Exercise-induced lowering of chemerin is associated with reduced cardiometabolic risk and glucose-stimulated insulin secretion in older adults

Objective: To determine the effect of exercise on chemerin in relation to changes in fat loss, insulin action, and dyslipidemia in older adults. Participants: Thirty older (65.9 +/- 0.9yr) obese adults (BMI:34.5 +/- 0.7kg/m(2)). Setting: Single-center, Cleveland Clinic. Design: Prospective clinical trial. Intervention: Twelve-weeks of exercise training (60minutes/day, 5day/week at similar to 85% HRmax). Subjects were instructed to maintain habitual nutrient intake. Measurements: Plasma chemerin was analyzed using an enzyme-linked immunosorbent assay. Peripheral and hepatic insulin sensitivity was assessed using a euglycemic-hyperinsulinic clamp with glucose kinetics. First-phase and total glucose-stimulated insulin secretion (GSIS) was calculated from an oral glucose tolerance test. Fasting blood lipids (cholesterol, triglycerides), total/visceral fat (dual-x-ray absorptiometry and computerized tomography) and cardiorespiratory fitness (treadmill test) were also tested pre and post intervention. Results: Exercise increased fitness and reduced total/visceral fat, blood lipids, and firstphase GSIS (P < 0.05). Training also increased peripheral insulin sensitivity and lowered basal/insulin-related hepatic glucose production (P < 0.01). The intervention reduced chemerin (87.1 +/- 6.0 vs. 78.1 +/- 5.8ng/ml; P=0.02), and the reduction correlated with decreased visceral fat (r=0.50, P=0.009), total body fat (r=0.42, P=0.02), cholesterol (r=0.38, P=0.04), triglycerides (r=0.36, P=0.05), and first-phase and total GSIS (r=0.39, P=0.03 and r=0.43, P=0.02, respectively). Conclusions: Lower chemerin appears to be an important hormone involved in cardiometabolic risk and GSIS reduction following exercise in older adults.