Risk factors for development of bronchial asthma in children in Delhi

Life Course of Asthma

Asthma is a heterogeneous chronic airway disease that can vary over a lifetime. Although broad categories of asthma by severity and type have been constructed, there remains a tremendous opportunity to discover an approach to managing asthma with additional factors in mind. Many in the field have suggested and are pursuing a novel paradigm shift in how asthma might be better managed, considering the life course of exposures, management priorities, and predicted trajectory of lung function growth. This approach will require a more holistic view of prenatal, postnatal, adolescence, hormonal and gender aspects, and the aging process. In addition, the environment, externally and internally, including in one's genetic code and epigenetic changes, are factors that affect how asthma progresses or becomes more stable in individuals. This chapter focuses on the various influences that may, to differing degrees, affect people with asthma, which can develop at any time in their lives. Shifting the paradigm of thought and strategies for care and advocating for public policies and health delivery that focus on this philosophy is paramount to advance asthma care for all.

Oral health assessment in children aging 8–15 years with bronchial asthma using inhalation medication

Objectives:

Materials and Methods:

Results:

Conclusion:

Risk factors of asthma in the Asian population: a systematic review and meta-analysis

Background and objective

An increasing trend of asthma prevalence was observed in Asia; however, contributions of environmental and host-related risk factors to the development of this disease remain uncertain. This study aimed to perform a systematic review and meta-analysis for asthma-associated risk factors reported in Asia.

Methods

We systematically searched three public databases (Web of Science, PubMed, and Scopus) in Feb 2021. We only included articles that reported environmental and host-related risk factors associated with asthma in the Asian population. Random-effect meta-analyses were conducted for frequently reported asthma-associated risk factors to provide an overall risk estimate of asthma development.

Results

Of 4030 records obtained from public databases, 289 articles were selected for review. The most frequently reported asthma-associated risk factor was the family history of allergy-related conditions. The random-effect asthma risk estimates (pooled odds ratio, OR) were 4.66 (95% confidence interval (CI): 3.73–5.82) for the family history of asthma, 3.50 (95% CI: 2.62–4.67) for the family history of atopy, 3.57 (95% CI: 3.03–4.22) for the family history of any allergic diseases, 1.96 (95% CI: 1.47–2.61) for the family history of allergic rhinitis, and 2.75 (95% CI: 1.12–6.76) for the family history of atopic dermatitis. For housing-related factors, including the presence of mold, mold spots, mold odor, cockroach, water damage, and incense burning, the random-effect pooled OR ranged from 1.43 to 1.73. Other risk factors with significant pooled OR for asthma development included male gender (1.30, 95% CI: 1.23–1.38), cigarette smoke exposure (1.44, 95% CI: 1.30–1.60), cigarette smoking (1.66, 95% CI: 1.44–1.90), body mass index (BMI)–related parameters (pooled OR ranged from 1.06 to 2.02), various types of air pollution (NO₂, PM10, and O₃; pooled OR ranged from 1.03 to 1.22), and pre- and perinatal factors (low birth weight, preterm birth, and cesarean section; pooled OR ranged from 1.14 to 1.32).

Conclusions

The family history of asthma was the most frequently reported risk factor for asthma development in Asia with the highest risk estimate for asthma development. This suggests a major role of the genetic component in asthma pathogenesis. Further study on asthma genetics is required to improve the current understanding of asthma etiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40101-021-00273-x.

Association between air pollution, body mass index, respiratory symptoms, and asthma among adolescent school children living in Delhi, India

Background:

Delhi is one of the most polluted cities in the world with annual average ambient PM₁₀ and PM_2.5 levels exceeding the World Health Organization standards by over 15 fold. We aimed to study the prevalence of respiratory and allergic symptoms and asthma among adolescent children living in Delhi (D) and compare it with children living in lesser polluted cities of Kottayam (K) and Mysore (M) located in Southern India.

Methods:

4361 boys and girls between the age group of 13–14 and 16–17 years from 12 randomly selected private schools from D, K, and M were invited to participate. Modified and expanded International Study for Asthma and Allergies in Children (ISAAC) questionnaires (Q) were filled by the students who also performed spirometry using the ultrasonic flow-sensor-based nDD Spirometer.

