IGFBP-1 levels in adult women born small for gestational age suggest insulin resistance in spite of normal BMI

Cardiovascular risk factors in those born preterm - systematic review and meta-analysis

Emerging evidence demonstrates a link between preterm birth (PTB) and later life cardiovascular disease (CVD). We conducted a systematic review and meta-analysis to compare conventional CVD risk factors between those born preterm and at term. PubMed, CINAHL, SCOPUS, and EMBASE databases were searched. The review protocol is registered in PROSPERO (CRD42018095005). CVD risk factors including systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index, lipid profile, blood glucose, and fasting insulin among those born preterm (<37 weeks' gestation) were compared with those born at term (≥37 weeks' gestation). Subgroup analyses based on gender, age, gestational at birth (<32 weeks' gestation and <28 weeks' gestation), and PTB associated with small for gestational age or average for gestational age were also performed. Fifty-six studies provided data on 308,987 individuals. Being born preterm was associated with 3.26 mmHg (95% confidence interval [CI] 2.08 to 4.44) higher mean SBP and 1.32 mmHg (95% CI: 0.61 to 2.04) higher mean DBP compared to being born at term. Subgroup analyses demonstrated that SBP was higher among (a) preterm compared to term groups from early adolescence until adulthood; (b) females born preterm but not among males born preterm compared to term controls; and (c) those born at <32 weeks or <28 weeks compared to term. Our meta-analyses demonstrate higher SBP and DBP among those born preterm compared to term. The difference in SBP is evident from early adolescence until adulthood.

Premature birth, low birth weight, small for gestational age and chronic non-communicable diseases in adult life: A systematic review with meta-analysis

BACKGROUND

Individuals who were born prematurely (PT), with low birth weight (LBW), or small for gestational age (SGA) appear to present a set of permanent changes that make them more susceptible to develop chronic non-communicable diseases (CNCD) in adult life.

AIM

Investigating the association between PT birth, LBW or SGA at birth and CNCD incidence in adult life.

METHODS

Systematic review with meta-analysis of studies available in three databases - two of them are official (PubMed and Web of Science) and one is gray literature (OpenGrey) - based on pre-established search and eligibility criteria.

RESULTS

Sixty-four studies were included in the review, 93.7% of them only investigated one of the exposure variables (46.7% LBW, 35.0% PT and 18.3% SGA at birth), whereas 6.3% investigated more than one exposure variable (50.0% LBW and PT; 50.0% SGA and PT). There was association among all exposure variables in the following outcomes: cardiometabolic (CMD) and glycidic metabolism (GMD) disorders, changes in body composition and risk of developing metabolic syndrome (MS). Female sex was identified as risk factor in the exposure-outcome association. Eighteen (18) articles were included in the meta-analysis. There was positive association between LBW and incidence of CMD (OR: 1.25 [95%CI: 1.11; 1.41]; 07 studies), GMD (OR: 1.70 [95%CI: 1.25; 2.30]; 03 studies) and MS (OR: 1.75 [95%CI: 1.27; 2.40]; 02 studies) in adult life. PT was positively associated with CMD (OR: 1.38 [95%CI: 1.27; 1.51]; 05 studies).

CONCLUSIONS

LBW and PT are associated with CMD and GMD development, as well as with the risk of developing MS in adult life.

Preterm Birth as a Risk Factor for Metabolic Syndrome and Cardiovascular Disease in Adult Life: A Systematic Review and Meta-Analysis

OBJECTIVE

To determine if preterm birth is associated with components of the metabolic syndrome in adult life.

STUDY DESIGN

A structured literature search was performed using PubMed. All comparative studies reported metabolic and cardiovascular outcomes in adults (≥18 years of age) born preterm (<37 weeks of gestation) compared with adults born at term (37-42 weeks of gestation) and published through March 2018 were included. The major outcomes assessed were body mass index, waist circumference, waist-to-hip ratio, fat mass, systolic blood pressure (SBP), diastolic blood pressure (DBP), 24-hour SBP, 24-hour DBP, endothelium-dependent brachial artery flow-mediated dilation, carotid intima-media thickness, pulse wave velocity, fasting glucose and insulin, Homeostasis Model Assessment-Estimated Insulin Resistance Index, and lipid profiles. Quality appraisal was performed using a modified version of the Newcastle-Ottawa scale. A meta-analysis was performed for comparable studies which reported sufficient data.

