Study of Body Mass Index and Serum Leptin in Asthmatics

Background: Given the parallel increases in obesity and asthma, it is not surprising that the prevalence and incidence of asthma and its related symptoms and phenotypes have been increasingly associated with Body Mass Index (BMI) and obesity. Aim of Work: The aim of our study is to assess the relation between different grades of body mass index, serum leptin and pulmonary functions (lung volumes and spirometry) in patients with bronchial asthma. Subject and Methods: This study was conducted at Chest and Clinical Pathology Departments, Kasr El-Aini Hospital. This work included 2 groups, 52 asthmatic patients and 10 controls with different grades of body mass index. The 2 groups were subjected to the following: Full history taking, Clinical examination, Chest X-ray, Demographic data acquisition (age, sex, weight, height, BMI=weight/height2, waist to hip calculation), Pulmonary function tests (spirometry and lung volumes) and Serum Leptin. According to BMI the subjects were divided into 3 subgroups: Average, overbuilt and obese. Serum Leptin was measured by DRG leptin (Sandwich) ELISA. The DRG Leptin Enzyme Immunoassay Kit provides materials for the quantitative determination of Leptin in serum and plasma. Results: The number of cases in the obese subgroup were higher than in the other subgroups (average and overweight). Also the number of females was higher than males in each subgroup. There was a statistically significant difference in serum Leptin value between asthmatics and controls being higher in asthmatics (p=0.034). There was also a statistically significant difference in serum leptin value between different subgroups being higher in obese tha average and overweight subgroups. (p=0.002). There was a negative correlation be-tween spirometric parameters, lung volumes and serum leptin being significant concerning FEF 50% (p=0.002). Also, a negative correlation was seen between BMI and lung volumes such as SVC in addition to other spirometric values such as PEF and FEF 25%. Conclusion: Our study was able to emphasize the fact that increased body weight was associated with increased incidence of asthma whether this was due to changes in airway diameter or alternative mechanisms. Serum leptin was always found to be elevated in our asthmatic cases regardless their body weight. The highest levels were found naturally in the obese subgroup.