Abstract
OBJECTIVE: Examine if adding aerobic exercise to standard medical care (EX+SC) prior to bariatric surgery improves metabolic health in relation to surgical outcomes. METHODS: Fourteen bariatric patients (age: 42.3±2.5y, BMI: 45.1±2.5 kg/m2) met inclusion criteria and were match-paired to pre-operative SC (n = 7) or EX+SC (n = 7; walking 30min/d, 5d/wk, 65-85% HRpeak) for 30d. A 120min mixed meal tolerance test was performed pre- and post-intervention (~2d prior to surgery) to assess insulin sensitivity (Matsuda Index) and metabolic flexibility (indirect calorimetry). Aerobic fitness (VO2peak), body composition (BodPod), and adipokines (adiponectin, leptin) were also measured. Omental adipose tissue was collected during surgery to quantify gene expression of adiponectin and leptin, and operating time and length of hospital stay were recorded. ANOVA and Cohen's d effect size (ES) was used to test group differences. RESULTS: SC tended to increase percent body fat (P = 0.06) after the intervention compared to EX+SC. Although SC and EX+SC tended to raise insulin sensitivity (P = 0.11), EX+SC enhanced metabolic flexibility (P = 0.01, ES = 1.55), reduced total adiponectin (P = 0.01, ES = 1.54) with no change in HMW adiponectin and decreased the length of hospital stay (P = 0.05) compared to SC. Albeit not statistically significant, EX+SC increased VO2peak 2.9% compared to a 5.9% decrease with SC (P = 0.24, ES = 0.91). This increased fitness correlated to shorter operating time (r = -0.57, P = 0.03) and length of stay (r = -0.58, P = 0.03). Less omental total adiponectin (r = 0.52, P = 0.09) and leptin (r = 0.58, P = 0.05) expression correlated with shorter operating time, and low leptin expression was linked to shorter length of stay (r = 0.70, P = 0.01), and low leptin expression was linked to shorter length of stay (r = 0.70, P = 0.01). CONCLUSION: Adding pre-operative aerobic exercise to standard care may improve surgical outcomes through a fitness and adipose tissue derived mechanism.