Daniel O. Obaseki

Chronic Airflow Obstruction in a Black African Population: Results of BOLD Study, Ile-Ife, Nigeria

Abstract Global estimates suggest that Chronic Obstructive Pulmonary Disease (COPD) is emerging as a leading cause of death in developing countries but there are few spirometry-based general population data on its prevalence and risk factors in sub-Saharan Africa. We used the Burden of Obstructive Lung Disease (BOLD) protocol to select a representative sample of adults aged 40 years and above in Ile-Ife, Nigeria. All the participants underwent spirometry and provided information on smoking history, biomass and occupational exposures as well as diagnosed respiratory diseases and symptoms. Chronic Airflow Obstruction (CAO) was defined as the ratio of post-bronchodilator (BD) one second Forced Expiratory Volume (FEV1) to Forced Vital Capacity (FVC) below the lower limit of normal (LLN) of the population distribution for FEV1/FVC. The overall prevalence of obstruction (post-BD FEV1/FVC < LLN) was 7.7% (2.7% above LLN) using Global Lung Function Initiative (GLI) equations. It was associated with few respiratory symptoms; 0.3% reported a previous doctor-diagnosed chronic bronchitis, emphysema or COPD. Independent predictors included a lack of education (OR 2·5, 95% CI: 1.0, 6.4) and a diagnosis of either TB (OR 23.4, 95% CI: 2.0, 278.6) or asthma (OR 35.4, 95%CI: 4.9, 255.8). There was no association with the use of firewood or coal for cooking or heating. The vast majority of this population (89%) are never smokers. We conclude that the prevalence of CAO is low in Ile-Ife, Nigeria and unrelated to biomass exposure. The key independent predictors are poor education, and previous diagnosis of tuberculosis or asthma.

Prevalence and predictors of obstructive sleep apnea syndrome in a sample of patients with type 2 Diabetes Mellitus in Nigeria.

Introduction: Obstructive sleep apnea (OSA) and Diabetes Mellitus (DM) are growing health challenges worldwide. However, the relation of OSA with type 2 diabetes is not well understood in developing countries. This study described the prevalence and predictors of OSA in type 2 DM patients using a screening questionnaire. Materials and Methods: Patients aged 40years and above with type 2 diabetes mellitus were recruited into the study consecutively from the outpatient clinics of a university hospital. They were all administered the Berlin questionnaire and the Epworth sleepiness scale (ESS) to assess the risk of OSA and the tendency to doze off, respectively. Anthropometric details like height, weight and body mass index (BMI) were measured and short-term glycaemic control was determined using fasting blood glucose. Results: A total of 117 patients with type 2 diabetes mellitus were recruited into the study. The mean (SD) age, height and BMI was 63 years (11), 160 cm (9) and 27.5 kg/ m2 (5.7), respectively. Twenty-seven percent of the respondents had a high risk for OSA and 22% had excessive daytime sleepiness denoted by ESS score above 10. In addition, the regression model showed that for every 1 cm increase in neck circumference, there is a 56% independent increase in the likelihood of high risk of OSA after adjusting for age, sex, BMI, waist, hip circumferences and blood glucose. Conclusion: Our study shows a substantial proportion of patients with type 2 diabetes may have OSA, the key predictor being neck circumference after controlling for obesity.

