Abstract MP92: Changes in Ectopic Fat are Associated with Changes in Adipokines in Healthy, Overweight/Obese Young Adults
Background: Excess ectopic fat has been associated with increased cardiometabolic risk, which may partially stem from changes in adipokines such as leptin and adiponectin. Prior studies have demonstrated that increased leptin and decreased adiponectin are associated with an increase in body mass index (BMI), but few have examined changes in adipokines related to changes in ectopic fat. We hypothesized that in healthy overweight and obese young adults, a decrease in ectopic fat will be associated with decreased levels of leptin and increased levels of adiponectin.
Methods: We analyzed 244 subjects participating in the Slow Adverse Vascular Effects (SAVE) study, a randomized trial of a behavioral weight loss intervention in 349 overweight and obese (BMI 25-40 kg/m2) men and women ages 20-45 years. Subjects underwent a CT scan of their abdomen and left thigh to quantify their amount of visceral (VAT) and intramuscular (IMAT) adipose tissue at baseline and 12 months. Serum concentrations of leptin and adiponectin were also measured at baseline and 12 months. We generated variables for the change in VAT, IMAT, adiponectin and leptin by subtracting 12-month from baseline values. To evaluate the association between changes in serum adipokine (dependent variable) levels with changes in VAT and left thigh IMAT (independent variables), we performed a series of multiple linear regression analyses controlling for: 1) age, sex, race and 2) previous variables + change in BMI tertile.
Results: The mean age at baseline was 38 ± 6 years; 181 (74.5%) subjects were female; and 198 (81.5%) were white. Mean VAT at baseline was 115.27 ± 53.58 cm2 with a mean decrease of 17.54 ± 36.71 cm2 at 12 months. Mean left thigh IMAT was 12.76 ± 4.87 cm2 at baseline with a mean decrease of 5.05 ± 3.20 cm2 at 12 months. Serum adiponectin was 11.90 ± 6.15 μg/mL at baseline, with a mean increase of 0.14 ± 3.79 μg/mL at 12 months. Serum leptin was 25.11 ± 13.38 μg/mL at baseline, with a mean decrease of 4.26 ± 10.71μg/mL at 12 months. After adjusting for age, sex, and race, a decrease in VAT was significantly associated with an increase in adiponectin (P=0.010) and decrease in leptin (P<0.001); a decrease in IMAT was significantly associated with an increase in adiponectin (P=0.003), but was not significantly associated with a decrease in leptin (P=0.297). Except for the association between a decrease in IMAT and decrease in leptin (P=0.048), these relationships were no longer significant after adjusting for change in BMI tertile.
Conclusion: A decrease in ectopic fat was associated with an increase in adiponectin and a decrease in leptin in young overweight/obese adults after adjusting for age, sex, and race. This underscores the metabolic activity of ectopic fat and supports the role of adiponectin and leptin as mediators of cardiometabolic risk.
Author Disclosures: T.R. Radomski: None. L. Bai: None. E. Barinas-Mitchell: None. M.B. Conroy: None.
- © 2015 by American Heart Association, Inc.