RESUMEN
AIMS: To investigate the effect of sulphonylurea (SU) treatment on all-cause and cardiovascular mortality as compared with metformin (MET), when used in combination with insulin (INS) in type 2 diabetes. METHODS: All type 2 diabetes patients aged ≥40 years were included at their first prescription of INS+MET or INS+SU, during 2001-2008. They were considered at risk until death or December 31st, 2011. Mortality rates were calculated per 1000 person-years. Crude and adjusted rate ratios (RR) were calculated using time dependent analysis with INS+MET as reference. RESULTS: There were 7122 patients (60.8% women) included in the analysis, with a mean age at baseline of 62.0±9.9 years. During the 11 years of study, patients on INS+MET contributed 13620 person-years and 330 deaths (mortality rate 24, CI95% 22-27), while those on INS+SU contributed 8720 person-years and 393 deaths (mortality rate 45, CI95% 41-50). Adjusted all-cause mortality RR were: SU 1.6 (CI95% 1.21-2.11, p<0.001), glimepiride 1.18 (CI95% 0.73-1.91, p=0.51), gliclazide 1.78 (CI95% 1.07-2.95, p=0.024), glibenclamide 1.66 (CI95% 0.71-3.88, p=0.23), glipizide 1.24 (CI95% 0.68-2.27, p=0.49), and gliquidonum 2.32 (CI95% 1.54-3.50, p=0.001). CONCLUSIONS: When combined with insulin as dual therapy, patients treated with SU were at increased mortality risk as compared with insulin + MET.