Objective To investigate the association between non-high-density lipoprotein cholesterol (non-HDL-C) and nocturnal hypoxic burden in patients with obstructive sleep apnea (OSA).

Methods A retrospective cross-sectional design was employed. A total of 231 patients with OSA who completed overnight polysomnography at the Sleep Medicine Center of the Fifth Affiliated Hospital of Sun Yat-sen University between January 1, 2023 and December 30, 2024 were enrolled. Patients were stratified by OSA severity according to the apnea–hypopnea index and further categorized into non-HDL-C tertiles. Sleep and lipid parameters were compared, and multivariable logistic regression was used to assess associations with prespecified outcomes.

Results The mild, moderate, and severe OSA groups comprised 11, 50, and 170 patients, respectively. With increasing OSA severity, the oxygen desaturation index and the percentage of sleep time with oxygen saturation below 90% increased, whereas minimum and mean oxygen saturation decreased (all P ＜ 0.05). After adjustment for age, sex, body mass index, smoking, alcohol consumption, hypertension, diabetes, and cardiovascular disease, each one-standard-deviation increase in non-HDL-C was associated with higher odds of severe OSA, high T90 burden (≥10% of sleep time with oxygen saturation below 90%), and minimum oxygen saturation ＜ 80%. The corresponding odds ratios (ORs) and 95% confidence intervals (CIs) were 1.93 (1.33, 2.80), 1.73 (1.25, 2.41), and 1.54 (1.07, 2.22), respectively.

Conclusion Higher non-HDL-C levels were associated with greater nocturnal hypoxic burden in patients with OSA.