Effects of gender, body composition and birth size on IGF-I in 7- and 8-year-old children

Effect of a Fortified Dairy-Based Drink on Micronutrient Status, Growth, and Cognitive Development of Nigerian Toddlers- A Dose-Response Study

Malnutrition results in a high prevalence of stunting, underweight, and micronutrient deficiencies. This study investigated the effect of a multi-nutrient fortified dairy-based drink on micronutrient status, growth, and cognitive development in malnourished [height-for-age z-score (HAZ) and/or weight-for-age z-score (WAZ) < -1 SD and >-3 SD] Nigerian toddlers (n = 184, 1-3 years). The product was provided in different daily amounts (200, 400, or 600 ml) for 6 months. At baseline and endline, venous blood and urine samples were collected to determine micronutrient status. Bodyweight, height, waist, and head circumference were measured, and corresponding Z-scores were calculated. The Bayley-III Screening Test was used to classify the cognitive development of the children. In a modified per-protocol (PP) population, the highest prevalence's of micronutrient deficiencies were found for vitamin A (35.5%) and selenium (17.9%). At endline, there were no significant improvements in iodine, zinc, vitamin B12, and folate status in any of the three groups. Regarding vitamin D status (25OHD), consumption of 600 and 400 ml resulted in an improved status as compared to baseline, and in a difference between the 600- and 200-ml groups. Consumption of 600 ml also increased vitamin A and selenium status as compared to baseline, but no differences were found between groups. Within the groups, WAZ, weight-for-height z-score (WHZ), and BMI-for-age z-score (BAZ) improved, but without differences between the groups. For HAZ, only the 600 ml group showed improvement within the group, but it was not different between groups. For the absolute weight, height, and head circumference only trends for differences between groups were indicated. Cognition results did not differ between the groups. Within groups, all showed a decline in the per cent of competent children for receptive language. To study the effects of a nutritional intervention on linear growth and cognition, a longer study duration might be necessary. Regarding the improvement of micronutrient status, 600 ml of fortified dairy-based drink seems most effective.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT03411590?term=NCT03411590.&draw=2&rank=1, identifier: NCT03411590.

Factors affecting IGF-I level and correlation with growth response during growth hormone treatment in LG Growth Study

Growth hormone treatment strategies to achieve the goal include the titration of GH doses according to serum insulin-like growth factor I (IGF-I) concentrations. However, IGF-I levels do not always correlate well with the growth response. This study aims to identify the factors affecting the IGF-I concentration and identify the relationship between IGF-I and the treatment response. The data of prepubertal children treated with recombinant human GH for more than one year were obtained from the LG Growth Study (LGS) Database. This study includes patients with idiopathic growth hormone deficiency (IGHD), organic growth hormone deficiency (OGHD), or Turner syndrome (TS) or small for gestational age (SGA). Among 2,021 participants registered in LGS, 366 subjects were selected, 252 had IGHD, 16 had OGHD, 31 had TS, and 67 were SGA. In the IGHD and SGA groups, IGF-I levels had a positive correlation with weight SDS. There was no significant relationship between the pre-treatment IGF-I level and growth response. However, in the IGHD group, the growth response was significantly higher when the change in the IGF-I SDS value was 1 or more (p = 0.0013). Therefore, IGF-I concentrations should be used as an indicator to monitor the treatment compliance rather than for efficacy determination in Korean children of short stature with GH treatment.

Association between Dairy Intake and Linear Growth in Chinese Pre-School Children

