| Objective: Leptin is a kind of proteohormone that was found in recent years.Leptin is secreted by adipocyte .The main physiological actions of leptin to are inform the central nervous systerm about the state of nutritions, then to restrain appetite ,reduce food intake and increase energy expenditure to regulate body adiposity homeostasis.Study on leptin has become into focal issue in the field of pediatric.Foreign scientists reported that leptin is present in breast milk.Leptin receptor is in gastraintestine.Leptin may be absorbed from breast milk by gastraintestine.Breast-fed infants will gain more outside leptin than formula-fed infants.different serum leptin concentrations maybe involved between breastfed and formula fed infants.Leptin maybe have important modulation on neonatal food intake and energy balance and growth and development.The aim of the study is to observe the dynamic change of serum leptin levels.And measure the leptin concentrations in breast milk and formula milk. And explored difference of serum leptin concentrations in breast-fed and formula-fed neonates and the relationship between leptin and metabolic hormones —insulin(RI), growth hormone(GH), triiodothyroxine (T3), thyroxine (T4), thyoid-stimulating-hormone(TSH). Provide theoretic foundation for leptin in clinic application. Methods: 100 neonates from the First Hospital of Hebei Medical University were selected during 2003 to 2004.Among them there were 66 healthy full term neonates(37males, 29 females;35 breast-feds,31 formula-feds),and 34 preterm neonates (19 males,15 females;18 breast-feds,16 formula-feds).These neonates were consent to be visited.The umbilical venous blood speciman about 5ml were collected immediately after newborns delivered. And at 3th,7th,28th day.Venous blood and breast milk samples about 2ml were drawn in the morning at fasting state. The serum and breast milk samples were stored at -70 ℃until analyzed.Leptin concentrations were measured by IRMA.Formula is nestle lactogen powder. the proportion is 1 spoon powder vs 30ml warter. The temperature is 50 ℃to measure leptin concentrations level.Concentrations of RI and GH and T3 and T4 and TSH were measured by MAIR at the 7th day after birth in two groups. In the morning at fasting state the naked body weight and body length were measured .Then calculateBMI [BMI=body weight( kg)/body length(m2)] to evaluate the neonatal nutrition state. Results: 1.The average cord blood and venous serum leptin concentrations was 10.25±4.31ug/L,1.35±0.89 ug/L,2.84±1.36 ug/L ,5.39±2.64ug/L(F=16.55, p<0.01) for the healthy full term neonates at birth,3th ,7th ,28thday respectively. The average cord blood and venous serum leptin concentrations for the preterms was 4.14±2.18ug/L ,0.49±0.47 ug/L ,1.27±0.52ug/L,2.43±1.04 ug/L(F=26.31,p<0.01) respectively at same time. Neonate serum leptin levels took on dynamic changes. The leptin level at 3th day was lowest.The serum leptin levels in healthy full term neonates were significantly higher than that of preterm infants(t=6.036,t=3.2116, t =3.5566,t =4.1834,p å‡<0.01). There was significantly positive correlation between neonate serum leptin level and BMI(r=0.6680 , p<0.05). There was no significant difference in serum leptin level between males and females (t=0.0940,p0.05). 2.Leptin levels in breast milk of healthy full term neonates was 1.31±0.67ug/ L,1.33±0.04ug/L,1.26±0.98ug/L at 3th ,7th ,28th day after birth respectively. There was no difference between earlier breast milk and later on(eF=1.78, p>0.05.Leptin was not present in formula milk samples. The leptin concentration in formula milk was 0 ug/L.3.The average serum leptin concentration for the breast-fed group was 10.53±4.08 ug/L,2.45±1.04 ug/L,3.38±1.54 ug/L,4.98±2.16 ug/L at birth(cord blood) ,3th day ,7th day ,28th day respectively; The average serum leptin concentration for the formula –fed group was 9.97±3.16 ug/L,1.23±0.67 ug/L,1.91±0.32 ug/L,2.63±1.19ug/ L at birth(cord blood) ,3th day ,7th day ,28th day respectively. Breast-fed neonates serum... |
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