Association between serum leptin and anthropometric parameters at birth and at 15th day of life in infants born asymmetrically small for gestational age

The aim of this study was to investigate changes in skinfold measurements taken at three sites, mid-arm circumference and umbilical circumference during the first 15 days of life; and to evaluate relationships between anthropometric measurements and umbilical cord blood serum leptin levels in infants born small for gestational age (SGA) and appropriate for gestational age (AGA) infants. Of 50 newborn infants, 25 were SGA and 25 were AGA. Neonates' weight, mid-arm circumference (MAC), umbilical circumference (UC), and triceps, subscapular and periumbilical skinfold thicknesses were measured (Holtain callipers) immediately after delivery. Anthropometric parameters were measured again at 15th days of age. At birth, mean birth weight, mean skinfold thickness, MAC and UC measurements in the AGA group were significantly higher than those of the SGA group. These differences were also found on the 15th day. Birth weight correlated with all skinfold thicknesses, MAC and UC at birth. Weight at 15th day of life correlated with skinfold thicknesses, MAC and UC at 15th day of life. Cord blood leptin level was significantly lower in the SGA than in the AGA infants. This difference continued on the 15th day. When cord blood leptin level was compared with that of the 15th day, we found that leptin levels in the cord blood were significantly higher. There were significantly positive correlations between leptin levels and birth weight and skinfold thicknesses when the infants were all grouped together. When the newborns were grouped according to birth weight, there were positive correlations between cord blood serum leptin levels and these parameters in the AGA group, but no correlation in the SGA group. At the 15th day of life serum leptin levels correlated with weight, subscapular and triceps skinfold thickness in the AGA group, but only with triceps skinfold thickness in the SGA group.     

Common adipokine features of neonates and centenarians

Adipose tissue seems to be a pivotal organ in the aging process. We investigated whether healthy aging could have its roots in a sound metabolic condition from the first year of life by evaluating leptin and adiponectin levels in neonates [33 adequate for gestational age (AGA) and 29 small for gestational age (SGA)], 48 centenarians, and 50 healthy elderly subjects. At birth, SGA neonates showed lower leptin levels (SGA 0.88 +/- 0.28; AGA 2.22 +/- 0.91 ng/mL; p < 0.05) and comparable adiponectin levels with respect to AGA. At 1 year, SGA showed increased leptin (SGA 1.74 +/- 0.28; AGA 1.31 +/- 0.19 ng/mL) and slightly reduced adiponectin concentrations (SGA 35.51 +/- 2.53; AGA 38.56 +/- 3.18 microg/mL) than AGA. Centenarians showed lower leptin (centenarians 18.71 +/- 3.78; elderly 34.81 +/- 7.27 ng/mL; p < 0.05) and higher adiponectin levels (centenarians 55.63 +/- 7.7; elderly 33.51 +/- 4.1 microg/mL; p < 0.05) than elderly subjects. Centenarians, like AGA infants during the first year of life, show a favorable adipokine profile, suggesting that the metabolic condition at early age could affect the longevity of an individual.     

脑源性神经营养因子与新生儿出生体重的关系

目的：该文通过检测新生儿脐血脑源性神经营养因子（brain-derived neurotrophic factor,BDNF）的水平,探讨BDNF与新生儿出生体重的关系,并对相关因素进行分析。方法：根据出生体重,将51 例足月第1胎健康新生儿分为3 组:①小于胎龄组（SGA）8例;②适于胎龄组（AGA ）31例;③大于胎龄组（LGA）12例。测量新生儿身长、体重及其母亲的身高、体重,并对脐血中BDNF、瘦素（LEP）、胰岛素（INS）、总胆固醇（TC）、甘油三酯（TG）进行检测。结果：SGA组的BDNF明显高于AGA组和大于LGA组,AGA组和LGA组中BDNF没有差异;多元逐步回归分析显示BDNF值与新生儿出生体重、体重指数存在负相关关系。LEP与BDNF不呈相关趋势（P>0.05）,INS与BDNF也不呈相关趋势（P>0.05）。INS 与LEP呈现正相关（P<0.05）。LEP与新生儿体重、产妇体重及其BMI呈正相关,而TC,TG在3组新生儿中差异无显著性。结论：BDNF是新生儿体重的重要影响因素,而且不受LEP,INS的影响。     

Increased energy expenditure and fecal fat excretion do not impair weight gain in small-for-gestational-age preterm infants.