Results:

3157 students (50.4% boys) completed the Q and performed good quality spirometry. The prevalence of asthma and airflow obstruction among children living in Delhi was 21.7% using the ISAAC Q and 29.4% on spirometry, respectively. This was accompanied by significantly higher rates of self-reported cough, shortness of breath, chest tightness, sneezing, itchy and watery eyes, itchy skin, and eczema among Delhi children (vs. K-M, all P < 0.05). Delhi children were more overweight and obese (39.8% vs. 16.4%, P < 0.0001), and this was the only risk factor that was strongly associated with asthma (odds ratio [OR]: 1.79; confidence interval: 1.49–2.14), with a more pronounced effect in Delhi children (P = 0.04). Forced expiratory volume₁ and Forced vital capacity values were significantly higher in Delhi children (vs. K-M P < 0.0001). Preserved ratio impaired spirometry was more common in K-M children (P < 0.0001).

Conclusion:

Adolescent children living in the polluted city of Delhi had a high prevalence of asthma, respiratory symptoms, allergic rhinitis, and eczema that was strongly associated with a high body mass index (BMI). Our study suggests an association between air pollution, high BMI, and asthma/allergic diseases, which needs to be explored further.

Exercise-induced bronchoconstriction: prevalence, pathophysiology, patient impact, diagnosis and management

Exercise-induced bronchoconstriction (EIB) can occur in individuals with and without asthma, and is prevalent among athletes of all levels. In patients with asthma, symptoms of EIB significantly increase the proportion reporting feelings of fearfulness, frustration, isolation, depression and embarrassment compared with those without symptoms. EIB can also prevent patients with asthma from participating in exercise and negatively impact their quality of life. Diagnosis of EIB is based on symptoms and spirometry or bronchial provocation tests; owing to low awareness of EIB and lack of simple, standardised diagnostic methods, under-diagnosis and mis-diagnosis of EIB are common. To improve the rates of diagnosis of EIB in primary care, validated and widely accepted symptom-based questionnaires are needed that can accurately replicate the current diagnostic standards (forced expiratory volume in 1 s reductions observed following exercise or bronchoprovocation challenge) in patients with and without asthma. In patients without asthma, EIB can be managed by various non-pharmacological methods and the use of pre-exercise short-acting β2-agonists (SABAs). In patients with asthma, EIB is often associated with poor asthma control but can also occur in individuals who have good control when not exercising. Inhaled corticosteroids are recommended when asthma control is suboptimal; however, pre-exercise SABAs are also widely used and are recommended as the first-line therapy. This review describes the burden, key features, diagnosis and current treatment approaches for EIB in patients with and without asthma and serves as a call to action for family physicians to be aware of EIB and consider it as a potential diagnosis.

Air pollution and public health: the challenges for Delhi, India

Mitigating the impact of pollution on human health worldwide is important to limit the morbidity and mortality arising from exposure to its effect. The level and type of pollutants vary in different urban and rural settings. Here, we explored the extent of air pollution and its impacts on human health in the megacity of Delhi (India) through a review of the published literature. The study aims at describing the extent of air pollution in Delhi, the magnitude of health problems due to air pollution and the risk relationship between air pollution and associated health effects. We found 234 published articles in the PubMed search. The search showed that the extent of air pollution in Delhi has been described by various researchers from about 1986 onwards. We synthesized the findings and discuss them at length with respect to reported values, their possible interpretations and any limitations of the methodology. The chemical composition of ambient air pollution is also discussed. Further, we discuss the magnitude of health problem with respect to chronic obstructive pulmonary diseases (COPD), bronchial asthma and other illnesses. The results of the literature search showed that data has been collected in last 28 years on ambient air quality in Delhi, though it lacks a scientific continuity, consistency of locations and variations in parameters chosen for reporting. As a result, it is difficult to construct a spatiotemporal picture of the air pollution status in Delhi over time. The number of sites from where data have been collected varied widely across studies and methods used for data collection is also non-uniform. Even the parameters studied are varied, as some studies focused on particulate matter ≤10 μm in aerodynamic diameter (PM10) and those ≤2.5 μm in aerodynamic diameter (PM2.5), and others on suspended particulate matter (SPM) and respirable suspended particulate matter (RSPM). Similarly, the locations of data collection have varied widely. Some of the sites were at busy traffic intersections, some on the terraces of offices and residential houses and others in university campuses or airports. As a result, the key question of the extent of pollution and its distribution across various parts of the city could be inferred. None of the studies or a combination of them could present a complete picture of the burden of diseases like COPD, bronchial asthma and other allergic conditions attributable to pollution in Delhi. Neither could it be established what fraction of the burden of the above diseases is attributable to ambient air pollution, given that other factors like tobacco smoke and indoor air pollution are also contributors to the causation of such diseases. In our discussion, we highlight the knowledge gaps and in the conclusion, we suggested what research can be undertaken to fill the these research gaps.

