Effects of Weight Loss and Weight Maintenance on Lipoprotein Insulin Resistance Scores in Adults with Overweight and Obesity.

Background: An elevated lipoprotein insulin resistance (LP-IR) score corresponds to insulin resistance in adults with overweight and obesity, yet data are lacking regarding the impact of exercise interventions on LP-IR. The purpose of this secondary analysis was to evaluate the effects of a weight loss and weight maintenance intervention on LP-IR score in adults with overweight and obesity. Methods: Thirty sedentary adults with overweight and obesity completed a 10-week OPTIFAST (R) weight loss program with supervised aerobic exercise to achieve clinical weight loss (CWL) (>= 7% from baseline). Aerobic exercise volume increased weekly until 700 MET min/week was reached. Participants who reached CWL were randomized to groups at volumes at either physical activity (PA-REC) or weight maintenance (WM-REC) recommendations (weeks 11-28). Plasma blood samples were analyzed via nuclear magnetic resonance spectroscopy at baseline, after weight loss (week 10), and following weight maintenance (week 28). Results: Following the weight loss phase, on average, participants significantly (p < 0.001) reduced LP-IR score (-12.1 +/- 13.5), body weight (-8.9 +/- 2.7%), and waist circumference (-7.7 +/- 4.1 cm). During the weight maintenance phase, there were no changes in LP-IR score between exercise groups (PA-REC: 4.1 +/- 13.6; WM-REC: -2.0 +/- 11.2; P = 0.7). The PA-REC group had improvements in LP-IR score from baseline (49.8 +/- 24.6 to 36.6 +/- 27.6, P < 0.001), yet there were no within-group changes during the weight maintenance phase (P > 0.05). Conclusion: LP-IR score improved during weight loss in adults with overweight and obesity and were sustained during the weight maintenance phase in the PA-REC group. Aerobic exercise at least at minimum guidelines following CWL can preserve LP-IR score improvements and may indicate a reduced T2DM risk in adults with overweight and obesity.