Brutto, Oscar Del

Abstract Introduction Sleep-related symptoms have been associated with adverse health outcomes, including increased mortality risk. Studies that analyzed the correlation between sleep and mortality focused on the single effect of self-reported sleep duration or relied on nonstructured questionnaires about sleep. In order to evaluate the detrimental effects of sleep disorders, studies should be based on well-structured and validated questionnaires that inquire about different components of sleep, including sleep quality. In addition, taking into consideration the fluctuations in sleep duration over the study period is essential. We aimed to assess the association between sleep quality and all-cause mortality in community-dwelling adults living in rural Ecuador. Methods Individuals aged ≥40 years enrolled in the prospective population-based Three Villages Study cohort were included. Sleep quality was assessed by means of the Pittsburgh Sleep Quality Index (PSQI). Study participants were evaluated at baseline and at every annual door-to-door survey until they remained enrolled in the study. Mixed models Poisson regression for repeated PSQI determinations and multivariate Cox-proportional hazards models were fitted to estimate mortality risk according to sleep quality. Results Analysis included 1494 individuals (mean age: 56.6 ± 12.5 years; 56% women) followed for a median of 6.3 ± 3.3 years. At baseline, 978 (65%) individuals had good sleep quality and 516 (35%) had poor sleep quality. The effects of PSQI scores changing over time on mortality was confounded by the impact of the SARS-CoV-2 pandemic on both. One hundred ninety-five individuals (13%) died during the follow-up, resulting in a crude mortality rate of 1.58 per 100 person years (95% C.I.: 1.27-1.88) for individuals with good sleep quality, and 3.18 (95% C.I.: 2.53-3.82) for those with poor sleep quality at baseline. A multivariate Cox-proportional hazards model showed that individuals with poor sleep quality at baseline were 1.38 times (95% C.I.: 1.02-1.85) more likely to die compared to those with good sleep quality; in this model, increased age, poor physical activity, and high fasting glucose remained significant. Conclusion Poor sleep quality is associated with increase mortality risk among middle-aged and older adults. Support (if any)