Stunting remains a major public health issue for pre-school children globally. Dairy product consumption is suboptimal in China. The aim of this study was to investigate the relationship between dairy intake and linear growth in Chinese pre-school children. A national representative survey (Chinese Nutrition and Health Surveillance) of children aged under 6 years was done in 2013. Stratified multistage cluster sampling was used to select study participants. A food frequency questionnaire was used to collect dietary information. We calculated height-for-age Z-scores (HAZs) and estimated stunting using the 2006 WHO growth standard. In total, 12,153 children aged two to four years old (24 to <60 months) were studied from 55 counties in 30 provinces in China. Approximately 39.2% (4759/12,153) of those children consumed dairy at least once per day, 11.9% (1450/12,153) consumed dairy at least once in the last week, and nearly half (48.9%, 5944/12,153) did not have any dairy in the last week. The HAZ was −0.15 ± 1.22 and the prevalence of stunting was 6.5% (785/12,153). The HAZ for children who consumed dairy at least once per day or per week was 0.11 points or 0.13 points higher than the children without dairy intake. The risk of stunting for children who consumed dairy at least once per day was 28% lower than the children without dairy intake in the last week, and the risk was similar between weekly dairy consumption and no dairy consumption (AOR: 1.03, 95% CI: 0.74–1.42) after adjusting for potential confounders, including socioeconomic characteristics, lifestyle, health status, and the intake frequency of other foods. Dairy intake was significantly associated with a higher HAZ and a lower risk of stunting for children aged 2–4 years old in China. The proportion of dairy intake was still low in Chinese pre-school children. The promotion of dairy consumption might be an effective and feasible measurement for improving linear growth in Chinese pre-school children.

Tracking of Serum DHEAS Concentrations from Age 1 to 6 Years: A Prospective Cohort Study

Context

Adrenarche is a gradual process, but its programming is unknown.

Objective

The objective of this article is to examine the trajectory of dehydroepiandrosterone sulfate (DHEAS) from age 1 to 6 years and the associations of early growth with DHEAS concentration by age 6 years.

Design and participants

Longitudinal data from a population sample of 78 children (43 girls) with serum samples for DHEAS and insulin-like growth factor 1 (IGF-1) measurements available at ages 1 and 6 years.

Main outcome measure

Serum DHEAS concentration at age 6 years.

Results

DHEAS concentration at age 1 year correlated with DHEAS concentration at age 6 years (r = 0.594, P < .001). DHEAS levels at age 6 years increased with tertiles of DHEAS at age 1 year (medians (µg/dL); 4.2, 14.4, 22.6; P < .001) and with those of greater increase in length by age 1 year (6.0, 11.7, 16.4; P = .047), and decreased with tertiles of birth length (17.7, 13.3, 7.1; P = .042). In a regression model including birth size, biochemical covariates at age 1 year, and growth measures by age 6 years, higher DHEAS concentration at age 1 year was an independent determinant of falling into the highest DHEAS tertile at age 6 years.

Conclusions

Higher serum DHEAS concentrations already at age 1 year are associated with those at age 6 years. Also, shorter birth length and rapid catch-up growth in length by age 1 year are associated with higher DHEAS concentrations at age 6 years. These results corroborate the early origin of adrenarche and strongly suggest that part of adrenarchal programming already takes place by the end of infancy.

A critical review of the role of milk and other dairy products in the development of obesity in children and adolescents

Existing reviews suggest that milk and other dairy products do not play a role in the development of obesity in childhood, but they do make an important contribution to children's nutrient intake. It is thus curious that public health advice on the consumption of dairy products for children is often perceived as unclear. The present review aimed to provide an overview of the totality of the evidence on the association between milk and other dairy products, and obesity and indicators of adiposity, in children. Our search identified forty-three cross-sectional studies, thirty-one longitudinal cohort studies and twenty randomised controlled trials. We found that milk and other dairy products are consistently found to be not associated, or inversely associated, with obesity and indicators of adiposity in children. Adjustment for energy intake tended to change inverse associations to neutral. Also, we found little evidence to suggest that the relationship varied by type of milk or dairy product, or age of the children, although there was a dearth of evidence for young children. Only nine of the ninety-four studies found a positive association between milk and other dairy products and body fatness. There may be some plausible mechanisms underlying the effect of milk and other dairy products on adiposity that influence energy and fat balance, possibly through fat absorption, appetite or metabolic activity of gut microbiota. In conclusion, there is little evidence to support a concern to limit the consumption of milk and other dairy products for children on the grounds that they may promote obesity.

Impact of insulin resistance on insulin-like growth factor-1/insulin like growth factor-binding protein-3 axis and on early weight gain in small for gestational age infants

OBJECTIVE

To assess insulin-like growth factor-1 (IGF-1)/IGF-binding protein-3 (IGFBP-3) axis and insulin resistance (IR) and the relationship of these parameters with growth in appropriate for gestational age (AGA) and small for gestational age (SGA) infants at birth and in early infancy.

