Association between obstructive sleep apnea and lipid metabolism during REM and NREM sleep

Study Objectives: Obstructive sleep apnea (OSA) is thought to be associated with dyslipidemia. However, differences concerning dyslipidemia during rapid eye movement (REM) and non-REM (NREM) sleep have yet to be determined. This study was designed to explore the association between lipid profiles and OSA during REM or NREM sleep. Methods: This is a clinical cohort. A total of 2,619 participants with at least 30 minutes of REM sleep were included. Sleep variables and fasting lipid profiles [total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (apo)A-I, apoB, apoE, and lipoprotein(a) (Lp(a))] were obtained from each participant. Apnea-hypopnea indices in REM and NREM sleep (AHI(REM) and AHI(NREM), respectively) were recorded. Linear regression analysis was used to assess the associations of AHI(REM) and AHI(NREM) with lipid profiles. Results: When stratified by the AHI(REM) severity of OSA, all demographics, clinical variables, and sleep parameters differed between the groups except for apoA-I. In fully-adjusted multivariate linear regression models, AHIREM was independently associated with increasing levels of TG, HDL-C, and apoE (P =.04, P =.01 and P =.01, respectively). AHI(NREM) was independently associated with increasing levels of TC, TG, LDL, and apoB, and lower level of HDL-C (all P <.05). In sensitivity analyses by only exploring associations in patients who had an AHI(NREM) or AHI(REM) < 5 events/h in separate regression models, AHI(REM) was not associated with all-lipid profile in almost all adjusted models (all P > .05), whereas AHI(NREM) was associated with elevated TC, LDL-C, and apoB (P = .03, P = .01 and P = .01, respectively). Conclusions: AHI(NREM) was independently associated with the greatest alterations in serum lipids, including TC, LDL-C, and apoB.