Abstract
Limited and controversial data exist on the natural evolution of sleep disordered breathing (SDB) in untreated individuals. This study examines the evolution of SDB over a three-year period in a community-based elderly sample.
From the initial cohort of 854 healthy subjects aged 68.4±0.8 yr, 519 untreated subjects accepted clinical and instrumental follow-up 3.6±1.6 yr later. SDB was defined as a respiratory disturbance index (RDI)>15.
At baseline, 202 subjects (39%) had an RDI£15 and 317 (61%) an RDI>15. Three years later, 280 subjects (54%) were non-SDB and 239 (46%) were SDB. Between evaluations, the RDI decreased from 22.3± 16.2 to 16.4 ± 13.0, with a greater fall in RDI>30 cases. In the non-SDB group, 81% had a stable RDI and 19% increased their RDI by a mean of 13.7. In the SDB group, the RDI decreased to values £15 in 36.6% of cases, 63.4% still having SDB. The RDI changes did not depend on weight changes .
In healthy elderly subjects the prevalence and severity of SDB did not show a tendency to natural worsening, some cases having improvement or a remission independent of weight changes. These findings also suggest that in the elderly the natural SDB progression is still hypothetical.
- ERS
