Is serum cystatin-C a reliable marker for metabolic syndrome?

Chronic kidney disease and metabolic syndrome are recognized as major cardiovascular risk factors. It has been shown that cystatin C has a stronger association with mortality risk than creatinine-based estimations of glomerular filtration rate. We measured cystatin values in dyslipidemic patients and looked for correlations between renal function, cystatin, and metabolic syndrome.

There were 925 dyslipidemic patients prospectively included in this cross-sectional study and evaluated over 10 months. Each visit included clinical and biological assessment.

Most patients exhibited cardiovascular risk factors other than dyslipidemia: hypertension in 34%, diabetes in 11%, and smoking in 18%. Mean triglycerides were 149 +/- 136 mg/dL, mean high-density lipoprotein cholesterol 54 +/- 14 mg/dL, and low-density lipoprotein 167 +/- 48 mg/dL. Metabolic syndrome was present in 238 (26%) patients. Plasma creatinine did not differ between control group and metabolic syndrome patients (80 +/- 26 vs 82 +/- 20 micromol/L, respectively, P = .2), but creatinine clearance evaluated by abbreviated Modification of Diet in Renal Disease Study formula was lower in the metabolic syndrome group than in the non-metabolic-syndrome group (83.3 +/- 18.8 mL/min/1.73 m(2) vs 86.8+/-16.9 mL/min/1.73 m(2), respectively, P < .007). Cystatin value was significantly higher in metabolic syndrome patients than in others (0.86 +/- 0.23 vs 0.79 +/- 0.20 mg/L, respectively, P < .0001), independently of serum creatinine level and creatinine clearance. Furthermore, there was a progressive increase in cystatin, as a function of the number of metabolic syndrome components.

Our study shows that cystatin is associated with metabolic syndrome in dyslipidemic patients. Cystatin may be an interesting marker of metabolic syndrome and of increased cardiovascular and renal risk.