C.C.B.LAM1, T.MINA2, E.RIBOLI3, J.LEE4, J.NGEOW5, E.S.LEE6, P.ELLIOT3, M.LOH2, J.CHAMBERS2
Khoo Teck Puat Hospital1, Nanyang Technological University2, Imperial College London3, Institute of Mental Health4, National Cancer Centre Singapore5, NHG Polyclinics6
Inadequate sleep has been associated with obesity. National health statistics show that Malays and South Asians are more susceptible to obesity than Chinese. We aim to confirm the relationship between sleep and adiposity and also hypothesize that inadequate sleep contributes to the different risks of obesity amongst the major ethnic groups in Singapore.
This study is based on cross-sectional data from the HELIOS study, a prospective cohort population study in Singapore. Clinical measurements were measured according to standardised protocols. Sleep, possibility of anxiety and depression were assessed by the Pittsburgh Sleep Quality Index (PSQI), Generalised Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire-9 (PHQ-9) respectively. Multivariable regression models were used to determine the relationship between sleep and adiposity.
Based on 5264 participants (77.3% Chinese, 7.7% Malays, 15.0% South Asians; Mean age: 51.1±11.8 years), Malays had the shortest mean sleep length and poorer sleep quality (based on global PSQI score) when compared to the Chinese (all P<0.001). Sleep quality consistently predicted adiposity, independent of sleep length, even after accounting for possible anxiety and/or depression (all P≤ 0.001). Stratification by ethnicity confirmed the relationship between sleep quality and adiposity in Chinese and Malays (despite the smaller sample size), but not in South Asians.
Sleep quality is the more significant predictor of adiposity. This is even after adjusting for the possibility of anxiety and/or depression. This is particularly true for Malays, and hence, it would seem that to prevent obesity in the Malays in Singapore, improving sleep quality would be one of the interventions.