Obesity and Its Relationship with Asthma Prevalence and Severity in Adolescents from Southern Brazil

Abstract

Obesity has been pointed out as a risk factor for higher prevalence of asthma and asthma-related symptoms in adolescents. The objective was to evaluate the relationship between the prevalence of asthma and obesity in adolescents living in Santa Maria and surroundings (state of Rio Grande do Sul, southern Brazil), applying the International Study of Asthma and Allergies in Childhood (ISAAC) protocol. A total of 4,010 of 6,123 schoolchildren, 13 to 14 years of age, enrolled in the ISAAC phase III protocol (asthma core questionnaire) and were nutritionally evaluated: height, weight, and triceps skinfold (TSF) measurements. Prevalence of asthma (wheeze in the last 12 months) and prevalence of severe asthma (two or more affirmative responses to: more than 4 acute attacks of asthma, speech disturbance, sleep disturbance, wheezing with exercise) were evaluated and compared according to their nutritional status: obese and non-obese. Obese adolescents were defined by body mass index (BMI, in kg/m(2)) > or =85th percentile and TSF > or =85th percentile. Obese and non-obese groups were compared for prevalence of asthma and asthma severity using the Chi-square test and odds ratio (OR) with 95% confidence interval. Analyzing all adolescents, we observed a significant positive relationship between the prevalence of obesity and affirmative responses to "wheeze ever" (OR = 1.28; 95% CI 1.08-1.52), "wheezing with exercise" (OR = 1.36; 95% CI 1.11-1.66), "asthma ever" (OR = 1.29; 95% CI 1.03-1.62), and severe asthma (OR = 1.55; 95% CI 1.12-2.14). Among the boys, there was a significant positive association between obesity and "wheeze ever" (OR = 1.49; 95% CI 1.13-1.86). In girls, there was a significant positive relationship with "asthma ever" (OR = 1.38; 95% CI 1.01-1.88) and "wheezing with exercise" (OR = 1.36; 95% CI 1.11-1.66). This cross-sectional study with adolescents living in the southern region of Brazil showed that there is a positive association between obesity and prevalence of asthma symptoms and asthma severity, a finding mainly confined to girls.

Frequency and Correlates of Overweight Status in Adolescent Asthma

“…These findings are consistent with other published studies documenting an overlap between asthma and overweight status (39,40), including similar casecontrol designs (41). Interestingly, disproportionately higher rates of overweight status were found consistently across males and females, while others have found sex differences in the relationship between asthma and obesity across different ages (42,43). Moreover, this is one of the first studies to report differences in obesity rates in a matched cohort design controlling for key demographic variables, such as sex, age, and racial/ethnic background.…”

Association of obesity with chronic disease and musculoskeletal factors

“…Cassol et al, 12 on the other hand, found a positive association between obesity and the prevalence of asthma in 4,010 adolescents in southern Brazil. Vlaski et al 16 found that being overweight was significantly associated with an increased risk of having asthma (OR: 2.36, 95% CI: 1.02-5.44, p=0.04).…”

“…9 In addition, several studies have assessed the possibility of obesity increasing the risk for development of asthma and other obstructive respiratory diseases. [10][11][12][13][14][15][16] The possible mechanisms for this relationship include airway inflammation, produced by substances in adipose tissue, hormonal influences and changes in physical activity. 10 Obesity can also cause changes in lung function, leading to restrictive respiratory disorders caused by parenchymal lung disease or disorders of the chest wall.…”

The effect of obesity on asthma in children

“…Obezitenin astım üzerine etkisini değerlendiren çalış-malarda, önceleri daha çok astım şiddeti araştırılmış-tır (5,6) . Fakat 2007'deki National Asthma Education and Prevention Program (NAEPP) klavuzunda, AKT'nin astımlı hastaların uzun dönem izleminde şiddettin yerine kullanılması önerilmiştir.…”

“…'deki zorlu ekspirasyon volümü (FEV1) ve zorlu vital kapasite (FVC)'de azalma, kronik inflamasyona neden olması (adipokinlerden leptin düzeylerinde artma, adiponektin düzeylerinde azalma, oksidatif streste artma), etiyolojideki epigenetik ve genetik benzerlikler, hormonal değişiklikler (progesteron azalması ve buna bağlı olarak beta-2 reseptör yanıtında azalma), komorbid hastalıklar (obezitenin astımı tetikleyebilen gastroö-zefageal reflü (GER), obsruktif uyku apne sendromu (OUAS), dislipidemi, tip 2 diabetes mellitus ve hipertansiyona neden olması) ve çevresel-davranışsal benzerliklerdir (4) . Öne sürülen tüm bu teorilerle obezite, astım şiddetini ve solunum fonksiyonlarını etkileyebilmektedir (5,6) . Vücut kitle indeksi (VKİ) obezitenin değerlendirilmesinde yaygın olarak kullanıl-maktadır.…”