more headache days per month, and a low- or moderate-frequency group experienced episodic migraines on fewer than 10 days per month.

The women also were classified based on menopausal status.

The premenopausal stage was characterized by regular menstrual cycles.

The perimenopausal stage included women with cycle lengths that varied by at least 7 days or periods of no periods lasting 2 to 11 months.

The postmenopausal stage was defined by no periods persisting for at least 12 months.

The analysis included more than 3600 women, mean age 45 years, with about one-third of them in each of the 3 groups.

FREQUENT HEADACHES MORE OFTEN AROUND MENOPAUSE

Frequent headache (10 or more days per month) was 50% to 60% more common among perimenopausal women (12.2%) and menopausal women (12%) compared with premenopausal women (8%).

Consistent with the clinical impression that migraine worsens during the menopausal transition, these data show that the risk of high-frequency headache is greater during perimenopause and postmenopause as compared with premenopause, Dr. Lipton said.

The researchers concluded that longitudinal studies should examine within-person trajectories of headache frequency and the role of hormonal mechanisms among migraineurs during the menopausal transition.

“In the present report, we compared groups of women who were premenopausal and perimenopausal and postmenopausal in the year of the study,” Dr. Lipton said.

In a longitudinal study, we would follow individual women as they transitioned from premenopausal to perimenopausal to postmenopausal and examine the hormonal changes that underlie changes in headache frequency.”

He added: “Clinicians should know that headaches may get worse as women begin the menopausal transition.

When patients experience migraine worsening, clinicians can explain that hormonal changes may be driving the changes.

Controlling headache is one factor that may contribute to the complex decisions about when to recommend hormone replacement therapy.”

The researchers presented their results on June 20, 2014 at the 56th Annual Scientific Meeting of the American Headache Society in Los Angeles.

Chronic Migraine Burdens Whole Family

Chronic migraine has significant effects on family relationships and activities, according to the results of a new study.

“The effects of chronic migraine can be devastating and far-reaching.

The results of the Chronic Migraine Epidemiology and Outcomes (CaMEO) study highlight the significant impact of chronic migraine not only on the person with migraine but on the entire family,” said Dawn Buse, PhD, Director of Behavioral Medicine, Montefiore Headache Center, and Associate Professor, Clinical Neurology, at Albert Einstein College of Medicine.

Dr. Buse led a study to assess the nature and extent of chronic migraine on family activities and relationships.

“Among 994 women and men who met criteria for chronic migraine, respondents reported missing both routine and special family events on a regular basis and feeling guilty and sad about how this affected their relationships with their spouses and children,” she said.

BETTER SPOUSES, MORE SEX, BETTER PARENTS WITHOUT MIGRAINES

Almost three-fourths of respondents said they would be better spouses if they did not have chronic migraine.

Almost two-thirds felt guilty about being easily angered or annoyed by their partners because of headache, and at times two-thirds avoided sexual intimacy with their partners because of headache.

The majority of respondents also endorsed that they would be better parents if they did not have chronic migraine.

“About two-thirds of respondents reported that they became easily annoyed with their children due to headache,” Dr. Buse said.

“In addition, slightly more than half of respondents reported that they had reduced participation or enjoyment on a family vacation due to headache in the past year, and 20% cancelled or missed a family vacation altogether.”

WOMEN MORE AFFECTED THAN MEN

The data suggest that women with chronic migraine appear less impaired and burdened by the condition than men.

“However, it is not clear whether there is truly a qualitative difference between the sexes in the nature and severity of attacks or differences in responses and resiliency to migraine attacks,” Dr. Buse said.

“We could hypothesize that males may have a smaller number of family and parenting responsibilities and commitments than females, making their percentage of missed events higher than the percentage for females.

It is also possible that mothers and wives feel that they cannot miss a family event or drop a responsibility.

In this case they may continue their activities despite debilitating pain and associated symptoms.”

The study highlights the point that chronic migraine is a debilitating disease that can affect all aspects of life, including roles, responsibilities, and relationships within the family.

“We hope that these data will help health care professionals further realize the scope of the burden of this condition and be diligent in providing accurate diagnoses and thorough treatment plans,” Dr. Buse said.

