A 7-year follow-up study of obstructive sleep apnoea in healthy elderly: The PROOF cohort study.

Abstract

Clinical and epidemiological cohort studies have shown that obstructive sleep apnoea (OSA) is a common but largely undiagnosed disorder in senior subjects, where progressive deterioration of the pathology would be expected as a consequence of the ageing processes. Our study examines the longitudinal progression of OSA over a 7-year period in a community-based sample of healthy subjects. The sample consisted of 284 volunteers, aged >65 years (52% women, 48% men) accepting clinical and instrumental follow-up at 7 years. OSA was defined as an apnoea-hypopnoea index (AHI) of ≥15. Between evaluations in the total sample, AHI slightly decreased from 17.8 ± 14 to 16.7 ± 11 with a decrease affecting more the hypopnoea index (P < 0.001) and associated with significant changes (P < 0.001) in all indices of hypoxaemia. While in the non-OSA group there was a slight but significant increase of AHI, a significant AHI decrease was noted in mild-moderate patients (P < 0.01) and a significant rise of nocturnal hypoxaemia in severe OSA patients (P < 0.001). The AHI decrease was not associated with clinical, weight, metabolic and blood pressure changes between the two evaluations; the baseline AHI value being the only factor correlated to the degree of AHI decline. In elderlies, the severity and prevalence of OSA decrease progressively with ageing without effect of factors commonly influencing OSA severity. This trend may support the hypothesis that in healthy elderly, OSA is a phenomenon related to ageing.