Lower levels of leptin and adiponectin independent of body mass index in Japanese American women: The Multiethnic Cohort

Abstract

Ethnic differences in obesity and body fat distribution may contribute to varying chronic disease risks, e.g., for breast cancer and diabetes. To explore if adipokines mediate this connection, we evaluated the relation of body mass index (BMI as defined by WHO) and serum levels of leptin and adiponectin measured by ELISA among 936 white, Japanese American (JA), African American (AA), Latino (LA), and Native Hawaiian (NH) female control participants within the Multiethnic Cohort. BMI differed significantly by ethnicity (p<0.0001). As compared to whites (25.3±5.2 kg/m2), BMI was lower in JA (23.7±3.8 kg/m2) and higher among AA, LA, and NH (28.9±5.8, 28.0±5.2, 28.3±5.9 kg/m2, respectively). Linear models were applied to compare means of log‐transformed biomarkers by adiposity status and ethnicity. In all ethnic groups, leptin was higher in overweight and obese than in normal weight women, whereas adiponectin showed an inverse trend (p<0.0001 for all). JA women had significantly lower leptin and adiponectin levels than whites across the 3 BMI categories; the respective differences between the two ethnic groups were 4.0, 8.7, and 18.9 ng/mL for leptin (p=0.0004) and 5.9, 4.4, and 3.6 μg/mL for adiponectin (p<0.0001). The higher obesity‐related disease risk in JA and other ethnic groups may be in part mediated by differences in adipokine either stemming from endocrine genetics or fat distribution.