Those treatment plans should include both appropriate pharmacologic and nonpharmacologic (cognitive behavioral therapy, biofeedback, and relaxation training) interventions, she noted.

In addition, Dr. Buse advises health care professionals to encourage and facilitate patients in seeking help from mental health care professionals when these feelings become overwhelming.

Dr. Buse presented the results of the study on June 27, 2014 at the 56th Annual Scientific Meeting of the American Headache Society in Los Angeles.

Headaches Associated With Sex Are No Joke

Comedians have long joked about spouses avoiding sex by claiming to have a headache, but headaches associated with sex are no laughing matter, according to a headache specialist.

“Many people who experience headaches during sexual activity are too embarrassed to tell their physicians, and doctors often don’t ask,” said José Biller, MD, Chair of the Department of Neurology with the Loyola University Chicago Stritch School of Medicine and certified in Headache Medicine by the United Council for Neurologic Subspecialties.

Sexual activity is comparable to mild- to moderate-intensity exercise, he noted.

“Headaches associated with sexual activity can be extremely painful and scary,” Dr. Biller said.

“They also can be very frustrating, both to the individual suffering the headache and to the partner.”

About 1% of adults report that they have experienced headaches associated with sexual activity and that such headaches can be severe.

But the actual incidence is certainly higher, Dr. Biller noted.

Headaches usually are caused by disorders such as migraines or tension, and the vast majority of headaches associated with sexual activity are benign.

But headaches also can be secondary to other life-threatening conditions.

In a small percentage of cases, these headaches can result from a serious underlying condition, such as a hemorrhage, brain aneurysm, stroke, cervical artery dissection, or subdural hematoma.

“We recommend that patients undergo a thorough neurological evaluation to rule out secondary causes, which can be life-threatening,” Dr. Biller said.

“This is especially important when the headache is a first occurrence.”

3 TYPES OF SEX-RELATED HEADACHES

In 2004, the International Headache Society classified headaches associated with sexual activity as a distinct form of primary headache.

The following are the 3 main types of sex-related headaches:

• A dull ache in the head and neck that begins before orgasm and gets worse as sexual arousal increases.

It is similar to a tension headache.

• An intensely painful headache that begins during orgasm and can last for hours.

This so-called thunderclap headache grabs attention because it comes on like a clap of thunder.

Dr. Biller said patients describe this headache as “all of a sudden, there was a terrific pain in the back of my head. It was like someone hit me with a hammer.”

• A headache that occurs after sex and can range from mild to extremely painful.

This headache gets worse when the patient stands and lessens when the patient lies back down.

The cause is an internal leak of spinal fluid, which extends down from the skull into the spine.

When there is a leak in the fluid, the brain sags downward when the patient stands, causing pain, he explained.

Dr. Biller said men are 3 to 4 times more likely to get headaches associated with sexual activity than women.

Depending on the type of headache, medications can help relieve the pain or even prevent the headache, he said.

To reduce the risk of headaches associated with sexual activity, exercise regularly, avoid excessive alcohol intake, maintain a healthy weight and, if necessary, seek counseling, Dr. Biller said.

Just Eating Healthier Trims Diabetes Risk

Improve your overall diet quality and you will lower your risk of type 2 diabetes mellitus, independent of adopting other healthful behaviors, including increased physical activity and body weight loss, according to the results of a new study.

In an analysis of 3 large cohort studies of men and women by researchers at the Harvard School of Public Health, those who improved their diet quality index scores by 10 percent over 4 years reduced their risk for type 2 diabetes by about 20% compared to those who made no changes to their diets.

“We found that diet was indeed associated with diabetes independent of weight loss and increased physical activity,” said lead author Sylvia Ley, PhD, RD, a post-doctoral fellow at the Harvard School of Public Health, at the American Diabetes Association’s 74th Scientific Sessions®.

“If you improve other lifestyle factors you reduce your risk for type 2 diabetes even more, but improving diet quality alone has significant benefits.”

She noted that it is often difficult for people to maintain a calorie-restricted diet for a long time.