RESULTS

Forty-three studies were included, including a combined total of 18 295 preterm and 294 063 term-born adults. Prematurity was associated with significantly higher fat mass (P = .03), SBP (P < .0001), DBP (P < .0001), 24-hour SBP (P < .001), and 24-hour DBP (P < .001). Furthermore, preterm-born adults presented higher values of fasting glucose (P = .01), insulin (P = .002), Homeostasis Model Assessment-Estimated Insulin Resistance Index (P = .05), and total cholesterol levels (P = .05) in comparison with adults born at term, in random effect models. No statistically significant difference was found between preterm and term-born adults for the other outcomes studied.

CONCLUSIONS

Preterm birth is strongly associated with a number of components of the metabolic syndrome and cardiovascular disease in adult life.

Developmental programming of aging trajectory

There is accumulating evidence that aging phenotype and longevity may be developmentally programmed. Main mechanisms linking developmental conditions to later-life health outcomes include persistent changes in epigenetic regulation, (re)programming of major endocrine axes such as growth hormone/insulin-like growth factor axis and hypothalamic-pituitary-adrenal axis and also early-life immune maturation. Recently, evidence has also been generated on the role of telomere biology in developmental programming of aging trajectory. In addition, persisting changes of intestinal microbiota appears to be crucially involved in these processes. In this review, experimental and epidemiological evidence on the role of early-life conditions in programming of aging phenotypes are presented and mechanisms potentially underlying these associations are discussed.

Birth weight predicts aging trajectory: A hypothesis

Increasing evidence suggests that risk for age-related disease and longevity can be programmed early in life. In human populations, convincing evidence has been accumulated indicating that intrauterine growth restriction (IUGR) resulting in low birth weight (<2.5 kg) followed by postnatal catch-up growth is associated with various aspects of metabolic syndrome, type 2 diabetes and cardiovascular disease in adulthood. Fetal macrosomia (birth weight > 4.5 kg), by contrast, is associated with high risk of non-diabetic obesity and cancers in later life. Developmental modification of epigenetic patterns is considered to be a central mechanism in determining such developmentally programmed phenotypes. Growth hormone/insulin-like growth factor (GH/IGF) axis is likely a key driver of these processes. In this review, evidence is discussed that suggests that different aging trajectories can be realized depending on developmentally programmed life-course dynamics of IGF-1. In this hypothetical scenario, IUGR-induced deficit of IGF-1 causes "diabetic" aging trajectory associated with various metabolic disorders in adulthood, while fetal macrosomia-induced excessive levels of IGF-1 lead to "cancerous" aging trajectory. If the above reasoning is correct, then both low and high birth weights are predictors of short life expectancy, while the normal birth weight is a predictor of "normal" aging and maximum longevity.

Effects of prenatal micronutrient and early food supplementation on metabolic status of the offspring at 4.5 years of age. The MINIMat randomized trial in rural Bangladesh

Background: Fetal nutritional insults may alter the later metabolic phenotype. We hypothesized that early timing of prenatal food supplementation and multiple micronutrient supplementation (MMS) would favourably influence childhood metabolic phenotype.

Methods: Pregnant women recruited 1 January to 31 December 2002 in Matlab, Bangladesh, were randomized into supplementation with capsules of either 30 mg of iron and 400 μg of folic acid, 60 mg of iron and 400 μg of folic acid, or MMS containing a daily allowance of 15 micronutrients, and randomized to food supplementation (608 kcal) either with early invitation (9 weeks’ gestation) or usual invitation (at 20 weeks). Their children (n = 1667) were followed up at 4.5 years with assessment of biomarkers of lipid and glucose metabolism, inflammation and oxidative stress.

Results: Children in the group with early timing of food supplementation had lower cholesterol (difference -0.079 mmol/l, 95% confidence interval (CI) -0.156; -0.003), low-density lipoprotein (LDL) (difference -0.068 mmol/l, 95% CI -0.126; -0.011) and ApoB levels (difference -0.017 g/l, 95% CL -0.033; -0.001). MMS supplementation resulted in lower high-density lipoprotein (HDL) (difference -0.028 mmol/l, 95% CL -0.053; -0.002), lower glucose (difference -0.099 mmol/l, 95% CL -0.179; -0.019) and lower insulin-like growth factor 1 (IGF-1) (difference on log scale -0.141 µg/l, 95% CL -0.254; -0.028) than 60 mg iron and 400 μg folic acid. There were no effects on markers of inflammation or oxidative stress.

