Prevalence of asthma and allergic rhinitis among adults in Yaounde, Cameroon

The role of matrix metalloproteinase-2 and miR-196a2 in bronchial asthma pathogenesis and diagnosis

Background

Bronchial asthma is a persistent inflammatory respiratory condition that restricts the passage of air and causes hyperresponsiveness. Chronic asthma can be classified into three categories: mild, moderate, and severe. Remodeling took place as the extracellular matrix accumulated in the walls of the airways. Inflammation occurs as a result of the damage caused by matrix metalloproteinase-2 (MMP-2) to basement membrane type IV collagen. The severity of asthma may be associated with miR-196a2. The objective of our study was to investigate the underlying mechanisms and clinical relevance of miR-196a2 and MMP-2 serum levels in relation to the severity of asthma.

Methods

This study recruited 85 controls and 95 asthmatics classified as mild, moderate, or severe. Expression of miR-196a2 was measured by quantitative reverse transcriptase PCR. Using the enzyme-linked immunosorbent assay (ELISA), MMP-2, IL-6, and total immunoglobulin E (IgE) levels in the serum of asthmatics of various grades were compared to a control group. MMP-2's diagnostic and prognostic potential was determined using ROC curve analysis. This study also measured blood Eosinophils and PFTs. We examined MMP-2's connections with IgE, blood Eosinophils, and PFTs.

Results

The current investigation found that miR-196a2 expression was significantly higher in the control group than in asthmatic patients as a whole. The study found that severe asthmatics had higher MMP-2, IL-6, and IgE serum levels than healthy controls. We identified the MMP-2 serum concentration cutoff with great sensitivity and specificity. Significant relationships between MMP-2 serum level and miR-196a2 expression in the patient group with severe asthmatics were found. The MMP-2, IL-6, and IgE serum levels were considerably higher in mild, moderate, and severe asthmatics than controls. The miR-196a2 expression and MMP-2 serum concentration correlated positively with IgE and blood eosinophils % and negatively with all lung function tests in the asthmatic patient group.Conclusion: the study revealed that the elevated miR-196a2 expression and serum concentration of MMP-2, IL-6, and IgE associated with elevated blood eosinophils % is associated with pathophysiology and degree of asthma severity. The miR-196a2 expression and MMP-2 serum concentration have a promising diagnostic and prognostic ability in bronchial asthma.

Association between asthma, rhinitis and atopic dermatitis with leprosy: A case-control study

Background Considering the cross-regulation of Th1 and Th2 responses, we hypothesised that atopic diseases (Th2) inhibit the protective Th1 immune response to Mycobacterium leprae and exacerbates leprosy. Objective In this study, we aimed to evaluate the association between leprosy and atopic diseases. Methods To evaluate the association of atopic diseases with leprosy, we conducted a case-control study that included leprosy patients (n = 333) and their household contacts (n = 93). The questionnaire from the International Study of Asthma and Allergies in Childhood, which is validated in several countries for epidemiological diagnosis of atopic diseases, was applied to determine the occurrence of atopic diseases, allergic rhinitis, asthma, and atopic dermatitis among leprosy patients and the household contacts. Results Considering clinical and epidemiological data, among the leprosy group 51.6% (n = 172) were determined to have at least one atopic disease, while atopy was observed less frequently at 40.86% among household contacts (n = 38). When two or more atopic diseases were assessed, the frequency was significantly higher among the leprosy patients than in the household contacts (21.9% vs. 11.8%; P-value = 0.03). Likewise, the frequency of asthma was significantly higher among leprosy patients (21%) than in the household contacts (10.8%; P-value = 0.02). Thus, our analyses revealed an association of atopic diseases with leprosy, with a significant linear increase in the occurrence of leprosy with an increase in the number of atopic diseases (P-value = 0.01). Limitation Due to the difficulties in recruiting household contacts that have prolonged contact with patients, but are not genetically related to the patient, the household contacts group is smaller than the leprosy patient group. Conclusion The data reveal an association between atopic diseases and leprosy outcomes. This knowledge could improve the treatment of leprosy patients with co-incident atopic diseases.

