Obstructive Sleep Apnea Correlates with a Raised Risk of Later Dementia
Researchers here correlate obstructive sleep apnea in older individuals with a greater risk of the later development of dementia. In the present environment of widespread excess body weight, and the harms caused by excess visceral fat tissue, we might reasonably anticipate that correlations between obstructive sleep apnea and dementia risk are the result of excess weight contributing independently to both outcomes. The Stop-BANG screening questionnaire used to define the presence of obstructive sleep apnea in a patient includes a weight threshold as a factor, but it nonetheless seems an oversight to not also control for the weight of study participants.
This study included 18,815 women and men age 50+ years (dementia-free at baseline) who participated in the Health and Retirement Study (HRS), a nationally representative cohort of US adults. Presence of obstructive sleep apnea (OSA) was defined by self-reported diagnosis or key HRS items that correspond to elements of a validated OSA screening tool (STOP-Bang). Incident dementia cases were identified using a validated, HRS-based algorithm derived from objective cognitive assessments. Survey-weighted regression models based on pseudo-values were utilized to estimate sex- and age-specific differences in cumulative incidence of dementia by OSA status.
Data from 18,815 adults were analyzed, of which 9% of women and 8% of men (weighted proportions) met criteria for incident dementia. Known/suspected OSA was more prevalent in men than in women (weighted proportions 68% vs. 31%). Unadjusted sex-stratified analyses showed that known/suspected OSA was associated with higher cumulative incidence of dementia across ages 60-84 years for women and men. By age 80, relative to adults without known/suspected OSA, the cumulative incidence of dementia was 4.7% higher for women with known/suspected OSA, and 2.5% for men with known/suspected OSA, respectively. Adjusted associations between age-specific OSA and cumulative incidence of dementia attenuated for both women and men but remained statistically significant.