In order to optimize the nutrition of high-risk premature infants beyond the early postnatal period, a more precise knowledge of individual nutritional requirements is needed. We therefore studied the influence of intrauterine growth retardation on energy expenditure and nutrient utilization determined by indirect calorimetry and fecal fat excretion (steatocrit) in nineteen premature infants who were appropriate-for-gestational-age (AGA; mean gestational age 29.9+/-0.3 weeks, mean birth weight 1.30+/-0.05 kg) and thirteen small-for-gestational-age (SGA) premature infants [mean gestational age 32.4+/-0.5 weeks, mean birth weight 1.024+/-0.07 kg (i.e., below the 10th percentile)] during the first and second month of life. All infants were clinically stable during the study period. In nine SGA infants we observed a significantly higher steatocrit compared to twelve AGA infants (29+/-1 vs. 17+/-1% p = 0.0001). SGA infants (n = 12) also showed a slightly (albeit statistically not significantly) higher energy expenditure than AGA infants (n = 15) (58.7+/-1.9 vs. 53.6+/-1.5 kcal/kg per day, p = 0.054). Despite the increased fat excretion and higher energy expenditure, SGA infants gained weight more rapidly during the study period than AGA infants (20+/-1 vs. 17+/-1 g/kg per day, p = 0.026). We conclude that influences of intrauterine growth retardation on energy expenditure and nutrient utilization persist during the first weeks of extrauterine life. However, these metabolic changes do not impair the capability of SGA infants for extrauterine catch-up growth if adequate nutrition is provided.     

Serum adiponectin concentrations in newborn infants in early postnatal life

Serum adiponectin levels were investigated in 28 small-for-gestational-age (SGA) and 34 appropriate-for-gestational-age (AGA) term neonates to examine how fetal growth correlates with adiponectin levels. A blood sample for determination of adiponectin was obtained during the first 24 h of life. The levels of serum adiponectin were significantly higher in all newborn infants than in healthy children (28.7 +/- 17.0 versus 9.3 +/- 6.1 microg/mL; p < 0.01). There was a significant difference in adiponectin levels between SGA and AGA infants (23.2 +/- 14.8 versus 33.2 +/- 17.5 microg/mL; p=0.02). For all of the newborn groups, serum adiponectin levels correlated positively with birth weight (r=0.27, p <0.05) and head circumference (r=0.30, p <0.05). There was no relationship between serum adiponectin levels and gestational age, birth length, blood glucose levels, or blood sampling time after birth. There was no gender difference in adiponectin levels in the entire newborn group (30.0 +/- 19.7 versus 28.0 +/- 15.5 microg/mL, in male and female infants). Our results suggest that hyperadiponectinemia and a positive relationship between the serum levels of adiponectin and birth weight in newborns cannot be explained by the low percentage of body fat alone. Lower adiponectin levels in SGA infants than in AGA infants are unlikely to suggest insulin resistance in intrauterine growth-retarded infants in early postnatal life but may be a predisposing factor in the future development of insulin resistance or type 2 diabetes.     

Changes in circulating levels of adiponectin and leptin in children during the first two years of life

AIM: Adiponectin, leptin and insulin play an important role in the control of growth and glyco-metabolic homeostasis both during pre- and post-natal life. In order to find out markers indicative of post-natal growth, we evaluated circulating levels of these growth factors in full term small for gestational age (SGA) children, during the first 2 years of life, correlating them with the auxological parameters. METHODS: Fourteen SGA (8 males and 6 females) and 16 AGA (appropriate for gestional age) infants (7 males and 9 females) have been included in this study, recording length, weight, body mass index (BMI), adiponectin, leptin and insulin levels at birth. In SGA subjects, these biochemical and clinical parameters have also been evaluated at the first and at the second year of age. RESULTS: AGA and SGA adiponectin and insulin levels at birth did not show statistically significant differences, while leptin concentrations were significantly (P=0.011) lower in SGA children (median 418.49, range 157.68-903.67 pg/mL) in comparison with AGA ones (median 811.71, range 312.50-3085.95 pg/mL). CONCLUSIONS: In conclusion, at birth adiponectin and insulin levels do not differ between AGA and SGA subjects while leptin concentrations are significantly lower in SGA infants and positively correlated to the birthweight.     

