Association of serum adiponectin with asthma and pulmonary function in the Japanese population

Conflicting findings have been reported regarding the role of adiponectin in asthma. The aim of this study was to evaluate the association of adiponectin with pulmonary functions and asthma in the Japanese population. First, among a general population that participated in a previous study (group 1), we selected 329 subjects after excluding those with asthma, chronic obstructive pulmonary disease, and a smoking history and examined the associations of the serum total adiponectin levels with pulmonary functions. In a second cohort (group 2) consisting of 61 asthmatic patients and 175 control non-asthmatic subjects, we examined the associations between asthma and the levels of total, high (HMW), middle (MMW) and low (LMW) molecular weight adiponectin isoforms as well as the ratio of each isoform to total adiponectin level. Although the total adiponectin levels were not significantly different between the asthmatic and control subjects in group 2, the levels were significantly and positively associated with the forced expiratory volume in 1 s after adjustments for confounding factors (P < 0.05) in women in group 1. In group 2, the LMW adiponectin level was significantly higher and the MMW/total adiponectin ratio was significantly lower among the asthmatic subjects than among the control subjects after adjustments for confounding factors in both sexes (P < 0.05). The present study showed that a low total adiponectin level may lead to airway narrowing compatible with asthmatic airways in women, and higher LMW adiponectin levels and lower MMW/total adiponectin ratio are significantly associated with current asthma in both sexes.