MCP-1-2518 (A>G) polymorphism and asthma risk: a pilot case-control study in Cameroon

Introduction

there is little data on the genetic determinants of asthma in Cameroon and sub-Saharan Africa, yet the involvement of genetics in the pathogenesis of this disease has been reported in the literature for several years. This study aims to investigate the possible role of MCP-1 2518 for the risk of asthma in Cameroonians.

Methods

we performed a case-control study on 30 volunteers suffering from asthma, matched by aged and sex to 30 healthy subjects. We determine the polymorphism of MCP-1 2518 using restriction fragment length polymorphism following Polymerase Chain Reaction (RFLP-PCR). Fisher exact test was used to compare proportions, with a threshold of significance set at 0.05.

Results

the average age of cases was 21±10 years with 17 (56.7%) females. The distribution of the MCP-1-2518 (A>G) gene polymorphism in people with asthma was as follows: 3 for AA, 5 for GG, and 22 for AG. The minor G allele was predominant (90%) in people with asthma. It was significantly associated with asthma whether the genotype was heterozygous AG or homozygous GG (p<0.01).

Conclusion

MCP-1-2518 (A>G) shows an association with asthma in our sample. Future larger studies evaluating several polymorphisms are needed to describe the genetic determinants of asthma in Cameroon and sub-Saharan Africa.

Sociodemographic factors associated with time to discharge for hospitalised patients with asthma and asthma exacerbation using the Ghana Health Service District Information Management System 2 (DHIMS-2) database, 2012-2017

Objective

Data on asthma hospitalisations are a useful source of patient morbidity information. In Ghana, the length of stay (LoS) and sociodemographic factors of patients hospitalised for asthma and its exacerbation are understudied. We aimed to investigate the time to discharge and assessed factors associated with length of hospital stays of asthmatics in Ghana.

Methods

Retrospective analysis of hospitalised patient with asthma records between 2012 and 2017 from the nationwide Ghana Health Service District Health Information Management System 2 database. We calculated the cumulative incidence function for discharge stratified by age group and sex. Multivariable Cox regression was used to investigate the association of sociodemographic characteristics with the LoS.

Results

Of 19 926 asthma-associated hospitalisations, 730 (3.7%) were due to asthma exacerbation. Overall mean age was 34 years (SD=24.6), in 12 000 (60.2%) hospitalisations, patients were female. There were 224 deaths (1.1%). Median LoS was 2 days (IQR: 1–3) with almost 90% of all patients discharged by the seventh day. Age and region were among the covariates showing significant association with LoS. Age below 10 years (HR: 1.39 (1.11 to 1.78)) was associated with early discharge while comorbidity and health insurance ownership were associated with late discharge (p<0.001). LoS did not vary by sex. Compared with the Greater Accra region, patients in other regions had shorter LoS, especially the Ashanti and Upper West regions (p<0.001). LoS increased annually, but was highest in 2016 (HR: 0.94 (0.90 to 0.98)).

Conclusion

Disparities in LoS across regions, and an overall increasing annual trend in Ghana call for tailored healthcare resource allocation. Longer LoS implies that patients are often absent from school or work leading to substantial financial and emotional costs to individuals and families.

Chronic diseases of lifestyle risk factor profiles of a South African rural community

Globally, chronic diseases of lifestyle account for millions of dollars spent annually on health. These diseases share similar risk factors including: physical inactivity, obesity, cigarette smoking, and hypertension among others. This study sought to assess risk factors for chronic diseases of lifestyle of a rural community in South Africa. This study used a survey design with data randomly collected using the WHO STEPS Instrument for Chronic Disease Risk Factor Surveillance from participants who attended routine checks from February to October 2018 from a trained healthcare practitioner. Informed consent was sought from all participants before the administration of the instrument. The research setting was the community Primary Health Center. About 54.0% of participants presented with no family history of hypertension but 19.7% had a family history of type II diabetes mellitus. More women were found to be hypertensive, with the majority (93.4%) monitoring their blood pressure. The study revealed that more men were current smokers. A large number of participants were engaged in a sedentary lifestyle with about one-third of the participants reported being obese. Physical inactivity, sedentary lifestyle, and hypertension were among the lifestyle-related risk factors for chronic diseases among residents of this rural community.