Conclusions: Findings suggest that in a population where malnutrition is prevalent, nutrition interventions during pregnancy may modify the metabolic phenotype in the young child that could have consequences for later chronic disease risks.

Growth, metabolic markers, and cognition in 8-year old children born prematurely, follow-up of a randomized controlled trial with essential fatty acids

The study is a follow-up of a randomized, double-blinded, placebo-controlled trial of supplementation with docosahexaenoic acid (DHA) and arachidonic acid (AA) to 129 very low birth weight (VLBW; birth weight <1500 g) infants fed human milk. The main hypothesis was that supplementation would affect growth, metabolic markers, and cognitive function. The secondary aim was to describe predictors of metabolic markers and cognitive status at follow-up. Ninety-eight children met for 8-year follow-up with anthropometric measures, blood biomarkers, and cognitive testing. The intervention group had significantly lower insulin-like growth factor-1 (IGF-1) at 8 years, whereas no differences in growth or intelligence quotient (IQ) were found. For the total cohort, weight gain during first year of life was neither associated with BMI, metabolic markers, nor IQ at follow-up. Blood DHA at 8 years was positively associated with IQ.

CONCLUSIONS

The study is the first long-term follow-up of a randomized controlled trial with essential fatty acids investigating growth, metabolic factors, and IQ. IGF-1 levels were significantly lower in the intervention group at 8 years. First-year growth was not associated with BMI, metabolic markers, or IQ at follow-up. Current DHA status was a significant predictor of higher IQ at follow-up.

WHAT IS KNOWN

• Preterm children have increased risk of lower intelligence quotient (IQ), reduced growth, and abnormal metabolic status. • Early intake of docosahexaenoic acid (DHA) and arachidonic acid (AA), as well as early growth pattern, may influence both IQ and metabolic status. What is New: • Early intervention with DHA and AA led to reduced insulin-like growth factor-1 in blood at 8 years of age. • Weight gain during first year of life was neither associated with impaired metabolic markers nor improved IQ at follow-up. • Current DHA status was a significant predictor of higher IQ at 8 years, also when maternal education and birth weight were included in the model.

Premature birth and insulin resistance in infancy: A prospective cohort study

OBJECTIVE

This study was done to determine the role of prematurity and other variables to predict insulin sensitivity in infancy.

SUBJECTS AND METHODS

In this prospective study, 36 preterm appropriate for gestational age (AGA), 11 preterm small for gestational age (SGA), and 17 term SGA included as study cohort and 36 term AGA as control cohort. Detailed anthropometry assessment was performed at birth, 3, 6, and 9 months and at 9 months, fasting plasma glucose and serum insulin was done. Insulin resistance was determined by using homeostasis model assessment version 2.

RESULTS

It is found that preterm AGA (mean difference 0.617, 95% confidence interval [CI]; 0.43-0.80, P = 0.0001), preterm SGA (mean difference 0.764, 95% CI; 0.44-1.09, P = 0.0001), and term AGA (mean difference 0.725, 95% CI; 0.49-0.96, P = 0.0001) group had significantly higher insulin resistance than control. There was no significant difference in between preterm SGA and preterm AGA (mean difference 0.147 95% CI; -0.13-0.42, P = 0.927). In multiple regression models, SGA status (β =0.505) was more significant predictor of insulin resistance index than gestational age (β = -0.481), weight-for-length (β =0.315), and ponderal index (β = -0.194).

CONCLUSION

Preterm birth is a risk factor for the future development of insulin resistance which may develop as early as infancy.

Preterm birth and subsequent insulin sensitivity: a systematic review

OBJECTIVE

The incidence of preterm birth is increasing worldwide. Evidence suggests that in later life these children are at increased risk of 'metabolic syndrome', which is itself associated with reduced insulin sensitivity (IS). We carried out a systematic review to examine whether preterm birth is associated with later changes in IS and whether a difference exists between those born small-for-gestational age (SGA) and appropriate-for-gestational age (AGA).

METHODS

We used the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidance to structure our review with a priori data extraction criteria to answer the questions posed and then carried out our literature search. Only papers which included preterm infants in their study population and specifically assessed IS were included. Findings are reported by age group to enable change over the life course to be examined, even though the studies were mostly cross-sectional, observation studies.