METHODS

Postnatal blood samples for measurement of glucose, insulin, IGF-1, and IGFBP-3 were taken from 60 infants (30 AGA and 30 SGA) at birth and at one, three, and six months of age. Both SGA and AGA infants were divided into two groups: growing well and not growing well. Blood glucose, insulin, IGF-1, and IGFBP-3 values were assessed in all infants.

RESULTS

Homeostasis model assessment-IR (HOMA-IR) values in well-growing SGA infants in the third and sixth months were found to be higher than in not well-growing SGA infants (3.9±0.8 vs. 1.0±0.3 at 3 months and 3.3±0.9 vs. 2.4±0.9 at 6 months, p<0.05). IGF-1 levels in well-growing SGA infants at 3 and 6 months were found to be higher than those in not well-growing SGA infants (83.80±44.50 vs. 73.50±17.60 ng/mL at 3 months and 95.12±50.74 vs. 87.67±22.91 ng/mL at 6 months, p<0.05). The IGF-1 values were significantly lower in well-growing SGA infants than in well-growing AGA infants (83.80±44.50 vs. 103.31±30.81 ng/mL at 3 months and 95.12±50.74 vs. 110.87±26.44 ng/mL at 6 months, p<0.05).

CONCLUSIONS

This study demonstrates the effects of accelerated early infant growth on IGF-1/IGFBP-3 axis in SGA-born infants.

Body size in early life and adult levels of insulin-like growth factor 1 and insulin-like growth factor binding protein 3

Body size in early life has been associated with breast cancer risk. This may be partly mediated through the insulin-like growth factor (IGF) pathway. The authors assessed whether birth weight, body fatness at ages 5 and 10 years, and body mass index (BMI; weight (kg)/height (m)(2)) at age 18 years were associated with plasma concentrations of insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 in 6,520 women aged 32-70 years at blood draw from the Nurses' Health Study (1990-2006) and Nurses' Health Study II (1997-2005). Birth weight, body fatness in childhood, and BMI at age 18 years were inversely associated with adult IGF-1 levels. For example, IGF-1 levels were 11.9% lower in women who reported being heaviest at age 10 years than in those who were leanest at age 10 (P-trend < 0.0001). Further, women who reported their birth weight as ≥10 pounds (≥4.5 kg) (vs. <5.5 pounds (<2.5 kg)) had 7.9% lower IGF-1 levels (P-trend = 0.002). Women whose BMI at age 18 years was ≥30 (vs. <20) had 14.1% lower IGF-1 levels (P-trend < 0.0001). Similar inverse associations were observed for insulin-like growth factor binding protein 3. These observations did not vary by adult BMI or menopausal status at blood draw. These findings suggest that altered IGF-1 levels in adulthood may be a mechanism through which early-life body size influences subsequent breast cancer risk.

IGF-I and IGFBP-3 in healthy 9 month old infants from the SKOT cohort: breastfeeding, diet, and later obesity

BACKGROUND

High IGF-I concentrations in infancy have been associated with later obesity but the interactions between diet, IGF-I concentrations and growth in early life are complex and involve programming of the IGF-I axis.

OBJECTIVE

This paper examines how IGF-I and IGFBP-3 concentrations measured at age 9 months are related to diet and growth in infancy.

DESIGN

In the Danish SKOT cohort healthy term infants were included at age 9 months with follow-up at age 18 months. Total 252 infants had a full data set and were included in the analysis. Measurements include weight, length, skinfold thickness, waist circumference, 7-d food records, and blood analysis of IGF-I, and IGFBP-3.

RESULTS

Infants not being breastfed at 9 months of age (46%) had higher median IGF-I concentration than breastfed infants (51.6 vs. 44.2 ng/mL, P=0.0005) and there was a negative dose response effect of daily numbers of breastfeedings on IGF-I concentration. IGF-I concentration was negatively associated with birth weight and positively related to increase in weight, length and BMI between birth and 9 months. Between 9 months and 18 months of age increase in length was positively and increase in BMI was negatively related to IGF-I concentration.

