Relationship between obstructive sleep apnea and neuroimaging signatures of cerebral small vessel disease in community-dwelling older adults. The Atahualpa Project.

BACKGROUND/
OBJECTIVES: Evidence of a relationship between obstructive sleep apnea (OSA) and neuroimaging signatures of cerebral small vessel disease (SVD) is limited. The present study aimed to evaluate this association in older adults living in rural Ecuador, where small vessel disease is a major pathogenetic mechanism underlying stroke.
METHODS: A representative random sample of Atahualpa residents aged ≥60 years enrolled in the Atahualpa Project neuroimaging substudy underwent a single-night diagnostic polysomnography. We evaluated whether OSA associates with severity of white matter hyperintensities (WMH), silent lacunar infarctions and deep cerebral microbleeds, using multivariate models adjusted for relevant confounders.
RESULTS: Of 351 candidates, 104 (30%) were randomly selected. Of these, 97 individuals (mean age 72.3 ± 7 years, 65% women) had adequate recordings and were included. Mean apnea/hypopnea index was 13.8 ± 14.1 episodes per hour; 27 persons (28%) had ≥15 episodes per hour and were considered to have moderate-to-severe OSA. Moderate-to-severe WMH were noticed in 25 individuals (25.8%), silent lacunar infarctions in 22 (22.7%) and deep cerebral microbleeds in 12 (12.4%). In multivariate models, OSA was associated with moderate-to-severe WMH (OR: 3.94; 95% C.I.: 1.09-14.97; p = 0.037), but not with silent lacunar infarctions (p = 0.195) or deep cerebral microbleeds (p = 0.405). A linear regression model confirmed the independent association between the apnea/hypopnea index and moderate-to-severe WMH (β: -7.14; 95% C.I.: -13.6 to -0.69; p = 0.031).
CONCLUSIONS: Individuals with moderate-to-severe OSA are almost four times more likely to have diffuse subcortical damage of vascular origin than those with none-to-mild OSA, independently of demographics and cardiovascular risk factors.