RESULTS

We identified and reviewed 26 suitable publications representing 20 separate cohorts, of which 16 had a term control group. The heterogeneity of the methods used to measure IS precluded meta-analysis. In infancy and early childhood there is a measurable association between IS and preterm birth. In later childhood and adulthood the strength of this association reduces, and current body composition becomes the variable most strongly associated with IS.

CONCLUSIONS

There is an association between preterm birth and IS throughout the life course, but the data are conflicting and associations are likely to be affected by the heterogeneity of each study population and multiple confounding factors that may change over time. While the optimal nutritional strategy for preterm infants remains to be determined, standard public health guidance to avoid obesogenic lifestyle factors remains equally important to individuals born preterm.

Preterm birth and the metabolic syndrome in adult life: a systematic review and meta-analysis

BACKGROUND

Preterm birth is associated with features of the metabolic syndrome in later life. We performed a systematic review and meta-analysis of studies reporting markers of the metabolic syndrome in adults born preterm.

METHODS

Reports of metabolic syndrome-associated features in adults (≥18 years of age) born at <37-week gestational age and at term (37- to 42-week gestational age) were included. Outcomes assessed were BMI, waist-hip ratio, percentage fat mass, systolic (SBP) and diastolic (DBP) blood pressure, 24-hour ambulatory SBP and DBP, flow-mediated dilatation, intima-media thickness, and fasting glucose, insulin, and lipid profiles.

RESULTS

Twenty-seven studies, comprising a combined total of 17,030 preterm and 295,261 term-born adults, were included. In adults, preterm birth was associated with significantly higher SBP (mean difference, 4.2 mm Hg; 95% confidence interval [CI], 2.8 to 5.7; P < .001), DBP (mean difference, 2.6 mm Hg; 95% CI, 1.2 to 4.0; P < .001), 24-hour ambulatory SBP (mean difference, 3.1 mm Hg; 95% CI, 0.3 to 6.0; P = .03), and low-density lipoprotein (mean difference, 0.14 mmol/L; 95% CI, 0.05 to 0.21; P = .01). The preterm-term differences for women was greater than the preterm-term difference in men by 2.9 mm Hg for SBP (95% CI [1.1 to 4.6], P = .004) and 1.6 mm Hg for DBP (95% CI [0.3 to 2.9], P = .02).

CONCLUSIONS

For the majority of outcome measures associated with the metabolic syndrome, we found no difference between preterm and term-born adults. Increased plasma low-density lipoprotein in young adults born preterm may represent a greater risk for atherosclerosis and cardiovascular disease in later life. Preterm birth is associated with higher blood pressure in adult life, with women appearing to be at greater risk than men.

Leptin may enhance hepatic insulin sensitivity in children and women born small for gestational age

OBJECTIVE

Children born small for gestational age (SGA) are at risk for developing type 2 diabetes. Lipodystrophy leads to early type 2 diabetes and leptin reverses the metabolic consequences of the disease. Low IGF-binding protein 1 (IGFBP1) can predict the development of type 2 diabetes. The aim of this study was to determine leptin, insulin, and IGFBP1 in children and adult women born preterm or SGA to evaluate the role of leptin as a compensatory mechanism in insulin resistance development.

METHODS

Seventy-six children (8.5-10 years, 41 girls and 35 boys) and 45 women (23-30 years) were studied. The children comprised subjects born appropriate for gestational age (<30 gestational weeks) (n=22), born SGA at term (n=23), and full-term normal-weight controls (n=31). Among the women, the corresponding figures were, n=10, n=18, and n=17 respectively. Fasting levels of IGFBP1, leptin, insulin, and IGF1 were determined and total adiponectin only in women.

RESULTS

In girls and women, term SGA subjects had higher leptin levels in relation to BMI SDS (P=0.042 and P=0.03 respectively). More than half of IGFBP1 variability was explained by leptin and insulin in children. In term SGA women, IGFBP1 level was lower compared with controls (P=0.012) and the regression line of IGFBP1 on insulin was suppressed below -1 s.d. of a reference material.

CONCLUSION

Leptin levels were elevated in term SGA girls and women, in particular in adult women, but not found in preterm girls and women. IGFBP1 was lower in term SGA women. In children, leptin and insulin were strong suppressors of IGFBP1. We speculate that higher leptin levels could be a protective event to enhance hepatic insulin sensitivity.

