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

BackgroundAlthough 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.ObjectiveWe 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.MethodsThis was a cross-sectional study where 1659 T2DM patients were studied. Low GFR was defined as estimated-GFR (e-GFR) <60 ml min−1 × 1.73 m−2 (modification of diet in renal disease, MDRD, formula).Resultse-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 × 1.73 m−2 of patients MetSyn+MA+ (adjusted p < 0.0001). A progressive gradient of the frequency of patients with 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).ConclusionsMetSyn 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.