The impact of early nutrition in premature infants on later childhood insulin sensitivity and growth

Insulin resistance prior to term age in very low birthweight infants: a prospective study

OBJECTIVE

To explore the glucose-related hormone profile of very low birthweight (VLBW) infants and assess the association between neonatal hyperglycaemia and insulin resistance during the admission period.

DESIGN

A prospective observational study-the Very Low Birth Weight Infants, Glucose and Hormonal Profiles over Time study.

SETTING

A tertiary neonatal intensive care unit and four neonatal units in county hospitals in Sweden.

PATIENTS

48 infants born <1500 g (VLBW) during 2016-2019.

OUTCOME MEASURES

Plasma concentrations of glucose-related hormones and proteins (C-peptide, insulin, ghrelin, glucagon-like peptide 1 (GLP-1), glucagon, leptin, resistin and proinsulin), insulin:C-peptide and proinsulin:insulin ratios, Homoeostatic Model Assessment 2 (HOMA2) and Quantitative Insulin Sensitivity Check (QUICKI) indices, measured on day of life (DOL) 7 and at postmenstrual age 36 weeks.

RESULTS

Lower gestational age was significantly associated with higher glucose, C-peptide, insulin, proinsulin, leptin, ghrelin, resistin and GLP-1 concentrations, increased HOMA2 index, and decreased QUICKI index and proinsulin:insulin ratio. Hyperglycaemic infants had significantly higher glucose, C-peptide, insulin, leptin and proinsulin concentrations, and lower QUICKI index, than normoglycaemic infants. Higher glucose and proinsulin concentrations and insulin:C-peptide ratio, and lower QUICKI index on DOL 7 were significantly associated with longer duration of hyperglycaemia during the admission period.

CONCLUSIONS

VLBW infants seem to have a hormone profile consistent with insulin resistance. Lower gestational age and hyperglycaemia are associated with higher concentrations of insulin resistance markers.

Comparison of direct effects of rice-thickened formula vs routine feeds on symptoms and gastroesophageal reflux indices: A crossover cohort study

BACKGROUND

We compared the direct effects of routine vs rice-thickened formula on 24-h pH-impedance and symptom characteristics and then examined if dietary effects were modified by acid reflux index severity in infants.

METHODS

Forty infants under consideration for gastroesophageal reflux disease and therapies were evaluated at 43 ± 1 weeks postmenstrual age. Each infant was equally fed routine diet and thickened formula during evaluations. Postprandial sessions were analyzed for acid reflux index, reflux events, clearance times, distal baseline impedance, and symptoms.

RESULTS

Thickened formula has no effect (P ≥ 0.05) on acid reflux events' characteristics or overall symptom frequency. However, refluxate height and frequency of weakly acidic events and cough were decreased (P < 0.05). Prolonged bolus clearance and a decrease in distal baseline impedance were noted with thickened feeds (vs routine feeds) when acid reflux index was >7 (P < 0.05).

CONCLUSION

Our pH-impedance testing protocol identifies direct effects of potential therapies at the point of care. Acutely, thickened formula does not impact acid-specific reflux indices but decreases full-column reflux and cough reflexes. In those with an acid reflux index of >7, thickened formula prolongs the distal esophageal bolus clearance (the mechanisms of which are uncertain). Clinical trials are needed to clarify objective indications and therapeutic use of thickened formulas for infants with gastroesophageal reflux disease, along with short- and long-term side effects.

Improved Macro- and Micronutrient Supply for Favorable Growth and Metabolomic Profile with Standardized Parenteral Nutrition Solutions for Very Preterm Infants

Very preterm infants are at high risk for suboptimal nutrition in the first weeks of life leading to insufficient weight gain and complications arising from metabolic imbalances such as insufficient bone mineral accretion. We investigated the use of a novel set of standardized parenteral nutrition (PN; MUC PREPARE) solutions regarding improving nutritional intake, accelerating termination of parenteral feeding, and positively affecting growth in comparison to individually prescribed and compounded PN solutions. We studied the effect of MUC PREPARE on macro- and micronutrient intake, metabolism, and growth in 58 very preterm infants and compared results to a historic reference group of 58 very preterm infants matched for clinical characteristics. Infants receiving MUC PREPARE demonstrated improved macro- and micronutrient intake resulting in balanced electrolyte levels and stable metabolomic profiles. Subsequently, improved energy supply was associated with up to 1.5 weeks earlier termination of parenteral feeding, while simultaneously reaching up to 1.9 times higher weight gain at day 28 in extremely immature infants (<27 GA weeks) as well as overall improved growth at 2 years of age for all infants. The use of the new standardized PN solution MUC PREPARE improved nutritional supply and short- and long-term growth and reduced PN duration in very preterm infants and is considered a superior therapeutic strategy.

Early supplementation of folate and vitamin B12 improves insulin resistance in intrauterine growth retardation rats

BACKGROUND

Insulin sensitivity is changed during the neonatal period in small for gestational age (SGA) infants. Yet, the interventional strategies are still limited. We aimed to investigate the effects of supplementation with high folate and vitamin B12 diets in the early postnatal period on the changes in insulin sensitivity in an intrauterine growth retardation (IUGR) rat model.

METHODS

IUGR rat model was established by both low-protein diet feeding and daily diet restriction. High folate and vitamin B12 diet was supplied in IUGR as nutritional interventional group (IUGR-I), otherwise, the non-intervened IUGR group (IUGR-NI). In this study, male rats were studied in order to avoid hormonal and gender influence. At 21, 60 and 120 days, fasting plasma glucose, insulin, triglyceride, cholesterol, and homocysteine levels were measured among the control, IUGR-I, and IUGR-NI groups. Pearson analysis was used to evaluate the correlation between homocysteine and fasting blood glucose, insulin, HOMA-IR, triglyceride, and cholesterol levels.

RESULTS

We established IUGR rat model by both low protein and restricted diet feeding during pregnancy and the incidence of IUGR pups was 93.33%. There was no difference in fasting glucose, insulin, HOMA-IR, triglyceride and cholesterol levels between the control, the IUGR-NI and the IUGR-I group at day 21. At day 60, insulin, HOMA-IR and triglyceride levels in the IUGR-I group were remarkably lower than those in the IUGR-NI group, but still higher than those in the control group (F=38.34, P=0.02; F=49.48, P=0.02; F=17.93, P<0.001, respectively). At day 120, glucose, insulin, HOMA-IR and Hcy levels in the IUGR-I group were obviously lower than those in the IUGR-NI group, although still higher than those in the control group (F=21.60, P<0.001; F=164.46, P<0.001; F=75.15, P<0.001; F=35.46, P<0.001, respectively). There were no significant differences in triglyceride and cholesterol levels between the IUGR-I group and the control group at day 120. At 120-day, homocysteine in IUGR-I group was highly positively correlated with fasting glucose and HOMA-IR (r=0.863, P=0.006; r=0.725, P=0.042, respectively); Only homocysteine was positively correlated with fasting glucose in IUGR-NI group (r=0.721, P=0.044).

CONCLUSIONS

Early supplementation of folate and vitamin B12 improved insulin resistance and lipid levels in IUGR rats to some extent, along with decreasing homocysteine levels, but not enough to completely repair glucose and lipid metabolism.

Postnatal growth and gut microbiota development influenced early childhood growth in preterm infants

BACKGROUND

Preterm infants are at high risk for growth failure and childhood weight problems due to the disruption of normal intrauterine growth and nutrition. Early nutritional support and microbiome acquisition can play an important role in childhood growth.

OBJECTIVE

Our study examined potential postnatal indicators, including gut bacterial compositions, macronutrients, and catch-up growth, of growth pattern from infancy into early childhood.