Feeding preterm infants today for later metabolic and cardiovascular outcomes

Preterm birth continues to contribute disproportionately to neonatal morbidity and subsequent physical and neurodevelopmental disabilities. Epidemiologic studies have described additional long-term health consequences of preterm birth such as an increased risk of hypertension and insulin resistance in adult life. It is not known whether the influence of infant and childhood growth rates and early nutrition on long-term outcomes is the same or different among preterm infants and neonates with intrauterine growth restriction. Our goal is to review the effects of fetal growth, postnatal growth, and early nutrition on long-term cardiovascular and metabolic outcomes in preterm infants. Present evidence suggests that even brief periods of relative undernutrition during a sensitive period of development have significant adverse effects on later development. Our review suggests that growth between birth and expected term and 12-18 months post-term has no significant effect on later blood pressure and metabolic syndrome, whereas reduced growth during hospitalization significantly impacts later neurodevelopment. In contrast, growth during late infancy and childhood appears to be a major determinant of later metabolic and cardiovascular well being, which suggests that nutritional interventions during this period are worthy of more study. Our review also highlights the paucity of well-designed, controlled studies in preterm infants of the effects of nutrition during hospitalization and after discharge on development, the risk of developing hypertension, or insulin resistance.

Differences in insulin resistance markers between children born small for gestational age or born preterm appropriate for gestational age

AIM

To evaluate the impact of prenatal or postnatal compromised environment on glucose homoeostasis in children born preterm and appropriate for gestational age or small for gestational age (SGA) at term.

METHOD

Seventy-seven children (median 9.9 years, range 8.5-10) born at Karolinska Hospital were allocated to three groups: 21 subjects born before 30 weeks of gestational age (preterm), 26 SGA at term and 30 at term with appropriate birth weight (control). Anthropometric measurements were taken, and fasting blood samples for haemoglobin A1c, glucose, insulin, IGFBP-1, IGF-1 and lipid profile were taken. Glucose, insulin and IGFBP-1 samples were taken at 0, 30 and 120 min during an oral glucose tolerance test (OGTT).

RESULTS

Subjects born preterm or SGA were shorter and thinner compared with Controls. After adjustment for body mass index (BMI), the SGA group had higher basal insulin levels (p = 0.029), higher homoeostasis model assessment-insulin resistance (p = 0.012) and lower whole-body insulin sensitivity index (p = 0.007) than Controls. IGFBP-1 decrease during OGTT was attenuated in the Preterm group compared with the Control (p = 0.045) and SGA groups (p = 0.007).

CONCLUSION

The higher fasting insulin level in the SGA children, adjusted for BMI, could indicate peripheral insulin resistance. Preterm born children had reduced suppression of IGFBP-1 during OGTT, suggesting hepatic insulin resistance.

Insulin resistance and adiponectin levels are associated with height catch-up growth in pre-pubertal Chinese individuals born small for gestational age

Abstracts

Early markers of adult obesity: a review

The purpose of this review was to evaluate factors in early childhood (≤5 years of age) that are the most significant predictors of the development of obesity in adulthood. Factors of interest included exposures/insults in the prenatal period, infancy and early childhood, as well as other socio-demographic variables such as socioeconomic status (SES) or birth place that could impact all three time periods. An extensive electronic and systematic search initially resulted in 8,880 citations, after duplicates were removed. Specific inclusion and exclusion criteria were set, and following two screening processes, 135 studies were retained for detailed abstraction and analysis. A total of 42 variables were associated with obesity in adulthood; however, of these, only seven variables may be considered as potential early markers of obesity based on the reported associations. Possible early markers of obesity included maternal smoking and maternal weight gain during pregnancy. Probable early markers of obesity included maternal body mass index, childhood growth patterns (early rapid growth and early adiposity rebound), childhood obesity and father's employment (a proxy measure for SES in many studies). Health promotion programmes/agencies should consider these factors as reasonable targets to reduce the risk of adult obesity.