Assessment of proportional growth of very low birth weight infants fed banked human milk

Twenty appropriate (mean +/- S.D., gestational age (AGA): 29.9 +/- 1.5 weeks) and 15 small (GA: 34.6 +/- 2.4 weeks) for gestational age (SGA) very low birth weight infants fed banked mature human milk were studied until term for anthropometric parameters: midarm (MAC), chest (CC), head (HC) circumferences, triceps (TSKF) and subscapular (SSKF) skinfold thickness recorded at 15 and 60 s, dynamic skinfold (delta % SKF), muscle (AMA) and fat (AFA) areas, weight and length. In AGA infants, all the parameters at term were significantly lower in extrauterine (EUL) that in intrauterine life (IUL). At term the relative proportion of AFA to total arm area was increased in EUL compared to IUL both in AGA (25.87 +/- 3.8 vs. 23.26 +/- 1.27% respectively, P less than 0.01) and in SGA infants (21.89 +/- 4.63 vs. 18.81 +/- 3.9 respectively, P less than 0.05). SGA infants showed a similar growth in EUL compared to IUL, and a significantly lower AMA and AFA than in AGA infants in EUL. Although HC was in both infants below the 10th centile at term, the ratio weight/HC2 suggests a relative preservation of head growth in EUL compared to IUL (AGA: 20.72 less than 0.87 vs. 22.65 +/- 1.46 respectively, P less than 0.001; SGA; 20.82 +/- 1.16 vs. 21.62 +/- 1.86 respectively, NS). Delta %SKF were negatively correlated with post-conceptional age suggesting a loss of extracellular water in AGA (delta %TSKF: r = -0.287, P less than 0.02) and in SGA infants (delta %TSKF: r = -0.301, P less than 0.02; delta %SSKF: r = -0.316, P less than 0.02). An intrauterine model of discrimination between AGA and SGA infants does not apply to EUL. An equation was established in SGA infants with the best discriminant parameters giving a predictive post-conceptional age: post-conceptual age (PCA) (weeks) = 0.276 HC (cm) + 0.723 CC (cm) - 0.122 MAC (cm) + 0.5 TSKF (mm) + 10.173, (r = 0.867, P less than 0.001) allowing a clear discrimination between AGA and SGA infants. These results suggest that infants show quite different growth patterns between IUL and EUL both for AGA and SGA infants.     

The influence of gestational age, size for dates, and prenatal steroids on cord transferrin levels in newborn infants

Serum transferrin levels assess protein status in older children and adults. To generate standards for its use in newborn infants, we measured umbilical cord serum transferrin levels in 161 appropriate (AGA), 25 large (LGA) and 16 small (SGA) for gestational age infants between 25 and 43 weeks' gestation. We also assessed the effects of intrauterine growth, exposure to prenatal steroids, and presence of pulmonary maturity on neonatal transferrin levels. Cord transferrin levels in AGA infants were significantly correlated with increasing gestational age (r = 0.60; p less than 0.001). Infants born before 37 weeks' gestation had significantly lower transferrin levels, when compared with those born at term (p less than 0.001). LGA infants had significantly higher levels than age-matched AGA infants (253 +/- 75 vs. 214 +/- 53 mg/dl; p less than 0.025). Despite significantly lower mean birth weights (p less than 0.001), SGA infants also had significantly higher levels than gestational age-matched AGA controls (227 +/- 63 vs. 167 +/- 40 mg/dl; p less than 0.005). For infants less than 35 weeks' gestation, neither the 20 preterm infants with exposure to prenatal steroids (maternal betamethasone), nor the 26 infants with pulmonary maturity had significantly elevated transferrin levels, when compared with gestational age-matched control infants. Newborn transferrin levels correlate well with gestational age and are significantly affected by size for dates, but not by a brief course of prenatal steroids or by pulmonary maturity.     

