Abstract
OBJECTIVES: To compare the effects of 4 years of intensive lifestyle intervention on weight, fitness, and cardiovascular disease risk factors in older and younger individuals. DESIGN: Randomized controlled clinical trial. SETTING: Sixteen U.S. clinical sites. PARTICIPANTS: Individuals with type 2 diabetes mellitus: 1,053 aged 65 to 76 and 4,092 aged 45 to 64. INTERVENTIONS: An intensive behavioral intervention designed to promote and maintain weight loss through caloric restriction and increased physical activity was compared with diabetes mellitus support and education. MEASUREMENTS: Standardized assessments of weight, fitness (based on graded exercise testing), and cardiovascular disease risk factors. RESULTS: Over 4 years, older individuals had greater intervention-related mean weight losses (6.2%) than younger participants (5.1%; interaction P = .006) and comparable relative mean increases in fitness (0.56 vs 0.53 metabolic equivalents; interaction P = .72). These benefits were seen consistently across subgroups of older adults formed according to many demographic and health factors. Of a panel of age-related health conditions, only self-reported worsening vision was associated with poorer intervention-related weight loss in older individuals. The intensive lifestyle intervention produced mean increases in high-density lipoprotein cholesterol (2.03 mg/dL; P < .001) and decreases in glycated hemoglobin (0.21%; P < .001) and waist circumference (3.52 cm; P < .001) over 4 years that were at least as large in older as in younger individuals. CONCLUSION: Intensive lifestyle intervention targeting weight loss and increased physical activity is effective in overweight and obese older individuals to produce sustained weight loss and improvements in fitness and cardiovascular risk factors.