Self-care practice and associated factors among adult asthmatic patients on follow-up care at Northwest Amhara referral hospitals, Northwest Ethiopia 2020

BACKGROUND

Self-care practice of asthma is the strategy for asthma symptom control and future reduction of exacerbation, but it is poorly implemented in clinical settings due to the patients, professionals, and organizational related factors. Therefore, the study aimed to assess the self-care practice and associated factors among adult asthmatic patients at Northwest Amhara referral hospitals.

METHODS

Institution-based cross-sectional study was conducted among asthmatic patients on follow-up care at Northwest Amhara Regional State referral hospitals from February 1st, 2020 to March 30, 2020. Data were collected through an interviewer-administered technique. Asthma self-care practice tool was used to measure the outcome. Data were entered into EPI info version 7 and exported to SPSS version 22 for analysis. A binary logistic regression analysis was used. In multivariable logistic regression analysis, those independent variables having p value < 0.05 were considered as statistically significant with poor self-care practice of asthma.

RESULTS

A total of 470 participants enrolled in the study with a response rate of 100%. The proportion of good self-care practice among asthmatic patients was found to be 42.3%. The study revealed that; age group ≥ 55 years, having a co-morbid illness and borderline anxiety, having no social support, and drinking alcohol were significantly associated with poor asthma self-care practice.

CONCLUSIONS

Poor-self care practice in this study was high. Efforts need to be implemented for asthmatic patients with older age, having co-morbid illness and borderline anxiety, having no social support, and drinking alcohol.

Prevalence, socio-demographic and environmental determinants of asthma in 4621 Ghanaian adults: Evidence from Wave 2 of the World Health Organization's study on global AGEing and adult health

Background

A previous multi-site study involving lower- and middle-income countries demonstrated that asthma in older adults is associated with long-term exposure to particulate matter, male gender and smoking. However, variations may occur within individual countries, which are relevant to inform health promoting policies as populations live longer. The present study estimates asthma prevalence and examines the sociodemographic characteristics and environmental determinants associated with asthma in older adults in Ghana.

Methods

This study utilised data from the nationally representative World Health Organization Study on global AGEing and adult health (SAGE) Ghana Wave 2. A final sample of 4621 individuals residing in 3970 households was used in analytical modelling. Factors associated with asthma were investigated using single level and multilevel binary logistic regression models.

Results

Asthma was reported by 102 (2.2%) respondents. Factors associated with asthma in the univariate model were: those aged 60–69 (OR = 5.22, 95% CI: 1.24, 21.95) and 70 or more (OR = 5.56, 95% CI: 1.33, 23.26) years, Ga-Adangbe dialect group (OR = 1.65, 95% CI: 1.01, 2.71), no religion (OR = 3.59, 95% CI: 1.77, 7.28), having moderate (OR = 1.76, 95% CI: 1.13, 2.75) and bad/very bad (OR = 2.75, 95% CI: 1.58, 4.80) health state, and severe/extreme difficulty with self-care (OR = 3.49, 95% CI: 1.23, 9.88) and non-flush toilet facility (OR = 0.62, 95% CI: 0.39, 0.99). Factors independently associated with asthma in the adjusted models were: those aged 60–69 (OR = 4.49, 95% CI: 1.03, 19.55) years, father with primary education or less (OR = 0.40, 95% CI: 0.17, 0.94), no religion (OR = 2.52, 95% CI: 1.18, 5.41), and households with non-flush toilet facility (OR = 0.58, 95% CI: 0.35, 0.96). Significant residual household-level variation in asthma was observed. Over 40% of variance in asthma episodes could be attributable to residual household-level variations.

Conclusion

Individual as well as household factors were seen to influence the prevalence of asthma in this national survey. Clinical management of these patients in health facilities should consider household factors in addition to individual level factors.

Regulatory mechanisms of Sesn2 and its role in multi-organ diseases

Sestrin2 (Sesn2) is a powerful anti-oxidant that can prevent acute and chronic diseases. The role of Sesn2 has been thoroughly reviewed in liver, nervous system, and immune system diseases. However, there is a limited number of reviews that have summarized the effects of Sesn2 in heart and vascular diseases, and very less literature-based information is available on involvement of Sesn2 in renal and respiratory pathologies. This review summarizes the latest research on Sesn2 in multi-organ stress responses, with a particular focus on the protective role of Sesn2 in cardiovascular, respiratory, and renal diseases, emphasizing the potential therapeutic benefit of targeting Sesn2 in stress-related diseases.

