Serum Level of Resistin in Asthmatic Children

Introduction Epidemiologic studies suggest that the rates of asthma and obesity are rising concurrently (1,2). Moreover, obesity with severe asthma has resulted in unresponsiveness to drug therapy (2,3). The causes of the link between asthma and obesity are not known clearly, but the possible mechanism is said to include a sedentary lifestyle, nutritional factors, genetics, hormonal factors, systemic inflammation and obesity-related declined respiratory capacity, insulin resistance, gastroesophageal reflux, as well as the changes in the immune system by obesityrelated factors such as resistin (3,4). Adipose tissue is an active endocrine organ that generates energy by producing regulatory hormones such as resistin. Macrophage accumulation occurs in obese people and will cause the production of inflammatory cytokines and adiponectin which are associated with not only body mass index (BMI) level but also with obesityrelated diseases including cardiovascular atherosclerosis, type 2 diabetes mellitus, hypertension, and asthma. It was reported in previous studies that resistin is associated with asthma (5, 6). As a 108-amino acid peptide, resistin is part of the cysteine-rich secreted protein family and a possible factor involved in insulin resistance, obesity, and asthma. It has been proposed by various studies as a possible cause of inflammation and allergic responses in atopic asthma (7). Researchers have reported high levels of resistin in patients with atopic asthma (8). In a study by Muc et al, resistin level was high in overweight asthmatic children and there was a direct relationship between serum level of resistin and severity of asthma (9). In another study on the resistin level in schoolchildren with atopic asthma, increased resistin level was reported in these patients (10). It was reported that patients with asthma have higher levels of resistin and resistin levels increase with the severity of asthma (8). Considering that asthma and intermittent asthma attacks impose a heavy mental and financial burden on Abstract Objectives: Asthma and intermittent asthma attacks impose a heavy mental and financial burden on families and serum level of resistin influences the incidence of childhood asthma and response to drug therapies. The purpose of this paper was to assess the serum level of resistin in asthmatic children in the division of pulmonary and respiratory diseases at Tabriz Children’s hospital. Materials and Methods: This study was conducted on 50 subjects in the control group and 50 subjects in the case group (asthmatic and healthy prepubertal children under 12 years old with a normal (BMI) (5-84th percentile); asthmatic and healthy overweight prepubertal children under 12 years old (85-94th percentile); and obese prepubertal children under 12 years old (BMI ≥95) without any other illnesses. The control group was matched to the case group in terms of age and sex and did not have inflammatory, acute and chronic infectious diseases or a history of medication consumption. Venous blood samples were collected from the subjects after 8 hours of fasting. Serum levels of resistin were measured using Elisa. Results: The level of resistin increased with asthma severity. Increased weight and BMI also led to a significant increase in the severity of asthma. The serum levels of resistin were significantly higher in the subjects of the control group who did not receive drug therapy. Response to drug therapy was significantly poorer in tall, heavier and high-BMI subjects than in other groups. The number of cases with severe persistent asthma was greater in formula-fed and breastmilk/formula-fed babies. History of allergy or asthma in first-degree relatives was significantly higher in the case group than in the control group (P = 0.001). Indoor smoking had a significant effect on the type of asthma (P = 0.001). The history of non-asthmatic allergy had a significant effect on the type of asthma (P = 0.001). Conclusions: Obesity and overweight are among the influential factors in the severity of asthma. The amount of resistin is significantly higher in children with severe persistent asthma and uncontrolled asthma than in healthy children. However, the results showed that smoking may also increase serum resistin in at-risk individuals.