小于胎龄足月新生儿和适于胎龄足月新生儿血清瘦素及胰岛素水平的变化

目的 探讨不同类型足月新生儿血清瘦素及胰岛素水平及其与胎儿宫内生长发育的关系.方法 收集2009年9月-2010年5月在山西省儿童医院新生儿科住院的无严重疾病的88例足月新生儿的临床资料,其中44例小于胎龄儿(SGA),44例适于胎龄儿(AGA),用酶联免疫吸附测定法(ELISA)检测其出生24 h内血清瘦素及胰岛素水平,并分析血清瘦素和胰岛素水平与出生体质量的关系.采用SPSS 17.0软件进行统计学分析.结果 AGA组血清瘦素水平及血清胰岛素水平均高于SGA组(t=-73.624、-11.729,Pa<0.01);血清瘦素水平及血清胰岛素水平与出生体质量均呈正相关(r=0.96、0.91,Pa<0.01);血清瘦素与胰岛素之间也存在正相关(r=0.85,P<0.01).结论 瘦素及胰岛素在一定程度上反映了胎儿宫内生长发育的情况,在调节足月儿的生长代谢中发挥了重要作用.     

脐血脂联素、瘦素水平与胎儿发育的相关性

目的 探讨脐血脂联素、瘦素水平与胎儿生长发育的关系.方法 选择2006年10月至2007年10月在我院产科出生的新生儿86例,根据不同出生体质量分为小于胎龄儿(SGA)组16例,适于胎龄儿(AGA)组41例,大于胎龄儿(LGA)组29例.胎儿娩出后立即断脐留脐血20ml,采用放射免疫分析法测定血清脂联素、瘦素水平,同时检测其血脂水平,测量新生儿生长参数,计算体质量指数(BMI).结果 (1)3组脐血瘦素和脂联素水平差异有统计学意义(P<0.001),LGA组明显高于AGA及SAG组(P<0.01);(2)脐血瘦素水平与体质量、胎龄、头围、身长、足长及胎盘重量呈正相关(P<0.01),脐血脂联素水平与出生体质量、头围、足长、BMI水平呈正相关(P<0.05).(3)脐血瘦素与脂联素水平呈显著正相关(P<0.01).(4)3组血脂水平比较差异无统计学意义;脐血脂联素、瘦素水平与血脂各指标间无明显相关性(P>0.05).结论 瘦素与脂联素在胎儿宫内生长和发育过程中起重要的调节作用.     

Maternal and fetal serum insulin-like growth factor-I (IGF-I) IGF binding protein-3 (IGFBP-3), leptin levels and early postnatal growth in infants born asymmetrically small for gestational age

This study was planned to investigate the relationship between birth weight and insulin-like growth factor-I (IGF-I), IGF binding protein-3 (IGFBP-3), and leptin levels in neonates with normal growth (appropriate for gestational age: AGA) and retarded growth (small for gestational age: SGA); and to evaluate these growth factors' effects in early postnatal growth. All newborns were full-term: gestational age 3,841 weeks. Of 50 neonates, 25 were SGA. IGF-I, IGFBP-3 and leptin levels were measured in maternal serum and venous cord blood at birth and at 15 days of life of neonates using specific RIAs. Maternal serum leptin concentrations were significantly higher than cord blood leptin concentrations (p < 0.001). Maternal serum IGF-I, IGFBP-3 and leptin levels did not show correlations with birth weight. In contrast, there were significantly positive correlations between birth weight and venous cord blood IGF-I, IGFBP-3 and leptin levels (p < 0.001). In the SGA group, the newborns with a slow postnatal growth pattern had lower umbilical cord serum IGF-I levels compared with newborns with a normal growth pattern. A similar result was also found in the AGA group. Similar results were not found for serum leptin and IGFBP-3. In conclusion, cord blood IGF-I, IGFBP-3 and leptin levels play an important role in the regulation of fetal and neonatal growth. It is likely that IGF-I has a more important role than the other factors in early postnatal growth.     