METHODS

This is a retrospective study of preterm infants born < 35 weeks who were followed up in the university complex care clinic from 2012-2018. Weight and length z-scores at birth, 1, 2, 4, 6, 12 and 15 months, and body mass index (BMI) and length z-scores from 2 to 5 years of age were collected. Catch-up growths were calculated by changes in z-scores and divided into early (birth-4 months) and late (4-18 months). Postnatal nutritional data and fecal samples were collected. Fecal microbiome data obtained from 16S RNA V4 sequencing was analyzed against clinical and growth data using a regression model.

RESULTS

160 infants included in the final analysis had birth weight and gestational age of 1,149 ± 496 grams and 28 ± 3 weeks. Early weight gain positively correlated with length z-scores but not with BMI at 2 years of age. BMI at 2 years of age strongly correlated with BMI at 3, 4, and 5 years of age. Postnatal abundance of Gammaproteobacteria was negatively associated with early growth while Bacteroides and Lactobacillus were positively associated with childhood BMI.

CONCLUSION

Our findings suggest that optimal postnatal nutrition promoted early catch-up growth in weight as well as improved linear growth without influence on childhood BMI. Postnatal gut microbial colonization, which is a modifiable factor, was associated with childhood growth in preterm infants.

Early weight gain trajectories and body composition in infancy in infants born very preterm

BACKGROUND

Concerns are raised about the influence of rapid growth on excessive fat mass (FM) gain in early life and later cardiometabolic health of infants born preterm.

OBJECTIVES

To study the association between postnatal weight gain trajectories and body composition in infancy in infants born very preterm.

METHODS

In infants born <30 weeks gestation, we evaluated associations between weight Z-score trajectories for three consecutive timeframes (NICU stay, level-II hospital stay and at home) and body composition, measured at 2 and 6 months corrected age by air-displacement plethysmography.

RESULTS

Of 120 infants included, median gestational age at birth was 27⁺⁵ (interquartile range 26⁺¹ ;28⁺⁵ ) and birth weight 1015 g (801;1250). The majority of infants did not make up for their initial loss of weight Z-score, but growth and later body composition were within term reference values. Weight gain during NICU stay was not associated with fat mass (absolute, %FM or FM index) in infancy. Weight gain during NICU and level II hospital stay was weakly associated with higher absolute lean mass (LM), but not after adjustment for length (LM index). Weight gain in the level-II hospital was positively associated with fat mass parameters at 2 months but not at 6 months. Strongest associations were found between weight gain at home and body composition (at both time points), especially fat mass.

CONCLUSIONS

Weight gain in different timeframes after preterm birth is associated with distinct parameters of body composition in infancy, with weight gain at home being most strongly related to fat mass.

Lower insulin sensitivity remains a feature of children born very preterm

BACKGROUND

The first report of children born very preterm (<32 weeks of gestation) having insulin resistance was made 16 years ago. However, neonatal care has improved since. Thus, we aimed to assess whether children born very preterm still have lower insulin sensitivity than term controls.

METHODS

Participants were prepubertal children aged 5 to 11 years born very preterm (<32 weeks of gestation; n = 51; 61% boys) or at term (37-41 weeks; n = 50; 62% boys). Frequently sampled intravenous glucose tolerance tests were performed, and insulin sensitivity was calculated using Bergman's minimal model. Additional clinical assessments included anthropometry, body composition using whole-body dual-energy X-ray absorptiometry scans, clinic blood pressure, and 24-hour ambulatory blood pressure monitoring.

RESULTS

Children born very preterm were 0.69 standard deviation score (SDS) lighter (P < .001), 0.53 SDS shorter (P = .003), and had body mass index 0.57 SDS lower (P = .003) than children born at term. Notably, children born very preterm had insulin sensitivity that was 25% lower than term controls (9.4 vs 12.6 × 10^-4 minutes^-1 ·[mU/L]; P = .001). Other parameters of glucose metabolism, including fasting insulin levels, were similar in the two groups. The awake systolic blood pressure (from 24-hour monitoring) tended to be 3.1 mm Hg higher on average in children born very preterm (P = .054), while the clinic systolic blood pressure was 5.4 mm Hg higher (P = .002).

CONCLUSIONS

Lower insulin sensitivity remains a feature of children born very preterm, despite improvements in neonatal intensive care. As reported in our original study, our findings suggest the defect in insulin action in prepubertal children born very pretermis primarily peripheral and not hepatic.

Antenatal and neonatal factors contributing to extra uterine growth failure (EUGR) among preterm infants in Boston Birth Cohort (BBC)

OBJECTIVE

Identify antenatal and neonatal factors associated with primary outcome of EUGR.

METHODS

1063 preterm infants from a subset of the BBC were included in this prospective cohort study. Regression analysis was carried out to evaluate associations of EUGR with antenatal factors and neonatal factors.

RESULTS

6.1% of the infants had in-utero growth restriction (IUGR) at birth and 21.7% of infants had EUGR. The adjusted odds ratio for EUGR status were significant for birth weight (OR 0.99, p = 0.00, CI 0.99-0.99), for GA at birth (OR 4.58, p = 0.00, CI 3.25-6.44), for PDA (OR 2.9, p = 0.02, CI 1.17-7.1), for NEC (OR 5.14, p = 0.012, CI 1.44-18.3) and for day of life of reaching full feeds (OR 1.04, p = 0.001, CI 1.01-1.06).

CONCLUSION

This study highlights important factors associated with EUGR. Additional studies are needed to gain further insight.

Early postnatal nutrition after preterm birth and cardiometabolic risk factors in young adulthood

Objectives

Adults born preterm at very low birthweight (VLBW; <1500 g) have a non-optimal cardiometabolic risk factor profile. Since higher protein intake during the first weeks of life predicted a healthier body composition in adulthood in our previous studies, we hypothesized that it would also predict a favorable cardiometabolic profile.

Study design

The Helsinki Study of VLBW Adults includes 166 VLBW and preterm infants born between 1978 and 1985. We collected postnatal nutrition data among 125 unimpaired subjects, who attended two study visits at the mean ages of 22.5 and 25.1 years. We evaluated the effects of energy and macronutrient intakes during the first three 3-week periods of life on key cardiometabolic risk factors with multiple linear regression models. We also report results adjusted for prenatal, postnatal and adult characteristics.

Results

Macronutrient and energy intakes were not associated with blood pressure, heart rate, or lipid levels in adulthood. Intakes were neither associated with fasting glucose or most other markers of glucose metabolism. An exception was that the first-three-weeks-of-life intakes predicted higher fasting insulin levels: 1 g/kg/day higher protein intake by 37.6% (95% CI: 8.0%, 75.2%), and 10 kcal/kg/day higher energy intake by 8.6% (2.6%, 14.9%), when adjusted for sex and age. These early intakes similarly predicted the adult homeostasis model assessment index. Further adjustments strengthened these findings.

Conclusions

Among VLBW infants with relatively low early energy intake, early macronutrient and energy intakes were unrelated to blood pressure, lipid levels and intravenous glucose tolerance test results. Contrary to our hypothesis, a higher macronutrient intake during the first three weeks of life predicted higher fasting insulin concentration in young adulthood.

Patterns of Infancy Growth and Metabolic Hormonal Profile Are Different in Very-Low-Birth-Weight Preterm Infants Born Small for Gestational Age Compared to Those Born Appropriate for Gestational Age

BACKGROUND/AIMS

An increased preterm birth survival rate is associated with long-term neurological and metabolic risks; thus, our aim was to evaluate whether early patterns of infancy anthropometry and metabolic hormonal profile differ in preterm infants born small for gestational age (SGA) or appropriate for gestational age (AGA) from birth to 36 months of corrected age (CA).

METHODS

We recruited 110 very-low-birth-weight (VLBW) preterm infants (AGA = 60 and SGA = 50) with a mean birth weight of -2.39 ± 0.77 versus 0.57 ± 0.54 standard deviation scores (SDS) (p < 0.01) and birth length of -2.1 ± 1.05 versus -0.44 ± 0.82 SDS (p < 0.01), respectively. Anthropometry and blood sampling for insulin, insulin-like growth factor (IGF)-II, IGF-I, and leptin were performed for up to 3 years.