CONCLUSION

Breastfeeding has a strong negative effect on IGF-I concentrations in late infancy. Although IGF-I concentrations at 9 months of age were negatively associated with change in BMI during the following 9 months we speculate that this could reflect an early adiposity rebound and thereby an increased risk of obesity later in life.

Dairy and milk consumption and child growth: Is BMI involved? An analysis of NHANES 1999-2004

Humans are unique among mammals in that many consume cow's milk or other dairy products well beyond the traditional age of weaning. Milk provides various nutrients and bioactive molecules to support growth and development, and the question arises as to whether this dietary behavior influences growth parameters. There is evidence that milk makes positive contributions to growth in height, but its associations with other aspects of body size, such as body mass index (BMI), are not well-established. National Health and Nutrition Examination Survey (NHANES) data from 1999 to 2004 and multivariate regression analysis were used to test the hypothesis that milk (g) or total dairy product consumption (kJ) is associated with higher BMI percentile among US White, Black, and Mexican-American children of age 2-4 years (n = 1,493) and 5-10 years (n = 2,526). Younger children in the highest quartile of dairy intake had higher BMIs (beta = 7.5-8.0; P < 0.01) than those in the lowest two quartiles. Controlling for energy intake eliminated differences between QIV and QI. Among children of 5-10 years of age dairy intake had no relationship to BMI. Young children in the highest quartile of milk intake had higher BMIs than all lower quartiles (beta = 7.1-12.8; beta = 6.3-11.8 in energy-controlled models; P < 0.05). Among children of 5-10 years of age, those in QIV for milk intake had higher BMIs than those in QII (beta = 8.3; beta = 7.1 in energy-controlled model; P < 0.01). Controlling for total protein or calcium did not change the results. Milk had more consistent positive associations with BMI than did dairy products, and these were strongest among children of 2-4 years of age.

Early programming of the IGF-I axis: negative association between IGF-I in infancy and late adolescence in a 17-year longitudinal follow-up study of healthy subjects

BACKGROUND

IGF-I is a major regulator of growth, influenced primarily by diet in infancy and primarily by GH in childhood. Breastfed infants have lower IGF-I levels compared to formula fed and tend to be shorter. The higher protein content of infant formula has a stimulatory effect on IGF-I production. Conversely, studies suggest that later in childhood, those breastfed are taller and have higher IGF-I levels. Therefore, it has been suggested that the IGF-I axis may be programmed by diet during infancy. The association between IGF-I in infancy and later life is not known.

OBJECTIVE

To examine the association between IGF-I in infancy and adolescence.

DESIGN

Infants (109) from the observational Copenhagen cohort study.

METHODS

Serum-IGF-I was measured during infancy (2, 6, and 9 months) and at follow-up at 17 years. Associations were examined by correlation tests and linear regression controlling for gender, breastfeeding, and other covariates. Likelihood ratio test based on residual log likelihood was applied for analysis including all measurements during infancy.

RESULTS

There was an inverse association between IGF-I at 9 months and 17 years (r=-0.39, P=0.014, and n=40). A 1 ng/ml higher IGF-I concentration at 9 months corresponded to 0.95 ng/ml lower IGF-I concentration at 17 years. IGF-I levels at 2 and 6 months were not significantly associated with IGF-I at 17 years, but the estimated directions were negative. These associations were not changed when adjusted for breastfeeding and other covariates except IGF-I at 2 months which was significantly negatively associated with IGF-I at 17 years (P=0.030) corresponding to a 0.96 ng/ml lower IGF-I concentration at 17 years per ng/ml IGF-I at 2 months. Inclusion of all measurements during infancy showed a negative association with 17-year values (r=-0.26, P=0.043, and n=109).

CONCLUSION

The results support the hypothesis that the IGF-I axis can be programmed early in life.

Insulin resistance and body composition in preterm born children during prepubertal ages

BACKGROUND

Premature born children may show insulin resistance in childhood which may be due to intrauterine or postnatal adverse environmental factors.

OBJECTIVE

Aim of this study was to evaluate insulin resistance and body composition in preterm born children born appropriate for gestational age (AGA) or small for gestational age (SGA) and relations with IGF-I, IGFBP-3 axis.

