Explaining the decline in early mortality in men and women with type 2 diabetes: a population-based cohort study

Abstract

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.

Figure 1

Trends in drug utilization by patients with type 2 diabetes by year of diagnosis and duration of diabetes. Solid lines connect values for patients diagnosed in the same year and with data points representing increasing durations of diabetes. A: Men. B: Women.