Treatment of Metabolic Syndrome Slows Progression of Diabetic Nephropathy

BACKGROUND: Metabolic syndrome contributes to the development of albuminuria and to the decrease of glomerular filtration rate (GFR) in type 2 diabetes patients. The aim of this study was to analyze the effect of MS treatment on the progression of diabetic nephropathy (DN). METHODS: This was a retrospective and comparative cohort study. Baseline and follow-up data related to the presence of metabolic syndrome, microalbuminuria (mA), and GFR were obtained in individuals with type 2 diabetes. Subjects were classified in two groups: (1) With correction of metabolic syndrome and (2) without correction of metabolic syndrome at follow-up. Furthermore, they were stratified in four subgroups: (A) Without metabolic syndrome at baseline and at follow-up, (B) with metabolic syndrome and correction of metabolic syndrome, (C) without metabolic syndrome and development of metabolic syndrome, and (D) with metabolic syndrome and persistence of metabolic syndrome. RESULTS: Final GFR and mA were lower and higher, respectively, in group 2 versus 1 [89.8±3 2.3 vs. 98.3±32.0 mL/min, P=0.010, and 51.0 (13.5-195) vs. 7.9 (4-31) mg/day, P<0.001, respectively]. Lack of metabolic syndrome correction [hazard ratio (HR)=2.8, 95% confidence interval (CI) 1.9-4.2, P<0.001], being in subgroups C (HR=2.05, 95% CI 1.03-4.1, P=0.04) and D (HR=3.3, 95% CI 2.0-5.3, P<0.001), and the presence of two (HR=3.4, 95% CI 1.9-6.1, P<0.001), three (HR=5.0, 95% CI 2.5-9.9, P<0.001), and four (HR=4.2, 95% CI 1.5-12.1, P=0.006) metabolic syndrome components were independent factors associated with development of mA in Cox regression analysis adjusted for age, gender, baseline mA and GFR, glycosylated hemoglobin (HbA1c), hypertension, and obesity. CONCLUSIONS: Metabolic syndrome treatment and control are independently associated with a lesser progression of DN.