Impact of sleep disturbances on kidney function decline in the elderly

While sleep disturbances are frequent in renal disease patients, no studies have examined prospectively the associations between sleep disturbances and kidney function decline in community-dwelling elderly subjects.Glomerular filtration rates (eGFRs) were estimated at baseline and at 11-year follow-up. A glomerular filtration decline over the follow-up period was defined as a percentage decline greater than or equal to the cut-off value of the highest tertile of kidney function decline (22%) in 1105 subjects. Excessive daytime sleepiness (EDS) and insomnia complaints were self-rated at baseline. Restless legs syndrome (RLS) and its age at onset were assessed at study end-point. An ambulatory polysomnography recording was performed during the follow-up in 277 subjects. Apnoea-hypopnoea index (AHI), periodic limb movements during sleep (PLMS) and total sleep time were analysed.An increased risk of eGFR decline was associated with EDS (OR 1.67, 95% CI 1.18-2.34) and RLS (OR 1.98, 95% CI 1.18-3.30) independently of potential confounders including cardiovascular risk factors. Among insomnia complaints, a borderline association with eGFR decline was found for early morning awakening only. High AHI (≥30 events·h(-1)) and short total sleep time (<6 h), but not PLMS were linked to eGFR decline in crude associations, but only AHI remained significantly associated after multi-adjustments.EDS, RLS and AHI constitute independent risk factors for kidney glomerular function decline.