Prevalence and determinants of current asthma in Cameroon

INTRODUCTION

The prevalence of asthma varies from one country to another due to differences in ethnicity, socio-economics status, environmental and climatic risk factors. The aim of this study was to determine the prevalence and determinants of current asthma in Cameroonian adults.

MATERIAL AND METHODS

Data from 4 cross-sectional community-based studies from 2014 to 2018 were analyzed. Participants aged 19 years and above were selected through multilevel stratified random sampling methods across 2 urban areas, 2 semi-urban areas and 1 rural area. Current asthma was defined as "wheezing in the last 12 months in a subject with self-reported asthma or having used drugs for asthma treatment". Logistic regression was used to investigate the determinants of current asthma.

RESULTS

A total of 10,707 adults [median age (interquartile range)=36 (26-52) years, 44.5% of men] were definitively enrolled in the study. The overall prevalence [95% confidence interval (CI)] of current asthma was 3.9% (3.5-4.3)%. Determinants [odd's ratio (OR), (95%CI)] of current asthma were: Sudanese ethnicity [1.9(1.4-2.7)], rural area [1.5(1.1-2.1)], urban area [1.6(1.2-2.2)], past history of pneumonia [1.9(1.1-3.4)], allergic rhino-conjunctivitis [6.5(4.7-8.9)], atopic eczema [2.3(1.5-3.6)], body mass index (BMI)≥40kg/m² [1.9(1.0-3.4)] and BMI<18kg/m² [1.8(1.2-2.9)].

CONCLUSION

The prevalence of current asthma is close to the low value of the Sub-Saharan African range. Sudanese ethnicity, rural area, urban area, history of pneumonia, allergic disease, severe obesity and underweight were determinants of current asthma in Cameroon. More research is surely warranted to understand the mechanisms underlying the association of asthma with Sudanese ethnicity.

Ethnobotanical study of curative plants used by traditional healers to treat rhinitis in the Limpopo Province, South Africa

BACKGROUND

Studies focusing on plants used medicinally to heal and manage rhinitis are very scarce in Africa and elsewhere.

OBJECTIVES

To document plants used by traditional healers (THs) in the treatment and management of rhinitis and related symptoms in the Limpopo Province of South Africa.

METHODS

Data was gathered using a semi structured interviews with 105 THs in the Limpopo Province, supplemented by field expeditions for plant specimen collection and observation.

RESULTS

63 plant species from 59 genera distributed across 40 botanical families, mainly the Asteraceae (7 spp.) and Euphorbiaceae (6 spp.) were therapeutically used by THs. Overall, 77 herbal recipes (87%=mono and 12.9%=poly), mainly prepared from roots (55.5%) and leaves (19%) were recorded. Most of these recipes were processed via pounding (59.7%) and boiling (20.7%). Oral (44.1%) and nasal (33.7%) was the preferred modes of dispensing remedies by THs. Artemisia afra, Clerodendrum ternatum, Cryptocarya transvaalensis, Enicostema axillare, Kalanchoe brachyloba, Lasiosiphon caffer, Lippia javanica, Schkuhria pinnata, Securidaca longepedunculata, Spirostachys africana, Stylochaeton natalensis and Zanthoxylum capense were the most widely used and preferred species for treatment of rhinitis and/or related symptom by all questioned THs.

CONCLUSION

This study is the first to document plants used traditionally to treat rhinitis in Africa. Therefore, it provides a baseline data on the plants used to heal rhinitis in the Limpopo Province. Finding of this study can be used as apedestal for further investigation in to effective plant-based anti-rhinitis drugs.

