Outdoor respirable particulate matter and the lung function status of residents of selected communities in Ibadan, Nigeria

BACKGROUND

Ambient air pollution remains a major public health hazard in urban communities. In Nigeria, air quality management especially in the urban centres, is fraught with enormous challenges including limited data. We assessed the outdoor respirable particulate matter (PM10) concentration and the pulmonary function status of residents in four selected communities in Ibadan.

METHODS

A cross-sectional study design was employed. Four locations - Ojoo Park (OP = high traffic area), Bodija Market (BM = commercial area), Oluyole Estate (OE = industrial area) and the University of Ibadan (UI = academic community - reference) - were selected based on varying intensities of urban activity. PM10 levels were recorded in the morning and afternoon for 12 weeks between January and March 2008. Lung function status (FEV1) of 140 randomly selected participants was measured. Daily mean of PM10 levels were compared with WHO guideline limits. Data analysis was done using descriptive, χ(2), ANOVA and Spearman-rank correlation tests at 5% level of significance.

RESULTS

For all sites, PM10 concentration was generally higher in the afternoon. The highest daily mean PM10 concentration was recorded at BM, followed by OP, OE and UI. These values when compared with WHO guideline limits showed: BM eightfold > OP sevenfold > OE sixfold > UI fivefold (p < .05). Weekly mean PM10 levels and mean FEV1(obs) gave the following order: UI > OE > OP > BM. There was a significant negative correlation between PM10 burden and FEV1(obs) across the study locations (r =-0.371, p < .05).

CONCLUSION

Most of the locations with higher particulate burden were observed to have declining lung function status. A longitudinal study to establish more robust associations is advocated.

Allergy sensitization and asthma among 13-14 year old school children in Nigeria

BACKGROUND

The prevalence of asthma and role of atopy in asthma among children has not been clearly defined in Nigeria.

OBJECTIVE

To determine the prevalence of asthma and investigate risk factors related to allergy sensitization among urban and rural school children in southwest Nigeria.

METHODS

Validated ISAAC questionnaire was administered to 1736 high school children in randomly selected schools in rural and urban communities. Identified asthma cases were matched to controls. Allergy skin tests, blood eosinophil count, serum IgE and stool examination for parasites were performed. Dust samples from homes were also collected and analyzed for allergens.

RESULTS

The prevalence of asthma was 7.5% (95% CI 6.0 to 9.2%) and 8% (95% CI 6.0-10.4%) in the rural and urban communities respectively . Risk factors for asthma included cigarette-smoking, cats in the home and family size. Eosinophil count (109/L) was elevated in asthmatics [0.70 (95% CI 0.48-1.11) vs. 0.32 (95% CI 0.19-0.69); p<0.01], but IgE levels were similar between the two groups (298±229 IU/mL vs. 288±257; p=0.97). Positive skin tests to cat hair, cockroach, mango blossom and mouse epithelium were more frequent in asthmatics than in healthy controls, especially in the rural communities. There was no correlation between allergens in dust collected from homes and skin test reactivity.

CONCLUSION

Asthma prevalence is similar in rural and urban children in Southwest Nigeria and atopy with elevated IgE was not observed to be a major factor for asthma in our cohort of children in both communities.

Comparison of the efficacy and safety of budesonide turbuhaler administered once daily with twice the dose of beclomethasone dipropionate using pressurised metered dose inhaler in patients with mild to moderate asthma

BACKGROUND

Current treatment guidelines have clearly defined the central place and benefits of inhaled glucocorticoids in the management of bronchial asthma. However, compliance with therapy is often poor due to complexity of treatment regimens. Therefore, a single once daily regimen with a simple device, the turbuhaler might be expected to result in improved compliance and better efficiency.

STUDY DESIGN

This was a prospective open randomized trial with parallel groups conducted in five tertiary medical institutions. Asthmatic patients who met the enrolment criteria were randomized to receive either budesonide 400 microg daily or beclomethasone dipropionate 400 microg twice daily for eight weeks.

RESULT

At the end of the study, both drugs were found to be effective in reducing the symptoms of asthma, reduction of beta2 agonist usage and improvement in lung function tests. However Budesonide Turbuhaler provided better effects in all parameters (p < 0.05). Both drugs were well tolerated.

CONCLUSION

It is therefore concluded that Budesonide Turbuhaler administered once daily at a dose of 400 microg is more efficacious than Beclomethasone dipropionate 400 microg twice daily administered via pressurized metered dose inhaler.

Efficacy and safety of Zafirlukast ('Accolate') in the management of patients with mild-to-moderate asthma

The efficacy and safety of the oral leukotriene receptor antagonist Zafirlukast ('Accolate') was assessed as maintenance therapy for black (Nigerian) patients with mild to moderate asthma. A total of eighty-one patients aged 16-70 years were screened and sixty patients were enrolled in a 7-week multicenter open study to receive 20 mg of 'Accolate' twice daily. Those enrolled had FEV1 > or = 60%, reversibility > or = 15% and cumulative daytime asthma symptoms score > or = 10 over seven consecutive days before visit 2 to be considered eligible to receive trial therapy, and the patients were maintained on as required beta 2-agonist therapy. Efficacy was assessed by changes in symptoms, number of times beta 2-agonist was used and results of pulmonary function tests. Safety was assessed by adverse event experiences, results of laboratory tests and physical examination. At the endpoint, patients reported a statistically significant increase in lung function and a significant reduction in episodes of asthma symptoms either in the morning, day or night. The mean beta 2-agonist use was also statistically reduced over the weeks as treatment progressed while the cumulative daytime total asthma score showed a sharp decline following drug use. Change in symptoms, beta 2-agonist use and pulmonary function occurred within one week of Zafirlukast treatment and continued throughout the trial. Zafirlukast was well tolerated. Headaches and pneumonia were the only side effects in three patients and these were not considered to be related to trial therapy. No clinically significant changes were observed in laboratory test results, or on physical examination. We conclude that Zafirlukast ('Accolate') 20 mg b.d. is an effective and well tolerated medication for maintenance therapy in black (Nigerian) patients with mild-to-moderate asthma.