In the overall JPAD 2 population, the dementia incidence rate was 3.6 per 1,000 person-years in the low-dose aspirin group compared with 4.9 per 1,000 person-years in controls, for a highly significant 35% relative risk reduction in a fully adjusted multivariate intention to treat analysis.
During follow-up, 15% of patients switched from low-dose aspirin to no aspirin or vice versa, prompting Dr. Matsumoto and her coinvestigators to perform a per protocol analysis of the data. The results were essentially the same as in the intent-to-treat analysis.
JPAD 2 was the first-ever study to evaluate the long-term efficacy of low-dose aspirin for prevention of dementia specifically in patients with T2DM, a known risk factor for dementia. Other observational and randomized controlled studies have yielded inconsistent results. For example, a recent meta-analysis of five studies with a median 6-year follow-up found an 18% relative risk reduction in onset of dementia or cognitive impairment, a difference that didn’t achieve statistical significance ().
Some priorhave suggested there is a sex-based difference in the risk of dementia, which prompted Dr. Matsumoto and her coinvestigators to analyze the JPAD 2 results separately in men and women.