Qingfeijianpi therapy for persistent allergic rhinitis: A randomized, positive-controlled clinical trial

This study aims to investigate the effectiveness and safety of Qingfeijianpi therapy for persistent allergic rhinitis (AR).A total of 101 patients with persistent AR were included into the study. These patients were randomly divided into 2 groups: treatment group, in which patients were given Qingfeijianpi decoction (1 dose/day for 4 weeks); control group, in which patients were given an oral dose of loratadine (tablet, 10 mg/time, once per day for 4 weeks). A total of 96 patients completed the 16-week course of treatment. The nasal symptom and traditional Chinese medicine syndrome were scored to evaluate symptom improvement, and the Rhinoconjunctivitis Quality of Life Questionnaire was used to assess the quality of life of patients. Furthermore, the 4-week clinical treatment effect and 16-week follow up were evaluated.After the 4-week treatment, the mean difference in symptom score in the treatment group was similar to that in the control group. However, during the follow-up, the decrease in symptom score was better with the Qingfeijianpi therapy than with loratadine.Compared to loratadine, the Qingfeijianpi decoction exhibited a significant benefit in symptom improvement of persistent AR.

Asthma prevalence and severity in low-resource communities

PURPOSE OF REVIEW

The prevalence of asthma was thought to be low in most low-income countries, but several reports have indicated this is not always true. This is a narrative review of recent publications on the burden of asthma in low and middle-income countries (LMIC) and underprivileged communities from developed countries.

RECENT FINDINGS

Several studies have reported a low prevalence of asthma is LMIC, but indicate it is increasing. In the last few years, however, many surveys demonstrated this may not always be true. An analysis of the International Study for Asthma and Allergy in Childhood phase III database indicated although the prevalence of asthma among children and adolescents is higher in the developed countries, symptoms of asthma are often more severe in less affluent nations. The rate of uncontrolled asthma is also higher among underprivileged communities of developed countries. Secondary analysis of data generated by the WHO's world health survey performed among adults of 70 countries indicate symptoms of asthma are less frequent in middle-income countries and more frequent in the extremes, low income and high income. This sort of U shaped distribution suggests the disease (or syndrome) comprise more than one major phenotype related to diverse underlying mechanisms. In fact, recent reports show symptoms of asthma among the poor are associated with unhygienic living conditions, which may reduce the risk of atopy but increase the risk of nonatopic wheezing. Urbanization and exposure to air pollution also seem to contribute to an increasing prevalence severity of asthma in LMIC. Access to proper diagnosis and treatment with controller medications for asthma, specially with inhaled corticosteroids is feasible and cost-effective, reduce symptoms, health resource utilization, improves quality of life, and reduce mortality in low-resource settings.

SUMMARY

Prevalence of asthma was thought to be low in low-income countries, but several reports have indicated this is not always true. Under diagnosis, under treatment, exposure to air pollution, and unhygienic living conditions may contribute to a higher frequency and severity of symptoms of asthma among the poor. Proper diagnosis and treatment with controller medications for asthma is feasible and cost-effective in low-resource settings.

Peak nasal inspiratory flow as outcome for provocation studies in allergen exposure chambers: a GA2LEN study

Background

The GA²LEN chamber has been developed as a novel mobile allergen exposure chamber (AEC) allowing standardized multicenter trials in allergy. Hitherto, subjective nasal symptom scores have been the most often used outcome parameter, but in standardized modern trials objective parameters are preferred. Despite its practicability, the objective parameter peak nasal inspiratory flow (PNIF) has been rarely used for allergy trials in the setting of allergen exposure chambers. This study aims to evaluate PNIF as an outcome parameter for provocation studies in AECs.

Methods

In a randomized controlled blinded setting subjects suffering from allergic rhinitis were exposed to grass pollen, birch pollen, house dust mite and/or placebo in the GA²LEN chamber. Different allergen concentrations were used to evaluate symptom severities. Patients had to perform PNIF before and every 30 min during a challenge using a portable PNIF meter.

Results

86 subjects participated in 203 challenges, altogether. House dust mite provocations caused the greatest reduction in PNIF values, followed by grass pollen and birch pollen. Provocations with every allergen or pollen concentration led to a significant decrease (p < 0.05) in PNIF compared to baseline. Furthermore, positive correlations were obtained between PNIF and peak expiratory flow, height and weight, and inverse correlations between PNIF and total nasal symptom score, nasal congestion score and visual analog scale of overall subjective symptoms.

