Background and aims: Adiponectin is an adipokine highly and specifically expressed by adipose cells with antiatherogenic and antiinflammatory activities. The aim of the present study was to evaluate plasma adiponectin concentration in patients with primary hypertriglyceridemia and its relationship with metabolic parameters.
Methods and results: Male patients with primary hypertriglyceridemia and without the metabolic syndrome (n=22) were compared with normotriglyceridemic individuals (n=25). Plasma adiponectin concentration was measured by standardised enzyme-linked immunosorbent assay. Body mass index, waist circumference, glucose, insulin and non-esterified fatty acid levels, lipoprotein profile, and CETP activity were evaluated. Adiponectin levels were significantly decreased in hypertriglyceridemic patients in comparison with normotriglyceridemic subjects (4292+/-1717 vs. 6939+/-3249 ng/ml, p<0.005, respectively). Adiponectin was negatively associated with glucose (r=-0.44, p<0.01), insulin (r=-0.37, p<0.01), HOMA (r=-0.40, p<0.01), triglycerides (r=-0.36, p<0.01), VLDL-C (r=-0.34, p<0.05), and CETP (r=-0.47, p<0.001). Positive and significant correlations were observed with QUICKI (r=0.49, p<0.001) and HDL-C (r=0.33, p<0.05). In the multiple linear regression analysis, considering waist circumference, QUICKI, Log-triglycerides, HDL-C, and CETP as independent variables, Log-adiponectin showed a positive correlation with QUICKI, with an r(2)=0.229 and p<0.001. Therefore, the independent variable QUICKI explained the 23% of the variance in Log-adiponectin concentration.
Conclusions: We found low adiponectin levels in a population of primary hypertriglyceridemic men without the metabolic syndrome and an independent relationship between adiponectin concentration and insulin resistance. A reduction in insulin sensitivity and its impact on adiponectin concentration could be linked to high non-esterified fatty acid levels, increased triglyceride synthesis in the liver and impaired catabolism of triglyceride-rich lipoproteins.