RESULTS

All neonates increased their weight, length, and head circumference SDS during the early inpatient period. Up to 90% reached a normal length within this period. The IGF-II, insulin, and glycemia concentrations changed in parallel with weight. In the first year of CA, only SGA infants gained weight and height SDS. The homoeostatic model assessment had a trend toward higher values in SGA infants at 24 and 36 months (p = 0.06 and p = 0.07).

CONCLUSION

Being SGA is the strongest predictor of early recovery of height in VLBW preterm infants. Follow-up will allow us to determine whether the differences in the growth patterns of VLBW preterm infants by birth weight SDS persist.

Parenteral nutrition for preterm infants: Issues and strategy

Due to transient gut immaturity, most very preterm infants receive parenteral nutrition (PN) in the first few weeks of life. Yet providing enough protein and energy to sustain optimal growth in such infants remains a challenge. Extrauterine growth restriction is frequently observed in very preterm infants at the time of discharge from hospital, and has been found to be associated with later impaired neurodevelopment. A few recent randomized trials suggest that intensified PN can improve early growth; whether or not such early PN improves long-term neurological outcome is still unclear. Several other questions regarding what is optimal PN for very preterm infants remain unanswered. Amino acid mixtures designed for infants contain large amounts of branched-chain amino acids and taurine, but there is no consensus on the need for some nonessential amino acids such as glutamine, arginine, and cysteine. Whether excess growth in the first few weeks of life, at a time when very preterm infants receive PN, has an imprinting effect, increasing the risk of metabolic or vascular disease at adulthood continues to be debated. Even though uncertainty remains regarding the long-term effect of early PN, it appears reasonable to propose intensified initial PN. The aim of the current position paper is to review the evidence supporting such a strategy with regards to the early phase of nutrition, which is mainly covered by parenteral nutrition. More randomized trials are, however, needed to further support this type of approach and to demonstrate that this strategy improves short- and long-term outcome.

Sex-Specific Skeletal Muscle Fatigability and Decreased Mitochondrial Oxidative Capacity in Adult Rats Exposed to Postnatal Hyperoxia

Premature birth affects more than 10% of live births, and is characterized by relative hyperoxia exposure in an immature host. Long-term consequences of preterm birth include decreased aerobic capacity, decreased muscular strength and endurance, and increased prevalence of metabolic diseases such as type 2 diabetes mellitus. Postnatal hyperoxia exposure in rodents is a well-established model of chronic lung disease of prematurity, and also recapitulates the pulmonary vascular, cardiovascular, and renal phenotype of premature birth. The objective of this study was to evaluate whether postnatal hyperoxia exposure in rats could recapitulate the skeletal and metabolic phenotype of premature birth, and to characterize the subcellular metabolic changes associated with postnatal hyperoxia exposure, with a secondary aim to evaluate sex differences in this model. Compared to control rats, male rats exposed to 14 days of postnatal hyperoxia then aged to 1 year demonstrated higher skeletal muscle fatigability, lower muscle mitochondrial oxidative capacity, more mitochondrial damage, and higher glycolytic enzyme expression. These differences were not present in female rats with the same postnatal hyperoxia exposure. This study demonstrates detrimental mitochondrial and muscular outcomes in the adult male rat exposed to postnatal hyperoxia. Given that young adults born premature also demonstrate skeletal muscle dysfunction, future studies are merited to determine whether this dysfunction as well as reduced aerobic capacity is due to reduced mitochondrial oxidative capacity and metabolic dysfunction.

Neonatal Nutrition Predicts Energy Balance in Young Adults Born Preterm at Very Low Birth Weight

Epidemiological studies and animal models suggest that early postnatal nutrition and growth can influence adult health. However, few human studies have objective recordings of early nutrient intake. We studied whether nutrient intake and growth during the first 9 weeks after preterm birth with very low birth weight (VLBW, <1500 g) predict total energy intake, resting energy expenditure (REE), physical activity and food preferences in young adulthood. We collected daily nutritional intakes and weights during the initial hospital stay from hospital records for 127 unimpaired VLBW participants. At an average age 22.5 years, they completed a three-day food record and a physical activity questionnaire and underwent measurements of body composition (dual X-ray absorptiometry; n = 115 with adequate data) and REE (n = 92 with adequate data). We used linear regression and path analysis to investigate associations between neonatal nutrient intake and adult outcomes. Higher energy, protein and fat intakes during the first three weeks of life predicted lower relative (=per unit lean body mass) energy intake and relative REE in adulthood, independent of other pre- and neonatal factors. In path analysis, total effects of early nutrition and growth on relative energy intake were mostly explained by direct effects of early life nutrition. A path mediated by early growth reached statistical significance only for protein intake. There were no associations of neonatal intakes with physical activity or food preferences in adulthood. As a conclusion, higher intake of energy and nutrients during first three weeks of life of VLBW infants predicts energy balance after 20 years. This association is partly mediated through postnatal growth.

The impact of intrauterine and extrauterine weight gain in premature infants on later body composition

BackgroundThe impact of intrauterine and extrauterine growth on later insulin resistance and fat mass (FM) in very low birth weight (VLBW) infants is not well established. The aim of our study was to evaluate the effects of intrauterine and early/late extrauterine growth on later insulin resistance and body composition in VLBW infants from 6 months' corrected age (CA) to 36 months.MethodsProspective measurements of body composition by dual-energy X-ray absorptiometry and insulin resistance by homeostasis model assessment insulin resistance (HOMA-IR) along with other fasting plasma biochemistries were made in 95 VLBW infants at 6, 12, 18, and 24 months' CA and 36 months' postnatal age. Mixed-effect models were used to evaluate the effects of age, sex, maturation status, and Δweight SD score on percentage FM (PFM), FM index (FMI), fat-free mass index (FFMI), and HOMA-IR.ResultsPFM and FMI were negatively associated with a decrease in weight-SD scores from birth to 36 weeks' postmenstrual age (PMA; P=0.001) and from 36 weeks' PMA to 6 months' CA (P=0.003). PFM and FMI were higher in AGA than in small for gestational age (SGA) infants. HOMA-IR was not associated with the Δweight-SD scores in either period.ConclusionsCatch-down growth in terms of weight is associated with persistently lower adiposity but not insulin resistance up to 36 months of age.

Insulin sensitivity, leptin, adiponectin, resistin, and testosterone in adult male and female rats after maternal-neonatal separation and environmental stress

Care of premature infants often requires parental and caregiver separation, particularly during hypoxic and hypothermic episodes. We have established a neonatal rat model of human prematurity involving maternal-neonatal separation and hypoxia with spontaneous hypothermia prevented by external heat. Adults previously exposed to these neonatal stressors show a sex difference in the insulin and glucose response to arginine stimulation suggesting a state of insulin resistance. The current study used this cohort of adult rats to evaluate insulin resistance [homeostatic model assessment of insulin resistance (HOMA-IR)], plasma adipokines (reflecting insulin resistance states), and testosterone. The major findings were that daily maternal-neonatal separation led to an increase in body weight and HOMA-IR in adult male and female rats and increased plasma leptin in adult male rats only; neither prior neonatal hypoxia (without or with body temperature control) nor neonatal hypothermia altered subsequent adult HOMA-IR or plasma adiponectin. Adult male-female differences in plasma leptin were lost with prior exposure to neonatal hypoxia or hypothermia; male-female differences in resistin were lost in the adults that were exposed to hypoxia and spontaneous hypothermia as neonates. Exposure of neonates to daily hypoxia without spontaneous hypothermia led to a decrease in plasma testosterone in adult male rats. We conclude that neonatal stressors result in subsequent adult sex-dependent increases in insulin resistance and adipokines and that our rat model of prematurity with hypoxia without hypothermia alters adult testosterone dynamics.

