News from the latest research

Obese Children May Lose Pounds With SELF-HELP

Self-help guides may offer obese children an opportunity to lose weight on their own, according to a new study.

Recent estimates put the number of overweight or obese children in the U.S. at 12.5 million, but losing the excess pounds is an uphill battle that often requires treatment at weight loss management clinics that are not an option for many families.

In the study published in Pediatrics, researchers from the University of California, San Diego, evaluated 50 overweight or obese children (ages 8–12) to see whether a guided selfhelp treatment program would result in weight loss. The children and their parents were divided into two groups—one receiving a five-month self-help program immediately and the other getting delayed treatment. The program included just 12 visits with a pediatrician over five months and taught healthy lifestyle habits, including healthy eating, exercise, and how parents can set limits on food consumption.

At the end of the study, children in the treatment group significantly decreased their body mass index compared to the second group. The authors concluded, however, that additional efficacy and translational studies are needed to evaluate the guided self-help treatment.

— Glenda Fauntleroy

Antidepressants and Weight Regain in
PRE-DIABETES

The use of antidepressants pose a threat to weight maintenance in people with impaired glucose tolerance (pre-diabetes) who have shed a few pounds, say researchers in the nationwide, multicenter Diabetes Prevention Program (DPP) and its follow-up study, the Diabetes Prevention Program Outcome Study (DPPOS). A paper in the February issue of Diabetes Care describes the research, a collective effort of the Diabetes Prevention Program Research Group.

The team analyzed the medical records of 1,442 participants who had lost at least 3% of their body weight one year into the DPP. Throughout the DPP and DPPOS, researchers recorded participants’ weight and antidepressant use every six months, and assessed participants for symptoms of depression once a year, all for an average of 10 years per participant.

Among the participants who had lost weight, 826, or 57%, had regained the weight after an average of 5.1 years. When assessing antidepressant use among the participants, the researchers found that the risk of weight regain was 72% higher in those who took the drugs than those who did not. In their conclusion, the researchers note that the weight regain may be a side effect of the drugs.

—Terri D’Arrigo

DIET-SLEEP LINK Investigated

If you have trouble getting out of bed in the morning — or falling asleep at night — your diet might be the culprit. Then again, it could be lack of adequate sleep or excess shut-eye wreaking havoc on your diet.

Scientists have understood for some time that suboptimal sleep patterns are correlated with weight gain. A study published in Appetite provides new insight into this link.

Researchers from the Perelman School of Medicine at the University of Pennsylvania divided study participants into four groups based on self-reported nightly sleep patterns: very short sleepers (< 5 hours); short sleepers (5 to 6 hours); standard sleepers (7 to 8 hours); and long sleepers (9 or more hours). Very short sleepers reported eating the least variety of foods and consumed the third highest calories among the groups. Short sleepers took in the second most variety but topped the calorie scale. Normal sleepers ate the most varied diets, consuming the second highest number of calories, while long sleepers took in the least calories and third greatest variety of foods. Certain micronutrients contributed to the variance in sleep duration. Theobromine had the greatest effect, followed by vitamin C, tap water, Lutein + zeaxanthin, dodecanoic acid, choline, lycopene, total carbohydrates, selenium, and alcohol. Researchers did not identify the mechanism underlying diff erential micronutrient intake. The findings pose a “which came first, chicken or egg” dilemma, since researchers were unable to pinpoint the direction of effect. They did conclude certain nutrients may play an underlying role in short and long sleep duration and that people who report eating a large variety of foods had the healthiest sleep patterns. Future research in the form of a prospective study using objectively measured sleep duration is needed, the Perelman team noted. — Carol Bengle Gilbert

Diabetes Ups Risk of
SEVERE OSTEOARTHRITIS

Osteoarthritis is thought to be caused by wear and tear on joints associated with age and weight. But data from the Bruneck Study, which tracked 927 men and women aged 40–80 in Bruneck, Italy, from 1990 to 2010, suggest that type 2 diabetes may also play a role. The research appears in the February issue of Diabetes Care.

