Metabolic syndrome and albuminuria show an additive effect in modulating glomerular filtration rate in patients with Type 2 Diabetes Mellitus

Background: Although metabolic syndrome (MetSyn) or albuminuria (MA) most often occurs in concomitance in Type 2 Diabetes Mellitus patients (T2DM), their mode of interaction in increasing the risk of low glomerular filtration rate (GFR) has been poorly investigated. Objective: We evaluated in a cohort of 1659 T2DM patients the relationship between MetSyn and MA in modulating the risk for low GFR. The risk of developing low GFR by graded number of MetSyn traits was also evaluated. Methods: This was a cross-sectional study where 1659 T2DM patients were studied. Low GFR was defined as estimated-GFR (e-GFR) < 60 ml min(1) x 1.73 m(2) (modification of diet in renal disease, MDRD, formula). Results: e-GFR progressively decreased from 91 +/- 25 of patients MetSyn +/- MA +/-, to 82 +/- 27 of patients MetSyn +/- MA+, 81 +/- 24 of patients MetSyn+ MA +/- and 76 +/- 30 ml min(1) x 1.73 m(2) of patients MetSyn+ MA+ (adjusted p < 0.0001). A progressive gradient of the frequency of patientswith low e-GFR with concomitance of MetSyn and MA was also observed [ MetSyn+MA-(6.1%), MetSyn+MA+ (15.3%), MetSyn+ MA+ (16.6%), MetSyn+ MA+ (26.8%); p < 0.0001]. As compared to patients with MetSyn-MA-, the risk progressively increased to 2.80 (95% C. I. 1.46-5.37; p = 0.002) in MetSyn+ MA+, to 2.83 (95% C. I. 1.12-7.10; p = 0.027) in MetSyn-MA+ and to 5.73 (95% C. I. 2.99-10.9; p < 0.0001) in MetSyn+ MA+ patients. Estimated-GFR progressively decreased by number of MetSyn traits in the whole population (adjusted p < 0.0001). Conclusions: MetSyn or MA has an additive effect in increasing the risk of having low GFR in patients with T2DM. Furthermore, e-GFR is negatively affected by graded number of MetSyn traits independently of albuminuria. (C) 2009 Diabetes India. Published by Elsevier Ltd. All rights reserved.