The association between plasma metabolites and sleep quality in the Southall and Brent Revisited Study (SABRE): A cross-sectional analysis.

ABSTRACT Background: Disordered metabolic processes have been associated with abnormal sleep patterns. However, the biological triggers and pathways are yet to be elucidated. Methods: Participants were from the Southall and Brent REvisited (SABRE) cohort. Nuclear Magnetic Resonance spectroscopy provided 146 circulating plasma metabolites. Sleep questionnaires identified the presence or absence of: difficulty falling asleep (DFA), early morning waking (EMW), waking up tired (WUT) and snoring. Metabolites were compared between the sleep quality categories using the t-test, then filtered using a false discovery rate of 0.05. Generalized linear models with logit-link assessed the associations between filtered metabolites and sleep phenotypes. Adjustment was made for important demographic and health-related covariates. Results: 2718 SABRE participants were included. After correcting for multiple testing, 3 metabolites remained for DFA, 59 for snoring and none for EMW and WUT. In fully-adjusted models, 1 standard deviation increase in serum histidine, leucine and valine associated with lower odds of DFA by 0.84-0.89 (95% confidence intervals [CIs]: 0.75-0.99). Branched chain amino acids (ORs 1.11-1.15, 95%CIs 1.01-1.26) were positively associated with snoring. Docosahexaenoic acid (DHA) (OR 0.89, 95% CI 0.82-0.96) and total cholesterol in low-density lipoprotein (LDL) (OR 0.89, 95% CI 0.82-0.96) and high-density lipoprotein (HDL) (ORs 0.90, 95% CIs 0.83-0.99) associated with lower odds of snoring. Conclusion: Histidine, leucine and valine associated with lower odds of difficulty falling asleep, while docosahexaenoic acid and cholesterol LDL and HDL subfractions associated with lower odds of snoring. Identified metabolites could provide guidance on the metabolic pathways behind the adverse sleep quality.