Why does gender influence survival in obstructive sleep apnoea?

Area of Science:

• Medicine
• Pulmonology
• Sleep Medicine

Background:

• Obstructive sleep apnoea (OSA) is a common condition affecting sleep quality and potentially long-term health.
• Continuous positive airway pressure (CPAP) is a standard treatment for OSA.
• Sex-based differences in OSA prevalence and severity are recognized, but mortality risk disparities require further investigation.

Purpose of the Study:

• To compare the mortality risk between men and women diagnosed with OSA and initiated on CPAP therapy.
• To identify factors associated with increased mortality risk in OSA patients undergoing CPAP treatment.

Main Methods:

• Retrospective review of hospital records for patients who started CPAP for OSA between July 1995 and June 1998.
• Comparison of mortality rates between male and female patient cohorts.
• Univariate and multivariate Cox's proportional hazards regression analyses to determine associations with mortality risk.

Main Results:

• The study included 292 men and 47 women; 8% of men and 23% of women died (p=0.003).
• Factors associated with increased mortality included female sex, older age at CPAP initiation, low pre-treatment SpO(2) (<75%), higher Charlson comorbidity index, and CPAP discontinuation.
• Female sex remained an independent risk factor for mortality, except when considering the Charlson score. Women exhibited a 3.44-fold higher mortality risk than men, largely attributed to comorbidities.

Conclusions:

• Women with OSA treated with CPAP have a substantially higher mortality risk compared to men.
• Greater comorbidity burden in women is the primary driver of this increased mortality.
• Clinical management of OSA in women may need to consider sex-specific factors and comorbidity profiles more closely.