Reduced circulating oxytocin and High-Molecular-Weight adiponectin are risk factors for metabolic syndrome

The neurohypophysial hormone, oxytocin, is involved in the regulation of energy metabolism. Adiponectin (APN) is an adipose tissue-specific serum protein that inversely associates with metabolic syndrome (MetS). High-molecular-weight adiponectin (HMW APN) is considered the active form. In the present study, we aimed to determine the relationships of oxytocin and HMW APN to MetS and investigate whether or not the combination of oxytocin and HMW APN is associated with further metabolic abnormalities compared to each of them alone. A total of 170 subjects (75 with MetS and 95 non-MetS) were enrolled. Anthropometric parameters, oral glucose tolerance test (OGTT), blood lipids, hs-CRP, oxytocin and HMW APN levels were measured. Compared with non-MetS subjects, serum oxytocin and HMW APN levels were significantly lower in subjects with MetS (P<0.01). We then classified the subjects into three groups: high oxytocin and high HMW APN levels (high score group), low oxytocin and low HMW APN levels (low score group) and others. Participants in low score group showed the worst metabolic profiles and were more likely to have MetS compared to the other two group. In Spearman rank correlation coefficient, the classification by the combination of oxytocin and HMW APN was significantly correlated with a larger number of metabolic risk factors compared with classification by each of them alone. Individuals with low circulating oxytocin levels coupled with low HMW APN levels were at significantly increased risk of MetS. The combination of both markers would be useful for identifying MetS high risk patients.