Objective: To examine if the beneficial effect of statin medication on mortality seen in randomised clinical trials of type 2 diabetes applies equally to observational studies in the general population of older people.
Design: A prospective, population-based cohort study.
Setting: Reykjavik, Iceland.
Participants: 5152 men and women from the Age, Gene/Environment Susceptibility-Reykjavik Study, mean age 77 years, range of 66-96 years.
Main outcome measure: Cardiovascular and all-cause mortalities and the RR of dying according to statin use and history of coronary heart disease (CHD) in persons with type 2 diabetes and those without diabetes with a median follow-up time of 5.3 years, until end of 2009.
Results: The prevalence of type 2 diabetes was 12.4% of which 35% used statins. Statin use was associated with a 50% (95% CI 8% to 72%) lower cardiovascular mortality and 53% (29% to 68%) lower all-cause mortalities in persons with diabetes. For those without diabetes, statin use was associated with a 16% (-24% to 43%) lower cardiovascular and 30% (11% to 46%) lower all-cause mortalities. Persons with diabetes using statins had a comparable risk of cardiovascular and all-cause mortality to that of the general population without diabetes. The effect was independent of the level of glycaemic control.
Conclusion: This observational study lends important support to existing data from randomised clinical trials. These data suggest that in the general population of older people with diabetes, statin medication markedly reduces the excess cardiovascular and all-cause mortality risk, irrespective of the presence or absence of coronary heart disease or glucose-lowering medication.