Conclusion

PNIF is a helpful and feasible tool for conducting provocation trials with allergens, especially grass pollen and house dust mite, in an AEC.

Electronic supplementary material

The online version of this article (doi:10.1186/s13601-017-0169-4) contains supplementary material, which is available to authorized users.

Symptoms of allergic rhinitis in Parakou, Benin: Prevalence, severity and associated factors

AIMS

Allergic rhinitis (AR) is an extremely common disease. This study aimed to determine the prevalence and severity of AR symptoms and potential associated factors, in Parakou, a city in Benin.

MATERIALS AND METHODS

A cross-sectional study was conducted between April and July 2016, involving inhabitants of the city aged between 6 and 65 years. Cluster sampling was carried out. AR symptoms were defined as the simultaneous presence of rhinorrhea, nasal obstruction and sneezing without evidence of respiratory infection. Data were analyzed on EpiData Analysis v2.2.2.183 and then on R.3.2.1.

RESULTS

Three hundred and ninety-five inhabitants were questioned, with a male/female ratio of 1.32, and median age of 19 years. One hundred and forty-one (35.7%) had AR symptoms, 47 (33.3%) had family history of atopy, and 87 (61.7%) had allergic conjunctivitis. The main triggers were house dust (139; 98.5%) and air pollution (111; 78.7%). On multivariate analysis, associated factors were age<18 years (P<0.05), exposure to house dust (P<0.001), and personal history of urticaria (P<0.001) or allergic conjunctivitis (P<0.01). Twenty-eight subjects (19.9%) had persistent symptoms. Forty-three (30.5%) had moderate/severe symptoms, associated with age≥18 years (P<0.01), family history of atopy (P<0.01), personal history of atopic eczema/dermatitis (P<0.01), and presence of a dog or cat at home (P=0.01).

CONCLUSION

The prevalence of AR symptoms in Parakou was high. A non-negligible proportion of symptoms were severe. This disease merits special attention in the city.

Prevalence and determinants of asthma in adults in Kinshasa

BACKGROUND

Epidemiological data on asthma among adults in sub-Saharan Africa are sparse.

OBJECTIVE

To determine the prevalence of and factors associated with asthma among adults in Kinshasa.

METHODS

A previously validated asthma questionnaire was administered to an adult population aged ≥18 years in urban and peri-urban suburbs of Kinshasa. A random stratified multi-stage sampling plan was used to select the study participants. Logistic regression was used to identify factors associated with asthma.

RESULTS

The mean age of respondents was 36.7 (SD 15.36) years, 75% lived in an urban environment, and 57% were women. The prevalence of asthma-ever was 6.9% (95% CI: 5.4-8.4). Among asthmatic patients, intermittent asthma was estimated at 75.7% and severe asthma at 9.3%. Family atopy (OR: 3.97; 95% CI: 2.42-6.50; p<0.001), and the presence of a cat in the house (OR: 1.82; 95% CI: 1.01-3.28; p = 0.045) were associated with self-reported asthma.

CONCLUSION

Asthma is relatively frequent in adults in Kinshasa, a prevalence similar to those reported elsewhere in Africa. Family atopy and the presence of a cat in the house could be the most common determinants to be confirmed with national survey in order to design guidelines for the control of asthma.

Self-Reported Allergic Rhinitis and/or Allergic Conjunctivitis Associate with IL13 rs20541 Polymorphism in Finnish Adult Asthma Patients

BACKGROUND

Our aim was to observe factors associated with IL13 rs20541 polymorphism and other factors with or without allergic comorbidities such as subject-reported allergic rhinitis (AR) and/or allergic conjunctivitis (AC) symptoms in adult asthmatics.

METHODS

A population-based sample of Finnish adult asthma patients (n = 1,156) and matched controls (n = 1,792) filled in a questionnaire. Asthma was diagnosed based on a typical history of asthma symptoms and lung function tests. Skin prick tests with 17 aeroallergens and blood tests including analysis of interleukin 13 (IL13) rs20541 (G/A) genotypes were performed for a subsample (n = 193).