Epidemiology of bronchial asthma in school children (10-16 years) in Srinagar

Objectives:

To assess the epidemiological profile of asthma in school going children in Srinagar, Kashmir.

Study design:

Cross-sectional study.

Setting:

Thirty-one schools with proportionate representation from both government and private schools as well as from primary, middle, and high schools.

Participants:

School children aged 10–16 years with equal representation of sex and all ages.

Main Outcome Measure:

Prevalence of current and past asthma.

Methods and Results:

After administering a modified pretested questionnaire, peak expiratory flow measurement was carried. Children who had asthma-like symptoms or positive family history of asthma or physician-labeled asthma were subjected to spirometry and bronchodilator reversibility. Out of 806 children, bronchial asthma was seen in 60 (prevalence of 7.4%) which included 34 boys and 26 girls. Majority of asthmatic children (78.3% [n = 47]) had probable asthma; 6.7% (n = 4) had definite asthma; and 15% (n = 9) had physician-diagnosed asthma. Majority of children had intermittent asthma (78.3% [n = 47]). Mild persistent asthma was seen in 12.7% (n = 7) and 10% (n = 6) had moderate persistent asthma. None of the children had severe persistent asthma. The prevalence of current asthma was 3.2% (n = 26). On univariate analysis, the factors found to be statistically significant were family history of asthma (odds ratio [OR] =8.174; confidence interval [CI] =4.403–15.178), seasonal cough (OR = 4.266; CI = 2.336–7.791), allergic rhinitis (OR = 2.877; CI = 1.414–5.852), atopic dermatitis (OR = 6.597; CI = 2.72–16.004), and obesity (OR = 6.074; CI = 2.308–18.034). On multivariate analysis, family history, seasonal cough, allergic rhinitis, atopic dermatitis, and obesity were found to be significant independent risk factors.

Conclusions:

Srinagar qualifies as a low prevalence area for bronchial asthma in the age group of 10–16 years. Majority of children had mild intermittent asthma resulting in under diagnosis and wrong treatment.

Prevalence and risk factors for self-reported asthma in an adult Indian population: a cross-sectional survey

BACKGROUND AND METHODS:

We estimated the prevalence of self-reported asthma in adult Indians and examined several risk factors influencing disease prevalence. Analysis is based on 99 574 women and 56 742 men aged 20–49 years included in India’s third National Family Health Survey, 2005–2006. Multiple logistic regression analysis was used to estimate the prevalence odds ratios for asthma, adjusting for various risk factors.

RESULTS:

The prevalence of self-reported asthma was 1.8% (95%CI 1.6–2.0) among men and 1.9% (95%CI 1.8–2.0) among women, with higher rates in rural than in urban areas and marked geographic differences. After adjustment for known asthma risk factors, women were 1.2 times more likely to have asthma than men. Daily/weekly consumption of milk/milk products, green leafy vegetables and fruits were associated with a lower asthma risk, whereas consumption of chicken/meat, a lower body mass index (BMI; <16 kg/m², OR 2.08, 95%CI 1.73–2.50) as well as a higher BMI (>30 kg/m², OR 1.67, 95%CI 1.36–2.06), current tobacco smoking (OR 1.30, 95%CI 1.12–1.50) and ever use of alcohol (OR 1.21, 95%CI 1.05–1.39) were associated with an increased asthma risk.

CONCLUSIONS:

There are wide regional variations in the prevalence of asthma in India. With the exception of the findings for BMI, however, most of the associations of asthma with the risk factors are relatively weak and account for only a small proportion of cases.

Prevalence of asthma in urban school children in Jaipur, Rajasthan

A cross sectional survey of 3321 school going children (5-15 years) using modified ISAAC questionnaire in Jaipur city showed 7.59% children to have asthma (in last 12 months) and 8.4% wheezing in last 12 months. Only 5.3% children had physician diagnosed asthma ever suggesting under diagnoses.