The path to chronic kidney disease following acute kidney injury: a neonatal perspective

The risk of acute kidney injury (AKI) in hospitalized critically ill neonatal populations without primary renal disease continues to be high, in both term and premature infants. Observational studies have revealed high rates of chronic kidney disease (CKD) in survivors of neonatal AKI. Proposed mechanisms underlying the progression of CKD following AKI include nephron loss and hyperfiltration, vascular insufficiency and maladaptive repair mechanisms. Other factors, including prematurity and low birth weight, have an independent relationship with the development of CKD, but they may also be positive effect modifiers in the relationship of AKI and CKD. The large degree of heterogeneity in the literature on AKI in the neonatal population, including the use of various AKI definitions and CKD outcomes, has hampered the medical community's ability to properly assess the relationship of AKI and CKD in this vulnerable population. Larger prospective cohort studies with control groups which utilize recently proposed neonatal AKI definitions and standardized CKD definitions are much needed to properly quantify the risk of CKD following an episode of AKI. Until there is further evidence to guide us, we recommend that all neonates with an identified episode of AKI should have an appropriate longitudinal follow-up in order to identify CKD at its earliest stages.

Long-term metabolic risk among children born premature or small for gestational age

Accumulating evidence suggests that both the intrauterine environment and growth during early life can influence the development of chronic noncommunicable diseases, such as type 2 diabetes mellitus and cardiovascular disease, in adulthood. Here, we review the available human data supporting increased metabolic risk among children born premature or small for gestational age; the adrenal and pubertal modifications that contribute to this risk; metabolic changes that occur during adolescence and early adulthood; and approaches to potentially modify or decrease risk of metabolic disease. The risks associated with delivery at term or preterm are compared for each period of life. Knowledge of these associations is fundamental for the paediatric community to develop preventive strategies early during postnatal life.

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.

Cord Blood Levels of Insulin, Cortisol and HOMA2-IR in Very Preterm, Late Preterm and Term Newborns

INTRODUCTION

Alteration in the glucose homeostasis is still the major cause of morbidity and mortality in the newborns. Intrauterine undernutrition plays an important role in causing adult insulin resistance and diabetes but the exact cause is still unknown.

AIM

To estimate the plasma glucose, serum insulin and cortisol levels at birth in newborns at different gestational age.

MATERIALS AND METHODS

The present cross-sectional study conducted from December 2014 to June 2015 included 58 newborns enrolled as per the inclusion criteria and further categorized into Group I (very preterm; n=19; gestational age < 32 weeks), Group II (late preterm; n=20; gestational age between 32-37 weeks) and Group III (full term; n=19; gestational age >37 weeks) newborns. Venous Cord Blood (VCB) was collected and plasma glucose was analysed by GOD-POD (Glucose Oxidase-Peroxidase) method in auto analyser whereas serum insulin and cortisol were analysed by ELISA (Enzyme Linked Immunosorbent Assay). HOMA2-IR (Homeostatic Model Assessment) calculator was used to assess insulin resistance. All parametric data was expressed as mean±SD and analysed using ANOVA with Tukey's as the Post-Hoc test. Correlation analysis was done using Pearson's correlation co-efficient with scatter plot as the graphical representation.

RESULTS

Significantly increased insulin and HOMA2-IR levels were found in group I (13.7±4.7μIU/mL and 1.6±0.58 respectively) when compared to group II (8.3±2.9μIU/mL and 0.93±0.2 respectively) and group III (8.3±2.1μIU/mL and 1.03±0.26 respectively). A positive correlation between cortisol levels and gestational age (r = 0.6, n = 58, p < 0.001) and a negative correlation between insulin and gestational age (r = -0.654, n = 58, p < 0.001) was observed in the study population.

CONCLUSION

Increased levels of insulin and HOMA2-IR as seen in the very preterm newborns signify the predisposition of these newborns to development of diabetes in later stages of life. The inverse association of cortisol and insulin with gestational age suggests that cortisol could also be responsible for impaired β cell function and insulin sensitivity.

Early Protein Intake Is Associated with Body Composition and Resting Energy Expenditure in Young Adults Born with Very Low Birth Weight

BACKGROUND

Suboptimal nutrition during fetal life and early childhood may be important in early programming of health and disease. Preterm infants born with very low birth weight (VLBW; <1500 g) frequently receive inadequate neonatal nutrition; the long-term consequences are poorly known.

OBJECTIVE

We evaluated the association between early macronutrient intake and body composition in young adults born with VLBW.

METHODS

We collected comprehensive information on daily nutritional intake during the initial hospital stay for 127 participants of the Helsinki Study of Very Low Birth Weight Adults. We calculated mean daily intakes of energy, protein, fat, and carbohydrate during the first 9 wk of life. At the mean age of 22.5 y, the subjects underwent measurements of weight, height, body composition by dual-energy X-ray absorptiometry, and resting energy expenditure. The associations were examined by linear regression.

RESULTS

We found that energy, protein, and fat intakes during the first 3 wk of life, all below current recommendations, predicted adult body composition. When adjusted for sex, age, birth weight SD score, and gestational age, a 1 g · kg(-1) · d(-1) higher protein intake predicted 11.1% higher lean body mass (LBM) (95% CI: 3.7%, 18.9%) and 8.5% higher resting energy expenditure (REE) (95% CI: 0.2%, 17.0%). Among those born before 28 wk of gestation, the numbers were 22.5% (95% CI: 1.9%, 47.4%) for LBM and 22.1% (95% CI: 3.6%, 44.0%) for REE. Similar associations were seen with energy (P = 0.01, P = 0.05) and fat (P < 0.01, P = 0.03) but not with carbohydrate. Energy intake was also associated with BMI (P = 0.01) and fat intake with BMI (P < 0.01) and percentage body fat (P = 0.05). The results were little changed when adjusted for prenatal and postnatal characteristics.

CONCLUSIONS

At relatively low neonatal protein intake levels, additional protein intake is reflected in a healthier body composition, accompanied by a higher metabolic rate, in young adults born with VLBW 20 y earlier.

Effects of postnatal growth restriction and subsequent catch-up growth on neurodevelopment and glucose homeostasis in rats

Background

There is increasing evidence that poor growth of preterm infants is a risk factor for poor long-term development, while the effects of early postnatal growth restriction are not well known. We utilized a rat model to examine the consequences of different patterns of postnatal growth and hypothesized that early growth failure leads to impaired development and insulin resistance. Rat pups were separated at birth into normal (N, n = 10) or restricted intake (R, n = 16) litters. At d11, R pups were re-randomized into litters of 6 (R-6), 10 (R-10) or 16 (R-16) pups/dam. N pups remained in litters of 10 pups/dam (N-10). Memory and learning were examined through T-maze test. Insulin sensitivity was measured by i.p. insulin tolerance test and glucose tolerance test.

Results

By d10, N pups weighed 20 % more than R pups (p < 0.001). By d15, the R-6 group caught up to the N-10 group in weight, the R-10 group showed partial catch-up growth and the R-16 group showed no catch-up growth. All R groups showed poorer scores in developmental testing when compared with the N-10 group during T-Maze test (p < 0.05). Although R-16 were more insulin sensitive than R-6 and R-10, all R groups were more glucose tolerant than N-10.

Conclusion

In rats, differences in postnatal growth restriction leads to changes in development and in insulin sensitivity. These results may contribute to better elucidating the causes of poor developmental outcomes in human preterm infants.

