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.