Objectives: To determine if long-term weight loss with associated improvement in physical and metabolic health can be maintained after lifestyle intervention in frail, obese older adults.
Design: Thirty-month follow-up pilot study of a 1-year lifestyle intervention trial.
Participants: Sixteen frail, obese (body mass index=36±2 kg/m2) older (71±1 yr.) adults.
Measurements: Body weight and composition, physical function, markers of the metabolic syndrome, glucose and insulin response to an oral glucose tolerance test, bone mineral density (BMD), liver and renal function tests, and food diaries.
Results: At 30-month follow-up, weight (101.5±3.8 vs. 94.5±3.9 kg) and BMI (36.0 ±1.7 vs. 33.5±1.7 kg/m2) remained significantly below baseline (all p<0.05). No significant change in fat-free mass (56.7±2.1 vs. 56.9±2.2 kg) or appendicular lean mass (24.1±1.0 vs. 24.1±1.1kg, all p>0.05) occurred between 12 months (end of trial) and 30 months. Improvements in the physical performance test (PPT 27±0.7 vs. 30.2±0.6), insulin sensitivity (4.1±0.8 vs. 3.0±0.6), and insulin area under the curve (12484±2042 vs. 9270±1139 min.mg/dl) remained at 30 months compared to baseline (all p<0.05). Waist circumference (116±3 vs. 109±3 cm) and systolic blood pressure (134±6 vs. 123±5 mm HG) remained decreased at 30 months compared to baseline (all p<0.05). Whole body and lumbar spine BMD did not change; however, total hip BMD progressively decreased at 30 months compared to baseline (0.985±.026 vs. 0.941±.024 g/cm2; p<0.05). There were no adverse effects on liver or renal function. Food frequency questionnaire data showed lower overall caloric intake (-619±157 kcal/day) at 30 months compared to baseline (p<0.05).
Conclusion: These findings suggest that long-term maintenance of clinically important weight loss is possible in frail, obese older adults. Weight maintenance appears to be achieved through continued caloric restriction. Larger, long-term studies are needed to follow up on these findings and investigate mechanisms and behaviors underlying maintenance of weight loss and physical function.