Effects of protein intake on blood pressure, insulin sensitivity and blood lipids in children: a systematic review

High protein intake in early childhood is associated with obesity, suggesting possible adverse effects on other cardiometabolic outcomes. However, studies in adults have suggested beneficial effects of protein intake on blood pressure (BP) and lipid profile. Whether dietary protein intake is associated with cardiovascular and metabolic health in children is unclear. Therefore, we aimed to systematically review the evidence on the associations of protein intake with BP, insulin sensitivity and blood lipids in children. We searched the databases Medline, Embase, Cochrane Central and PubMed for interventional and observational studies in healthy children up to the age of 18 years, in which associations of total, animal and/or vegetable protein intake with one or more of the following outcomes were reported: BP; measures of insulin sensitivity; cholesterol levels; or TAG levels. In the search, we identified 6636 abstracts, of which fifty-six studies met all selection criteria. In general, the quality of the included studies was low. Most studies were cross-sectional, and many did not control for potential confounders. No overall associations were observed between protein intake and insulin sensitivity or blood lipids. A few studies suggested an inverse association between dietary protein intake and BP, but evidence was inconclusive. Only four studies examined the effects of vegetable or animal protein intake, but with inconsistent results. In conclusion, the literature, to date provides insufficient evidence for effects of protein intake on BP, insulin sensitivity or blood lipids in children. Future studies could be improved by adequately adjusting for key confounders such as energy intake and obesity.

Instability of glucose values in very preterm babies at term postmenstrual age

OBJECTIVE

To determine if very preterm (VPT) babies are capable of maintaining glucose levels within normal ranges at or near term postmenstrual age.

STUDY DESIGN

Glucose levels were intermittently or continuously monitored during 48 hours in a cohort of 60 VPT infants near hospital discharge. Hypoglycemic (≤45 mg/dL, 2.5 mmol/L) and hyperglycemic (≥140 mg/dL or 7.8 mmol/L, severe if ≥180 mg/dL or 10 mmol/L) episodes were considered relevant if they lasted longer than 30 minutes. Feeding regimes followed current practice.

RESULTS

With intermittent capillary, 2 hypoglycemic values and another 3 that were abnormally high were detected. With continuous monitoring, 6 babies (10.0%) had isolated hypoglycemia ≤45 mg/dL (2.5 mmol/L) (3 of them reaching 40 mg/dL, 2.2 mmol/L), 14 (23.3%) had isolated hyperglycemia, and 8 (13.3%) had episodes of both. The mean duration of hypoglycemia per patient was 2.8 ± 2.9 hours and 4.68 ± 4.35 hours in the case of hyperglycemia, with 12 infants becoming severely hyperglycemic. Of the 12 severely hyperglycemic patients, 5 also developed severe hypoglycemia. No specific characteristics identified the hypoglycemic babies. A history of intrauterine growth restriction (P = .037) and female sex (P = .063) seemed to increase the risk of severe hyperglycemia.

CONCLUSIONS

VPT infants continue to have abnormal glucose values, especially hyperglycemia, by the time of hospital discharge. No specific factors identify babies at higher risk for hypoglycemia, and intrauterine growth restriction and female sex seemed to predispose to hyperglycemia.

Prematurity and programming of cardiovascular disease risk: a future challenge for public health?

There is substantial epidemiological evidence linking low birth weight with adult cardiometabolic disease risk factors. This has led to the concept of 'early life programming' or the 'developmental origins of disease' which proposes that exposure to adverse conditions during critical stages of early development results in compensatory mechanisms predicted to aid survival. There is growing evidence that preterm infants, many of whom are of low birth weight, are also at increased risk of adult cardiometabolic disease. In this article, we provide a broad overview of the evidence linking preterm birth and cardiovascular disease risk and discuss potential consequences for public health.

Practical preterm parenteral nutrition: systematic literature review and recommendations for practice

Current practice in relation to the prescribing, compounding and administration of parenteral nutrition for extremely preterm infants is inconsistent and based on largely historical evidence. Increasingly there are calls for more 'aggressive' nutritional interventions to prevent 'postnatal growth failure'. However the evidence base for these recommendations is weak, and there are no long-term studies examining the impact of such practices. Here we summarise the evidence for preterm parenteral nutrition interventions. We suggest principles to guide practice based on evidence from a systematic search and review of evidence to date, and recommend actions necessary to advance the understanding of this important aspect of preterm care.

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.

The failure of cancer chemoprevention

Chemoprevention is proposed as a clinical analogue of population prevention, aimed at reducing likelihood of disease progression, not across the population, but in identified high-risk individuals and not by behavioral or lifestyle modification, but by the use of pharmaceutical agents. Cardiovascular chemoprevention is successful via control of hyperlipidemias and hypertension. However, chemoprevention of cancer is an almost universal failure: not only are some results null; even more frequently, there is an excess of disease, including disease that the agents were chosen specifically to reduce. A brief introduction is followed by the evidence for a wide variety of agents and their largely deleterious, sometimes null, and in one case, largely beneficial, consequences as possible chemopreventives. The agents include (i) those that are food derived and their synthetic analogues: β-carotene, folic acid, retinol and retinoids, vitamin E, multivitamin supplements, vitamin C, calcium and selenium and (ii) agents targeted at metabolic and hormonal pathways: statins, estrogen and antagonists, 5α-reductase inhibitors. There are two agents for which there is good evidence of benefit when the strategy is focused on those at defined high risk but where wider application is much more problematic: aspirin and tamoxifen. The major problems with cancer chemoprevention are presented. This is followed by a hypothesis to explain the failure of cancer chemoprevention as an enterprise, arguing that the central tenets that underpin it are flawed and showing why, far from doing good, cancer chemoprevention causes harm.

Fetal placental inflammation is associated with poor neonatal growth of preterm infants: a case-control study

OBJECTIVE

To determine whether there is an association between histological chorioamnionitis (HCA) and postnatal growth of preterm infants in the neonatal period.

METHOD

This case-control study is part of a larger prospective histological study on placentas performed in all deliveries prior to 32 weeks of gestation. Eligible cases involved all placentas with a diagnosis of HCA. Control subjects were those without HCA, matched 1:1 with case subjects according to gestational age (±1 week). Placental inflammatory status and serial weight gain were analyzed for all infants during the first four postnatal weeks. Based on placental inflammation extension, HCA was defined as maternal HCA (MHCA) or fetal HCA (FHCA).

RESULTS

Of the 320 mother-infant pairs, 71 (22.1%) presented with HCA (27 MHCA and 44 FHCA). Decreases in weight gain at 21 and 28 days were associated with the presence of FHCA (β coefficient ± SE = -4.40 ± 2.21, p = 0.05 and -6.92 ± 2.96, p = 0.02, respectively), whereas no significant differences were found between MHCA and no-HCA groups. FHCA and MHCA were not identified as risk factors of weekly weight gain, after adjusting for possible confounders (maternal ethnicity, parity, smoking during pregnancy, infant gender, IUGR status, SGA status, antenatal steroids, total fluid intake, late-onset sepsis, BPD).

CONCLUSIONS

We found an association between fetal placental inflammation and poor neonatal growth but we were not able to identify a specific week wherein weight gain could be mostly affected. Placental findings may be used to identify preterm infants at risk of postnatal growth failure.

Four-week nutritional audit of preterm infants born <33 weeks gestation

AIM

Preterm nutritional audits have previously been conducted using assumed milk composition. We audited protein and energy intakes in the first 28 days of preterm life using both assumed milk composition and milk analysis to assess their effect on weight gain and to determine if the recommended reasonable range of intakes were met.

METHODS

Parenteral and enteral intakes and weight gain were recorded daily for infants (n = 63) born <33 weeks gestation, using assumed milk composition. Macronutrient composition was determined by milk analysis for a subset of infants (n = 36). Linear mixed models analysis was used to assess the influence of energy and protein intakes on weight gain.

RESULTS

(Data median (range)): Infants (n = 63) gestation and birth weight were 30 (24-32) weeks and 1400 (540-2580) g, respectively. Macronutrient milk composition was variable: protein 16.6 (13.4-27.6) g/L, fat 46.1 (35.0-62.4) g/L, lactose 68.0 (50.9-74.8) g/L, energy 3074 (2631-3761) kJ/L. Intakes based on measured composition differed from assumed. Protein intake was significantly associated with weight gain. Compared to infants with longer gestations, those born <28 weeks gestation were fed lower volumes, were more reliant on parenteral nutrition, took an additional seven days to transition to fortified feeds and median weight gain velocity took a fortnight longer to reach targets.

