PURPOSE: Gender differences influence upper airway anatomy and physiology. In patients with obstructive sleep apnea (OSA), this may result in significant differences in disease severity as well as CPAP pressure requirements, but this has not been well-studied. The purpose of our study was to evaluate the influence of gender as well as anthropometric measures on severity of OSA and CPAP pressure requirements in patients with OSA.
METHODS: Patients referred to our sleep lab for evaluation of OSA had anthropometric measurement done. We measured height, weight, BMI (calculated), neck size and waist hip ratio. Patients with a diagnosis of OSA (RDI>10) who underwent a subsequent full-night CPAP titration study were included in the study.
RESULTS: 54 women and 91 men were included. Age and BMI were comparable in both groups. Significant differences were seen in neck size, and waist/hip ratios. The mean respiratory disturbance index (RDI) as well as mean CPAP requirement was higher in men compared to women (see table 1). Severity of OSA correlated better with neck circumference, than with BMI (p=0.0148). There was a significant gender difference in correlation values for neck circumference and RDI (See table 2).
CONCLUSION: Neck circumference, rather than BMI, is more predictive of severity of obstructive sleep apnea and this seems to be more significant for women than men. Both BMI and neck circumference, but not the waist-hip ratio is significantly correlated with CPAP pressure requirements in both males and females.
CLINICAL IMPLICATIONS: Neck circumference, more so than BMI, could be the single best predictor of OSA severity, especially in women. For the same degree of BMI, women have lower CPAP requirements compared to men.
DISCLOSURE: Gnananandh Jayaraman, No Financial Disclosure Information; No Product/Research Disclosure Information