Doppler velocimetry in cerebral vessels of small for gestational age infants.

Using the duplex Doppler system, blood velocity was measured serially at two sites of the anterior cerebral artery (ACA) and in the middle cerebral artery (MCA) during the first 3 days of life, in eight term, small for gestational age (SGA) infants (birthweight, 2179 +/- 230 g; mean +/- S.D.), and 13 term, appropriate for gestational age (AGA) infants (3376 +/- 441 g). All infants in both groups had normal Apgar scores and none manifested signs of respiratory distress. At 1 h post partum, the average MCA mean velocity in the SGA group (25.8 +/- 6.9 cm/s) was higher than that in the AGA group (19.6 +/- 5.7 cm/s), whereas the average values of the two ACA sites did not differ between the groups. A significantly increased value of the average mean velocity as compared to the value at 4 h post partum was reached earlier in the AGA group at all three vessel sites. The pulsatility index (as defined by Gosling) was lower at all vessel sites up to 72 h in the SGA group. Pulse pressure was significantly lower in the SGA group due to increased diastolic blood pressure. We suggest the results imply a state of cerebral vasodilation in the SGA infants and a poor ability to respond with an increased perfusion in the frontal regions supplied by the ACA. Changes in blood pressure and cerebral haemodynamics appear to exist in SGA infants in the absence of postnatal hypoxia which might explain the vulnerability of the growth-retarded infant to perinatal hypoxia.     

脐血脂联素、瘦素水平与胎儿发育的相关性

目的 探讨脐血脂联素、瘦素水平与胎儿生长发育的关系.方法 选择2006年10月至2007年10月在我院产科出生的新生儿86例,根据不同出生体质量分为小于胎龄儿(SGA)组16例,适于胎龄儿(AGA)组41例,大于胎龄儿(LGA)组29例.胎儿娩出后立即断脐留脐血20ml,采用放射免疫分析法测定血清脂联素、瘦素水平,同时检测其血脂水平,测量新生儿生长参数,计算体质量指数(BMI).结果 (1)3组脐血瘦素和脂联素水平差异有统计学意义(P<0.001),LGA组明显高于AGA及SAG组(P<0.01);(2)脐血瘦素水平与体质量、胎龄、头围、身长、足长及胎盘重量呈正相关(P<0.01),脐血脂联素水平与出生体质量、头围、足长、BMI水平呈正相关(P<0.05).(3)脐血瘦素与脂联素水平呈显著正相关(P<0.01).(4)3组血脂水平比较差异无统计学意义;脐血脂联素、瘦素水平与血脂各指标间无明显相关性(P>0.05).结论 瘦素与脂联素在胎儿宫内生长和发育过程中起重要的调节作用.     

脐血脂联素、瘦素水平与胎儿发育的相关性

目的 探讨脐血脂联素、瘦素水平与胎儿生长发育的关系.方法 选择2006年10月至2007年10月在我院产科出生的新生儿86例,根据不同出生体质量分为小于胎龄儿(SGA)组16例,适于胎龄儿(AGA)组41例,大于胎龄儿(LGA)组29例.胎儿娩出后立即断脐留脐血20ml,采用放射免疫分析法测定血清脂联素、瘦素水平,同时检测其血脂水平,测量新生儿生长参数,计算体质量指数(BMI).结果 (1)3组脐血瘦素和脂联素水平差异有统计学意义(P<0.001),LGA组明显高于AGA及SAG组(P<0.01);(2)脐血瘦素水平与体质量、胎龄、头围、身长、足长及胎盘重量呈正相关(P<0.01),脐血脂联素水平与出生体质量、头围、足长、BMI水平呈正相关(P<0.05).(3)脐血瘦素与脂联素水平呈显著正相关(P<0.01).(4)3组血脂水平比较差异无统计学意义;脐血脂联素、瘦素水平与血脂各指标间无明显相关性(P>0.05).结论 瘦素与脂联素在胎儿宫内生长和发育过程中起重要的调节作用.     