“We want them to know that if they can improve the overall quality of what they eat – consume less red meat and sugar-sweetened beverages, and more fruits, vegetables and whole grains – they are going to improve their health and reduce their risk for diabetes,” Dr Ley said.

Lifestyle changes, including individually tailored, macronutrient composition focused, calorie-restricted interventions, can prevent or delay type 2 diabetes among those at high risk, according to randomized controlled trials.

However, it is unclear whether improving overall diet quality by itself is associated with reduced risk of diabetes among healthy adults.

DIET QUALITY CHANGES LOWER RISK

Dr. Ley and colleagues investigated the association between diet quality changes during a 4-year period and subsequent 4-year type 2 diabetes risk, and simultaneous changes in multiple lifestyle factors on that risk (Abstract 74-OR).

They prospectively followed more than 148,000 participants without diabetes at baseline in the Nurses’ Health Study (1986-2006), Nurses’ Health Study II (1991-2011), and Health Professionals Follow-up Study (1986-2010).

The Alternative Healthy Eating Index score was used to assess diet quality.

Associations between changes in diet quality, physical activity, and body weight and diabetes risk were evaluated simultaneously.

The researchers documented more than 9,000 incident cases of type 2 diabetes during the more than 2.3 million person-year follow-up.

Greater than 10% decrease in diet quality scores over 4 years was associated with higher subsequent diabetes risk with multiple adjustments, while at least 10% improvement in dietary scores was associated with lower risk, Dr Ley said during her presentation at the ADA meeting.

When simultaneous relationships among 4-year changes in diet quality, physical activity, and body weight were assessed, improvement in each behavioral factor was independently associated with lower incident diabetes.

“Regardless of where participants started, improving diet quality was beneficial for all,” she noted.

Diabetes in Men Often Goes Under the Radar

Men are more than twice as likely to have undiagnosed diabetes as women, despite the fact that their overall risk for diabetes is similar.

That’s one of the messages of a new campaign by the American Diabetes Association to raise health awareness among men when it comes to conditions like diabetes, sexual dysfunction, and sleep apnea as the Association celebrates Men’s Health Month this June.

“When it comes to men and diabetes management, the main barriers to good health are often a lack of understanding and education of the disease, as well as a fear of having to change their current lifestyle,” said Robert E. Ratner, MD, FACP, FACE, Chief Scientific & Medical Officer, American Diabetes Association.

“During Men’s Health Month, the American Diabetes Association is encouraging all men to get out, get active, and get informed to help Stop Diabetes®.”

Nearly 1 in 8 American men has diabetes, and 1 in 3 has pre-diabetes.

The complications of diabetes are well known and serious, and those risk factors can be significantly controlled through control of the ABCs: A1C (as a measure of glucose control), blood pressure, and cholesterol, particularly low-density lipoprotein.

The health risks for men with diabetes who smoke are even greater than the risks for men who don’t have diabetes, so smoking cessation is even more important.

Studies show an increased risk for heart disease for men both with and without diabetes.

An easy-to-implement diabetes screening score for undiagnosed diabetes, defined as fasting plasma glucose level of 7.0 mmol/L (126 mg/dL) or greater without known diabetes, developed from National Health and Nutrition Examination Survey data, has been demonstrated to be an improvement over existing methods.

Historically, men are not as comfortable as women when it comes to discussing health issues, which can result in shorter and less healthy lives for men in the US compared to women, says the Association.

SLEEP APNEA

Being male also means being more likely to suffer from obstructive sleep apnea (OSA).

Cross-sectional studies have documented the co-occurrence of OSA with glucose intolerance, insulin resistance, and type 2 diabetes mellitus.

OSA is linked to an increased risk for diabetes and can also make diabetes harder to control.

Studies show that sleep apnea increases the risk of developing diabetes, independent of other risk factors.

Among patients with more severe sleep apnea, regular positive airway pressure use may attenuate this risk.

SEXUAL DYSFUNCTION

In addition, diabetes can often have sexual implications for males, including erectile dysfunction.

However, there are many steps men can do to take better care of their diabetes and general health.

The Association recommends finding a family doctor the patient can trust and to discussion health issues.

