Role of sleep quality in the acceleration of biological aging and its potential for preventive interaction on air pollution insults: findings from the UK Biobank cohort

BackgroundSleep has been associated with aging and relevant health outcomes, but their causal relationship remains inconclusive. MethodsIn this study, we investigated the associations of sleep behaviors with biological ages (BAs) among 363,886 middle and elderly-aged adults from UK Biobank. Sleep index (0 [worst]-6 [best]) of each participant was retrieved from six sleep behaviors: snoring, chronotype, daytime sleepiness, sleep duration, insomnia, and difficulties in getting up. Two BAs, the KDM-biological age and PhenoAge, were estimated by corresponding algorithms based on clinical traits, and their discrepancies with chronological age were defined as the age accelerations (AAs). ResultsWe first observed negative associations between the sleep index and the two AAs, and demonstrated that the change of AAs could be the consequence of sleep quality using Mendelian randomization with genetic risk scores of sleep index and BAs. Particularly, one unit increase in sleep index was associated with 0.105- and 0.125-year decreases in KDM-biological age acceleration and PhenoAge acceleration, respectively. Furthermore, we observed significant independent and joint effects of sleep and air pollution (i.e. PM2.5 and NO2), another key driver of aging, on BAs. Sleep quality also showed modifying effect on the associations of elevated PM2.5 and NO2 levels with accelerated aging. For instance, an interquartile range increase in PM2.5 level was associated with 0.011-, 0.047-, and 0.078-year increase in PhenoAge acceleration among people with high (5-6), medium (3-4), and low (0-2) sleep index, respectively. ConclusionsOur findings elucidate that better sleep quality could lessen accelerated biological aging resulting from exogenous exposures including air pollution. FundingPeking University Start-up Grant (BMU2021YJ044)