Domestic solid fuel combustion in an adult population in Nigeria: A cross sectional analysis of association with respiratory symptoms, quality of life and lung function.

BACKGROUND AND OBJECTIVES: We examined the association of respiratory symptoms, health status, and lung function with the use of solid fuel (wood, charcoal, coal or crop residue) for cooking or heating in a predominantly non-smoking population. METHODS: Using the protocol of the Burden of Obstructive Lung Diseases (BOLD) initiative, we collected representative population data using questionnaires and spirometry tests. We categorized solid fuel use into 'never user', 'ex user' and 'current user' based on responses to the survey. We developed regression models to evaluate the relation between use of solid fuel and the prevalence of respiratory symptoms, quality of life and lung function adjusting for confounding variables. RESULTS: Out of 1147 respondents with complete information on domestic fuel type, 33% were 'never-users', 19% were 'ex-users' while 48% reported current use of solid fuel for domestic cooking and/or indoor heating. Compared with never-users, current solid fuel users were more likely to report cough (OR: 1.7, 95% CI: 1.0, 2.9), cough or phlegm (OR: 1.6, 95% CI: 1.0, 2.5) and the association was stronger among women (OR: 3.0, 95% CI: 1.3, 7.1 and OR: 2.3, 95% CI: 1.1, 5.2, respectively). Current solid fuel users also had lower mental health status (coefficient: ?1.5, 95% CI: ?2.8, - 0.2) compared with the group of never-users. Current or previous domestic use of solid fuels for cooking or heating was not associated with higher prevalence of chronic airflow obstruction (FEV1/FVC < LLN). CONCLUSIONS: Using solid fuel for domestic cooking or heating was associated with a higher risk of cough or phlegm and a lower mental quality of life. However we found no significant effect in the prevalence of chronic airflow obstruction in Ife, Nigeria.

Reduced Forced Vital Capacity in an African Population. Prevalence and Risk Factors.

RATIONALE: Black Africans have reduced FVC compared with white persons, but the prevalence and determinants of reduced values are not well understood. OBJECTIVES: To evaluate the prevalence and factors leading to reduced FVC in a Nigerian population and to examine current theories regarding the determinants of this difference. METHODS: We studied the ventilatory function of 883 adults aged 40 years or older participating in the Burden of Obstructive Lung Disease Study in Ile-Ife, Nigeria. Respondents completed pre- and post-bronchodilator spirometry test and provided information on their smoking history, respiratory symptoms, risk factors, and diagnoses, including anthropometric details. We used standard categories to define body mass index as either underweight, normal, overweight, or obese. We defined reduced FVC as a post-bronchodilator FVC below the lower limit of normal using National Health and Nutrition Examination Survey (NHANES) equations, Global Lung Function Initiative 2012 equations, and local reference equations based on nonsmoking study participants without a respiratory diagnosis. We fit multivariate linear regression models to FVC as a continuous measure, adjusting for age, sex, height, and other confounders. RESULTS: The prevalence of reduced FVC was 70.4% for men and 72.8% for women when using NHANES values for white Americans, 17.8% for men and 14.4% for women using NHANES equations for African Americans, and 15.5% for men and 20.5% for women using the Global Lung Function Initiative 2012 equations. Using the equations derived from nonsmoking respondents in the survey without a respiratory diagnosis, the prevalence of reduced FVC was less than 4% for both men and women. FVC was lower in participants who had less than 7 years of education (FVC, -96 ml; 95% confidence interval [CI], -172 to -19), were underweight (FVC, -269 ml; 95% CI, -464 to -73), were overweight (FVC, -132 ml; 95% CI, -219 to -46), and were obese (FVC, -222 ml; 95% CI, -332 to -112). CONCLUSIONS: There is a wide variation in the prevalence of reduced FVC based on the reference standard used. This variation is not satisfactorily explained by factors thought to affect FVC within individual populations. However, the prevalence strongly associates with both education level and body mass index in this population, regardless of the specific standard used.

Asthma in a university campus: a survey of students and staff of Obafemi Awolowo University, Ile-Ife, Nigeria.

