Serum leptin levels depend on allergen exposure in patients with seasonal allergic rhinitis.

Several studies have outlined a possible relationship between an increased body mass index (BMI) and respiratory allergic diseases, such as asthma and rhinitis. There are conflicting data about the role for leptin in allergic rhinitis. Therefore, the aim of the study was to evaluate the serum leptin levels in patients with seasonal allergic rhinitis (SAR), enrolled during and outside the pollen season, and in a group of healthy controls. The study included 137 subjects; 62 symptomatic SAR patients evaluated in season, 41 symptomless SAR patients out season, and 34 normal subjects. All subjects were consecutively evaluated. A skin prick test and blood sampling for assessing serum leptin levels were performed in all subjects. After analysing genders separately, symptomatic male patients had significantly higher levels than symptomless and normal subjects (p = 0.0004 and 0.0031 respectively), symptomatic female patients showed significantly higher levels than normal females (p = 0.0002). This study provides the evidence that leptin serum levels depend on allergen exposure in SAR patients.