CONCLUSION

Preterm milk composition is variable and routine fortification using assumed composition may result in inappropriate nutrition. Fortification regimens stratified by birth gestation may be necessary to achieve preterm nutrition and growth targets. Milk analysis is required for accurate nutritional audit.

Embryo-transfer of the F2 postnatal calorie restricted female rat offspring into a control intra-uterine environment normalizes the metabolic phenotype

OBJECTIVE

Postnatal calorie and growth restriction (PNGR) in the first generation (F1) rat female offspring causes a lean and glucose tolerant phenotype associated with hypoinsulinemia and reduced glucose-stimulated insulin secretion (GSIS). Despite the absence of gestational hyperglycemia in the F1 PNGR female, naturally born second generation (F2) PNGR female adult offspring reportedly exhibit obesity, hyperglycemia with insulin resistance. The objective of this study was to determine the role of the intrauterine environment on the heritability of the trans-generational phenotypic expression in the F2 PNGR female adult offspring.

MATERIALS/METHODS

We performed embryo transfer (ET) of the F2 embryos from the procreating F1 pregnant PNGR or control (CON) females to gestate in control recipient rat mothers. Employing stable isotopes glucose metabolic kinetics was determined.

RESULTS

Birth weight, postnatal growth pattern and white adipose tissue in female F2 ET-PNGR were similar to ET-CON. Similarly, no differences in basal glucose and insulin concentrations, GSIS, glucose futile cycling and glucose clearance were seen. When compared to F2 ET-CON, F2 ET-PNGR showed no overall difference in glucose or hepatic glucose production (HGP) AUCs with minimal hyperglycemia (p<0.04) as a result of unsuppressed endogenous HGP (p<0.02) observed only during the first phase of IVGTT.

CONCLUSIONS

We conclude that the lean, glucose tolerant and hypoinsulinemic phenotype with reduced GSIS in the F1 generation is nearly normalized when the embryo-transferred F2 offspring gestates in a normal metabolic environment. This observation supports a role for the intra-uterine environment in modifying the heritability of the trans-generational PNGR phenotype.

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.

Early nutritional determinants of intrahepatocellular lipid deposition in preterm infants at term age

BACKGROUND

We have previously shown that by term age, preterm infants have elevated intrahepatocellular lipid (IHCL) content and altered regional adiposity, both of which are risk factors for cardiometabolic illness in adult life. Preterm nutritional intake is a plausible determinant of these aberrant trajectories of development.

OBJECTIVE

We aimed to establish if macronutritional components of the preterm diet were determinants of IHCL deposition measured at term equivalent age, using (1)H Magnetic Resonance spectroscopy (MRS).

METHODS

Prospective observational case-control study in a single UK neonatal unit. (1)H MR spectra were acquired from 18 preterm infants (<32 weeks gestational age at birth) at term age and 31 healthy term infants, who acted as a control group. Neonatal nutritional information was collected from birth to 34(+6) weeks postmenstrual age.

RESULTS

IHCL (median, interquartile range) was significantly higher in preterm-at-term infants compared with term-born infants: 0.735, 0-1.46 versus 0.138, 0-0.58; P=0.003. In preterm infants, IHCL was positively correlated with lipid intake in the first week of life (r=0.52, P=0.04).

CONCLUSIONS

This study confirms our previous observation of elevated IHCL in preterm infants at term and suggests that early lipid intake may be a determinant. Future work is warranted to establish the clinical relevance and the role of nutritional intervention in attenuating or exacerbating this effect in preterm infants.

Parenteral nutrition additive shortages: the short-term, long-term and potential epigenetic implications in premature and hospitalized infants

Nutrition support practitioners are currently dealing with shortages of parenteral nutrition micronutrients, including multivitamins (MVI), selenium and zinc. A recent survey from the American Society of Enteral and Parenteral Nutrition (ASPEN) indicates that this shortage is having a profound effect on clinical practice. A majority of respondents reported taking some aggressive measures to ration existing supplies. Most premature infants and many infants with congenital anomalies are dependent on parenteral nutrition for the first weeks of life to meet nutritional needs. Because of fragile health and poor reserves, they are uniquely susceptible to this problem. It should be understood that shortages and rationing have been associated with adverse outcomes, such as lactic acidosis and Wernicke encephalopathy from thiamine deficiency or pulmonary and skeletal development concerns related to inadequate stores of Vitamin A and D. In this review, we will discuss the current parenteral shortages and the possible impact on a population of very low birth weight infants. This review will also present a case study of a neonate who was impacted by these current shortages.

Is carbohydrate intake in the first years of life related to future risk of NCDs?

Studies on children's carbohydrate intake, especially fibre intake, and its associations with later health are rare. The current recommendations for fibre intake in children are based on average assumptions and data extrapolated from intakes in adults. Generally, increase in whole-grain consumption and decrease in sucrose intake are considered healthy. Due to fibre's high bulk volume however, excessive dietary fibre has been feared to decrease energy density have effects on growth, at least in developing countries and in children consuming very restricted diets. Furthermore, it has been speculated that if fats are reduced from the diet, it may become high in sucrose. In STRIP study, which is a long-term, randomized controlled trial designed to decrease the exposure of children to known risk factors of atherosclerosis, carbohydrate intakes have been investigated in detail in children aged 13 months to 9 years. The intervention was successful in decreasing saturated fat intake and cholesterol concentrations throughout childhood and adolescence. The study results also show that a higher than average fibre intake does not displace energy or disturb growth in children and that children with high fibre intake have better dietary quality than those with low fibre intake. Dietary fibre intake associated with lower serum total cholesterol concentrations whereas increases in total carbohydrate, sucrose and fructose intakes associated with increases in serum triglyceride concentrations. In conclusion, from the point of view of CHD risk factor prevention, efforts aiming at increasing the fibre intake while restricting that of refined sugar seem justified in the child population in developed countries.

CLINICAL TRIAL REGISTRATION INFORMATION

NCT00223600.

Birth-weight, insulin levels, and HOMA-IR in newborns at term

Background

Recent studies have demonstrated that low and high birth-weight at birth are risk factors of developing diabetes. The aim of this study was to determine if the abnormal birth-weight is related with hyperinsulinemia and elevated index of the Homeostasis Model assessment for Insulin Resistance (HOMA-IR) at birth, in at term newborns.

Methods

Newborns with gestational age between 38 and 41 weeks, products of normal pregnancies of healthy mothers aged 18 to 39 years, were eligible to participate. Small-for-gestational age (SGA) and large-for-gestational age (LGA) newborns were compared with appropriate-for-gestational (AGA) age newborns. Incomplete or unclear data about mother’s health status, diabetes, gestational diabetes, history of gestational diabetes, hypertension, pre-eclampsia, eclampsia, and other conditions that affect glucose metabolism were exclusion criteria. Hyperinsulinemia was defined by serum insulin levels ≥13.0 μU/mL and IR by HOMA-IR ≥2.60. Multiple logistic regression analysis was used to determine the odds ratio (OR) that computes the association between birth-weight (independent variable) with hyperinsulinemia and HOMA-IR index (dependent variables).

Results

A total of 107 newborns were enrolled; 13, 22, and 72 with SGA, LGA, and AGA, respectively. Hyperinsulinemia was identified in 2 (15.4%), 6 (27.3%), and 5 (6.9%) with SGA, LGA, and AGA (p=0.03), whereas IR in 3 (23.1%), 8 (36.4%), and 10 (13.9%) newborns with SGA, LGA and AGA (p=0.06). The LGA showed a strong association with hyperinsulinemia (OR 5.02; CI 95%, 1.15-22.3; p=0.01) and HOMA-IR (OR 3.54; CI 95%, 1.03-12.16; p=0.02); although without statistical significance, the SGA showed a tendency of association with hyperinsulinemia (OR 2.43; CI 95%, 0.43-17.3 p=0.29) and HOMA-IR (OR 1.86; CI 95%, 0.33-9.37; p=0.41).

