Inflammation markers in moderate and severe obstructive sleep apnea: the influence of sex

Obstructive sleep apnea (OSA) is the most prevalent sleep-related breathing disorder, with a negative impact on cardiovascular health. Different OSA symptoms and treatment response in males and females have been reported. The aim of this study was to investigate inflammatory markers in patients with OSA and the relationship of those markers to disease severity in male and female subjects.

We considered consecutive subjects referred to the outpatient Sleep Disorder Service of the Respiratory Medicine Department, San Marino Hospital. We included patients with a diagnosis of moderate or severe OSAS and an age range of 45-80 years. Concomitant inflammatory conditions were an exclusion criterion. A polygraphic study and a blood draw for inflammatory markers were performed for each subject.

Of 110 subjects, 59 were males. Severe OSA affected 72 subjects. We analyzed data through a 4-level categorical variable according to sex and OSA severity (moderate OSA, males; severe OSA, males; moderate OSA, females; severe OSA, females), which showed significant differences for interleukin-6 (IL-6) and C-reactive protein (CRP) levels. A significant difference in IL-6 levels with a significant ascending trend (p = 0.045) from females with moderate OSAS to males with severe OSAS emerged in our pairwise comparison for estimated marginal means. Also, a significant trend (p = 0.0001) for CRP levels from males with moderate OSAS to females with severe OSAS was shown.

OSA and inflammation are interconnected, and both are associated with vascular diseases. Sex-related differences in OSA phenotypes may help the clinicians aim for a more personalized approach.