The concentration of adiponectin in breast milk is related to maternal hormonal and inflammatory status during 6 months of lactation

Background: Varying concentrations of adiponectin are present in human breast milk. This study aimed to determine the relationship between milk adiponectin concentration and the hormonal and inflammatory status of breast-feeding women. Methods: Blood and breast milk samples were collected from 157 breast-feeding women enrolled at 1-180 post-partum lactation days. The milk and serum adiponectin concentrations were measured by radioimmunoassays. The serum oestradiol, prolactin, thyroxine, triiodothyronine, cortisol and insulin concentrations were measured by the chemiluminescent immunometric method. The leptin, resistin and ghrelin concentrations were measured by the immunometric methods. Results: The milk, but not serum, adiponectin concentration increased during the 180-day lactation period and displayed a positive correlation (r=0.748; p<0.001) to the lactation day. The milk adiponectin concentration was positively correlated to the maternal serum ghrelin concentration (r=0.299; p<0.001) and inversely to the maternal serum oestradiol (r=-0.366; p<0.001), prolactin (r=-0.444; p<0.001), thyroxine (r=-0.355; p<0.001), triiodothyronine (r=-0.291; p<0.001), cortisol (r=-0.537; p<0.001), and C-reactive protein (r=-0.483; p<0.001) concentrations. The milk adiponectin concentration was positively correlated to the milk leptin (r=0.344; p<0.001) and ghrelin (r=0.458; p<0.001) concentrations, and inversely to milk resistin concentration (r=-0.518; p<0.001). The serum adiponectin concentration in breastfed infants was positively correlated (r=0.711; p<0.001) to the adiponectin concentration in the consumed breast milk. Conclusions: The adiponectin concentration in breast milk increases over time during lactation and is affected by the maternal hormonal and inflammatory status.