Abstract P029: Associations between Weight Loss and Regain and Metabolic Measures in Obese Adults: Results from a 24-Month Behavioral Weight Loss Trial
Introduction: Obesity is linked to the development of insulin resistance (IR) and type 2 diabetes. Weight loss achieved by lifestyle modification could improve insulin sensitivity (IS). However, weight loss is difficult to maintain, and individuals often weight cycle, potentially placing them at greater risk for adverse health outcomes.
Objective: The purpose of this secondary analysis was to examine how long-term changes in weight are associated with changes in factors related to the development of diabetes (IR and IS) among obese adults enrolled in a 24-month behavioral weight loss trial.
Methods: The sample (N=66) included non-diabetic adults who lost and regained at least 10 lbs during the 24-month trial. All participants received standard behavioral weight loss treatment during the first 18 months. Assessments were conducted at baseline, 6, 12, 18, and 24 months. IR was assessed using the homeostatic model assessment (HOMA), and IS was assessed using the quantitative insulin sensitivity check for insulin sensitivity (QUICKI). Linear mixed modeling was used to examine the association between % changes in weight and % changes in fasting insulin, HOMA, and QUICKI. All models were adjusted for time, age, gender, race, % change in energy intake, and % change in physical activity.
Results: The sample was 80% female and 86% White. At baseline, the mean (±SD) values were: age, 48.4±7.4 years; BMI, 34.5±4.4 kg/m2; energy intake, 2176.8±603.8 kcal/day; physical activity, 11.4±13.6 MET- hr/week; plasma insulin, 16.9±6.0 μU/mL; HOMA, 4.1±1.7; and QUICKI, 0.3±.02. On average, compared to baseline, participants experienced an 11% decrease in weight (p<.0001), a 9% decrease in insulin (p=.004), a 10% decrease in HOMA (p=.01), and a 2% increase in QUICKI (p=.0003) at 6 months. Following 6-month weight loss, an average of 8.4% weight was regained by 24 months (p<.0001), and the positive changes observed in the other measures were partially reversed, e.g., a 19% increase in insulin (p=.001), a 26% increase in HOMA (p=.001), and a 2% decrease in QUICKI (p=.0002). Overall, weight change was positively associated with changes in insulin [b(se)=0.5(0.1), p≤.0001] and HOMA [b(se)=0.8(0.2), p≤.0001], and negatively associated with a change in QUICKI [b(se)= -0.2(0.1), p≤.0001].
Conclusion: In this unique sample of participants who weight cycled during a 24-month trial, weight loss improved metabolic outcomes; however, this was partially attenuated when weight was regained. These results reveal the effects of changes in weight on metabolic outcomes and highlight the importance of sustaining healthy lifestyle changes that support weight loss maintenance and improved metabolic outcomes.
- © 2013 by American Heart Association, Inc.