P136 Sleep Quality and Obesity: an investigation into the relationship between obesity and poor sleep quality as measured by polysomnography

BACKGROUND: Studies have demonstrated a link between obesity and poor sleep quality. However, definitions of sleep quality vary, and are often subjective. Furthermore, these studies do not explore whether this link is independent of comorbidities associated with obesity. We aim to establish whether an independent link exists between poor sleep and obesity, with sleep quality measured objectively through polysomnography. METHODS: A retrospective observational study of patients undergoing level 1 or 2 diagnostic polysomnography over one year. We recorded demographics, body mass index (BMI), comorbidities; and polysomnography data including apnoea-hypopnoea index, total sleep time (TST), percentage slow-wave sleep (%SWS) and percentage rapid eye movement (%REM) sleep. Primary outcome was %SWS, with secondary outcomes TST, %REM sleep and O2 nadir. Linear regression analysis was used to investigate correlations between variables and the outcomes proposed. PROGRESS TO DATE: 297 patients were included. The average BMI was 37.9 (17.8-79.5). BMI was not significantly correlated with %SWS. Howevere, a significant negative correlation was found between BMI and %REM (β = -0.196, p = 0.013), BMI and TST (β = -0.199, p = 0.018) as well as BMI and O2 nadir (β = -0.140, p = 0.054). Statistical analysis is ongoing, and additional interesting correlations are being explored. INTENDED OUTCOME AND IMPACT: To investigate if an independent correlation between obesity and abnormal sleep architecture exists. To explore if commonly associated obesity comorbidities are significantly correlated with polysomnographic indices of sleep quality, to help target interventions aimed at both investigating and improving sleep quality.