Conclusions

Our results suggest that LGA is associated with hyperinsulinemia and elevated HOMA-IR at birth whereas the SGA show a tendency of association.

Women born preterm or with inappropriate weight for gestational age are at risk of subsequent gestational diabetes and pre-eclampsia

Introduction

Low birthweight, which can be caused by inappropriate intrauterine growth or prematurity, is associated with development of gestational diabetes mellitus (GDM) as well as pre-eclampsia later in life, but the relative effects of prematurity and inappropriate intrauterine growth remain uncertain.

Methods

Through nation-wide registries we identified all Danish mothers in the years 1989–2007. Two separate cohorts consisting mothers born 1974–1977 (n = 84219) and 1978–1981 (n = 32376) were studied, due to different methods of registering birthweight and gestational age in the two periods. Data was linked with information on GDM, pre-eclampsia and education.

Results

In a multivariate logistic regression model the odds of developing GDM was increased by 5–7% for each week the mother was born before term (p = 0.018 for 1974–1977, p = 0.048 for 1978–1981), while the odds were increased by 13–17% for each standard deviation (SD) reduction in birthweight for gestational age for those who were small or normal for gestational age (p<0.0001 and p = 0.035) and increased by 118–122% for each SD increase above the normal range (p<0.0001 and p = 0.024). The odds of pre-eclampsia was increased by 3–5% for each week the mother was born before term (p = 0.064 and p = 0.04), while the odds were increased 11–12% for each SD reduction in birthweight for gestational age (p<0.0001 and p = 0.0002).

Conclusion

In this cohort of young Danish mothers, being born premature or with increasingly low birthweight for gestational age was associated with an increased risk of GDM and pre-eclampsia in adulthood, while increasingly high birthweight for gestational age was associated with an increased risk of GDM and a decreased risk of pre-eclampsia. Inappropriate weight for gestational age was a more important risk factor than prematurity.

The long-term renal and cardiovascular consequences of prematurity

Infants born prematurely at <37 weeks' gestation account for over 80% of infants weighing <2,500 g at birth-low birth weight (LBW) infants. This designation remains the surrogate marker for developmental origins of adult disease. Landmark studies spanning four decades have shown that individuals born with a LBW are more likely to develop cardiovascular and renal disease in later life, which is believed to be related to 'developmental programming' of such adult disease during vulnerable periods of growth in utero and in the early postnatal period. There has long been ambiguity regarding the distinction between infants with intrauterine growth restriction and preterm infants since both show a low nephron endowment that is associated with subsequent hypertension and chronic kidney disease. Knowledge is growing specific to the preterm infant and the developmental associations of being born preterm with the interruption of normal organogenesis relative to the vascular tree and kidney. Both systems develop by branching morphogenesis and interruptions lead to considerable deficits in their structure and function. These developmental aberrations can lead to endothelial dysfunction, hypertension, proteinuria and metabolic abnormalities that persist throughout life. This Review will examine the effect of preterm birth on the development of cardiovascular and kidney disease in later life and will also discuss potential early interventions to alter the progression of disease.

Evolution of obesity in a low birth weight cohort

OBJECTIVE

The objective of this study was to determine the evolution of obesity status (OS) in a longitudinal cohort of low birth weight preterm (LBWPT) infants to an age of 8 years, and to determine whether rapid weight gain in the first year of life independently predicts 8-year OS.

STUDY DESIGN

In total, 985 infants (birth weight ≤2500 g, gestation age ≤37 weeks) were recruited from the nursery in an eight-site intervention research program and were evaluated at an age of 3, 5, 6.5 and 8 years. Weight and height were measured by standard protocol at each visit and body mass index was calculated. Obesity status is ≥95% for age and sex. Multiple logistic analyses were performed on 8-year OS with predictor variables including infant race, gender, small for gestational age status, birth weight category, neonatal health index, treatment group and first-year weight gain; maternal education and weight status before conception; and HOME Inventory.

RESULT

Overall, 2.3% were OS at an age of 3 years, 6.1% at an age of 5 years, 7.7% at age 6.5 years and 8.7% at an age 8 years. OS varied by birth weight category at each visit. The infants born ≤1500 g had the lowest prevalence of OS at each age. In the logistic regression, maternal race (Hispanic) (adjusted odds ratio=2.8, confidence interval=1.2 to 6.8), maternal obese status (adjusted odds ratio 3.4, confidence interval=1.5 to 7.8) and first-year weight gain (adjusted odds ratio=2.7, confidence interval=1.9 to 3.9), significantly predicted 8-year OS.

CONCLUSION

OS is common in LBWPT infants during childhood, and prevalence varies by birth weight category. High weight gain in the first year of life is an important predictor of the development of OS in LBWPT children.

Circulating visfatin levels in healthy preterm infants are independently associated with high-density lipoprotein cholesterol levels and dietary long-chain polyunsaturated fatty acids

The adipokine visfatin has been proposed to exert insulin-mimicking effects and to play a role in the development of metabolic syndrome. Preterm infants are at risk for the later development of insulin resistance and, possibly, for other components of metabolic syndrome. Dietary long-chain polyunsaturated fatty acids (LCPUFAs) during the perinatal period may reduce the risk of metabolic syndrome. The authors' objective was to study the circulating concentrations of visfatin in preterm infants and to examine associations of visfatin with anthropometric measurements, metabolic indices, and dietary LCPUFAs. Serum visfatin concentrations were determined by enzyme-linked immunosorbent assay at mean (SD) 33.8 (11.7) days of life in 60 healthy preterm infants (gestational age, 32.7 [1.9] weeks) randomly assigned to be fed since birth either a formula containing LCPUFA (arachidonic and docosahexaenoic acid) (+LCPUFA group) or the same formula without LCPUFA (-LCPUFA group). Associations of visfatin with anthropometric parameters, serum glucose, insulin, homeostasis model assessment index of insulin resistance, blood lipids, and adiponectin levels were examined. Serum visfatin levels were significantly higher in the +LCPUFA than in the -LCPUFA group (P < .001) and correlated positively with body weight z score (β = 0.31, P = .02), total cholesterol (β = 0.34, P = .01), high-density lipoprotein cholesterol (HDL-C) (β = 0.47, P < .001), and adiponectin levels (β = 0.29, P = .03), but not with indices of insulin sensitivity. In multiple regression analysis, HDL-C and dietary LCPUFAs correlated independently with serum visfatin levels. Circulating visfatin levels in preterm infants are independently associated with HDL-C levels and dietary LCPUFAs. Whether the higher visfatin levels in the +LCPUFA preterm infant group are beneficial for the later health of these infants remains to be determined.

Prematurity and insulin sensitivity

Nowadays, an increased number of premature infants survive. The medical challenge is to reduce their postnatal morbidities with a special focus towards a decrease in metabolic risks. In this manuscript, we will examine available evidence of perinatal, infancy, and childhood consequences of prematurity on insulin sensitivity and glucose homeostasis. Moreover, we add some recent data on how nutritional intervention could modify these risks.

Current and potential roles of ghrelin in clinical practice

Ghrelin is a novel GH-releasing peptide, which has been identified as an endogenous ligand for GH-secretagogue receptor. Ghrelin is mainly secreted by the stomach and plays a critical role in a variety of physiological processes including endocrine, metabolic, cardiovascular, immunological, and other actions. Ghrelin stimulates food intake via hypothalamic neurons and causes a positive energy balance and body weight gain by decreasing fat utilization and promoting adiposity. Given the multiple effects of ghrelin, its potential clinical applications have been evaluated in various conditions. Preliminary trials have shown that it may prove valuable in the management of disease-induced cachexia. Ghrelin may improve the wasting syndrome through GH-dependent or GH-independent effects. Moreover, ghrelin may play a role in the management of disorders of gut motility and obesity. Finally, other potential clinical applications of ghrelin include the treatment of patients with diabetes mellitus, infections, rheumatological diseases or GH deficiency and the diagnosis of this hormonal disorder.

