[Analysis of correlative factors of serum leptin levels in asthmatic patients]

Objective: To analysis the correlative factors that probably affect serum leptin levels in asthmatic patients. Methods: Seventy-eight patients with asthma and 29 health controls who were admitted into outpatient clinic of Peking University Third Hospital from April 2014 to December 2015 were consecutively enrolled in our study prospectively. Serum leptin level was measured by enzyme-linked immunosorbent assay (ELISA). The sex, body mass index (BMI), onset age of asthma, allergen detection test, induced sputum cell count and classification, lung function test and asthma control level were recorded. Asthmatic patients were further divided into groups according to these factors and serum leptin levels were compared among groups. Results: Serum leptin levels were not different between asthmatic patients and health controls [(15.0±10.4) vs (15.2±11.7) μg/L, P=0.939]. Female asthmatic patients had significantly higher serum leptin levels than male [(18.2±10.7) vs (7.9±4.8) μg/L, P<0.001]. Asthmatic patients with obesity had significantly higher serum leptin levels than asthmatic patients with overweight, with normal BMI, with underweight and health controls [(29.7±10.8) vs (17.1±11.1), (11.8±7.7), (9.1±0.96), (15.2±11.7) μg/L, all P<0.01]. Serum leptin level was positively related to percentage of induced sputum eosinophil in female asthmatic patients (r=0.331, P=0.032). Onset age of asthma, positive allergen detection, airflow limitation or asthma control level did not affect serum leptin level. Conclusion: Sex and BMI are important factors affecting serum leptin levels in patients with asthma.