The role of socioeconomic and environmental factors in the risk of obstructive lung disease and impaired lung function in urban Nigerian adults

The prevalence of obstructive lung disease is rising in the United States, particularly among those of African descent. Few studies in Africa have measured lung function in adults with limited exposure to industrial respiratory irritants. Lung function and related factors were examined in a cross-sectional study of urban Nigerian civil servants who are in transition to a westernized lifestyle.;Spirometric measurements of lung function (forced vital capacity (FVC), expiratory flow rate in 1 sec (FEV1), FEV1/FVC ratio, and peak expiratory flow rate (PEFR)] were obtained to examine respiratory health in 410 civil servants (235 men, 175 women) aged 30--69 years in Benin City. Demographic characteristics, respiratory symptoms, social class, and home environment were ascertained by questionnaire. Data on 3397 African-Americans enrolled in NHANES III (1988--94) were used for comparisons.;Nigerians had lower age and height adjusted FVC and FEV1 than African-Americans in both genders, independent of smoking and symptoms (p < 0.001). However, the prevalence of FEV1/FVC ratio below 0.70, a screening measure for airway obstruction, was lower in Nigerians than in African-Americans (10.54 versus 14.10/100 men, 6.29 versus 8.67/100 women). Similarly, the age-adjusted prevalence of any self reported respiratory symptoms was lower in Nigerians than in African-Americans (3.65 versus 22.90/100 men, 4.57 versus 35.28/100 women). The age-adjusted prevalence of current smoking among Nigerian and African-American men was 10.82 and 46.50/100, respectively. While the age-adjusted rate for African-American women was 30.93/100, none of the Nigerian women were current smokers. Current smoking was unrelated to lung function in Nigerian men. Occupational status, education, and home environment were unrelated to lung function in either sex.;The peak flow meter was found to be efficacious as a screening device for identifying individuals with a measured FEV1/FVC ratio below 70%. Based on a cut point of 470 L/min in the PEF readings, the sensitivity and specificity were 91.7% and 39.0%, respectively.;Urban Nigerians who have limited exposure to cigarette smoke and who work in a non-industrial setting have a low prevalence of obstructive lung disease. Peak flow meters were found to be efficacious for lung function screening in this adult population of Nigerians.