Diet-induced weight loss alone improved risk factors in older obese adults
HOUSTON — Diet-induced weight loss independently contributed to improved insulin sensitivity and cardiometabolic risk factors in older obese adults, as indicated by data presented here.
In a study published in The New England Journal of Medicine on March 31, Dennis T. Villareal, MD, adjunct associate professor of medicine at Washington University School of Medicine in St. Louis, and a team of researchers reported that combining weight loss and exercise yielded marked improvement in physical function, compared with either intervention alone.
Contrary to these reported data, Villareal and Matthew F. Bouchonville, MD, clinical endocrinologist in Albuquerque, N.M., and colleagues presented results addressing the independent and combined effects of weight loss and exercise on cardiometabolic risk factors in older obese adults, here at the Endocrine Society’s 94th Annual Meeting and Expo.
“Over this past month there have been several headlines describing the fact that the obesity epidemic is not expected to get better any time soon, with recent projections by the CDC that the prevalence of obesity will continue to increase by 42% by 2030. And while the population isn’t expected to get thinner, it’s also not getting younger. In fact, the first of the baby boomers turned 65 this past year. So, we can expect to see continued growth at this older segment of the population,” Bouchonville said during a presentation.
“At present, over half of older adults meet criteria for the metabolic syndrome, which is predictive of CVD and mortality. Despite these trends and the associated public health implications, the appropriate treatment for obese older adults remains controversial.”
In a 1-year randomized controlled trial, Bouchonville and colleagues examined 107 obese (BMI ≥30) adults aged 65 years or older. Of the 107 adults, 93 (87%) completed the trial. The patients were randomly assigned to 4 groups: control, diet, exercise and combined diet-exercise.
During the intention-to-treat analyses, researchers reported the insulin sensitivity index (ISI) improved in the diet group by 70% and in the diet-exercise group by 86%. However, ISI did not improve in the exercise group or the control group (between-group, P<.05).
Additionally, the glucose and insulin area under curves during the oral glucose tolerance test improved in the diet group by 10% and in the diet-exercise group by 15% to 20%. Again, the exercise and control groups did not see an improvement (between-group, P<.05).
More data demonstrated that systolic BP, diastolic BP, waist circumference, abdominal visceral fat, serum triglycerides, C-reactive protein and tumor necrosis factor receptors (TNF-R) decreased in the diet and the diet-exercise groups. Yet, adiponectin increased in these groups, they said. These findings were not replicated in the exercise or the control groups.
Researchers also found that body weight was reduced by 10% in the diet group and by 9% in the diet-exercise group. There was no decrease in the exercise group or control group regarding body weight.
“Diet-induced weight loss with or without exercise, but not exercise training alone, improves insulin sensitivity and multiple other cardiometabolic risk factors simultaneously in obese older adults. However, the combination of these interventions is associated with an even greater improvement in insulin sensitivity,” Bouchonville said.
Researchers concluded that diet-induced weight loss is essential to decreasing risk for cardiometabolic syndrome – by Samantha Costa
For more information:
Bouchonville MF. Abstract S18-1. Presented at: the Endocrine Society’s 94th Annual Meeting & Expo; June 23-26, 2012; Houston.
Disclosure: The researchers report no relevant financial disclosures.