We previously reported in the study of preventive effects of
alogliptin on diabetic
atherosclerosis (SPEAD-A) that
alogliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, attenuated the progression of
carotid atherosclerosis in subjects with
type 2 diabetes and no history of
cardiovascular disease. This extension study of the SPEAD-A trial investigated whether early
alogliptin initiation improved long-term cardiovascular outcomes. The SPEAD-A trial randomized 341 subjects with
type 2 diabetes to either
alogliptin or conventional treatment to investigate the effects of
alogliptin on
atherosclerosis. All subjects who completed that trial were eligible for this prospective, observational cohort study. The primary endpoint was the first occurrence of a major cardiovascular event, defined as death due to any cause, acute
myocardial infarction, or
stroke. During the 520-week follow-up period, composite primary outcome events occurred in only a few subjects in each group [8 (5.4%) in the
alogliptin group and 9 in the conventional treatment group (5.9%)]. There were no significant differences in the incidence rate of the primary outcome between the two groups. Post hoc Poisson regression analysis showed no significant difference between the two groups in the incidence rate of composite recurrence events for the same outcomes as the primary endpoint. On the other hand, this incidence rate was significantly lower in subjects who received
DPP-4 inhibitors before an initial cardiovascular event than in those who did not (5.8 vs. 13.3 per 1000 person-years, respectively, p = 0.04). Early initiation of
alogliptin was not associated with a reduced risk of composite
cardiovascular disease, which could be attributed to fewer events and/or the addition of
DPP-4 inhibitors during the follow-up period.