Airflow Obstruction and Use of Solid Fuels for Cooking or Heating: BOLD Results

RATIONALE Evidence supporting the association of COPD or airflow obstruction with use of solid fuels is conflicting and inconsistent. OBJECTIVE To assess the association of airflow obstruction with self-reported use of solid fuels for cooking or heating. METHODS We analysed 18,554 adults from the BOLD study, who had provided acceptable post-bronchodilator spirometry measurements and information on use of solid fuels. The association of airflow obstruction with use of solid fuels for cooking or heating was assessed by sex, within each site, using regression analysis. Estimates were stratified by national income and meta-analysed. We carried out similar analyses for spirometric restriction, chronic cough and chronic phlegm. MEASUREMENTS AND MAIN RESULTS We found no association between airflow obstruction and use of solid fuels for cooking or heating (ORmen=1.20, 95%CI 0.94-1.53; ORwomen=0.88, 95%CI 0.67-1.15). This was true for low/middle and high income sites. Among never smokers there was also no evidence of an association of airflow obstruction with use of solid fuels (ORmen=1.00, 95%CI 0.57-1.76; ORwomen=1.00, 95%CI 0.76-1.32). Overall, we found no association of spirometric restriction, chronic cough or chronic phlegm with the use of solid fuels. However, we found that chronic phlegm was more likely to be reported among female never smokers and those who had been exposed for ≥20 years. CONCLUSION Airflow obstruction assessed from post-bronchodilator spirometry was not associated with use of solid fuels for cooking or heating.Rationale: Evidence supporting the association of chronic obstructive pulmonary disease or airflow obstruction with use of solid fuels is conflicting and inconsistent. Objectives: To assess the association of airflow obstruction with self‐reported use of solid fuels for cooking or heating. Methods: We analyzed 18,554 adults from the BOLD (Burden of Obstructive Lung Disease) study, who had provided acceptable post‐bronchodilator spirometry measurements, and information on use of solid fuels. The association of airflow obstruction with use of solid fuels for cooking or heating was assessed by sex, within each site, using regression analysis. Estimates were stratified by national income and meta‐analyzed. We performed similar analyses for spirometric restriction, chronic cough, and chronic phlegm. Measurements and Main Results: We found no association between airflow obstruction and use of solid fuels for cooking or heating (odds ratio [OR] for men, 1.20 [95% confidence interval (CI), 0.94‐1.53]; OR for women, 0.88 [95% CI, 0.67‐1.15]). This was true for low‐/middle‐ and high‐income sites. Among never‐smokers, there was also no evidence of an association of airflow obstruction with use of solid fuels (OR for men, 1.00 [95% CI, 0.57‐1.76]; OR for women, 1.00 [95% CI, 0.76‐1.32]). Overall, we found no association of spirometric restriction, chronic cough, or chronic phlegm with the use of solid fuels. However, we found that chronic phlegm was more likely to be reported among female never‐smokers and those who had been exposed for 20 years or longer. Conclusions: Airflow obstruction assessed from post‐bronchodilator spirometry was not associated with use of solid fuels for cooking or heating.

HIV associated chronic obstructive pulmonary disease in Nigeria.

OBJECTIVE To determine the prevalence and risk factors for chronic obstructive pulmonary disease (COPD) among HIV-infected adults in Nigeria. DESIGN Cross-sectional study. METHODS HIV-infected adults aged ≥ 30 years with no acute ailments accessing care at the antiretroviral therapy clinic of Jos University Teaching Hospital were enrolled consecutively. Participants were interviewed to obtain pertinent demographic and clinical information, including exposure to risk factors for COPD. Post-bronchodilator spirometry was carried out. HIV related information was retrieved from the clinic medical records. COPD case-definition was based on the Global Initiative for Obstructive Lung Disease (GOLD) criteria using post-bronchodilator FEV1/FVC <0.7. COPD prevalence was also calculated using the lower limit of normal for FEV1/FVC criteria (LLN) from the European Respiratory Society normative equation. Factors associated with COPD were determined using logistic regression models. RESULTS Study population comprised 356 HIV infected adults with mean age of 44.5 (standard deviation, 7.1) years and 59% were female. The mean time elapsed since HIV diagnosis was 7.0 (SD, 2.6) years and 97.5% of the respondents were on stable ART with virologic suppression present in 67.2%. Prevalence of COPD were 15.4% (95% confidence interval [CI] 11.7-19.2), 12.07% (95% CI 8.67-15.48), 22.19% (95% CI 18.16-26.83) using GOLD, ERS LLN and GLI LLN diagnostic criteria respectively. In multivariate analyses adjusting for gender, exposure to cigarette smoke or biomass, history of pulmonary tuberculosis, use of antiretroviral therapy, current CD4 T-cell count and HIV RNA, only age > 50 years was independently associated with COPD with OR 3.4; 95% CI 1.42-8.17 when compared to ages 30-40 years. CONCLUSION HIV-associated COPD is common in our population of HIV patients.

