Abstract B2: Effects of individual and combined diet and exercise intervention in postmenopausal women on adiponectin and leptin

Abstract

Abstract Introduction: Obesity and sedentary lifestyles are modifiable risk factors for several chronic diseases. Adiponectin and leptin play central roles in energy balance, insulin homeostasis and lipid/glucose metabolism. We examined the individual and combined effects of dietary weight loss and/or exercise on serum adiponectin and leptin concentrations. Methods: We conducted a 12-month randomized controlled trial in 439 overweight/obese postmenopausal women to examine biomarkers of breast cancer risk. Participants were randomly assigned to dietary weight loss (D) (N=118), moderate-to-vigorous intensity aerobic exercise (E), 225 minutes/week (N=117), combined diet + exercise (D+E) (N=117), or control (N=87). Blood samples were taken at baseline and 12 months follow-up. Changes in adiponectin and leptin were measured via radioimmunoassay. Results: Adiponectin increased significantly over the intervention period in the D+E (+6.6%; p=.0001) and D group (+9.5%; p<.0001), compared to controls (−0.4%). No statistically significant adiponectin changes were observed in the E intervention. In all intervention groups leptin decreased significantly compared to controls (D+E −40.1% p<.0001; D −27.1% p<.0001; E −12.1% p=0.005). When stratified by baseline BMI, we observed slightly stronger increases in adiponectin among those with BMI ≥ 30kg/m2 in the D+E intervention. Changes in leptin with the intervention were equally strong independent of baseline BMI. With increasing weight loss, adiponectin increased independent of the intervention group (D, D+E or E). Conclusion: Our study showed that a dietary weight-loss intervention had strong effects on adiponectin levels, independent of exercise. We also observed that lifestyle interventions associated with weight loss, are successful in reducing serum leptin concentrations. Citation Information: Cancer Prev Res 2011;4(10 Suppl):B2.