Background: Cardiovascular complications remain the main cause of mortality in patients with chronic kidney disease (CKD). Adiponectin is an adipose tissue-derived protein that carries important cardioprotective properties. We aimed at investigating the determinants of adiponectin levels in CKD patients.
Methods: This prospective observational study included 98 CKD patients [glomerular filtration rate (GFR) 36.1+-14.4 ml/min, 56.5+-10.4 y, 63% male, 31% diabetics, and body mass index (BMI) 27.1+-5.2 kg/m²]. Evaluation of adiponectin (imunoenzimatic assay), laboratory parameters, nutritional status (subjective global assessment), total body fat (dual x-ray energy absorptiometry), and visceral and subcutaneous abdominal fat (computed tomography) was performed at baseline and after 12 months.
Results: Adiponectin correlated with GFR (r = -0.45; p < 0.001), proteinuria (r = 0.21; p = 0.04), BMI (r = -0.33; p < 0.01), and visceral fat (r = -0.49; p < 0.001). In the linear regression analysis, the determinants of adiponectin levels were sex (female β = 3.8; p < 0.01), age (β = 0.14; p = 0.03), GFR (β = -0.15; p < 0.01) and visceral fat (β = -0.04; p < 0.001) (R² = 0.41). After 12 months, a progression of the disease was evidenced by the reduction of GFR (-1.6+-6.3 ml/min; p = 0.01) and increase of proteinuria (0.3+-0.8 g/d; p < 0.01). An accumulation of visceral fat was observed, from 97+-73 cm² to 111+-82 cm² (p < 0.001), with a concomitant reduction of adiponectin concentration, from 27.6+-7.5 mg/l to 22.2+-11.6 mg/l (p < 0.001). Body weight, BMI, total body fat, and subcutaneous abdominal fat remained unchanged. After adjustments for the baseline determinants of adiponectin, the increase in visceral fat was independently associated with overtime decrease in adiponectin levels (β = -0.04; p = 0.025; R² = 0.21).
Conclusion: Age, sex, renal function and visceral fat were independently associated with adiponectin levels in nondialyzed CKD patients. However, variation in visceral fat was the only predictor of variation in adiponectin levels over 12 months.