Clinical and prognostic characteristics of obstructive sleep apnea among smokers

Smoking is a major public challenge, with profound implications for individual and societal health, intertwining with many medical issues such as the on growing of obstructive sleep apnea (OSA) incidence with studies highlighting a potential association between these two entities, suggesting that smoking may contribute to the pathophysiology of OSA and the worsening of the severity degree of OSA symptoms.

This study seeks to determine the clinical and prognostic characteristics of OSA among smokers and secondly to look for factors predictive of OSA severity.

A cross-sectional study carried out in the Pneumology Department at the Charles Nicolle University Hospital in Tunis from January 2023 to June 2024, enrolling 172 patients with a confirmed OSA by a respiratory polygraphy realized in hospital. We divided patients into two groups according to smoking status. G1: smoking patients and G2: non-smoking patients. Statistical analyses were performed to compare the results of the two groups.

A total of 172 patients were included. Forty-seven patients (27.3%) were smokers (G1) with a sex ratio at 3 and a mean age at 59±13 years. Univariate study showed that smoking patients were predominantly men (p<0.001). There was no significant relation between smoking status and cardiovascular and metabolic comorbidities except for COPD that was prevalent among G1(p=0.001) and insomnia (p=0.04). Screening scores such NoSAS and StopBang were more performant in G1 (p=0.03 and p= 0.01 respectively). Polygraphy finding showed that smoking patients had more severe OSA with higher AHI (p=0.007), AI (p=0.01),ODI (p=0.006) and higher capnia (p=0.04) and as a result more frequent recourse to CPAP use (p=0.036). Multi variate study suggested that male sex and hypercapnia characterize the presentation of OSAS in patients who smoke with respectively (OR=1.85; p<0.05) and (OR=5.57; p=0.015). We also carried on a multivariate study to look for predictive factors of OSA severity, and we found that smoking status was not significantly associated with OSA severity (p= 0.9).

This study clearly shows that OSA appears to be more severe among smokers. It emphasizes the performance of screening scores and proposes male sex and hypercapnia as two factors that suggest the severity of this sleep disorder. Thus, targeted interventions for smokers at risk of OSA and encouraging smoking cessation are needed.