Cord Blood Leptin of Newborns with Normal Intrauterine Growth in 30-42 Weeks of Gestation. |
Sun Young Kim, Byung Kyu Suh |
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Abstract |
PURPOSE To evaluate leptin values in placental cord blood of newborns with normal intruterine growth after 30 weeks of gestation and to study the relationship of leptin with gestational age, birth size, ponderal index, BMI, placental weight, gender difference, Insulin-like Growth Factor-I(IGF-I) and Insulin-like Growth Factor binding protein-3(IGFBP-3).
METHODS: Ninety healthy newborns(49 males and 41 females) with normal intrauterine growth were studied. They were classified into 4 groups according to the gestational age(GA):group I(30-33 weeks GA, n=17), group II(34-36 weeks GA, n= 24), group III(37-39 weeks GA, n=32) and group IV(40-42 weeks GA, n=17). At the time of delivery, newborn infant' weight, length, head circumference and placental weight were measured and BMI, ponderal index were calculated. A venous cord blood sample was collected at the time of delivery and serum leptin(RIA), IGF-I (IRMA) and IGFBP-3(IRMA) were measured.
RESULTS Cord blood leptin correlated positively with gestational age(r=0.730, P>0.01), body weight(r=0.686, P<0.01), length(r=0.419, P<0.01), head circumference(r= 0.498, P<0.01), BMI(r=0.750, P<0.01), ponderal index(r=0.704, P<0.01), placental weight(r=0.536, P<0.01), IGF-I(r=307, P<0.01) and IGFBP-3(r=0.736, P<0.01). Multiple linear regression analysis showed BMI, IGFBP-3 and sex(female) were independent predictors of leptin values.
Leptin values increased progressively throughout gestation.
Mean leptin values of group II(3.90+/-.28ng/mL) were significantly higher (P<0.01) than those of group I(1.92+/-.09ng/mL) and also values of group III(5.37+/-.52ng/mL) were higher than those of group II(P<0.05). But there was no significant difference between group III and group IV(6.45+/-.36ng/mL). Mean leptin values in females(5.07+/-.54ng/mL, n=41) were significantly higher than in males(4.07+/-.76 ng/mL, n=49) but there was no inter-gender difference in body weight, BMI, ponderal index, IGF-I, IGFBP-3. In addition, mean leptin values in females(7.45+/-.07 ng/mL) were significantly higher than in males(5.02+/-.09ng/mL) after 40 weeks of gestation.
CONCLUSION BMI, IGFBP-3 and sex(female) were independent predictors of leptin values. Leptin values increased significantly after 34 weeks of gestation and females had higher leptin values than males, especially in fullterm newborns. Leptin values in newborns had higher correlations with IGFBP-3 than with IGF-I as gestational age increased. |
Keywords:
Leptin;IGF-I;IGFBP-3 |
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