METHODS

Ninety-three preterm born children grouped as premature SGA (n = 30) and premature AGA (n = 63) were evaluated at age 4.6 +/- 0.2 years and 4.7 +/- 0.1 years with respect to their glucose, insulin, IGF-I, IGFBP-3, IGFBP-1, leptin levels and body composition by dual-energy X-ray absorptiometry. Their data were compared to that of body mass index (BMI) matched term SGA (n = 42) and term AGA (n = 44) children of age 4.5 +/- 0.2 and 3.8 +/- 0.1 years. All children had height appropriate for their target height. Insulin resistance was evaluated by basal insulin and homeostasis model assessment for insulin resistance (HOMA-IR).

RESULTS

Basal insulin level was similar in preterm AGA (4.3 +/- 1.4 pmol/l) and term AGA (7.9 +/- 6.4 pmol/l) children at similar and normal BMI levels. Preterm SGA children had insulin levels (5.0 +/- 3.6 pmol/l) similar to preterm AGA children but significantly lower than that in term SGA children (23.7 +/- 20.8 pmol/l) (P = 0.001). Similar results were obtained for HOMA-IR. Term SGA children had also significantly lower IGFBP-1 levels. Body composition, leptin and IGFBP-3 did not differ between the respective groups. IGF-I was lower in preterm AGA (5.0 +/- 0.6 nmol/l) than in term AGA (8.3 +/- 1.2 nmol/l) (P < 0.001) children.

CONCLUSIONS

Premature born AGA and SGA children do not have insulin resistance when compared to term children if they have made a catch-up growth appropriate for their target height and have normal BMI. The similar insulin levels in preterm SGA and preterm AGA children together with increased insulin levels in term SGA children points to the fact that it is the intrauterine restriction in the third trimester that has an adverse effect on future adverse metabolic outcome.

Milk as a food for growth? The insulin-like growth factors link

Objective

The mechanisms underlying the association of insulin-like growth factor-I (IGF-I) and leg length (a marker of prepubertal growth) with cancer risk are uncertain. One hypothesis is that diet in early childhood might provide the link. The aim of the present study was to examine the association between early diet – in particular, the intakes of cows' milk and dairy products – and height, leg length and IGF-I levels at age 7–8 years.

Subjects

Children participating in the Avon Longitudinal Study of Parents and Children.

Design

Diet was assessed using a 3-day unweighed food record. Anthropometry, IGF-I and insulin-like growth factor-binding protein-3 (IGFBP-3) were measured by standard methods.

Results

Data on both diet and height were available for 744 children (404 boys) and on diet and IGF for 538 (295 boys). After adjusting for energy, both cows' milk and dairy product intakes were positively associated with IGF-I (P=0.040 and 0.027, respectively) and IGFBP-3 levels (P=0.082 and 0.067, respectively). These associations persisted on adjustment for potential confounders, but were abolished on controlling for protein intake. In energy-adjusted models there was only weak evidence of associations of milk and dairy product intakes with anthropometry. In boys only, dairy product intake was positively associated with leg length (equivalent to a 0.058 (0.002, 0.114) standard deviation score increase in leg length per 100 g increase in daily intake).

Conclusions

These data provide some evidence that variation in childhood milk and dairy product intakes underlies associations of leg length, IGF-I and cancer risk. The association appears to be due to the protein content of milk.

Cow's milk and linear growth in industrialized and developing countries

The strongest evidence that cow's milk stimulates linear growth comes from observational and intervention studies in developing countries that show considerable effects. Additionally, many observational studies from well-nourished populations also show an association between milk intake and growth. These results suggest that milk has a growth-stimulating effect even in situations where the nutrient intake is adequate. This effect is supported by studies that show milk intake stimulates circulating insulin-like growth factor (IGF)-I, which suggests that at least part of the growth-stimulating effects of milk occur through the stimulation of IGFs. Given that the biological purpose of milk is to support the newborn during a period of high growth velocity, such an effect seems plausible. Adding cow's milk to the diet of stunted children is likely to improve linear growth and thereby reduce morbidity. In well-nourished children, the long-term consequences of an increased consumption of cow's milk, which may lead to higher levels of IGF-I in circulation or an increase in the velocity of linear growth, are likely to be both positive and negative. Based on emerging data that suggest both growth and diet during early life program the IGF axis, the association between milk intake and later health is likely to be complex.

