Explaining the Decline in Early Mortality in Men and Women With Type 2 Diabetes: A population-based cohort study

OBJECTIVE—The purpose of this study was to test the hypothesis that changing utilization of lipid-lowering, antihypertensive, and oral hypoglycemic drugs may be associated with trends in all-cause mortality in men and women with type 2 diabetes. RESEARCH DESIGN AND METHODS—This was a cohort study in 197 general practices in the U.K. General Practice Research Database including 48,579 subjects with type 2 diabetes first diagnosed between 1996 and 2006. Measures included all-cause mortality and prescription of hypoglycemic, lipid-lowering, and antihypertensive drugs. RESULTS—From 1996 to 2006, incidence of type 2 diabetes increased and the mean age at diagnosis declined in women. Prescription of statins within 12 months of diagnosis increased (1996, women 4.9%, men 5.1%; 2005, women 63.5%, men 71.0%), as did drugs acting on the renin-angiotensin system (1996, women 19.4%, men 21.5%; 2005, women 45.5%, men 54.6%) and metformin (1996, women 19.1%, men 15.8%; 2005, women 45.5%, men 42.8%), whereas prescription of sulfonylureas declined. All-cause mortality in the first 24 months after diabetes diagnosis declined in men from 47.9 per 1,000 person-years for subjects with diabetes diagnosed in 1996 to 25.2 for subjects with diabetes diagnosed in 2006 and in women from 37.4 in 1996 to 27.6 in 2006. In a multiple regression model adjusting for age and comorbidity, prescription of statins before or after diagnosis, renin-angiotensin system drugs before or after diagnosis, and metformin after diagnosis were associated with lower mortality. CONCLUSIONS—Widespread implementation of more effective prescribing to control lipids, blood glucose, and blood pressure may have contributed to recent declines in early mortality in men and women with type 2 diabetes.