Dyslipidemia prevalence in nonobese, nondiabetic patients with obstructive sleep apnea: does sex matter?

Study Objectives: Dyslipidemia in obstructive sleep apnea (OSA) has been attributed to confounding obesity and/or diabetes. This study aimed to examine lipid profiles in nondiabetic, nonobese patients with OSA and identify the possible effects of age and sex. Methods: We retrospectively evaluated the lipid parameters of 3,050 adults who underwent polysomnography. A total of 2,168 patients were excluded due to obesity (body mass index & GE; 30 kg/m2), diabetes, alcoholism, untreated hypothyroidism, lipid-lowering drug use, missing sleep data, or treatment for suspected OSA. Results: Of 882 patients (75% males, aged 46.8 & PLUSMN; 12.2 years) included in the study, 88.4% had OSA. Levels of total cholesterol (P = .003), low-density-lipoprotein (LDL) cholesterol (P = .005), non-high-density-lipoprotein (non-HDL) cholesterol (P = .001), and triglycerides (P = .007) were significantly higher in patients with OSA than in those without, whereas HDL-cholesterol levels did not differ. The proportion of patients with hypercholesterolemia and/or elevated non-HDL cholesterol (> 160 mg/dL) was significantly higher in OSA than in non-OSA. Correlation analyses by sex revealed stronger and more significant relationships between lipid parameters and apnea-hypopnea index in women than in men (r = .135, P < .001, vs r = .080, P = .043 for total cholesterol; r = .111, P < .001, vs r = .080, P = .046 for non-HDL cholesterol; r = .122, P < .001, vs r = .061, P = .107 for LDL cholesterol, respectively). In regression analysis, the rate of hypercholesterolemia increased with age (P < .001 for women and P = .031 for men); non-HDL-and LDL-cholesterol levels significantly increased with OSA severity (P = .035 and P = .023, respectively) and age (P = .004 and P = .001, respectively) in women. Conclusions: After excluding confounding obesity and diabetes, patients with OSA have an impaired lipid profile including total cholesterol, LDL cholesterol, non-HDL cholesterol, and triglycerides. A significant association between dyslipidemia and OSA severity was observed in women but not in men.