In addition, the Association recommends enlisting a friend or family member to help the patient adopt healthy behaviors, such as an exercise partner, to increase the level of physical activity and modify eating habits and portion control.

Also, the Association notes that regular professional care is crucial for keeping diabetes management on track.

Young Athletes More Likely to Suffer Serious Overuse Injuries If Their Parents Have High Incomes

The higher your annual income, the higher the chances that your young athlete will suffer an overuse injury.

That’s the eyebrow raising result of a new study that shows, for the first time, a link between overuse injury rates in young athletes and their socioeconomic status.

The rate of serious overuse injuries in athletes who come from families that can afford private insurance is 68% higher than the rate in lower-income athletes who are on public insurance (Medicaid), according to the study.Class AA-A Girls Soccer

Privately insured young athletes are also twice as likely as publicly insured athletes to be highly specialized in one sport, state Loyola University researchers who previously reported that young athletes who specialize in one sport are more likely to suffer serious overuse injuries.

Neeru Jayanthi, MD, medical director of Primary Care Sports Medicine and an associate professor in the departments of Family Medicine and Orthopaedic Surgery and Rehabilitation of Loyola University Chicago Stritch School of Medicine, recently reported the results at the International Olympic Committee World Conference on Prevention of Injury & Illness in Sport in Monaco.

The findings also were presented at the American Medical Society for Sports Medicine Annual Meeting in New Orleans, LA.

Intense specialization in one sport can cost thousands of dollars a year in equipment, fees, transportation, and private lessons,” Jayanthi said.

“Having the financial resources to afford such costs may provide increased opportunities for young athletes to participate in a single sport.”

RESULTS FROM ONGOING STUDY

Jayanthi and colleagues are conducting an ongoing collaborative study of athletes ages 7-18 who were seen at primary care and sports medicine clinics at Loyola University Health System and the Ann & Robert H. Lurie Children’s Hospital of Chicago.

So far, nearly 1,200 athletes have been enrolled in the study.

Both institutions care for a socioeconomically diverse population.

The median income of the families of the young athletes was approximately $70,000.

About 11% came from low-income neighborhoods, while 19% are on public aid.

Athletes completed surveys reporting training volumes, age of engagement in competitive sports, and degree of specialization.

The researchers found that 30% of privately insured athletes were highly specialized in one sport, compared with 18% of athletes who were publically insured.

SERIOUS OVERUSE INJURIES

Among the privately insured athletes, 13% suffered serious overuse injuries, compared with 8% of publicly insured athletes.

Serious overuse injuries can force young athletes to the sidelines for 1 to 6 months or longer.

These injuries include stress fractures in the back or limbs, elbow ligament injuries, and osteochondral injuries (injuries to cartilage and underlying bone).

Evidence on Testosterone Therapy Does Not Support Cardiac Risk

Does testosterone therapy to treat testosterone deficiency, or “low T,” increase a man’s risk of cardiovascular disease?

No, says a provocative editorial that asserts there are flaws in the cardiovascular risks quoted in recent articles in the scientific literature and mass media.

The public judgment of the overselling of testosterone therapy demands a response, stated the lead author, Martin Miner, MD, Clinical Associate Professor of Family Medicine and Urology, Warren Alpert Medical School of Brown University.

The editorial appeared in the April 8, 2014 issue of Journal of Men’s Health.

NO CREDIBLE EVIDENCE

“As researchers and clinicians with extensive experience with testosterone deficiency and its treatment, we do not find any credible evidence that testosterone prescriptions increase health risks.

We find the assertion that testosterone is prescribed to men ‘who are simply reluctant to accept the fact that they are getting older’ is without foundation, and we object to comments that question the reality of testosterone deficiency, regardless of whether it is called hypogonadism or, as in advertisements, ‘low T,’” Dr. Miner stated.

“In addition, in our opinion, the idea that physicians prescribe testosterone due to pressure from drug companies is irresponsible and not supported by scientific evidence.”

OVER-THE-TOP COMMENTS

Over-the-top comments tend to scare both patients and physicians.

“The FDA announcement that it is investigating the reports of increased cardiovascular risks has only added to the impression that a major study has determined serious problems with testosterone therapy,” he stated.

