High adiponectin concentrations are associated with the metabolically healthy obese phenotype

In the ob/ob mice, keeping adiponectin concentrations in the physiological range (through overexpression of this gene in the adipose tissue) results in expansion of fat mass and protection against metabolic co-morbidities.

The aim of the study was to test in humans whether plasma adiponectin levels, similar to those found in lean subjects, are associated with the metabolically healthy obese phenotype.

A cross-sectional analysis was performed of a cohort of obese and nonobese subjects aged 18-70 yr. A medical history was taken, and glucose, plasma lipids, and total adiponectin were measured.

We studied 189 men and 527 women. The majority were obese (n = 470, 65.6%). The metabolically healthy obese phenotype was found in 38 men and 133 women. This is defined as a body mass index (BMI) above 30 kg/m(2) plus high-density lipoprotein cholesterol of at least 40 mg/dl in the absence of type 2 diabetes and arterial hypertension.

Twenty percent of the cases with a BMI above 40 kg/m(2) had adiponectin concentrations above the median value of normal BMI subjects. Adiponectin levels above 12.49 mg/liter in obese women (odds ratio, 3.02; 95% confidence interval, 1.95-4.67; P < 0.001) and above 8.07 mg/liter in obese men (odds ratio, 2.14; 95% confidence interval, 1.1-4.06; P = 0.01) increased the probability of being metabolically healthy. The association remained significant (beta, 0.673 +/- 0.205, P < 0.001) in a logistic regression model (r(2) = 0.25, P < 0.001) after controlling for the confounding effect of age, insulin, and waist circumference.

Certain obese individuals have adiponectin levels similar to those found in normal BMI subjects; this is associated with the metabolically healthy obese phenotype.