Heightened sleep propensity: a novel and high-risk sleep health phenotype in older adults

Objectives: To reveal sleep health phenotypes in older adults and examine their associations with time to 5-year all-cause and cardiovascular mortality. Design: Prospective longitudinal cohorts. Setting: The Study of Osteoporotic Fractures and Outcomes of Sleep Disorders in Older Men Study. Participants: N = 1722 men and women aged ≥65 years matched 1:1 on sociodemographic and clinical measures. Measurements: Self-reported habitual sleep health characteristics (satisfaction, daytime sleepiness, timing, efficiency, and duration) measured at an initial visit and longitudinal follow-up for mortality. Results: Latent class analysis revealed 3 sleep health phenotypes: (1) heightened sleep propensity (HSP; medium to long duration, high sleepiness, high efficiency/satisfaction; n = 322), (2) average sleep (AS; medium duration, average efficiency, high satisfaction, low sleepiness; n = 1,109), and (3) insomnia with short sleep (ISS; short to medium duration, low efficiency/satisfaction, moderate sleepiness; n = 291). Phenotype predicted time to all-cause mortality (χ² = 9.4, P =.01), with HSP conferring greater risk than AS (hazard ratio [95% confidence interval] = 1.48 [1.15-1.92]) or ISS (1.52 [1.07-2.17]), despite ISS reporting the poorest mental and physical health. Although sex did not formally moderate the relationship between phenotype and mortality, subgroup analyses indicated that these findings were driven primarily by women. Phenotype did not predict cardiovascular mortality. Conclusions: These analyses support the utility of examining multidimensional sleep health profiles by suggesting that the combination of long sleep, high efficiency/satisfaction, and daytime sleepiness—previously identified as independent risk factors—may be components of a single high-risk sleep phenotype, HSP. Further investigation of sex differences and the mechanisms underlying mortality risk associated with HSP is warranted.