Prevalence of bronchial asthma in rural Indian children: a cross sectional study from South India

OBJECTIVE

To determine the prevalence and to study the socio-demographic correlates of bronchial asthma among children aged 6-15 yr.

METHODS

This is a cross-sectional community based study conducted by interview of parents of randomly selected 559 children using an International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire.

RESULTS

The prevalence of bronchial asthma was found to be 10.3%. The prevalence of asthma was higher among boys (12.1%). There was a significant inverse linear trend with increasing age. A statistically significant association of bronchial asthma with family history of asthma was also observed.

CONCLUSION

There is a high prevalence of bronchial asthma among children with a higher prevalence among boys than girls. There were significant inverse linear association with increasing age and also with family history of asthma. Efforts should be directed towards screening and early detection among the children, especially those of parents with history of asthma to enable treatment and reduce morbidity.

Prevalence of bronchial asthma in Indian children

BACKGROUND

The prevalence of childhood bronchial asthma and allergic disease has increased in developed countries. Studies have identified asthma among Indian children. Still, there is paucity of information on the overall prevalence of childhood asthma in India.

OBJECTIVE

To assess time trends and the overall prevalence rate of bronchial asthma among Indian children.

MATERIALS AND METHODS

Literature search for data sources was done through an extensive search in indexed literatures and website-based population survey reports. Fifteen epidemiological studies were identified on the development of asthma in Indian children from 300 potentially relevant articles. A broad criterion to define both allergic and non-allergic descriptions of asthma in Indian children was formed. Moreover, in the absence of universally accepted criteria by reporting of prevalence by researchers, weighted average data was considered during calculations of prevalence rates, irrespective of the criteria for diagnosis. Statistical analyses used were mean and median.

RESULTS

Wide differences in samples, primary outcome variables, lack of consistency in age category, rural-urban variation, criteria for positive diagnosis, and study instruments confounded the outcome variables. The mean prevalence was 7.24 +/- SD 5.42. The median prevalence was 4.75% [with IQR = 2.65 - 12.35%]. Overall weighted mean prevalence was found to be 2.74. Childhood asthma among children 13 - 14 years of age was lower than the younger children (6 - 7 years of age). Urban and male predominance with wide inter-regional variation in prevalence was observed.

CONCLUSIONS

Our findings indicate that the burden of bronchial asthma in Indian children is higher than was previously understood.

Total serum immunoglobulin E levels in a case-control study in asthmatic/allergic patients, their family members, and healthy subjects from India

BACKGROUND

Total immunoglobulin E (IgE) is an important indicator of allergic disorders. However, its role in allergic patients in India has not been evaluated in relation to atopic status for a reference range as compared with healthy subjects.

OBJECTIVE

The aim of the study was to establish serum IgE levels in a diseased group, study its relationship with atopy, and to compare the same with healthy volunteers in Indian subjects.

METHODS

Four hundred and eighty asthmatics/allergic patients, 100 first-degree relatives of asthmatics, and 120 unrelated normal healthy volunteers from Delhi region were recruited for the study. Atopy was established by family history and skin test to common indigenous allergens and, total and specific IgE measurements. Statistical analysis was performed with the help of SPSS software program.

RESULTS

The mean IgE levels were the highest in asthmatic patients and the lowest in the control healthy group. IgE was significantly high in the male than the female healthy volunteers (P<0.05), but not in the diseased group. Prosopis juliflora among pollen allergens and Alternaria alternata among fungal allergens were important sensitizers in allergic patients with 34.7% and 17.7% skin positivity, respectively. Atopic status and asthma were found to be the best predictor of IgE, which was highly significant (r(2)=0.239, P<0.00001). However, at 95% confidence interval as many as 50% of asthmatic patients had their IgE values in the normal range.

CONCLUSION

The IgE levels in Indian allergic patients is significantly related to atopy, but due to wide overlap of IgE levels in patients and healthy subjects, its diagnostic significance in Indian population seems to be limited.