A case in point is a recent report published in PLoS ONE that investigated the risk of acute nonfatal myocardial infarction (MI), or heart attack, in a retrospective cohort study of a health-claims database.

The authors compared the rates of heart attack within the first 90 days of an initial prescription for testosterone with the rates of heart attack for the 12 prior months in nearly 56,000 men.

They also examined pre- and post-prescription incidence rates for nonfatal heart attack in another large cohort of more than 167,000 men for whom only phosphodiesterase-5 inhibitor (PDE5i) medications (such as Viagra) were prescribed, and after adjusting for potential confounders, compared these results to those of men who received testosterone prescriptions.

The authors concluded that the risk of heart attack following testosterone prescription was “substantially” increased (at least twofold) in older men and younger men with preexisting, diagnosed heart disease.

STUDY IS “TOO FLAWED”

“A close examination reveals that this study is too flawed to provide meaningful information on the cardiovascular risk of testosterone therapy,” stated Dr. Miner.

“First, the overall rate of nonfatal MI in the testosterone-treated group increased in all ages from 3.48 to 4.75 per 1,000 person-years.

This amounts to just greater than 1 additional MI in 1,000 years of exposure to testosterone.

It is misleading to characterize this increase as ‘substantial’ based on relative risk when the absolute risk is so small and clinically meaningless.”

Also, the study duration (90 days) was short, and a true control group would have consisted of men with untreated testosterone deficiency, not those who received PDE5i medications.

The overall risk was low, and the number of events in subgroups was remarkably few, he noted.

More data from larger, longer term studies are needed to assess the potential effects of testosterone therapy on cardiovascular events in men.

Based on the current evidence, he stated, “we can find no foundation for suggesting new restrictions on testosterone therapy in men with cardiac disease.”

Irregular Heart Rhythm in Men Associated With Exercise Intensity Over Time

Young men who undertake endurance exercise for more than 5 hours a week may increase their risk of developing an irregular heart rhythm later in life, according to the results of a new study.

“Physical activity contributes to prevention of several diseases, and in general is good for the well-being of your body and mind.

However, frequent high-intensity exercise during many years could increase the risk for atrial fibrillation (AF),” lead author Dr Nikola Drca, Department of Cardiology, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden, said in an interview.

The increase in risk is real, but quite small, he added.

The researchers presented their results online in the May 14, 2014, issue of the journal Heart.

RISK FACTOR FOR STROKE

In the Swedish study, the researchers quizzed more than 44,000 men aged 45 to 79 years about their leisure-time physical activity patterns at the ages of 15, 30, 50, and during the past year, when their average age was 60.

They tracked the participants’ heart health for an average of 12 years from 1997 onward to gauge how many developed AF, which is a known risk factor for stroke.

The men who had exercised intensively for more than 5 hours a week were 19% more likely to have developed AF later in their lives than those exercising for less than 1 hour a week.

The level of risk rose to 49% among those who did more than 5 hours of exercise a week at the age of 30, but who subsequently did less than an hour by the time they were age 60.

But those who cycled or walked briskly for an hour a day or more at age 60 were about 13% less likely to develop AF than those who did virtually no exercise at all.

MODERATION, MODERATION, MODERATION

“It seems that moderate doses of physical activity are enough to get the positive effects without acquiring the negative effects, while these benefits are lost with very high intensity and prolonged efforts,” Dr. Drca noted.

There are several possible mechanisms by which frequent endurance exercise could increase the risk for AF, he said.

These include enlargement of the left atrium, enlargement of and left ventricular hypertrophy, inflammatory changes in the left atrium, and an increase in the activity of the parasympathetic nervous system.

“In our study, the men who had the highest risk of developing atrial fibrillation were those who were very physically active when they were young, but stopped being physical active.

I think that moderate intensity regular physical activity that you continue throughout your life is the best way to maximize the benefits obtained by regular exercise while preventing undesirable effects.”

He added: “Physical inactivity and a sedentary lifestyle is a far bigger problem in the general population than excessive physical activity.

However, frequent high-intensity exercise during many years is associated with an increased risk of AF.”