Subjective memory complaints and the risk of stroke

Persons with cognitive impairment, as assessed by cognitive tests, are at a higher risk of stroke. Subjective memory complaints might be an earlier marker for stroke, especially in persons with higher education. Their cognitive reserve might mask their cognitive impairment during cognitive testing. In a population-based setting, we investigated the association between subjective memory complaints and stroke. We simultaneously investigated the association between Mini-Mental State Examination and stroke. We also assessed whether these associations varied with educational level.

9152 participants from the Rotterdam Study (baseline 1990-1993 or 2000-2001) completed the subjective memory complaints questionnaire and underwent Mini-Mental State Examination assessment. Subsequently, the entire cohort was followed for incident stroke until 2012. We used Cox proportional hazard models to estimate the associations between subjective memory complaints and Mini-Mental State Examination, with stroke.

During a follow-up of 111 593 person years, 1134 strokes were identified, of which 663 were ischemic and 99 hemorrhagic. In the fully adjusted model, presence of subjective memory complaints was independently associated with a higher risk of stroke (hazard ratio, 1.20; 95% confidence interval, 1.04-1.39), but a higher Mini-Mental State Examination was not (hazard ratio per point increase, 0.99; 95% confidence interval, 0.95-1.02). The association between subjective memory complaints and risk of stroke was modified by educational level, with a higher risk of stroke in persons with a higher level of education (hazard ratio, 1.39; 95% confidence interval, 1.07-1.81).

Subjective memory complaints might be an early indicator of stroke risk, especially in highly educated individuals.