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 aged ≥70 years. METHODS In a retrospective population-based cohort study, new users of statins without cardiovascular disease or diabetes mellitus were stratified by ≥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, 5,970 (14%) were aged ≥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%. 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 to 0.88) and 0.68 (0.54 to 0.84), respectively. The respective hazard ratios were less favorable for the younger group: 0.80 (0.68 to 0.93) and 0.74 (0.58 to 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 aged ≥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.