All-cause mortality and estimated renal function in type 2 diabetes mellitus outpatients: is there a relationship with the equation used?

BACKGROUND: We investigated the relationship between serum creatinine (SCr) and estimated glomerular filtration rate (eGFR), evaluated by different formulae, and all-cause mortality (ACM) in type 2 diabetes mellitus (T2DM) outpatients. METHODS: This observational cohort study considered 1365 T2DM outpatients, who had been followed up for a period of up to 11 years. eGFR was estimated using several equations. RESULTS: Seventy subjects (5.1%) died after a follow-up of 9.8 ± 3 years. Univariate analysis showed that diagnosis of nephropathy (odds ratio (OR): 2.554, 95% confidence interval (CI): 1.616-4.038, p < 0.001) and microvascular complications (OR: 2.281, 95% CI: 1.449-3.593, p < 0.001) were associated with ACM. Receiving operating characteristic (ROC) curves showed that the areas under the curve for ACM were similar using the different eGFR equations. eGFR values were predictors of ACM, and the hazard ratios (HRs) of the different equations for eGFR estimation were similar. CONCLUSION: In our cohort of T2DM outpatients, different eGFR equations perform similarly in predicting ACM, whereas SCr did not.