Catch-down growth during infancy of children born small (SGA) or appropriate (AGA) for gestational age with short-statured parents

OBJECTIVE: We analyzed postnatal growth in children with familial short stature (FSS) with regard to small (SGA) or appropriate (AGA) for gestational age status at birth. STUDY DESIGN: We studied 96 otherwise healthy short-statured children (58 males; SGA: n = 41, AGA: n = 55). At least one of the parents was short-statured. Cross-sectional data for length/height and weight for the first 4 years of age were collected retrospectively. RESULTS: AGA children had a mean length of 0.09 +/- 1.02 standard deviation score (SDS) at birth, -1.57 +/- 1.16 SDS after 1 year of age, and -2.36 +/- 0.72 SDS after 4 years. SGA children had a mean length of -2.04 +/- 1.06 SDS at birth, -2.70 +/- 1.12 SDS at 1 year of age, and -3.05+/-0.86 SDS at 4 years. The loss of length SDS within the first 2 years of life was greater in AGA than in SGA children. SGA children were significantly shorter than AGA children at all of the study points (p <.001). CONCLUSIONS: Children with an FSS background born AGA show catch-down growth to their lower familial range during the first 2 years of life. SGA children did not catch up to their AGA peers at any time.     

Adequacy of expressed breast milk for early gwoth of preterm infants.

Poor weight gain observed in preterm infants who were fed expressed breast milk compared with those fed a cows'' milk formular prompted a detailed study of early postnatal growth in preterm infants fed these two milks. 68 infants were divided into two categories by gestational age at birth (i) 28-32 weeks (n=28), (ii) 33-36 weeks (n=40). They were randomly allocated to a feed of expressed breast milk or a milk formula (Ostermilk 1). Rates of weight gain, linear growth, and head circumference growth were evaluated over two periods: birth-1 month, 1-2 months. The younger group who were fed breast milk showed slower overall growth rates over the first month than those fed formula. In the second month, and for the older infants over both of the 2-monthly periods, growth rates were similar in the two feeding regimens. It is concluded that expressed breast milk is inadequate for the growth of very immature preterm infants during early postnatal life.     

早产和低出生体重及小于胎龄儿与脑性瘫痪发病的关系

目的 明确早产、低出生体重及小于胎龄儿(SGA)与脑性瘫痪(简称脑瘫)的关联程度。方法 1997年5—7月对江苏省7个市的1～6岁儿童进行了现况普查,共查305263名,并对其胎龄、出生体重及胎龄别出生体重与脑瘫的关系进行了分析。结果 本组儿童共发现脑瘫484例,发生率为1．59‰。早产儿及过期产儿脑瘫发生率相对危险性(RR)分别为足月儿的25．16倍及2．40倍;低出生体重及巨大儿的脑瘫发生率RR分别为正常出生体重儿的19．63倍及1．34倍;SGA及大于胎龄儿(LGA)脑瘫发生率RR为适于胎龄儿(AGA)的4．34倍及0．84倍。先按胎龄别出生体重分层再按胎龄分组,发现各层内早产儿脑瘫发生率均较足月儿高,RR最高AGA层为28．34倍,其次LGA层为21．41倍,最低SGA层为9．29倍,各层内过期产儿脑瘫发生率也较足月儿高,RR最高AGA层为2．63倍,其次SGA层为1．90倍,最低LGA层为1．55倍;先按胎龄分层再按胎龄别出生体重分组发现各层内SGA脑瘫发生率均较AGA高,RR最高足月儿层为4．41倍,其次过期产儿层为3．19倍,最低早产儿层为1．45倍,各层内LGA脑瘫发生率均不比AGA高,除足月儿层相近为0．98倍外,早产儿及过期产儿层均较AGA低,RR分别为0．74倍和0．58倍。按胎龄大小及胎龄别出生体重大小联合分成9组进行比较,发现多数组脑瘫发生率均较足月AGA组高,RR按次序为早产SGA40．99倍、早产AGA28．34倍、早产LGA21．08倍、过期SGA8．39倍、足月SGA4．41倍、过期AGA2．63倍、过期LGA1．53倍、足月LGA0．98倍;前6组差异均有显著性,后2组倍数接近1．0,差异无显著性。结论 早产及SGA两种因素均与小儿脑瘫发生率增加关联,这两个因素分别为小儿脑瘫独立的危险因素;过期产与脑瘫的关联很弱,LGA则与脑瘫的发生率增加无关。     

