Spirometric abnormalities in patients with sleep-related breathing disorders

Introduction: Patients with sleep-related breathing disorders (SRBD) have various structural and functional abnormalities of the upper airway during sleep which may get reflected on their pulmonary function tests. The aim of the study was to find the correlation between the spirometric indices and snoring, grades of apnea–hypoapnea index (AHI), and STOPBANG. There is scarcity of literature showing correlation of STOP BANG with spirometric variables. Material and Methods: Patient with SRBD fulfilling the inclusion and exclusion criteria were enrolled. The pretest probability sleep score STOPBANG and polysomnography (PSG) were calculated for all the patients. Spirometric indices like forced expiratory volume in one sec (FEV1), forced vital capacity (FVC), postbronchodilator ratio FEVI/FVC (PBDR), and peak expiratory flow rate (PEFR) were studied. Their association with snoring, different grades of obstructive sleep apnea (OSA), and STOPBANG were evaluated using statistical analysis. Results: A total of 70 patients were enrolled. Abnormalities of spirometric indices were found to be common in patients with SRBD but their association with snoring, grades of OSA, and STOPBANG were not statistically significant. There is no statistically significant correlation between body mass index (BMI) and grades of AHI. Conclusion: This study found no statistically significant correlation between spirometric parameters and STOPBANG and degree of AHI. Primary care physicians should be aware that obstructive lung disease does coexist with the sleep disordered breathing but as per this study, their statistically significant association needs further validation.