A community study of the risk for obstructive sleep apnea and respiratory inflammation in an adult Chinese population.

Objectives: We aimed to investigate the relationship between obstructive sleep apnea (OSA) risk and respiratory inflammation evaluated by the exhaled breath condensate (EBC) interleukin-6 (IL-6) and plasma surfactant protein-D (SP-D), based on the Berlin questionnaire (BQ) screening values in an adult, urban community in Beijing, China.Methods: Volunteers aged >40 years were recruited from the Shichahai community of central Beijing (Registration number: NCT04832711). Their general information and disease history were recorded. OSA risk was assessed using the BQ. IL-6 in EBC and plasma SP-D were d etected by enzyme-linked immunoassay through specimens collected while fasting. The differences in IL-6 and SP-D values between high-risk and low-risk groups for OSA were compared, and the factors affecting their values were analyzed.Results: Among 1,239 participants, 18.8% of participants were in the high-risk group. There were more participants with higher body mass index, chronic hypertension, coronary heart disease, and diabetes in the high-risk group than in the low-risk group (P < 0.05). There were no significant differences in EBC IL-6 and plasma SP-D between the high- and low-OSA risk groups (p > 0.05). After adjustment for age, sex and chronic comorbidities, multivariate logistic regression showed that there was no correlation between risk of OSA and IL-6 in EBC. However, the risk of OSA (odds ratio [OR] [95% CI]: 1.69 [1.15,2.48]; β = 0.522) and BMI (OR [95%CI]: 0.94 [0.91,0.98]; β = -0.061) were independently associated with plasma SP-D level (p < 0.05 for both). Stratification analysis showed that OSA risk were independently associated with plasma SP-D levels in participants <65 years, or men, or participants with BMI<25.Conclusion: This study showed that plasma SP-D, an inflammation biomarker, was associated with risk of OSA and BMI in a Chinese central urban community.The relationship between the risk of OSA and respiratory inflammation in community populations needs to be further evaluated.