Maximum Phonation Times as Biomarkers of Lung Function

Purpose To verify whether measurements of maximal phonation times are biomarkers of forced vital capacity in patients with chronic obstructive pulmonary disease, and to characterize the vocal aspects of these patients, taking into account variables, such as age, body mass index, use of bronchodilators, presence of symptoms, and quality of life related to voice. Methods Complete records of 25 subjects with chronic obstructive pulmonary disease, both sexes, aged 31 to 85 years, evaluated by forced vital capacity, maximum phonation times of /a/, and numerical count and number reached at this count, Vocal Symptom Scale, Voice Quality of Life. Data were presented descriptively and statistically analyzed using Student's t test for independent samples and Mann-Whitney U test. A significance level of 5% was accepted. The receiver operating characteristic curve was plotted and the standardized value of forced vital capacity <80% was considered as an indicator of pulmonary dysfunction. Results Patients exhibited reduced maximum phonation times for /a/, numeric counting, and reached digits in counting; discrepancies in Vocal Signs and Symptoms and Voice Quality of Life Scale scores. Numeric counting times of up to 12.5 seconds indicated that forced vital capacity may be impaired. Conclusion The patients with chronic obstructive pulmonary disease examined in this study exhibited vocal deviations as evidenced by reduced maximum phonation times of /a/, numeric counting, and the digit reached during counting, as well as deviations in vocal self-assessment. Maximum phonation time in numerical counting was considered a biomarker of pulmonary function impairment.