BACKGROUND: Hypotensive episodes detected by 24-hour ambulatory blood pressure (BP) monitoring capture daily cumulative hypotensive stress and could be clinically relevant to cognitive impairment, but this relationship remains unclear. METHODS: We included participants from the Systolic Blood Pressure Intervention Trial (receiving intensive or standard BP treatment) who had 24-hour ambulatory BP monitoring measured near the 27-month visit and subsequent biannual cognitive assessments. We evaluated the associations of hypotensive episodes (defined as systolic BP drops of ≥20 mm Hg between 2 consecutive measurements that reached <
100 mm Hg) and hypotensive duration (cumulative time of systolic BP <
100 mm Hg) with subsequent cognitive function using adjusted linear mixed models. We further assessed 24-hour average BP and variability. RESULTS: Among 842 participants with treated hypertension (mean age, 71±9 years
29% women), the presence (versus absence) of recurrent hypotensive episodes (11%) was associated with lower digit symbol coding scores (difference in CONCLUSION: Twenty-four-hour hypotensive episodes were associated with worse cognitive function, especially in processing speed, and could be a novel marker for optimal BP control and dementia prevention.