Energy expenditure and physical activity in recovering malnourished infants

Background. Malnourished infants are small for age and weight. Objectives. Determine profiles in 24-hour energy metabolism in recovering malnourished infants and compare to similarly aged healthy controls. Methods. 10 malnourished infants (58.1 +/- 5.9 cm, 7.7 +/- 5.6 months) were healthy prior to spending 22 hours in the Enhanced Metabolic Testing Activity Chamber for measurement of EE (kcal/min), sleeping metabolic rate (SMR; kcal/min), respiratory quotient (RQ; VCO(2)/VO(2)), and physical activity (PA; oscillations in wt/min/kg body weight). Metabolic data were extrapolated to 24 hours (kcal/kg/d). Energy intake (kcal/kg/d) and the proportions (%) of carbohydrate, protein, and fat were calculated. Anthropometrics for malnourished infants were obtained. Statistical differences (P < .05) between groups were determined (SPSS, version 13). Results. In comparison to controls, malnourished infants were lighter (4.1 +/- 1.2 versus 7.3 +/- 0.8 kg; P < .05), had less body fat % (10.3 +/- 7.6 versus 25.7 +/- 2.5), and lower BMI (12.0 +/- 1.7 versus 15.5 +/- 1.5; P < .05). In contrast, they had greater energy intake (142.7 +/- 14.6 versus 85.1 +/- 25.8; P < .05) with a greater percentage of carbohydrates (55.1 +/- 3.9 versus 47.2 +/- 5.2; P < .05). However, malnourished infants had greater 24-hour EE (101.3 +/- 20.1 versus 78.6 +/- 8.4; P < .05), SMR (92.6 +/- 17.1 versus 65.0 +/- 3.9; P < .05), and RQ (1.00 +/- 0.13 versus 0.86 +/- 0.08; P < .05) along with a lower amount of PA (2.3 +/- 0.94 versus 4.0 +/- 1.5; P < .05). Conclusions. Malnourished infants require more energy, possibly for growth.

Chronic placental ischemia alters amniotic fluid milieu and results in impaired glucose tolerance, insulin resistance and hyperleptinemia in young rats

Although small size at birth is associated with hypertension and associated co-morbidities such as insulin resistance and type II diabetes mellitus, many of the animal models employed to simulate this phenomenon do not closely mimic the ontogeny of growth restriction observed clinically. While intrauterine growth restriction (IUGR) is often detected near mid-pregnancy in women and persists until term, most rodent models of IUGR employ ligation of uterine arteries for a brief period during late gestation (days 19-21 of pregnancy). We hypothesized that IUGR associated with chronic reduction in uteroplacental perfusion (RUPP) and placental ischemia during the third trimester of pregnancy in the rat alters the amniotic fluid (AF) environment and results in hypertensive offspring presenting with metabolic abnormalities such as glucose intolerance and insulin resistance. Insulin-like growth factor-1 (IGF-1), IGF-2, Na(+) concentration and oxidative stress in the AF were increased, while K(+) concentration was decreased in the RUPP compared with normal pregnant (NP) fetuses. RUPP-offspring (RUPP-O) were smaller (6.1 +/- 0.2 versus 6.7 +/- 0.2 g; P < 0.05) at birth compared with NP-offspring (NP-O) groups. At nine weeks of age, mean arterial pressure (121 +/- 3 versus 107 +/- 5 mmHg; P < 0.05), fasting insulin (0.71 +/- 0.014 versus 0.30 +/- 0.08 ng/mL; P < 0.05), glucose (4.4 +/- 0.2 versus 3.1 +/- 0.3 mmol/L; P < 0.05), leptin (3.8 +/- 0.5 versus 2.3 +/- 0.3 ng/mL; P < 0.05) and the homeostasis model assessment of insulin resistance index was greater (2.9 +/- 0.6 versus 1.0 +/- 0.3; P < 0.05) in the RUPP-O compared with the NP-O rats. These data indicate that chronic placental ischemia results in numerous alterations to the fetal environment that contributes to the development of impaired glucose metabolism, insulin resistance and hyperleptinemia in young offspring.

Early nutritional support and outcomes in ELBW infants

Extrauterine growth restriction is a common finding among extremely low birth weight infants at discharge from neonatal intensive care units. It has been associated with significant caloric and protein deficits that accumulate during the hospitalization and with slower growth velocity observed with major neonatal morbidities. Recommendations to provide early nutritional support, both parenteral and enteral, have evolved in response to concern about the impact of poor in-hospital growth on growth and neurodevelopmental outcomes in early childhood. This paper will review the evidence supporting the provision of early nutritional support to extremely preterm infants by examining the outcomes associated with such practices.

Adiposity is not altered in preterm infants fed with a nutrient-enriched formula after hospital discharge

To determine whether adiposity was altered, body size (weight, length) and composition, determined by dual energy x-ray absorptiometry, were examined in preterm infants fed with a nutrient enriched (A, n=56), a term infant (B, n=57) or the nutrient enriched (discharge and term) plus the term formula (term and 6 mo; C, n=26), and a group of breast-fed preterm infants (D, n=25) at hospital discharge, 3, 6, and 12 mo corrected age. The results were analyzed using standard statistics. One hundred sixty-four infants (birth weight=1406+/-248 g, GA=31+/-1.7 wk) were studied. All infants underwent "catch-up," but weight and length were greater in infants in group A compared with groups B, C, or D. More rapid and complete "catch-up" was paralleled by increased total nonfat and fat mass (g) but not percentage of fat mass. Changes in fat mass (g) were primarily explained by increased fat accretion on the legs. More rapid and complete "catch-up" growth, therefore, reflected increased nonfat and peripheral fat mass. These data do not support the hypothesis of increased or central adiposity in infants fed a nutrient-enriched formula after hospital discharge.

Circulating adipocyte fatty acid binding protein levels in healthy preterm infants: Positive correlation with weight gain and total-cholesterol levels

BACKGROUND

Adipocyte fatty acid binding protein (a-FABP) has been suggested to play an important role in the pathogenesis of metabolic syndrome. Preterm infants are at risk for the later development of insulin resistance, and, possibly, other components of metabolic syndrome.

AIM

To determine circulating levels of a-FABP in preterm infants and examine possible associations of a-FABP with metabolic indices (serum lipids, glucose, and insulin levels, and homeostasis model assessment index of insulin resistance [HOMA-IR]), levels of leptin and adiponectin, anthropometric parameters and weight gain.

STUDY DESIGN

Prospective cohort study.

SUBJECTS

55 healthy preterm (mean [SD] gestational age 32.8 [1.8] weeks) and 23 fullterm infants (reference group).

OUTCOME MEASURES

Serum a-FABP, lipids, glucose, insulin, leptin and adiponectin levels at 31.9 [10.4] days of life.

RESULTS

Serum a-FABP levels did not differ significantly between preterm and fullterm infants. A-FABP levels correlated positively with total-cholesterol [total-C] in both preterm and fullterm infants (beta=0.33; p=0.01 and beta=0.33; p=0.04, respectively). In addition to total-C, weight gain correlated independently with a-FABP levels in preterm infants (beta=0.36, p=0.01).

CONCLUSIONS

An association between a-FABP levels and indices of insulin resistance was not present in infants studied. As the development of insulin resistance in children born prematurely is possibly associated with weight gain in early postnatal life, follow-up of our study population is necessary to demonstrate whether a-FABP levels, shown to correlate with weight gain in preterm infants, are a predictive marker for the later development of insulin resistance in these infants.