A 10-year study of 18,815 adults found that obstructive sleep apnea was associated with increased dementia incidence, with stronger correlations observed in women. By age 80, women with known or suspected obstructive sleep apnea demonstrated a 4.7% higher cumulative incidence of dementia compared with women without obstructive sleep apnea, whereas men with obstructive sleep apnea showed a 2.5% higher incidence.

In the study, published in Sleep Advances, investigators examined data from the Health and Retirement Study (HRS), analyzing 11,023 women and 7,792 men who were dementia free at baseline. The mean age was 61 years among women and 60 years among men at their first cognitive assessment.

The investigators identified obstructive sleep apnea (OSA) cases through both self-reported diagnoses and an adapted version of the STOP-Bang questionnaire, addressing the study's aim to capture undiagnosed cases. The modified STOP-Bang assessment included seven of eight traditional items, excluding neck circumference.

Among participants who screened positive for suspected OSA with the adapted STOP-Bang, 29% of men and 30% of women had a clinical OSA diagnosis. Among those screening negative, 10% of men and 7% of women reported a clinical diagnosis.

The study employed survey-weighted regression models based on pseudo-values to estimate sex- and age-specific differences in cumulative dementia incidence. The investigators controlled for race/ethnicity, educational attainment, and cohabitation status.

After adjustments, at 80 years, women with known or suspected OSA showed a 3.7% greater cumulative dementia risk (95% confidence interval [CI] = 1.8%–5.6%) compared with women without OSA. Men with OSA demonstrated 2.1% greater risk (95% CI = 0.1%–4.1%).

The population attributable risk percent of dementia associated with OSA at 80 years measured 10.3% among women and 13.2% among men, with the lower percentage in women attributed to lower OSA prevalence (31% vs 68% in men).

Cognitive assessments utilized the Weir-Langa classifications, mapping scores from immediate and delayed word recall, Serial Sevens Task, and backward count to a 27-point scale, with scores below seven considered a reliable proxy for dementia.

Conflict of interest disclosures can be found in the study.