Thursday, September 19, 2013
Physical activity/weight loss combined for older, overweight = lower cardiovascular
The medical community touts the importance of not carrying excess weight, but that has not always been the message delivered to older adults.
Weight loss has been discouraged among older adults, partly because of health concerns over inadvertent reductions in muscle and bone mass, which is known to accompany overall weight loss. However, new research from Wake Forest Baptist Medical Center shows that physical activity and weight loss conducted together for older, overweight and obese adults results in improved body composition, translating into lower cardiovascular disease risk (CVD) and improved mobility.
Lead study author Kristen Beavers, Ph.D., M.P.H., instructor of geriatrics and gerontology at Wake Forest Baptist, said these new findings are illustrative of an emerging body of research addressing the controversy surrounding the recommendation of weight loss in old age and suggest that intentional weight loss can have positive health benefits for older adults, at least for the short term.
"Our results show that improvements in several risk factors for cardiovascular and metabolic disease correlate with the magnitude of lost weight and are influenced primarily by loss of fat," Beavers said. "Weight loss was also associated with improvements in mobility."
Beavers and colleagues analyzed data from the Cooperative Lifestyle Intervention Program (CLIP), a randomized controlled trial of physical activity and weight loss on mobility in 288 overweight or obese older adults at risk of CVD over a 2.5 year period. CLIP was conducted within the North Carolina Cooperative Extension Centers by senior co-author W. Jack Rejeski, Ph.D., professor of health and exercise science at Wake Forest University. CLIP showed that an 18-month physical activity and weight loss intervention was successful in achieving and maintaining clinically significant weight loss for a majority of overweight and obese older adults.
Findings published online this month ahead of print in the journal Obesity show that although some of the weight lost by CLIP participants was muscle, a larger amount of lost weight was fat mass, resulting in an increase in the relative proportion of lean body mass.
"Importantly, this favorable shift in body weight and composition was associated with improvements in clinical parameters of cardiometabolic risk and mobility," Beavers said.
The average age of participants was 67 with an average body mass index (BMI) of 32.8 kg/m2. Sixty-seven percent were women and 82 percent were Caucasian. All participants reported limitations in mobility at the beginning of the study. DXA-acquired body composition measures (total body fat and lean mass), conventional biomarkers of cardiometabolic risk, and 400-meter walk time were obtained at the study start and 18 months. DXA stands for dual-energy X-ray absorptiometry and is the current gold standard for assessing body composition in clinical research studies.
"These results should help temper some of the safety concerns regarding the recommendation of intentional weight loss for older adults," Beavers said. "However, better understanding of how long-term intentional weight loss and associated shifts in body composition, affects the onset of chronic disease and disability on older adults is necessary to comprehensively evaluate the clinical recommendation for weight loss in this population."