In the study, a team led by the University of Erlangen-Nuremberg’s Georg Schett, MD, analyzed the medical records of all participants and found that 69 had type 2 diabetes. Thirteen participants in that group, or 17.7%, developed severe osteoarthritis that required either a knee or hip replacement, compared to 73 participants without diabetes, or just 5.3%. Results were similar when the team grouped participants of similar age and body mass index.

The researchers noted previous studies suggesting that high blood glucose may promote the destruction of cartilage and stimulate the expression of pro-inflammatory and pro-degenerative proteins. They also cited evidence that diabetic neuropathy may increase the risk of osteoarthritis by contributing to muscle weakness, which in turn can change the amount of stress placed on the affected joints.

—Terri D’Arrigo

Baldness Linked to Prostate Cancer
in AFRICAN AMERICANS

African-American men who lose their hair early in life may be at a higher risk of prostate cancer, finds new research.

Researchers from the University of Pennsylvania School of Medicine studied 318 African-American men with prostate cancer and 219 controls (ages 33–93). They were asked about any diagnosis of prostate cancer and the category of their hair loss at age 30.

In most cases, baldness increased the risk of prostate cancer. Men younger than age 60 with any baldness had more than three times the risk of being diagnosed with advanced prostate cancer, and younger men with frontal baldness were six times more likely to have advanced cancer than men without this pattern, according to the study published in Cancer, Epidemiology, Biomarkers & Prevention.

Lead author Charnita Zeigler-Johnson, PhD, said although their study found a link between hair loss and prostate cancer, they cannot recommend new screening guidelines at this time. “Our results need to be confirmed by future studies to be certain the associations that we observed are found in other populations,” she said.

— Glenda Fauntleroy

MEDITERRANEAN DIET Chops Cardiac Risks

People at high risk for cardiovascular disease can substantially reduce their risk of a major cardiovascular event by consuming a Mediterranean diet, according to a study published in the New England Journal of Medicine.

The Prevención con Dieta Mediterránea (PREDIMED) study was a parallel-group, multicenter, randomized, primary prevention trial with a sample of 7,447 participants on similar drug treatment regimens. The subjects were elderly men and women with no cardiovascular disease but either type 2 diabetes or three cardiovascular risk factors. The researchers randomly assigned them to one of three groups, two directed to consume Mediterranean diets, and the control group instructed to minimize dietary fats.

Both experimental groups significantly increased weekly servings of fish (by 0.3 servings) and legumes (by 0.4 servings) in comparison to the control group. Members of one experimental group supplemented their diets with 1 liter of olive oil weekly, while the other group added 30 g of nuts per day to their diets. The Mediterranean dieters avoided red meat while limiting sodas, partially solidified fats, and commercially baked sweets. There were no energy restrictions applied to any of the study population.

Researchers followed the groups for a mean of 4.8 years. Their identified end point was a composite of myocardial infarction, stroke, and death from cardiovascular causes, with secondary end points defined as any of those events individually or death from any cause. Of the 288 primary-outcome events, 96 (3.8%) occurred in the Mediterranean diet with extra-virgin olive oil group, 83 (3.4%) in the Mediterranean diet with nuts group, and 109 (4.4%) in the control group.

Both experimental groups experienced an absolute risk reduction approximating three major cardiovascular events per 1,000 person-years representing a 30% risk reduction. The study was published in the New England Journal of Medicine.

— Carol Bengle Gilbert

TEENS’ POOR HEALTH Raises Heart Disease Risks

In a new study published in Circulation, researchers evaluated 4,673 adolescents (ages 12–19) from all major ethnic groups who took part in the National Health and Nutrition Surveys. Adolescents’ cardiovascular health was judged based on seven components of the American Heart Association’s 2020 impact goals, which include blood pressure, cholesterol, body mass index, healthy diet, and physical activity.

The study reports that less than half of the adolescents had five or more acceptable levels of the health factors. One-third had cholesterol levels in the intermediate or poor range and just 44 percent of girls and 67 percent of boys reached their ideal physical activity levels. Also, more than 80 percent had a poor diet that didn’t include recommended levels of fruits and vegetables, fish, and wholegrains.

“The far less-than-optimal physical activity levels and dietary intake of current U.S. teenagers is translating into obesity and overweight that, in turn, is likely influencing worsening rates of high blood pressure, high cholesterol, and blood glucose at these young ages,” said lead author Christina Shay, PhD, assistant professor at the University of Oklahoma Health Sciences Center in Oklahoma City, in a statement.