RESULTS

The proportion of asthmatics reporting AR was 61.9% and reporting AC was 40.7%. After adjustments, the presence of the IL13 rs20541A- allele (OR 3.06, 95% CI 1.42-6.58, p = 0.004) or multisensitization (adjusted OR 4.59, 95% CI 1.48-14.26, p = 0.008) was associated with AR/AC asthma. Nasal polyps and acetylsalicylic acid-exacerbated respiratory disease was also associated with AR/AC asthma.

CONCLUSIONS

Adult AR/AC asthma could putatively be a phenotype, characterized by the presence of atopic and/or eosinophilic factors and a high prevalence of the IL13 rs20541A- allele. Studies on the mechanisms behind this and in other populations are needed.

Determinants of Restrictive Spirometric Pattern in a Sub-Saharan Urban Setting: A Cross-sectional Population-based Study

Background

Restrictive spirometric pattern is a risk factor for all-cause and cause-specific mortality.

Objective

We assessed the prevalence of restrictive pattern and investigated its determinants in a major sub-Saharan Africa city.

Methods

Participants were adults (≥ 19 years) who took part in a population-based survey in Yaounde (Cameroon) between December 2013 and April 2014. Restrictive pattern was based on a FVC below the lower limit of the normal (LLN) and a ratio forced expiratory volume in one second (FEV1)/FVC ≥ LLN (LLN-based restrictive pattern) or a FVC <80% and FEV1/FVC ≥ LLN (fixed cut-off based restrictive pattern). Determinants were investigated by logistic regressions.

Results

In all, 1003 participants [514 (51.2%) women] with a mean age of 33.7 years were included. The prevalence of restrictive pattern was 18.8% (95%CI: 16.6-21.2) based on LLN and 15.0% (13.0-17.2) based on fixed cut-off. LLN-based restrictive pattern was mild in 148 (78.3%) subjects, moderate in 35 (18.5%) and severe in 6 (3.2%). Determinants of LLN-based restrictive pattern were age ≥ 60 years [adjusted odds ratio 2.90 (95%CI 1.46-5.77), p=0.002), history of pulmonary tuberculosis [3.81(1.42-10.20), p=0.008], prevalent heart diseases [3.81 (1.20-12.12), p=0.024] and underweight [5.15(1.30-20.39), p=0.020]. Determinants were largely similar with slightly different effect sizes for fixed cut-off based restrictive pattern.

Conclusion

Restrictive pattern was very frequent in this city.

Clinical implications

These results enhance the needs to increase the efforts to prevent and control tuberculosis, cardiovascular diseases and underweight in this setting.

Urbanisation but not biomass fuel smoke exposure is associated with asthma prevalence in four resource-limited settings

BACKGROUND

Urbanisation is an important contributor to the prevalence of asthma worldwide, and the burden of this effect in low-income and middle-income countries undergoing rapid industrialisation appears to be growing. We sought to characterise adult asthma prevalence across four geographically diverse settings in Peru and identify both individual and environmental risk factors associated with adult asthma.

METHODS

We collected sociodemographics, clinical history and spirometry in adults aged ≥35 years. We defined asthma as meeting one of the three criteria: physician diagnosis, self-report of wheezing attack or use of asthma medications. We used multivariable logistic regression to assess individual and environmental factors associated with adult asthma.

RESULTS

We analysed data from 2953 participants (mean age 55 years; 49% male). Overall asthma prevalence was 7.1%, which varied with urbanisation: highest in Lima (14.5%), followed by urban Puno (4.0%), semiurban Tumbes (3.8%) and rural Puno (1.8%). In multivariable analysis, being male (OR=0.60, 95% CI 0.39 to 0.93) and living at high altitude (OR=0.26, 95% CI 0.16 to 0.42) were associated with lower odds of having asthma, whereas living in an urban setting (OR=4.72, 95% CI 3.15 to 7.23) and family history of asthma (OR=1.83, 95% CI 1.19 to 2.73) were associated with higher odds. Current daily exposure to biomass fuel smoke (OR=1.18, 95% CI 0.70 to 1.91) and smoking (OR=0.99, 95% CI 0.73 to 1.22) were not associated with asthma.

CONCLUSIONS

These findings confirm that urbanisation is an environmental risk factor of asthma, questions biomass fuel smoke exposure as an important risk factor and proposes high altitude as possibly protective against the development of asthma.