Posts Tagged ‘cardiovascular disease’

Night Shifts Upset Sleep, Up Heart Death Risk

Night shift work not only disrupts sleep patterns but also increases the risk of cardiovascular disease (CVD) and lung cancer deaths, according to one of the largest prospective cohort studies worldwide with a high proportion of rotating night shift workers and long follow-up time.

“Women working rotating night shifts for more than 5 years have a modest increase in all-cause and CVD mortality.

Those working more than 15 years of rotating night shift work have a modest increase in lung cancer mortality.

These results add to prior evidence of a potentially detrimental effect of rotating night shift work on health and longevity,” report researchers led by Eva S. Schernhammer, MD, DrPH, Associate Professor of Medicine, Harvard Medical School, and Associate Epidemiologist, Department of Medicine, Brigham and Women’s Hospital, Boston.

There is substantial biological evidence that night shift work enhances the development of CVD.

In 2007, the World Health Organization classified night shift work as a probable carcinogen because of circadian disruption.

HOW SLEEP AFFECTS THE HEART

Sleep and the circadian system play an important role in cardiovascular health and anti-tumor activity.

The circadian system and its prime marker, melatonin, are considered to have anti-tumor effects through multiple pathways — including antioxidant activity, anti-inflammatory effects, and immune enhancement — and they exhibit beneficial actions on cardiovascular health by enhancing endothelial function, maintaining metabolic homeostasis, and reducing inflammation, the researchers noted.

“Direct nocturnal light exposure suppresses melatonin production and resets the timing of the circadian clock,” they stated.

“In addition, sleep disruption may also accentuate the negative effects of night work on health.

Taken together, substantial biological evidence supports the role of night shift work in the development of poor health conditions, including cancer, CVD, and ultimately, mortality.”

NIGHT SHIFTS AND DEATHS

Using data from the Nurses’ Health Study, the international team of researchers analyzed 22 years of follow-up of nearly 75,000 women.

Night shift information was collected in 1988.

Rotating shift work was defined as working at least 3 nights per month in addition to days or evenings in that month.

The investigators found that working rotating night shifts for more than 5 years is associated with an increase in all-cause and CVD mortality.

Mortality from all causes appeared to be 11% higher for women with 6 to 14 years or more than 15 years of rotating night shift work.

CVD mortality appeared to be 19% and 23% higher for those groups, respectively.

There was no association between rotating shift work and any cancer mortality, except for lung cancer in those who worked the night shift for 15 or more years (25% higher risk).

“A single occupation (nursing) provides more internal validity than a range of different occupational groups, where the association between shift work and disease outcomes could be confounded by occupational differences,” the researchers noted.

“To derive practical implications for shift workers and their health, the role of duration and intensity of rotating night shift work and the interplay of shift schedules with individual traits (eg, chronotype) warrant further exploration,” they added.

The researchers published their results in the January 5, 2014 issue of the American Journal of Preventive 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.

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.”

Lifestyle Measures Cut Cardiovascular Deaths in Prediabetes

Weight loss and other lifestyle interventions can reduce the risk of long-term cardiovascular consequences of diabetes, according to the results of a clinical trial.

This is the first randomized clinical trial to show that lifestyle intervention in those with impaired glucose tolerance reduces all-cause and cardiovascular disease mortality.

Lifestyle intervention delays the onset of diabetes and reduces the incidence of diabetes.

We had assessed how mortality was affected by the time free from diabetes, which was defined as the time between randomization and onset of diabetes.

We found that the increased delay in the onset of diabetes was associated with significantly lower all-cause and cardiovascular disease mortality,” said lead author Professor Guangwei Li of the China-Japan Friendship Hospital, Beijing, China.

“After inclusion of time to onset of diabetes in the multivariable models the intervention variable was no longer statistically significant, suggesting that the reduction in mortality associated with the intervention is mediated by its effect in delaying the onset of diabetes,” he noted.

The researchers published their results online on April 3, 2014 in The Lancet Diabetes & Endocrinology.

LIFESTYLE INTERVENTIONS PREVENT DEATHS

Many research studies have shown that lifestyle interventions, such as exercise programs or weight loss, in persons with impaired glucose tolerance can prevent progression to overt type 2 diabetes.

However, until now, there has been a lack of high-quality, randomized controlled trial evidence to prove that lifestyle interventions prevent deaths from cardiovascular disease, such as heart attacks and stroke, in these patients.

Dr. Li and colleagues enrolled 438 patients assigned to the intervention arm and 138 patients who were assigned to the control arm.

The study intervention lasted for 6 years, and patients were then monitored for 23 years.

