Audiological assessment in patients with chronic obstructive pulmonary disease

Background Chronic obstructive pulmonary disease (COPD), as a multisystemic disease, might have an impact on the auditory function. Thus, this study was designed for the audiological assessment of COPD patients to investigate the effect of smoking, and to further assess its possible correlation with the severity of COPD. Patients and methods This prospective case–control study was conducted on 100 male patients with COPD with a mean age of 52.66±6.84 years. In addition, 25 healthy nonsmoker male participants with a mean age of 45.5±6.75 years were enrolled as the control group. For all COPD patients and controls, tympanometry and pure-tone audiometry at frequencies 250–8000 Hz were performed by an experienced audiologist. Results Tympanometry type C was observed in the right ear of 30 COPD patients and in the left ear of 28 COPD patients. All low and high frequency tone audiometry differed significantly between COPD patients and controls ( P <0.001), and the cutoff for changes in auditory function was 15 dB at both low and high frequency tones with 96% sensitivity and 100% specificity. Audiometry and tympanometry in COPD patients were not affected by either the smoking status or the type of smoking ( P >0.05). Both low and high frequency tone audiometry correlated significantly and inversely with partial pressure of oxygen and forced expiratory volume in the first second, whereas the annual COPD exacerbations correlated significantly and directly. Conclusion Changes in auditory function but not hearing loss is common in COPD and such audiological changes were not affected by smoking but correlates with the degree of airway obstruction and hypoxia as well as the rate of annual COPD exacerbation.