Obstructive Sleep Apnea, but not Markers of Sleep Irregularity or Duration, is Associated with Metabolic Syndrome: Data from ELSA-Brazil

Keywords

obstructive sleep apnea - sleep duration - sleep irregularity - metabolic syndrome

Introduction: Obstructive sleep apnea (OSA) is associated with metabolic impairment and increased incidence of metabolic syndrome (MetS). Recent evidence suggests that sleep duration (SD) and markers of sleep irregularity may contribute to some components of the MetS, but the relative roles of these associations with the diagnosis of MetS are unclear.

Objective: Our objective was to evaluate the associations of OSA, markers of sleep irregularity, and SD with MetS in a subsample of ELSA-Brazil, a cohort study of public employees in the city of São Paulo.

Methods: Participants underwent clinical and sleep assessments including: 1) OSA (defined by an apnea-hypopnea index ≥15 events/hour by portable polygraphy (Embletta GoldTM); 2) objective measures of SD by wrist actigraphy for 1-week (Actiwatch 2TM); 3) markers of sleep irregularity using actigraphy data: SD standard deviation (SD); SD of sleep latency onset; catch-up sleep (weekend catch-up sleep). MS was diagnosed according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP III) if at least 3 of the 5 factors were present: 1) waist circumference ≥88 cm for women and ≥102 cm for men; 2) triglycerides ≥150 mg/dL (or any specific treatment); 3) HDL-cholesterol <40 mg/dL for men and <50 mg/dL for women (or specific treatment); 4) Systolic blood pressure (BP) ≥130 or diastolic BP ≥85 mmHg (or antihypertensive treatment); 5) Fasting glucose ≥110 mg/dL (or specific medication). Multivariate analysis was used to determine the independent associations of sleep irregularity with MS. The model was adjusted for age, sex, race, intensity of physical activity, smoking, per capita income, excessive sleepiness, insomnia, SD, and sleep variables (irregularity) and OSA (only in the SD model).

Results: A total of 1,720 participants were studied (age: 49±8 years; 43.4/5 men, 26.7% met the diagnosis of MS; 33% had OSA). The mean SD was 394±59.0 hours. After adjustments, OSA was independently associated with MS, even when adjusted for SD SD (OR: 2.50; 95% CI: 1.97; 3.17; p.<0.001); SD sleep onset latency (OR: 2.49; 95% CI: 1.96; 3.15; p.<0.001) or catch-up sleep (OR: 2.51; 95% CI: 1.98; 3.18; p.<0.001). In contrast, we did not observe significant associations between sleep irregularity variables and SD with MS.

Conclusion: OSA, but not sleep irregularity or SD, was independently associated with MetS.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
16 September 2025