Respiratory symptom, lung function and exhaled carbon monoxide among a sample of traffic workers in Lagos, Nigeria: A pilot survey

Background: Traffic-related air pollution (TRAP) is a major source of air pollution but the impact on health in Nigeria is not well described. Patients and Methods: A descriptive cross-sectional study of road traffic workers and university students in Lagos. Eligible, accessible and willing participants were included in the sample. Respiratory symptoms and anthropometry were obtained from all the participants using an adapted Medical Research Council (MRC) questionnaire and they all did a spirometry test and exhaled carbon monoxide (CO) test. Results: Fifty-nine individuals participated with complete data, including 47 traffic policemen and 12 students who acted as controls. The mean age (SD) was 35.1 (8.0) and 35.4 years (6.3) for the traffic workers and students, respectively. All the respondents were men. The mean (SD) duration of occupation as a traffic policeman was 4.4 (4.4) and a median of 4 years (range 1-25). There was no significant difference in the presentation of respiratory and non-respiratory symptoms between the two groups. Compared with the students, the traffic workers had higher age, height and sex adjusted forced expiratory volume in one second and forced vital capacity. Traffic policemen had significantly higher levels of exhaled CO than the students (1.18 vs 0.73 ppm, P < 0.006). Conclusion: There is a high prevalence of respiratory symptoms in both traffic policemen and non-traffic residents of Lagos metropolis, indicating widespread pollution.

Prevalence and burden of chronic bronchitis symptoms: results from the BOLD study

We studied the prevalence, burden and potential risk factors for chronic bronchitis symptoms in the Burden of Obstructive Lung Disease study. Representative population-based samples of adults aged ≥40 years were selected in participating sites. Participants completed questionnaires and spirometry. Chronic bronchitis symptoms were defined as chronic cough and phlegm on most days for ≥3 months each year for ≥2 years. Data from 24 855 subjects from 33 sites in 29 countries were analysed. There were significant differences in the prevalence of self-reported symptoms meeting our definition of chronic bronchitis across sites, from 10.8% in Lexington (KY, USA), to 0% in Ile-Ife (Nigeria) and Blantyre (Malawi). Older age, less education, current smoking, occupational exposure to fumes, self-reported diagnosis of asthma or lung cancer and family history of chronic lung disease were all associated with increased risk of chronic bronchitis. Chronic bronchitis symptoms were associated with worse lung function, more dyspnoea, increased risk of respiratory exacerbations and reduced quality of life, independent of the presence of other lung diseases. The prevalence of chronic bronchitis symptoms varied widely across the studied sites. Chronic bronchitis symptoms were associated with significant burden both in individuals with chronic airflow obstruction and those with normal lung function. Chronic bronchitis symptoms are associated with significant burden regardless of the presence of airflow obstruction http://ow.ly/kP9P30eFELK

Gaps in Capacity for Respiratory Care in Developing Countries. Nigeria as a Case Study

There are unmet needs for respiratory medical care in developing countries. We sought to evaluate the quality and capacity for respiratory care in low- and lower-middle-income countries, using Nigeria as a case study. We obtained details of the respiratory practice of consultants and senior residents (fellows) in respiratory medicine in Nigeria via a semistructured questionnaire administered to physician attendees at the 2013 National Congress of the Nigerian Thoracic Society. Out of 76 society-registered members, 48 attended the congress, 40 completed the questionnaire, and 35 provided complete data (73% adjusted response rate). Respondents provided information on the process and costs of respiratory medicine training and facility, equipment, and supply capacities at the institutions they represented. Approximately 83% reported working at a tertiary level (teaching) hospital; 91% reported capacity for sputum smear analysis for acid alcohol-fast bacilli, 37% for GeneXpert test cartridges, and 20% for BACTEC liquid sputum culture. Only 34% of respondents could perform full spirometry on patients, and none had the capacity for performing a methacholine challenge test or for measuring the diffusion capacity for carbon monoxide. We estimated the proportion of registered respiratory physicians to the national population at 1 per 2.3 million individuals. Thirteen states with an estimated combined population of 57.7 million offer no specialist respiratory services. Barriers to development of this capacity include the high cost of training. We conclude that substantial gaps exist in the capacity and quality of respiratory care in Nigeria, a pattern that probably mirrors most of sub-Saharan Africa and other countries of similar economic status. Health policy makers should address these gaps systematically.