Risk factors of bronchial hyperresponsiveness in children with wheezing-associated respiratory infection

The objectives of this study were to identify possible risk factors of bronchial hyperesponsiveness (BHR) in children up to 5 years of age with wheezing-associated respiratory infection (WARI), and to study the prevalence of BHR. Children up to 5 years of age with WARI were enrolled in the study. The parents or caregivers of children were asked about their demographic data and clinical histories. Physical examination and clinical score assessment were performed. Pulmonary function tests, i.e., tidal breathing flow volume (TBFV), were performed to measure tidal breathing parameters before and after salbutamol nebulization. If volume at peak tidal expiratory flow/expiratory tidal volume and time to peak expiratory flow/total expiratory time increased > or = 20%, or tidal expiratory flow at 25% of tidal volume/peak tidal expiratory flow increased > or = 20% after nebulization therapy, BHR was diagnosed. The number in the positive BHR group was used to calculate the prevalence of BHR, and clinical features were compared with those of the negative BHR group. Categorical data were analyzed for statistical significance (P < 0.05) by chi-square test or Fisher's exact test, or Student's t-test, as appropriate. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for those with statistical significance. One hundred and six wheezing children underwent pulmonary function tests before and after salbutamol nebulization. With the aforementioned criteria, 41 cases (38.7%) were diagnosed with BHR. History of reactive airway disease, (OR, 6.31; 95% CI, 1.68-25), maternal history of asthma (OR, 3.45; 95% CI, 1.34-9), breastfeeding less than 3 months (OR, 3.18; 95% CI, 1.26-8.12), and passive smoking (OR, 3; 95% CI, 1.15-7.62) were significant risk factors of BHR. The eosinophil count was significantly higher in the BHR (+) group particularly, in children 1-5 years of age (P < or = 0.01). Patchy infiltrates were more commonly found in patients with negative BHR but not statistically significant. In conclusion, a history of reactive airway disease, maternal history, breastfeeding less than 3 months, and passive smoking were significant risk factors for BHR.

Family history as a predictor of asthma risk

Asthma, one of the most important chronic diseases of children, disproportionately affects minority and low-income children. Many environmental risk factors for asthma have been identified, including animal, mite, and other allergens; cigarette smoke; and air pollutants. Genetics also play an important causative role, as indicated by familial aggregation and the identification of candidate genes and chromosomal regions linked to asthma risk. Using a positive family history of asthma to identify children at increased risk could provide a basis for targeted prevention efforts, aimed at reducing exposure to environmental risk factors. To assess the predictive value of family history as an indicator of risk for childhood asthma, we reviewed population-based studies that evaluated family history of asthma and atopic disease in children with asthma. Our search identified 33 studies from all geographic regions of the world for review. The studies varied in definitions of positive family history and asthma phenotype and used study populations with asthma prevalence ranging from 2% to 26%. Nevertheless, family history of asthma in one or more first-degree relatives was consistently identified as a risk factor for asthma. In ten studies, sensitivity and predictive value of a positive family history of asthma could be calculated: sensitivity ranged from 4% to 43%, positive predictive value from 11% to 37%, and negative predictive value from 86% to 97%. Although a positive family history predicts an increased risk of asthma, it identifies a minority of children at risk. Positive family history may have utility in targeting some individual prevention efforts, but the low positive predictive value limits its value as a means to direct environmental remediation efforts.

Indian aerosols: present status

This article presents the status of aerosols in India based on the research activities undertaken during last few decades in this region. Programs, like International Geophysical Year (IGY), Monsoon Experiment (MONEX), Indian Middle Atmospheric Program (IMAP) and recently conducted Indian Ocean Experiment (INDOEX), have thrown new lights on the role of aerosols in global change. INDOEX has proved that the effects of aerosols are no longer confined to the local levels but extend at regional as well as global scales due to occurrence of long range transportation of aerosols from source regions along with wind trajectories. The loading of aerosols in the atmosphere is on rising due to energy intensive activities for developmental processes and other anthropogenic activities. One of the significant observation of INDOEX is the presence of high concentrations of carbonaceous aerosols in the near persistent winter time haze layer over tropical Indian Ocean which have probably been emitted from the burning of fossil-fuels and biofuels in the source region. These have significant bearing on the radiative forcing in the region and, therefore, have potential to alter monsoon and hydrological cycles. In general, the SPM concentrations have been found to be on higher sides in ambient atmosphere in many Indian cities but the NOx concentrations have been found to be on lower side. Even in the haze layer over Indian Ocean and surrounding areas, the NOx concentrations have been reported to be low which is not conducive of O3 formation in the haze/smog layer. The acid rain problem does not seem to exist at the moment in India because of the presence of neutralizing soil dust in the atmosphere. But the high particulate concentrations in most of the cities' atmosphere in India are of concern as it can cause deteriorated health conditions.