Health and Fitness News and Notes

Teenagers Need a Good Slumber

A good night’s sleep may be critical for the metabolic health of teenagers.

Researchers studied 829 boys and girls, average age 13, who wore electronic measuring devices that tracked sleep time, sleep quality and physical activity over seven to 10 days. They also recorded five factors associated with cardiovascular risk: waist circumference, blood pressure, HDL or “good” cholesterol, triglycerides and insulin resistance.

Inadequate sleep was common — 31 percent of the children slept less than seven hours a night, and 58 percent had poor sleep efficiency as measured by percentage of time awake after initial sleep onset. Shorter sleep duration and poorer sleep efficiency were associated with higher systolic blood pressure, lower HDL cholesterol, higher triglycerides and higher glucose levels, all indicators of poorer metabolic health.

Other studies have found that shorter sleep is associated with obesity, but in this study, published in Pediatrics, the associations were independent of body mass index. The researchers controlled for age and sex, race and ethnicity, TV viewing, fast food consumption and other factors.

“It was surprising that we found that the relationship was not fully explained by body mass index,” said the lead author, Elizabeth M. Cespedes Feliciano, a staff scientist at Kaiser Permanente Northern California.

Greater Risk From Heart Failure

The incidence of heart failure has declined overall in both sexes in recent years and remains higher in men. But women are more likely to die from the disease.

A study in the Canadian Medical Association Journal included 90,707 new diagnoses of heart failure among Ontario residents from 2009 to 2014. Almost 17 percent of women died within a year of follow-up, compared with just under 15 percent of men. Rates of hospitalization decreased over the study period in men and increased in women.

Part of the explanation may be that men are more likely to have a form of heart failure that can often be treated without the need for hospitalization, whereas women more often suffer a different type with few effective therapies. Also, women tend to present with symptoms that are different from men’s and not always as readily identifiable as heart failure.

Women in the study were more likely to be older and to have other diseases along with heart failure. But even after controlling for these and other factors, death rates were still higher in women.

“Public awareness is important, and for some reason heart failure doesn’t get much attention,” said the lead author, Dr. Louise Y. Sun, an assistant professor of anesthesiology at the University of Ottawa Heart Institute.

The Right Dose of Aspirin

A daily dose of baby aspirin is widely recommended for heart disease prevention, but a one-dose-fits-all approach may not work.

A new analysis, in The Lancet, looked at data from 10 randomized trials and found that the size of the dose and the weight of the patient have significant effects.

Researchers found that a daily dose of 75 to 100 milligrams of aspirin lowered the risk of cardiovascular events by 23 percent for people weighing less than 154 pounds, but had no effect in those weighing more. In people over 154 pounds, low-dose aspirin increased the risk for a fatal cardiovascular event. Higher doses — 325 to 500 milligrams a day — were effective in lowering cardiovascular risk in people who weighed more than 154.

Low-dose aspirin reduced the risk for colorectal cancer in people weighing less than 154 pounds, but not in those weighing more. High doses lowered the cancer risk in people between 154 and 176 pounds, but not in those heavier than that.

“There are a billion people worldwide taking aspirin regularly, and every randomized trial is based on the same dose for everyone,” said the lead author, Peter M. Rothwell, a professor of neurology at Oxford University. “It may be that we’ve got that wrong, and have to tailor dosage to the individual, as we do with other drugs.”