Early markers of adult obesity: a review

The purpose of this review was to evaluate factors in early childhood (≤5 years of age) that are the most significant predictors of the development of obesity in adulthood. Factors of interest included exposures/insults in the prenatal period, infancy and early childhood, as well as other socio-demographic variables such as socioeconomic status (SES) or birth place that could impact all three time periods. An extensive electronic and systematic search initially resulted in 8,880 citations, after duplicates were removed. Specific inclusion and exclusion criteria were set, and following two screening processes, 135 studies were retained for detailed abstraction and analysis. A total of 42 variables were associated with obesity in adulthood; however, of these, only seven variables may be considered as potential early markers of obesity based on the reported associations. Possible early markers of obesity included maternal smoking and maternal weight gain during pregnancy. Probable early markers of obesity included maternal body mass index, childhood growth patterns (early rapid growth and early adiposity rebound), childhood obesity and father's employment (a proxy measure for SES in many studies). Health promotion programmes/agencies should consider these factors as reasonable targets to reduce the risk of adult obesity.

Insulin-like growth factor-binding protein-1: serum levels, promoter polymorphism, and associations with components of the metabolic syndrome in short subjects born small for gestational age

CONTEXT

IGF binding protein (IGFBP)-1 is the only acute regulator of IGF-I bioavailability. Its production is suppressed by insulin, and low levels are associated with hyperinsulinemia and cardiovascular disease risk in adults. Data on IGFBP-1 levels in short, small for gestational age (SGA) subjects are scarce, and associations with IGFBP1 promoter single nucleotide polymorphisms have not been established.

OBJECTIVE

The aim of the study was to determine IGFBP-1 levels in short SGA subjects compared with those in controls, to assess genotype frequency of the -575 G/A single nucleotide polymorphism, and to determine its impact on IGFBP-1 levels.

SUBJECTS

A total of 272 short subjects born SGA and 330 subjects with normal stature (245 children, 85 young adults) participated in the study.

OUTCOME MEASURES

We measured fasting levels of IGFBP-1, IGF-I, insulin and lipid parameters, and body composition.

RESULTS

IGFBP-1 sd score (SDS) was comparable to controls in lean, short, SGA children but significantly lower in short SGA adults with normal fat mass (P < 0.001). IGFBP-1 SDS correlated significantly with insulin levels, systolic blood pressure SDS, and various lipid parameters. Baseline IGFBP-1 SDS was lowest in SGA children with -575 GG genotype and significantly higher in SGA children with one or two copies of the A allele. In response to a given insulin level, children with the AA genotype had a significantly higher IGFBP-1 SDS compared to children with the GG genotype.

CONCLUSION

Normal IGFBP-1 levels in lean, short, SGA children may reflect a normal metabolic state, despite reported hyperinsulinemia. IGFBP-1 is modulated by polymorphic variability and seems to be an additional player in the complex interaction between the IGF-IGFBP axis, glucose homeostasis, and lipid metabolism.

Mechanisms underlying developmental programming of elevated blood pressure and vascular dysfunction: evidence from human studies and experimental animal models

Cardiovascular-related diseases are the leading cause of death in the world in both men and women. In addition to the environmental and genetic factors, early life conditions are now also considered important contributing elements to these pathologies. The concept of 'fetal' or 'developmental' origins of adult diseases has received increased recognition over the last decade, yet the mechanism by which altered perinatal environment can lead to dysfunction mostly apparent in the adult are incompletely understood. This review will focus on the mechanisms and pathways that epidemiological studies and experimental models have revealed underlying the adult cardiovascular phenotype dictated by the perinatal experience, as well as the probable key causal or triggering elements. Programmed elevated blood pressure in the adult human or animal is characterized by vascular dysfunction and microvascular rarefaction. Developmental mechanisms that have been more extensively studied include glucocorticoid exposure, the role of the kidneys and the renin-angiotensin system. Other pathophysiological pathways have been explored, such as the role of the brain and the sympathetic nervous system, oxidative stress and epigenetic changes. As with many complex diseases, a unifying hypothesis linking the perinatal environment to elevated blood pressure and vascular dysfunction in later life cannot be presumed, and a better understanding of those mechanisms is critical before clinical trials of preventive or 'deprogramming' measures can be designed.

Comparison of leptin levels, body composition and insulin sensitivity and secretion by OGTT in healthy, early pubertal girls born at either appropriate- or small-for-gestational age

BACKGROUND

Small for gestational age (SGA) has been associated with decreased insulin sensitivity (IS). A possible mechanism is the postnatal development of a metabolically disadvantageous body composition (BC).

AIM

To determine whether there are differences between IS and BC in girls in early puberty who were SGA (birth weight < 10th percentile) or appropriate for gestational age (AGA, 10th-90th percentile).