Biomass smoke exposure as an occupational risk: cross-sectional study of respiratory health of women working as street cooks in Nigeria

Objective Little is known about respiratory health of women who are occupationally exposed to biomass smoke outside their homes. This study reports the exposure and respiratory health of street cooks in Ile-Ife, Nigeria. Methods We assessed exposure to biomass smoke by questionnaire in 188 street cooks and 197 control women and by personal diffusive samplers to quantify volatile organic compounds (VOCs) in a subsample of the women. Respiratory symptoms were assessed by a standardised questionnaire, and pulmonary function was assessed by spirometry before and after bronchodilation. Regression analysis was conducted to compare the outcome between the two groups. Results The study included 188 women (median age 40, IQR 30–50 years) who had worked as street cooks for a median of 7 years (IQR 3–15 years) and 197 control women with similar demographics. Benzene concentration in passive samplers worn by the street cooks was significantly higher compared with controls (median (IQR) 119.3 (82.7–343.7) µg/m3 vs 0.0 (0.0–51.2) µg/m3, p<0.001). The odds of reported respiratory symptoms were significantly higher among the street cooks than controls: cough (adjusted OR 4.4, 95% CI 2.2 to 8.5) and phlegm (adjusted OR 3.9, 95% CI 1.5 to 7.3). The street cooks also had higher odd of airway obstruction as measured by forced expiratory volume in 1 s/forced vital capacity <0.7: 11% 3% (adjusted OR of 3.3 (95% CI 1.3 to 8.7)). Conclusions This study provides evidence of adverse respiratory effects among street cooks using biomass fuels.

The association between chronic airflow obstruction and poverty in 12 sites of the multinational BOLD study

Poverty is strongly associated with mortality from COPD, but little is known of its relation to airflow obstruction. In a cross-sectional study of adults aged ≥40 years from 12 sites (N=9255), participating in the Burden of Obstructive Lung Disease (BOLD) study, poverty was evaluated using a wealth score (0–10) based on household assets. Obstruction, measured as forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) (%) after administration of 200 μg salbutamol, and prevalence of FEV1/FVC<lower limit of normal were tested for association with poverty for each site, and the results were combined by meta-analysis. Mean wealth scores ranged from 4 in Blantyre (Malawi) and Kashmir (India) to 10 in Riyadh (Saudi Arabia), and the prevalence of obstruction, from 16% in Kashmir to 3% in Riyadh and Penang (Malaysia). Following adjustments for age and sex, FEV1/FVC increased by 0.36% (absolute change) (95%CI: 0.22, 0.49; p<0.001) per unit increase in wealth score. Adjustments for other confounders reduced this effect to 0.23% (0.11, 0.34), but even this value remained highly significant (p<0.001). Results were consistent across sites (I2=1%; phet=0.44). Mean wealth scores explained 38% of the variation in mean FEV1/FVC between sites (r2=0.385, p=0.031). Airflow obstruction is consistently associated with poverty at individual and community levels across several countries. Poverty is a strong predictor of chronic airflow obstruction independent of age, sex, smoking and tuberculosis http://ow.ly/T2Sz30bdUNC

Unemployment in chronic airflow obstruction around the world: Results from the BOLD study

We aimed to examine associations between chronic airflow obstruction (CAO) and unemployment across the world. Cross-sectional data from 26 sites in the Burden of Obstructive Lung Disease (BOLD) study were used to analyse effects of CAO on unemployment. Odds ratios for unemployment in subjects aged 40–65 years were estimated using a multilevel mixed-effects generalised linear model with study site as random effect. Site-by-site heterogeneity was assessed using individual participant data meta-analyses. Out of 18 710 participants, 11.3% had CAO. The ratio of unemployed subjects with CAO divided by subjects without CAO showed large site discrepancies, although these were no longer significant after adjusting for age, sex, smoking and education. The site-adjusted odds ratio (95% CI) for unemployment was 1.79 (1.41–2.27) for CAO cases, decreasing to 1.43 (1.14–1.79) after adjusting for sociodemographic factors, comorbidities and forced vital capacity. Of other covariates that were associated with unemployment, age and education were important risk factors in high-income sites (4.02 (3.53–4.57) and 3.86 (2.80–5.30), respectively), while female sex was important in low- to middle-income sites (3.23 (2.66–3.91)). In the global BOLD study, CAO was associated with increased levels of unemployment, even after adjusting for sociodemographic factors, comorbidities and lung function. Chronic airflow obstruction increases risk of unemployment, and is a burden to welfare systems worldwide http://ow.ly/cxzv30cQ17A