Serum leptin and adiponectin levels and their association with allergic sensitization

Background: Obesity and respiratory allergies have increased in parallel in industrialized countries. We have recently shown an association between obesity and allergic sensitization whereby obesity diminished the protective effect of childhood farm contact. Objective: To assess whether taking obesity into account allergic sensitization is associated with adipokine levels in blood and whether this effect is modified by childhood farm contact. Methods: Serum samples of 231 adult participants (age 18-45 years) of the Lower Saxony Lung Study were analysed for leptin and adiponectin by ELISA. Subjects were elected to represent equal-sized groups with respect to obesity (< 30 vs >= 30 kg/m(2)), childhood farm contact, specific IgE to ubiquitous allergens and sex. Multiple logistic regression models were adjusted for potential confounders. Results: Leptin levels were positively related to the prevalence of sensitization (highest vs lowest quartile odds ratio 6.7, 95% confidence interval 2.0-22.4). For adiponectin levels, a weak, not statistically significant inverse association with sensitization was shown (highest vs lowest quartile 0.4, 0.2-1.1). The association between leptin and sensitization appeared to be more pronounced in subjects with farm contact; however, the effect modification was not statistically significant. Conclusion: These findings suggest that adipokines might be involved in the causal pathway between obesity and allergic sensitization.