Abstract 6214: Comparison of Adiponectin Levels in Healthy Americans and Japanese: Results from Framingham and Fukuoka

Abstract

Background and Objectives: Adiponectin is an adipocytokine with insulin-sensitizing and anti-atherosclerotic effects. Serum adiponectin levels have been reported to be negatively correlated with body weight and waist circumference (WC). Low plasma adiponectin levels are known to predispose to the development of insulin resistance and type 2 diabetes mellitus. Adiponectin levels may vary according to ethnic group. The aim of this study was to investigate potential differences in plasma adiponectin levels between Japanese and Americans. Methods: Subjects consisted of 2,060 healthy American male and female participants in exam 6 of the Framingham Offspring Study (mean age 57.0 ± 9.0 years, 57.4 ± 10.5 years, respectively), and 1131 healthy Japanese male and female participants in the Fukuoka Study (mean age 56.3 ± 5.5 years, 55.6 ± 5.4 years, respectively). Frozen plasma samples (at −80 degree C) from both studies were shipped to Tufts University, Boston. Plasma concentrations of direct LDL-C, fasting plasma glucose and adiponectin were measured using the same assay kits on the same machine (Hitachi 911) by the same staff. Anthropometric measurements including weight, height, body mass index (BMI) and WC, were also used in the analysis. Results: Plasma adiponectin levels were significantly and inversely correlated with BMI, WC, glucose, insulin, triglycerides, and systolic and diastolic blood pressure. Moreover adiponectin levels were significantly and positively correlated with HDL-C in both populations. Mean BMI and WC of Japanese men and women were significantly lower (23.8 kg/m 2 and 22.1 kg/m 2 , 86.0 cm and 78.7 cm, respectively) than in US men and women (28.2 kg/m 2 and 27.0 kg/m 2 , 100.4 cm and 92.8 cm, respectively) (all p<0.05). However, mean adiponectin levels (± SD) in Japanese men and women were significantly lower (9.3 ± 4.5 micro g/mL and 14.7 ± 7.3 micro g/mL, respectively) than in US men and women (10.3 ± 5.2 micro g/mL and 16.3 ± 7.7 micro g/mL, respectively)(p<0.05). Conclusion: Our data indicate a substantially lower prevalence of adiposity, but not higher adiponectin levels, in a healthy Japanese population as compared to an American population. The data indicate that population specific norms may have to be used for different ethnic groups.