Method: We analyzed the baseline database of the Korean Longitudinal Study on Health and Aging (KLoSHA) cohort study, which was conducted during 2005-2006. Atopic status was assessed by skin prick tests for 12 common inhalant allergens. Asthma and rhinitis was defined by structured questionnaires. Body mass index (BMI) and waist circumference (WC) were measured. Metabolic markers included serum adiponectin, retinol-binding proten-4 (RBP-4), cholesterols, C-reactive protein (CRP), vitamin D, fasting glucose levels, HbA1c and insulin resistance (HOMA-IR).
Results: A total of 854 elderly subjects were analyzed, and 17.2% had atopy. Atopy in the elderly had specifically significant associations with lower serum adiponectin (p=0.04), high RBP-4 levels (p=0.003) or RBP-4/adiponectin ratio (p=0.01); however, atopy was not related to other metabolic markers such as BMI, WC, or lipid levels. RBP-4 levels showed significant correlations with triglyceride (p<0.001) and CRP (p=0.001), but not with adiponectin (p=0.191). Both RBP and RBP-4/adiponection had significant associations with atopy, independent of co-variates including age, gender, smoking, log-triglyceride and log-CRP levels. RBP-4 levels also had significant associations with current rhinitis but not with wheeze or cough. However, neither of adiponectin levels or RBP-4/adiponectin ratio had no associations with rhinitis or asthma symptoms.
Conclusion: The present analyses indicate a potential role of metabolic dysregulation in the pathophysiology of atopy in the elderly. In particular, mechanistic roles of RBP-4 warrant further investigations.