Human milk mineral intake and serum concentrations of calcium and phosphorus in newborn term infants: influence of intrauterine growth restriction

A prospective case-control study was performed to test the hypothesis that the milk Ca and P contents of term, small-for-gestational-age (SGA) newborns' mothers differs from that of term, adequate-for-gestational-age (AGA) newborns' mothers. We studied 71 pairs of mothers and newborns, divided into two groups: I (control): 41 pairs of mothers and term AGA newborns and II (study): 30 pairs of mothers and term SGA newborns. This latter group was subdivided according to type (symmetric: birthweight, length and head circumference <10th percentile; asymmetric: birthweight <10th percentile) and severity (P3 - P3 - 相似文献   

Body composition in neonates: relationship between measured and derived anthropometry with dual-energy X-ray absorptiometry measurements

This study examined the relationship between measured and derived anthropometric measurements with dual-energy X-ray absorptiometry measured lean and fat mass at 3.0 +/- 2.8 (SD) days in 120 neonates with birth weights appropriate (AGA; n=74), large (LGA; n=30); or small (SGA, n=16) for gestational age. Anthropometric measurements, including total body weight and length, and regional measurements, including circumferences of head, chest, abdomen, midarm, and midthigh and dynamic skinfold thickness (15 and 60 s) at tricep, subscapular, suprailiac, and midthigh, were performed. Derived anthropometry included muscle and fat areas, and ratios were calculated from direct measurements. The skinfold thickness measurements between 15 and 60 s were highly correlated (r=0.973-0.996, p <0.001 for all comparisons). Strong correlations existed within the four circumferences of trunk and extremities, the four skinfolds, and the ratios of weight to length and its higher powers. Weight and length accounted for >97% of the variance of lean mass in AGA and SGA infants and 46% of the variance in LGA infants and for 80, 82, and 84% of the variance of fat mass in SGA, AGA, and LGA infants, respectively, whereas midarm:head circumference ratio and arm muscle and fat areas are the most important derived anthropometry in the prediction for body composition. They independently accounted for up to 16.5 and 10.2%, respectively, of the variance in body composition depending on the state of in utero growth. Thus, total body weight and length and some selected regional and derived anthropometry accounted for the vast majority of the variance of body composition.     

The relationship of the levels of leptin, insulin-like growth factor-I and insulin in cord blood with birth size, ponderal index, and gender difference

In humans, serum levels of leptin correlate with total body fat in both adults and children. After collecting cord blood from 156 term neonates (82 males, 74 females; 132 AGA and 22 LGA), we measured the cord levels of leptin, insulin and IGF-I to determine the relationships between these three hormones and relationships of these hormones with birth size (birth weight and ponderal index for adiposity in newborn) and gender. The leptin and IGF-I levels were significantly higher in the LGA group (9.2+/-4.0 ng/ml and 96.1+/-34.1 ng/ml, respectively) than in the AGA group (4.8+/-3.8 ng/ml and 56.4+/-37.6 ng/ml, respectively). A significant positive correlation was observed between leptin levels and birth weight, and a weaker correlation between leptin levels and birth height. IGF-I level significantly correlated with birth weight and birth height, but there was no correlation between the levels of insulin and birth weight. There was no relationship between the levels of IGF-I, insulin and leptin. Ponderal index was higher in LGA than in AGA. A significant correlation was also observed between the levels of leptin and ponderal index, but not between the levels of insulin or IGF-I and ponderal index. The levels of leptin and ponderal index were higher in females than males despite no gender differences in gestational age and birth weight. In conclusion, our results suggest that the level of IGF-I is a useful index for fetal growth during late gestation, and the development of adipose tissue is the major determinant of fetal serum leptin levels, the production of which is not regulated by insulin or IGF-I. In addition, a gender difference with a higher level of leptin in female neonates suggests that sexual dimorphism in adipose tissue already exists in utero.