— Glenda Fauntleroy

LEPTIN, OBESITY,
and Hypertension

Obesity is a well-known risk factor for the development of hypertension, but the scientific community is still sorting out the relationship between the two conditions. Now a small study by German researchers, appearing in the March issue of the Journal of Clinical Endocrinology and Metabolism, suggests that leptin, a key metabolic hormone often elevated in obese people, may play a role.

In the study, a team led by Felix Machleidt, MD, of the University Hospital of Schleswig-Holstein in Lübeck, observed the effects of high levels of leptin in 12 healthy, normal-weight men. In each of two visits, the men received an intravenous bolus of either leptin or saline (placebo). Using electrodes placed on the men’s skin, the team measured the men’s vasoconstrictory muscle sympathetic nerve activity (MSNA) 10 minutes before the bolus and 20, 60, and 140 minutes after the bolus. Vasoconstrictory MSNA is thought to play a role in the development of hypertension and, like leptin, is often elevated in the obese.

Although there were no significant changes in the men’s blood pressure or heart rate when they received leptin, their MSNA shot up as much as 135%. The researchers concluded that high levels of leptin may account for increased vasoconstrictory MSNA often seen in the obese, and therefore play a role in the development of hypertension in this population.

—Terri D’Arrigo

DISTRACTED EATING Bumps Up Later Consumption

Th e dangers of distracted driving are increasingly in the spotlight, but now researchers are pointing the finger at another deleterious distraction: eating. It seems paying attention to what you eat may help keep you from overeating.

A study published in the American Journal of Clinical Nutrition reviewed 24 prior studies to assess a technique called attentive eating. Th at’s when people pay attention to what and how much they’re putting in their mouths. Th e researchers found distracted eating caused moderate overeating on the spot and even greater increases in food intake two hours later. When the research design included prompts to jog subjects’ memory of what they’d eaten, their immediate consumption remained stable while their delayed intake declined moderately.

These findings could prove helpful in establishing behavioral strategies to discourage overeating. Such strategies may be an effective alternative to calorie counting for dieters. However, the researchers cautioned, most of the studies reviewed involved subjects with body mass indices in the healthy range. Further work is needed to see if the results hold up with overweight subjects.

— Carol Bengle Gilbert

New CT Angiography Technique Provides BETTER SCANS

Rapid kilovolt peakswitching dual-energy cardiac computed tomography (CT) angiography is superior to standard CT scans, according to a study published in Radiology. This prospective, diagnostic study funded by GE Healthcare was conducted in four centers in three countries. Thirty-nine patients underwent dualenergy CT scans with a subset of 25 also undergoing single-energy coronary CT angiography. The goal was to compare scanning techniques to determine if the dual-energy scans provided clearer imaging.

Artifacts, image features not present in the scanned objects, are an inherent pitfall of CT scanning. They can lead to inaccurate diagnosis if not recognized. One type of artifact, the beam-hardening (BH) artifact, occurs because X-ray beams are polychromatic or nonlinear. A previous study evaluating asymptomatic patients without a history, or CT fi ndings, of obstructive coronary artery disease identified BH-related differences between the inferobasal myocardial segment and the remainder of the myocardium, mimicking a perfusion defect, in 72% of patients.

The researchers used paired t tests to evaluate the difference in myocardial attenuation between the dual-energy and singleenergy images and compare the BH levels against an ideal scenario of no BH.

The dual-energy technology signifi cantly reduced myocardial BH artifact, improving signal-to-noise ratio (SNR) and contrastto-noise ratio (CNR) in the coronary arteries and the myocardium. CNR is the most important factor in imaging, allowing radiologists to distinguish between healthy and diseased tissue by comparing SNR in adjacent areas.

The researchers recommend reconstruction at 80 kiloelectron volts (keV) for myocardial SNR and CNR optimization, and 65 keV for optimal coronary artery evaluation. They say those parameters will help healthcare providers integrate the new technology into clinical practices. Because of the small study population, future testing is needed to confirm these findings.

—Carol Bengle Gilbert

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