ABSTRACT
BACKGROUND: Forced oscillation technique (FOT) is a technique to measure the mechanical properties of the lung. The present study was aimed to develop regression equations of within- and whole-breath respiratory impedance (Zrs) of healthy Indian adults. METHODS: Total 323 adults were sequentially screened. Smokers, individuals with respiratory symptoms or diseases, and unable to perform acceptable FOT were excluded. Within- and whole-breath resistance (Rrs) and reactance (Xrs) were measured at 5, 11, and 19 Hz by Resmon Pro® Full device. The regression equations of within- and whole-breath Rrs and Xrs were generated separately for men and women by multiple linear regression models. RESULTS: The FOT data of 253 individuals (122 men) aged 18-81 years were included in the analysis. The magnitudes of whole-breath Rrs at 5 Hz (4.53 ± 1.05 cmH2O/L/s in women vs. 3.26 ± 1.05 cmH2O/L/s in men; P = 0.000) and whole-breath Xrs at 5 Hz (-1.23 ± 0.66 cmH2O/L/s in women vs. -1.00 ± 0.54 cmH2O/L/s in men; P = 0.003) of women were significantly of higher magnitude as compared to men. The standing height was the best determinant of Zrs, followed by body weight; the effect of age was negligible and was observed in men only. The magnitudes of both Rrs and Xrs decrease with an increase in standing height of both men and women. CONCLUSIONS: The present study provides regression equations of within- and whole-breath respiratory impedance of Indian adults.
ABSTRACT
BACKGROUND: Traffic-related air pollution (TRAP) is a major source of ambient air pollution in urban areas. Shopkeepers of heavily trafficked roadside shops are persistently exposed to high levels of TRAP. OBJECTIVES: To estimate the prevalence of respiratory morbidity in shopkeepers of shops in heavily trafficked roadside areas in Bhopal city (India) and to determine any association with long term exposure to TRAP. METHODS: This cross-sectional study was conducted among 251 shopkeepers working in roadside shops of three major traffic corridors in Bhopal city. The demographic profile and prevalence of respiratory morbidity were collected by administering a validated questionnaire. The total exposure period (TEP) to TRAP was calculated for each individual by multiplying their work duration (in years) and average working hours per day. Odds ratios were calculated to estimate the association of TEP with respiratory morbidity. RESULTS: The age of the study population was 44.8±13.5 years old and 95% were male. Nearly 55% of the shopkeepers reported at least one respiratory symptom. The prevalence of bronchial asthma, chronic bronchitis, breathlessness, and cough was 3.6% (95% confidence interval (CI): 1.9-6.7), 13.9% (95% CI: 10.2-18.8), 41.8% (95% CI: 35.9-48.0), and 18.3% (95% CI: 14.0-23.6), respectively. The adjusted risk ratios of bronchial asthma 2.17 (95% CI: 0.35-13.41), chronic bronchitis 1.42 (95% CI: 0.58-3.48), breathlessness 1.71 (95% CI: 0.94-3.11), and cough 0.97 (95% CI: 0.47-2.03) for those with a TEP over 100. CONCLUSIONS: Shopkeepers working in heavily trafficked roadside shops suffer from respiratory morbidity and the risk increases with higher TEP. Total exposure period is a valuable indicator to estimate the effects of long-term TRAP exposure. INFORMED CONSENT: Obtained. ETHICS APPROVAL: The study was approved by the Institutional Ethics Committee of the National Institute for Research in Environmental Health (Bhopal, India). COMPETING INTERESTS: The authors declare no competing financial interests.
