Statin Therapy for Primary Prevention in the Elderly and Its Association with New-Onset Diabetes, Cardiovascular Events, and All-Cause Mortality

Purpose: This study assessed associations of the use of statins for primary prevention with cardiovascular outcomes among adults ages ≥70 years. Methods: In a retrospective population-based cohort study, new users of statins without cardiovascular disease or diabetes mellitus were stratified by ages ≥70 years and <70 years. Using a time-dependent approach, adherence to statins was evaluated according to the proportion of days covered: <25%, 25%-50%, 50%-75%, and ≥75%. We assessed associations of statin therapy with increased risk of new-onset diabetes mellitus and with decreased risks of major adverse cardiovascular events and all-cause mortality. Results: Of 42,767 new users of statins, 5970 (14%) were ages ≥70 years. The incident rates of major adverse cardiovascular events, all-cause mortality, and new-onset diabetes mellitus in the highest to lowest proportion of days covered categories were 16.9%, 16.7%, and 9.4% and 6.3%, 1.7%, and 9.4%, respectively. For the older group, the adjusted hazard ratios of major adverse cardiovascular events and mortality were significantly decreased for the highest adherence group (proportion of days covered ≥75%): 0.71 (0.57-0.88) and 0.68 (0.54-0.84), respectively. The respective hazard ratios were less favorable for the younger group: 0.80 (0.68-0.93) and 0.74 (0.58-1.03). The risk of new-onset diabetes mellitus was increased for the younger but not the older group. Conclusions: Statin use for primary prevention was associated with cardiovascular benefit in adults ages ≥70 years without a significant risk for the development of diabetes. These data may support the use of statin therapy for primary prevention in the elderly.