Aim. To study the peripheral blood level of leptin and adiponectin and their possible effect on the functional status of the respiratory system in young asthmatic patients in relation to body mass index (BMI) for the optimization of asthma therapy. Subjects and methods. Examinations were made in 133 people, including a study group of 93 patients with asthma who were divided into 2 groups according to BMI: 1) those with a BMI of less 25 kg/m2 and 2) those with a BMI of 30 kg/m2 or more, as well as a control group of 40 apparently healthy patients. The investigators studied external respiratory function (ERF), the peripheral blood levels of leptin and adiponectin, the biochemical composition of plasma, by determining total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. Results. Lipid metabolic disorders as dyslipidemia and hypercholesterolemia, increased severity of disease, and decreased ERF were recorded in the concomitance of obesity and asthma. The peripheral blood level of leptin in young asthmatic patients with obesity was found to be associated with higher BMI. Conclusion. A more severe course of disease presenting with decreased ERF, impaired lipid metabolism, and elevated peripheral blood leptin levels were noted in the concomitance of asthma and obesity at a young age.