Breast Milk Adiponectin Level And Its Relationship With The Mother And Child

Adiponectin is an adipose-derived peptide, which plays an important role in glycometabolism and lipid metabolism. Adiponectin is found in the human milk recently, but studies on the secretion of adiponectin in the human milk and its influencing factors are limited. Thus, we observed adiponectin levels in breast milk during lactation and explored the impact of maternal characters, including pregnant age, procedure, body mass index (BMI), metabolism and serum adiponectin concentrations on the levels of breast milk adiponectin. Moreover, we analyzed correlation between breast milk adiponectin and infantile body growth or metabolism.PartⅠ. Adiponectin concentrations in human milk and its correlations to mothers and infants.Objective To investigate the adiponectin level in human milk during the lactation and to explore the correlations between milk adiponectin levels and mothers or infants.Methods Healthy lactant mothers and their infants were included in this study. The clinical data, including their gestational age, gestational weeks, anthropometrics of mother and infants were investigated. The maternal blood and umbilical blood were collected from the mothers and infants. Colostrum (n=60) and mature milk (n=35) were collected from mother during early, mid and later lactation. The concentrations of adiponectin in serum and milk were determined by enzyme linked immunosorbent assay (ELISA); blood sugar was measured by the glucose oxidase method (GOD); insulin concentrations was determined by radioimmunoassay (RIA) and blood lipids were measured by autobiochemical equipment; mRNA expression of adiponectin in adipose tissue, mammary gland tissue, breast milk cells and placenta were measured with Real-time PCR.Results There was higher concentration of adiponectin in colostrums (27.9μg/L, 5.7～367.1μg/L) compared to that in mature milk (10.9μg/L, 3.0～179.6μg/L) (p＜0.001). The mRNA level of adiponectin was expressed abundantly in the maternal subcutaneous and omental adipose tissue, and weakly in mammary gland tissue, breast milk cells and placenta. The levels of colostrums adiponectin were borderline significantly correlated to the maternal body mass index (BMI) in late trimester of pregnancy (r=0.33, p=0.07), whereas the levels of adiponectin in mature milk were significant correlated to the maternal body mass index (BMI)in the periods of lactation (r=0.41, p＜0.05). Furthermore, the levels of colostrums adiponectin were significantly positive correlated to maternal serum adiponectin concentrations (r=0.53, P＜0.01), but were unrelated to the pregnant age, gestational weeks. Adiponectin concentrations in colostrums correlated positively with the levels of glucose (r=0.52, p＜0.01) and the levels of insulin (r=0.53, p＜0.01 ) in the umbilical blood but not in the maternal blood.Conclusions Adiponectin presents abundantly in colostrums and decreases in mature milk. Adiponectin in milk is correlated positively with serum adiponectin levels and BMI of mothers. Given the persistence of adiponectin in human milk, it may play a potential role in infantile metabolic development.PartⅡ: The implications of gestational diabetes mellitus and pregnancy-induced hypertension syndrome for the breast milkadiponectin levels.Objective To observe the breast milk adiponectin concentrations in the gestational diabetes mellitus (GDM), pregnancy-induced hypertension (PIH)Methods The maternal blood, umbilical blood and breast milk of third day after delivery were obtained from GDM (n=13) , PIH (n=17) and controls (n=28). Maternal subcutaneous and omental adipose tissue were collected during the abdominal delivery. Adiponectin concentrations were determined by ELISA, adiponectin mRNA level was measured by real-time PCR. Blood glucose, insulin and blood lipids (total cholesterol, TC; triglyride, TG; lipid A, LPa; high density lipoprotein -cholesterol, HDL-C; low density lipoprotein-cholesterol, LDL-C) were determined.Results There was no significance difference in adiponectin levels among control group (37.3 (14.8～82.6)μg/L), GDM (45.9 (15.7～77.7)μg/L) and PIH group (70.0 (33.5～229.9)μg/L). Maternal blood adiponectin level in GDM was similar to the control group (6.9±3.4mg /L vs 6.1±3.0mg /L, p＞0.05), while in PIH group, the maternal serum adiponectin level were much higher than that of controls (11.2±6.5mg/L vs 6.1±3.0mg/L, p＜0.01). The level of umbilical blood adiponectin were much lower in both of the GDM (GDM: 21.7±14.2mg/L) and PIH group (18.9±6.6mg/L )than that in control(30.8±13.8mg/L, p＜0.05). There was lower adiponectin mRNA expressions in the subcutaneous adipose tissue in the GDM group (0.16(0.09～0.24 ), p＜0.05) compared to control group (0.42 (0.17～0.69)), whereas there was no significance difference in adiponectin mRNA level between PIH and control group in both subcutaneous and omental adipose tissue. Moreover, human milk adiponectin levels correlated positively with the maternal blood (r=0.38, p＜0.05). The maternal blood adiponectin levels correlated negatively with the maternal age (r=-0.26, p＜0.05). The levels of adiponectin in the umbilical blood correlated negatively with the umbilical blood TC (r=-0.35, p＜0.05) andLDL-C (r=-0.46, p＜0.05)Conclusions The adiponectin concentrations are changed in the GDM and PIH. Adiponectin levels in mother are normal or increased, while their levels in umbilical blood decreased significantly. Adiponectin levels in breast milk maintained invariably. The milk adiponectin may play an important role in the infantile metabolic development for a short time or a long time, especially in the high risk infants.