METHODS

Age-matched (SGA/AGA) early pubertal girls (Tanner II) were recruited from local schools. We determined waist circumference (WC), the sum of four skinfolds (S4S), and per cent fat mass (fat %) by impedanciometry. Leptin and OGTT assays were performed. The insulinogenic index (I-In), HOMA-IR (homeostasis model assessment of insulin resistance) and WBISI (whole body insulin sensitivity) were calculated.

RESULTS

Median age (interquartile range) for 30 SGA and 35 AGA girls was 10.2 (1.1) vs. 9.8 (0.9), respectively (P = NS). BMI percentiles were 62.6 (56) vs. 67.4 (39); WC 60.5 (9.5) vs. 62.2 (6.5) cm; S4S 52 (30) vs. 52.2 (29.5) cm, and fat %[26.2 (6.7) vs. 28.5 (6.3)] was similar in both groups. SGA girls had higher leptin levels [15.4 (9.7) vs. 9.6 (11) ng/ml; P = 0.01] and I-In [2.05 (1.86) vs. 1.47 (1.27) microU/ml* mg/dl; P = 0.02]. No differences between HOMA-IR [2.07 (1.26) vs. 2.04 (1.4)] and WBISI [5.3 (3.3) vs. 5.1 (3.1)] were found between groups.

CONCLUSION

The higher leptin level and I-In in girls born SGA at the beginning of puberty may be early indicators of an underlying subtle degree of insulin resistance, despite similar BMI and BC to AGA girls.

Serum levels of adiponectin and IGFBP-1 in short children born small for gestational age

OBJECTIVE

The aim of this study was to quantify serum adiponectin concentrations in short children born small for gestational age (SGA) compared with those in children born appropriate for gestational age (AGA), and to assess the relationship between the serum levels of adiponectin and insulin-like growth factor binding protein-1 (IGFBP-1) known as a predictor of the development of type 2 diabetes mellitus and cardiovascular disease.

SUBJECTS AND METHODS

Sixteen prepubertal short children born SGA and 20 short children born AGA, matched for age, body mass index, height, pubertal status, gestational age, bone age and midparental height, were included in the study. The serum levels of adiponectin, IGFBP-1, insulin and insulin-like growth factor-I (IGF-I) were measured in the fasting state.

RESULTS

The levels of serum adiponectin were significantly lower in the SGA than in AGA children (10.5 +/- 4.2 vs. 13.9 +/- 5.1 micro g/ml, P < 0.05). The levels of serum IGFBP-1, insulin and IGF-I were all similar in both groups. Overall, there was a significant positive correlation between adiponectin and IGFBP-1 (r = 0.40, P < 0.05).

CONCLUSIONS

Our results suggest that hypoadiponectinaemia in short SGA children without catch-up growth may reflect insulin resistance and imply a higher risk of developing type 2 diabetes mellitus. Additionally, adiponectin may be a more sensitive indicator for latent insulin resistance than IGFBP-1 in short SGA children.

Associations of the IGF/IGFBP axis and respiratory diseases in neonatal patients during the first 6 months of life

OBJECTIVES

To analyse IGFs in respect to somatic growth and neonatal diseases during the first 6 months of life.

METHODS

IGF-I, IGF-II and IGF binding proteins (IGFBP-1, -2, -3) were determined by immunoassays in neonatal patients after birth (n = 67) and at 3 (3 mo; n = 75) and 6 months (6 mo; n = 47) of corrected postnatal age. Data on growth were tested for associations to the gestational age, birth weight (bw) SDS (/-2 SDS), neonatal morbidity and therapeutic strategies.

RESULTS

All IGFs and IGFBPs changed significantly between birth and 3 mo of corrected age (p < 0.05). Perinatal respiratory diseases influenced IGF-II at 3 mo, and bronchopulmonary dysplasia IGF-II at 3 and 6 mo (all p < 0.05). IGF-I differed between the subgroups bw /-2 SDS (p < 0.05). At 3 mo, IGFBP-1 was significantly increased in infants with glucocorticoid administration during the first four weeks of life.

CONCLUSION

The first months of life are characterised by a pole reversal of the somatotropic axis: IGFBP-1 and -2 decrease and IGFBP-3 increases. Respiratory diseases with an origin in the neonatal period, glucocorticoid therapy and low birth weight have an impact on the IGF pattern up to 6 mo. Prospective studies are necessary to investigate, whether the described link between the IGF/IGFBP axis and respiratory morbidity in neonatal patients has an impact on development in later infancy.