BACKGROUND: Asthma continues to be an important cause of morbidity and mortality in developing countries. But, its burden among adult populations in university campuses is not well described. METHOD: Through a multistage cluster sampling of students and staff of the Obafemi Awolowo University, Ile-Ife, Nigeria, we obtained a representative sample, each for students and staff. We administered the European Community Respiratory Health Survey (ECRHS) screening questionnaire to all the respondents. A subgroup did a spirometry test and completed a detailed questionnaire. Asthma was considered "possible", if a respondent provided affirmative response to symptoms of "wheezing or whistling", "attack of shortness of breath", "diagnosed attack of asthma" in the last 12 months or "currently taking medicines for asthma". RESULTS: From population of 13,750 students and 1428 staff of the university, we systematically sampled 2750 (20%) students and all the staff. Amongst these, 2372 students and 455 staff completed the screening questionnaire. The mean age (SD) of the responders was 21.9 (3.2) and 46.1 (8.9) for students and staff and most of them were men; 58.6% and 65.9%, respectively. While an estimated 2.6% (95% CI: 1.7-3.5) of students had an asthma attack in the preceding 12 months, 14.5% (95% CI: 12.5-16.5) and 25.2% (95% CI: 22.8-27.7) reported shortness of breath and nocturnal cough, respectively. The staff population reported fewer symptoms. The proportion with "possible asthma" was 18.2% (95% CI: 16.0-20.4) for students and 8.0% (95% CI: 5.4-10.7) for staff. CONCLUSION: The prevalence of asthma is high among students and staff of Obafemi Awolowo University, Nigeria.

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

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.

Secondhand smoke exposure among nonsmoking adults in two Nigerian cities.

BACKGROUND: Tobacco control policy can only succeed if the burdens of smoking are known. The objective of this study was to determine the prevalence and correlates of secondhand smoke (SHS) exposure among nonsmoking adults in two Nigerian cities. MATERIALS AND METHODS: We carried out a cross-sectional study from October 2009 to April 2010 among adult population of two Nigerian cities: Enugu and Ilorin. A semi-structured questionnaire was administered by interviewers to obtain socio-demographic information; and information regarding pattern of SHS exposure, awareness of tobacco control policy and the harmful effects of SHS. SHS exposure was defined as regular exposure to tobacco smoke in the previous 30 days in a nonsmoking adult. RESULTS: Of the 585 nonsmoking adults that completed the study, 38.8% had regular exposure to SHS; mostly, in public places (24.4%). More men were exposed at public places when compared with women (27.0% vs. 19.5%). The strongest factor associated with exposure to SHS in women was having a smoking spouse [prevalence rate (PR) ratio-7.76; 95% confidence interval (CI), 3.08-9.42]; and in men, it was lack of home smoking restriction (PR ratio-6.35; 95% CI, 4.51-8.93). Among men, SHS exposure at any location was associated with lack of secondary school education, residing in slum apartment (house with many households), living with a smoking family member (non-spouse), lack of home smoking restriction, and alcohol intake. Among women, SHS exposure at any location was associated with having a smoking spouse, residing in slum apartment and lack of home smoking restriction. Seventy-two percent of respondents were aware of the harmful effects of SHS on their health. Lack of awareness of the harmful effects was significantly associated with increasing age (r = +0.45; P = <0.01), lack of secondary school education (r = -0.10; P = 0.04), residing in slum apartment (r = -0.12; P = 0.03) and being a widow/widower (r = +0.24; P < 0.01). Only 17.4% of the employees reported availability of outdoor smoking area at their workplaces. CONCLUSION: Our results show that prevalence of SHS exposure was the highest in public places. These findings underscore the need for enactment of comprehensive smoke-free legislation and implementation of educational strategies to reduce SHS exposure in homes.

Prevalence and patient characteristics associated with pleural tuberculosis in Nigeria.

BACKGROUND: Tuberculosis is a leading cause of mortality worldwide, with a growing death rate. The pleural space is a common extrapulmonary site of involvement. The aim of this paper is to document prevalence and types of pleural involvement in pulmonary tuberculosis and patient characteristics associated with its occurrence. METHODOLOGY: The study was conducted in a hospital outpatient clinic in which consecutive patients with pulmonary tuberculosis (PTB) or suspects were recruited and studied for the presence of co existing pleural disease or involvement (PD). RESULTS: Of 100 patients studied, eighty-two (82%) had PTB alone and six (6%) patients had PD. Pleural effusion was responsible for the majority of the cases, accounting for 67% of PD. There was no case of empyema. Mean age between patients with PTB and PTB/PD was similar. On univariate analysis, patients with PD had a shorter duration of symptoms and increased reporting of fever (p value = 0.02) and were also different from those with only PTB in HIV seropositivity and sputum smear from AFB (p value = 0.02 and 0.00 respectively). However, after adjustment for multiple comparisons using the Bonferroni test, the only significant difference between them was in the HIV seropositivity rate (p value < 0.012). CONCLUSION: Less than one tenth of patients with PTB have co-existing and involvement of the pleural space. Pleural involvement is associated with HIV.