Clinical and Anthropometric Correlates of Polysomnography-Defined Severity in Obstructive Sleep Apnea Syndrome.
Level 4 - case-series / case-control
Retrospective cross-sectional observational study of patients undergoing polysomnography.
PubMed 41908345 · doi:10.14744/cpr.2026.30899
What was done
This retrospective cross-sectional study evaluated 339 adults (mean age 46.1 ± 12.0 years; 73.2% male; mean BMI 33.2 ± 6.2 kg/m²) who underwent overnight polysomnography (PSG) between January 2020 and December 2024. Researchers assessed associations between obstructive sleep apnea syndrome (OSAS) severity—categorized by the apnea-hypopnea index (AHI)—and routinely obtained clinical and anthropometric variables (body mass index, neck circumference [NC], waist circumference [WC], and Epworth Sleepiness Scale [ESS] score) using Spearman's correlation analysis.
What was found
The cohort had a median AHI of 10.1 (IQR: 6.3–32.2) and a median ESS score of 4 (IQR: 2–9). AHI showed a moderate positive correlation with ESS score (r = 0.649, p < 0.05) and weak positive correlations with NC (r = 0.273, p < 0.05), age (r = 0.207, p < 0.05), WC (r = 0.184, p < 0.05), and body weight (r = 0.136, p < 0.05). No statistically significant correlation was observed between AHI and BMI or height. Patients with moderate-to-severe OSAS had higher NC, WC, ESS scores, symptom burden, and cardiometabolic comorbidities compared to those with normal-to-mild OSAS.
Why it matters
These findings suggest that subjective daytime sleepiness and localized measures of central and cervical adiposity (neck and waist circumference) correlate better with OSAS severity than general BMI among referred sleep clinic patients.
Limits
The study is limited by its retrospective design, which carries selection and referral bias. The sample was predominantly male (73.2%), limiting generalizability to females. The abstract reports only bivariate correlation analyses without multivariable adjustment for confounding factors.
Cited by
- supports Having up to 4 or 5 breathing pauses per hour during sleep is clinically normal, with mild sleep apnea defined starting at 5 events per hour and moderate sleep apnea starting at 15 events per hour.