Biting behavior, aggression, and seizures

PURPOSE

To describe the semiologic features of aggressive behaviors observed in human epileptic seizures with particular reference to the act of biting a conspecific.

METHODS

We analyzed the biting behavior (BB) and other aggressive gestures occurring in a group of 11 patients retrospectively selected from >1,000 patients subjected to video-EEG/SEEG monitoring for presurgical evaluation of drug-resistant seizures.

RESULTS

Patients displaying BB showed (a) a male sex predominance, (b) heterogeneous etiologies and lesion locations, and (c) seizures involving the frontotemporal regions of both hemispheres. The act of biting was a rapid motor action, lasting approximately 600 ms, occurring in the context of strong emotional arousal, fear, and anger, with various bodily gestures with aggressive connotation. BB was mainly a "reflexive" behavior, in that biting acts were evoked (both during and after seizures) by actions of people in close contact with the patient. The sole intrusion of the examiner's hand in the space near the patient's face was effective in triggering BB. Rarely, self-directed or object-directed biting acts were not triggered by external stimuli. Intracranial data (SEEG) obtained in one subject showed that the amygdala/hippocampal region plus the orbitomedial prefrontal cortex had to be involved by ictal activity to observe BB.

CONCLUSIONS

Anatomic and electrophysiologic data in our patients suggest that a model of dual--temporal and frontal--dysfunction could account for the occurrence of ictal/postictal BB. Behavioral data suggest also that BB and related aggressive gestures can be considered as the emergence of instinctive behaviors with an adaptative significance of defense of the peripersonal space.

Serum markers of GH and insulin action in 12-year-old children born small for gestational age

OBJECTIVES

Our aim was to determine whether markers of growth hormone and insulin action differ between children born small for gestational age (SGA) and those born of an appropriate size for gestational age (AGA).

DESIGN

Fifty-five SGA children and their 55 age- and sex-matched AGA control subjects were studied in a case-control setting at 12 years of age.

METHODS

We examined serum concentrations of insulin-like growth factor (IGF)-I, IGF-II, IGF-binding protein (IGFBP)-1 and IGFBP-3, sex hormone binding globulin (SHBG), leptin, fasting insulin, and blood glucose. Insulin sensitivity was evaluated by the homeostasis model assessment for insulin resistance (HOMA-IR).

RESULTS

The body mass index (BMI), sex, and puberty-adjusted mean serum IGF-I concentration was higher in the SGA than in the AGA children (303.4 vs 282.3 microg/l, P = 0.006). The mean serum concentrations of IGF-II, IGFBP-I, IGFBP-3, SHBG, fasting insulin, blood glucose and HOMA-IR did not differ between the SGA and the AGA group. The BMI, sex, and puberty-adjusted mean serum leptin concentration was lower in the SGA than in the AGA children (7.9 vs 10.1 microg/l, P = 0.037). In multiple logistic regression analysis, high HOMA-IR predicted high serum IGF-I levels in the SGA children (odds ratio 8.3; 95% confidence interval 1.7-41; P = 0.010), whereas in the AGA group HOMA-IR did not associate with the serum IGF-I level.

CONCLUSIONS

The BMI, sex, and puberty-adjusted mean serum IGF-I concentration was significantly higher and the leptin concentration was lower in the SGA than in the AGA children. No differences were found in the indices of insulin action or sensitivity between the SGA and AGA children at 12 years of age. However, HOMA-IR strongly associated with serum IGF-I levels in the SGA children.

