Risk factors in metabolic syndrome predict the progression of diabetic nephropathy in patients with type 2 diabetes.

BACKGROUND: While metabolic syndrome can independently predict the development of diabetic kidney disease (DKD) in patients with type 2 diabetes, the risk factors for DKD progression have rarely been discussed. The purpose of this study is to evaluate the association between metabolic syndrome and the progression of DKD in patients with type 2 diabetes. MATERIAL AND METHODS: This retrospective observational cohort study lasted approximately five years. We defined metabolic syndrome using the criteria of the National Cholesterol Education Program Adult Treatment Panel III with the Asian definition of obesity. The progression of DKD was demonstrated by either the progression of albuminuria or worsening renal function. Progression of albuminuria was defined by the transition from normoalbuminuria (<30 mg/g) to microalbuminuria (30-300 mg/g) or from micro- to macroalbuminuria (>300 mg/g). Worsening renal function was defined by a reduction of eGFR to 50% of the baseline or the doubling of serum creatinine. We adopted multivariate Cox-regression analysis to determine the risk factors associated with DKD progression. RESULTS: This study consisted of 935 type 2 diabetic patients with a mean age of 64.62 years. We found progression of albuminuria in 172 patients (18.4%) and worsened renal function in 41 patients (4.4%). After Cox regression analysis, the multivariable-adjusted HR for the progression of albuminuria and worsened renal function was 1.65 (95% C.I.:1.07-2.53 P = 0.022) and 2.62 (95% C.I.:1.01-6.79 P = 0.047) respectively, for those with metabolic syndrome compared to those without metabolic syndrome. CONCLUSION: The presence of metabolic syndrome independently predicts DKD progression in patients with type 2 diabetes.