Web edition: June 26, 2012
Some gastric bypass patients see diabetes recur
Type 2 diabetes is often cured by gastric bypass, a form of obesity surgery that creates a short-cut for food in the gut and leads to substantial weight loss. But a new study finds that 14 of 66 gastric bypass patients who had thrown away their diabetes drugs after the operation saw the condition return two to five years later. Yessica Ramos, an internist at the Mayo Clinic Arizona in Scottsdale, reported that these patients saw the recurrence even though on average they maintained most of their weight loss. These 14 patients were more likely than patients who remained diabetes-free after the procedure to have had the disease for more than five years before surgery. Patients with long-term diabetes may have suffered more damage to insulin-making beta cells in the pancreas than the other patients, Ramos said. — Nathan Seppa
Secondhand smoke tied to diabetes, obesity
Being exposed to someone else’s tobacco smoke boosts a person’s risk of developing type 2 diabetes, a new study shows. Past research has associated smoking with a heightened risk of diabetes, even though smokers often are not overweight. In the new study, physician Theodore Friedman of Charles R. Drew University of Medicine and Science in Los Angeles reported that adult nonsmokers who were consistently exposed to smoke had a greater likelihood of being obese or having diabetes than nonsmokers who had only trace exposure to tobacco smoke. The risks of secondhand smoke exposure showed up even after the researchers accounted for differences in age, sex, race, alcohol consumption and physical activity. The researchers tapped medical data from more than 6,300 adults for the study and used blood levels of cotinine, a surefire marker of smoke inhalation, as a gauge of secondhand exposure.
— Nathan Seppa
Oxytocin may fight obesity, fatty liver disease, mouse study shows
A hormone better known for its role in social bonding, reproduction and possibly emotional attachment might also regulate appetite, tests in mice show. Oxytocin helped mice shed weight that they had put on while eating a high-fat diet, researchers reported. Yuko Maejima of Jichi Medical University in Shimotsuke, Japan, found that obese mice injected with oxytocin or given the hormone through a tiny implanted pump ate less and shed excess body weight. The hormone also lessened a pre-diabetic condition called impaired glucose tolerance in the mice, reduced belly fat and alleviated a dangerous condition called fatty liver. Oxytocin seemed to work better in male mice than females. Oxytocin has been considered for combating postpartum depression and as a treatment for autism or other neurological conditions (SN Online: 5/11/11). But questions linger regarding those applications (SN: 2/26/11, p. 15).
— Nathan Seppa
Vitamin D low in obese teens
Roughly half of teenagers getting ready to undergo bariatric surgery register exceptionally low levels of vitamin D. Researchers found that among 219 obese teens preparing for the operation, 54 percent were deficient in vitamin D as revealed by a blood test. Another 29 percent registered as having insufficient levels. Blacks were particularly deficient in the vitamin. These very obese children may not get outside much, limiting their sun exposure and their ability to make vitamin D, said study coauthor Marisa Censani, a pediatric endocrinologist at Columbia University Medical Center. “Also, since vitamin D is fat soluble, it may be sequestered in fat cells and not made available” to other tissues, she said, and consequently wouldn’t show up in blood measurements. Links between obesity and vitamin D deficiency are well documented in adults but less studied in kids. “These results support screening of all adolescents who are morbidly obese for vitamin D deficiency, especially prior to bariatric surgery,” Censani said. — Nathan Seppa
New thyroid assessment might lessen need for surgery
A new genetic test may help determine whether thyroid growths are malignant or benign and help doctors steer a patient toward surgery or ongoing monitoring, a study shows. Roughly 10 to 30 percent of thyroid growths, called nodules, are termed inconclusive by initial standard lab tests, so researchers analyzed 265 such tissue samples. By gauging the activity of 167 genes in these tissues, the new test correctly spotted 78 of 85 that more extensive testing had shown to be malignant. The seven false-negative findings “might have arisen from insufficient sampling of tissue,” said study coauthor Erik Alexander, a physician at Harvard Medical School. U.S. doctors do roughly 450,000 needle biopsies of thyroid nodules every year, and about 70,000 come back inconclusive and lead to more testing or surgery. “There is a lot of unnecessary intervention,” Alexander said. The gene test, with roughly 95 percent accuracy, could help to reclassify many of those nodules, he said. The test was made available in the United States in April. The new findings were also published online June 25 in the New England Journal of Medicine. — Nathan Seppa