Growth velocity during the first postnatal week of life is linked to a spurt of IGF-I effect

There is adequate evidence that growth during the perinatal period is linked to the risk of several adult onset diseases, and recent findings indicate that the insulin-like growth factor (IGF) system is involved in prenatal growth, as reflected in birthweight. However, whether major components of the IGF system are involved in the immediate post-natal growth has not been studied. Maternal questionnaires were completed, and laboratory measurements of several variables, including IGF-I, IGF-II and IGF-binding protein-3 (IGFBP-3), were made for a total of 331 apparently healthy full-term newborns, from whom routine blood samples were taken during the first 5 days of their life. Birthweight and weight at the time of bleeding were among the recorded variables, and the difference divided by the age in days of the newborn was considered as reflecting immediate postnatal growth velocity. Immediate postnatal growth velocity was strongly positively associated with IGF-I. The squared adjusted correlation coefficient was 0.29 when IGF-I was incorporated in the model predicting postnatal growth velocity but was only 0.08 when IGF-I was excluded. In contrast, IGF-II and IGFBP-3 had no effect on postnatal growth velocity. It thus appears that IGF-I underlies growth during the immediate postnatal period. To the extent that perinatal growth may affect adult onset diseases, the findings of this study suggest that the action of IGF-I during the immediate postnatal period may represent a process of major importance.

Insulin-like growth factor I and leptin in umbilical cord plasma and infant birth size at term

OBJECTIVE

To determine the independent contributions to infant birth size of insulin-like growth factor I (IGF-I) and leptin measured in umbilical cord plasma.

METHODS

Umbilical cord blood was collected in 12 804 consecutive deliveries, and cord plasma from 585 singleton infants born at term after uncomplicated pregnancies was analyzed for leptin, IGF-I, and 2 IGF-binding proteins (IGFBP-1 and IGFBP-3). In multivariable analyses, we assessed maternal and infant covariates of leptin and IGF-I, and we evaluated the independent contribution of cord levels of leptin and IGF-I on infant birth size.

RESULTS

Cord plasma levels of IGF-I were lower in women who reported smoking at the beginning of pregnancy compared with nonsmokers. In female infants, levels of IGF-I and leptin were higher than in male infants after adjustment for ponderal index and maternal factors. We found a strong parallel increase in umbilical IGF-I and leptin with increasing birth weight and birth length. For IGFBP-1, there was an opposite pattern: IGFBP-1 increased with decreasing birth size. The multivariable analysis, adjusted for length of gestation and maternal age, parity, prepregnancy weight, smoking during pregnancy, and offspring sex, showed that IGF-I and leptin, independent of each other, were associated with birth weight and birth length.

CONCLUSIONS

Levels of IGF-I and leptin in umbilical cord plasma were higher in girls than in boys, but in both sexes, these 2 factors contributed independently and positively to birth weight and length. For IGFBP-1, high levels were associated with low birth weight and reduced length. If intrauterine growth is related to the risk of developing adult diseases, IGF-I, IGFBP-1, and leptin may be involved in the underlying processes.1131-1135 insulin like growth factors, leptin, umbilical cord plasma, birth weight.

Familial, anthropometric, and metabolic associations of intramyocellular lipid levels in prepubertal males

The cause of skeletal muscle insulin resistance is unclear, but high levels of intramyocellular lipids are often present in affected individuals. We aimed to establish the metabolic, familial, and anthropometric associations of intramyocellular lipid in a pediatric population. We studied 41 boys aged 6.9-9.9 y and 23 of their mothers by proton magnetic resonance spectroscopy. We related muscle lipid levels to important factors that define an increased risk of developing insulin resistance in adult life. There were significant associations between the boys' intramyocellular lipid and their waist circumference (r = 0.42, p = 0.007), body mass index SD score (r = 0.32, p = 0.04), weight SD score (r = 0.32, p = 0.04), glucose:insulin ratio (r= -0.59, p = 0.04), maternal log fasting insulin levels (r = 0.44, p = 0.04), maternal body mass index (r = 0.46, p = 0.03), and maternal intramyocellular lipid (r = 0.62, p = 0.003). In the 41 boys, waist circumference explained 19% of the variance in the boys' intramyocellular lipid. Maternal intramyocellular lipid explained 39% of the variance in the boys' intramyocellular lipid in the sub-group of 23 boys. Intramyocellular lipid levels have both metabolic and anthropometric associations in childhood. Before puberty, children develop or inherit muscle metabolic characteristics that are associated both with insulin resistance and risk factors for the development of insulin resistance syndrome in adult life.