Exercise Appears Safe, Helpful For Pulmonary Hypertension

Exercise can be beneficial and safe for people with pulmonary hypertension(PH), researchers report. Pulmonary hypertension is a type of high blood pressure that affects the lungs and heart, causing breathing problems, fatigue and dizziness. Left untreated, it can lead to heart failure, according to background information from the study. "Clinicians have traditionally been skeptical about prescribing exercise for patients with chronic pulmonary hypertension due to concerns that training might put further strain on the heart," study senior author said. "Our analysis found those concerns may be misplaced. More importantly, exercise had a positive effect on several measures of heart function as well as overall quality of life," he added. Researchers analyzed studies that included more than 400 people with pulmonary hypertension. Their review found that exercise is safe and can reduce pressure in the arteries and boost patients' ability to exercise. However, people with pulmonary hypertension should not begin an exercise program without first consulting their doctor, he said. He noted that most patients in the analysis were in supervised exercise programs that had lower levels of intensity than those typically prescribed for heart failure patients.

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    Gut Bugs May Affect Body Fat, 'Good' Cholesterol Levels  

The size of waistline may depend to some degree on the specific bacteria dwelling within the gut, new research suggests. The study, of nearly 900 Dutch adults, found that certain gut bacteria might help determine not only body fat levels, but also blood concentrations of HDL cholesterol and triglycerides. This is the first study to offer "solid evidence" that gut bacteria are linked to cholesterol and triglyceride levels, lead researcher said. But it does not prove that the bacteria directly alter people's blood fats, researcher stressed. So it's too early to recommend probiotic supplements for heart disease prevention, experts said. However, the findings add to growing evidence that the intestinal microbiome plays an important role in human health. As recent research has revealed, those bugs do much more than support good digestion: They aid in everything from immune function, to metabolizing drugs to producing vitamins, anti-inflammatory compounds and even chemicals that relay messages among brain cells. Studies have also suggested that when the microbiome lacks diversity, that may contribute to health conditions such as obesity, asthma and type 1 diabetes. The findings, published online Sept. 10 in the journal Circulation Research, are based on 893 adults ranging in age from 18 to 80. Research team analyzed fecal samples to get a snapshot of each person's intestinal microbiome. Overall, the researchers found 34 types of bacteria that were associated with people's triglycerides and HDL levels, and with body mass index (BMI). The investigators estimated that the gut microbiome explained 4 percent to 6 percent of the variance in BMI, triglycerides and HDL across the study group. A few of the bacteria highlighted in the study are known to be involved in metabolizing bile acids that affect cholesterol levels. But researcher said much more research is needed to understand how different gut bacteria function in relation to cholesterol and other risk factors for heart disease. "At the current stage, this field is still in its infancy," lead researcher added. 

SOURCE: HealthDay News, September 2015

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                                            Light From Smartphones, Tablets May Lower Sleep Hormone In Kids

New research offers a compelling reason for parents to ban smartphones, tablets and laptops in their children's bedrooms at night: The bright light of these devices may lower levels of melatonin, a hormone that prompts sleep. The effect was most pronounced for kids just entering puberty, with nighttime melatonin levels suppressed by up to 37 percent in some cases, the investigators found. With a recent study suggesting that 96 percent of teens use at least one high-tech device in the hour before bedtime, the researchers have a suggestion for parents. "The message is that we really have to be careful about protecting our especially young teens from light at night, which means parents need to get all screens out of the bedroom, because ultimately they can be quite damaging to a child's capacity to get enough sleep," study co-author said. Puberty and changing sleep habits go hand-in-hand, the study authors noted, as growing kids start to push for later bedtimes. To some degree, the shift is likely prompted by several social factors, including the loosening of parental restrictions, budding friendships and media. But scientists believe that biological factors also play a role, as a child's internal sleep clock starts to change. At the heart of that change is light sensitivity, she said. Her team theorized that puberty increases a child's sensitivity to light at night, causing melatonin levels to stay low and delay sleep. But the researchers also suspected this natural process could be knocked out of whack when newly light-sensitive children are around the bright glare of modern technology. So the study authors focused on 38 children between the ages of 9 and 15 (early puberty), along with 29 boys and girls between the ages of 11 and 16 (later or post-puberty). For four nights, all were exposed to a single hour of light, involving four different brightness levels. Brightness levels ranged from near-dark "romantic restaurant lighting" all the way up to what she called "light you would find in the produce section of your favorite large supermarket." The exposures occurred either at 11 p.m. or 3 a.m., the authors said. The result: While melatonin readings were uniform during the early morning light tests, late-night light tests caused much greater melatonin suppression among boys and girls at the earliest stages of puberty. In that group, dim "mood" lighting suppressed melatonin by more than 9 percent, while "normal" room light triggered a 26 percent dip and "bright" light prompted a 37 percent plunge. Overall, older teens saw much smaller drops in melatonin levels, the study found. The study did not prove that bright light before bedtime causes adolescents to get less sleep, however. "We cannot say we found a sleep 'disturbance,'" she added. "But what we did find was that young children exposed to light at bedtime saw their melatonin production suppressed. And this could cause sleep rhythms to be affected in a way that causes children to stay up later, which is exactly what adolescents need not to be doing.".

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