At the end of the follow-up period, cumulative incidence of death from cardiovascular disease was 11.9% in the lifestyle intervention group versus 19.6% in the control group.

Death from all causes was 28.1% in the lifestyle group versus 38.4% in the control group.

The difference between groups for both outcomes was statistically significant.

“Although the association between duration of diabetes and mortality is well established, serious chronic complications and excess mortality typically only occur after at least 10 years of having diabetes,” Dr. Li said.

“In the present study, a difference in mortality between the intervention and control group started to emerge 12 years after the study began, slowly increased to a 17% difference by the 20-year follow-up, but became statistically significant only after 23 years.”

“TYPE 2 DIABETES CAN BE PREVENTED”

Dr. Li noted that a key difference between previous other studies and the Da Qing Diabetes Prevention Study is the length of follow-up.

In previous studies, the length of follow-up might have been insufficient to detect an effect of intervention on mortality.

Dr. Li’s bottom-line message: “Type 2 diabetes can be prevented.

Group-based lifestyle interventions over a 6-year period have long-term effects on prevention of diabetes beyond the period of active intervention.

The benefits of the intervention extended to a significantly favorable reduction of mortality.

These results emphasize the long-term benefits of the intervention and reinforce the overall value and importance of lifestyle interventions as public health strategies to prevent diabetes.”

Mediterranean Diet Reduces Diabetes, Inflammation

Two new studies show the heart-healthy benefits of eating a Mediterranean diet.

One study linked the diet to a lower risk of diabetes, especially among those at high risk for cardiovascular disease.

The other study tied the eating plan to lower levels of platelets and white blood cells, 2 markers of inflammation, which has been associated with a greater risk of heart attack and stroke.

The Mediterranean diet frequently emphasizes fresh fruits and vegetables, whole grains, beans, nuts, fish, olive oil, and even a glass of red wine.the_mediterranean_diet_

Eating an anti-inflammatory, Mediterranean style diet has been shown to not only be a delicious and enjoyable way to eat, but also is wonderful for your health.

Earlier research has shown that following the traditional Mediterranean diet also is linked to weight loss, a reduced risk of heart disease and related death, and lower blood pressure and blood cholesterol levels.

Mediterranean Diet Reduces Risk of Diabetes

In the first pooled analysis of studies evaluating the possible role of the Mediterranean diet in diabetes development, adherence to this diet was associated with a 21% reduced risk of diabetes compared with the control dietary groups.

The likelihood of developing diabetes was almost 27% less in those at high risk for cardiovascular disease than in controls.

“Adherence to the Mediterranean diet may prevent the development of diabetes irrespective of age, sex, race, or culture,” said lead investigator Demosthenes Panagiotakos, PhD, professor at Harokopio University, Athens, Greece.

“This diet has a beneficial effect, even in high risk groups, and speaks to the fact that it is never too late to start eating a healthy diet.”

Dr. Panagiotakos and colleagues systematically reviewed 19 original research studies that followed more than 162,000 participants for an average of 5.5 years.

These studies spanned European and non-European populations, which is important because most of the published studies have been European-based and there has been some question of possible confounding factors in these regions, including genetics, the environment, lifestyle, and lower stress levels.

Dr. Panagiotakos said he believes the Mediterranean diet lowers the risk of diabetes by helping guard against obesity.

He presented his study on March 27, 2014 at the American College of Cardiology’s 63rd Annual Scientific Session in Washington, DC.

Mediterranean Diet Lowers Inflammation

To understand whether a Mediterranean diet might favorably influence platelet and white blood cell levels, Italian researchers conducted an analysis of the eating habits of nearly 15,000 healthy Italian men and women aged 35 years or older as part of a large epidemiological study.

The investigators observed that consumption of the Mediterranean diet was directly related to lower levels of platelets and white blood cells, which in turn correlated to lower levels of inflammation.

Those who strictly followed a traditional Mediterranean diet were less likely to belong to study cohorts with relatively high platelet counts and were more likely to belong to cohorts with relatively low white blood cell counts.

“Because the study included healthy participants, the lower levels of platelets and white blood cells in those who were more strictly consuming a Mediterranean diet indicate that this eating plan could account for substantial changes within normal ranges of variability,” said lead author Marialaura Bonaccio, PhD.

“This is an important finding that has implications for how these anti-inflammatory markers are tracked among the general population.”

Dr Bonaccio is with the Department of Epidemiology and Prevention at the IRCCS Istituto Neurologico Mediterraneo NEUROMED in Italy.

The results of her study were published online in the March 31, 2014 issue of Blood.