Background: Serum adiponectin is inversely linked to obesity, impaired glucose homeostasis, dyslipidemia and hypertension and has been suggested as a possible marker of cardiovascular (CV) disease in the general population. However, its role in chronic kidney disease and following renal transplantation is not well established.
Methods: This study examined the relationship of adiponectin with CV risk factors and kidney function in patients with predialysis chronic kidney disease (CKD) (n=33) and those who had undergone a renal transplantation (n=43). Serum adiponectin was measured using ELISA. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease (MDRD) study formula. Associations of adiponectin with clinical and laboratory parameters were tested.
Results: Mean age of the population was 37 +/- 11 years, 83% were men, 18% had diabetes and mean GFR was 48 +/- 29 ml/min per 1.73 m2. Adiponectin levels inversely related with eGFR (p=0.021), body mass index (BMI) (p=0.024), waist circumference (p=0.018) and hemoglobin (p=0.004), and directly related with high-sensitivity C-reactive protein (hsCRP) (p=0.019). It did not correlate with blood pressure, lipids, fasting glucose or smoking. On multivariate analysis, eGFR (beta=-0.360, p=0.002) and BMI (beta=-0.346, p=0.003) were independent determinants of adiponectin, adjusted for age, sex, lipids, diabetes, hypertension and transplant status. Renal transplant patients had lower CV risk, however adiponectin was similar to CKD patients (22 +/- 17 vs. 23 +/- 21; p=0.8). Adiponectin was inversely related to eGFR (p=0.003).
Conclusion: This is the first study showing that serum adiponectin is a poor predictor of cardiovascular risk in both the CKD and renal transplant population. Serum adiponectin levels are influenced by renal function. Adiponectin levels increased with decreasing kidney function in CKD renal transplant recipients. Despite better CV risk profile, transplant patients had similar adiponectin levels to those of CKD patients. We conclude that adiponectin levels do not reflect the high CV risk in CKD.