Insulin resistance in pre-school very-low-birth weight pre-term children

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.

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.

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.

Growth patterns in the growth-retarded premature infant

Approximately 10% of all infants are born prematurely. A large proportion of these infants show evidence of postnatal growth impairment irrespective of whether birth weight was appropriate or small for gestational age. The timing and magnitude of catch-up growth is very variable, with the most immature infants showing markedly delayed catch up which is often incomplete. Long-term studies suggest that final stature may be affected significantly. Growth impairment in itself is of concern and there are suggestions that this group of infants should be eligible for growth hormone treatment. However, in addition, there is increasing evidence to suggest that there should be additional concerns in this group of infants, as abnormal early growth may influence disease susceptibility in adult life. This review assesses the patterns of postnatal growth and the possible later implications of early aberrant growth patterns in later life.