title: Cord Blood Levels of Insulin, Cortisol and HOMA2-IR in Very Preterm, Late Preterm and Term Newborns.
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  To estimate the plasma glucose, serum insulin and cortisol levels at birth in newborns at different gestational age.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Postgraduate, Department of Biochemistry, Center for Basic Sciences, Kasturba Medical College , Bejai, Mangalore, Karnataka India .
authors.forename: Afzal
authors.initials: A
authors.lastname: Ahmad
authors.affiliation: Associate Professor, Department of Biochemistry, Center for Basic Sciences, Kasturba Medical College , Bejai, Mangalore, Karnataka, India .
authors.forename: Rukmini Mysore
authors.initials: RM
authors.lastname: Srikantiah
authors.affiliation: Postgraduate, Department of Biochemistry, Center for Basic Sciences, Kasturba Medical College , Bejai, Mangalore, Karnataka, India .
authors.forename: Charu
authors.initials: C
authors.lastname: Yadav
authors.affiliation: Postgraduate, Department of Biochemistry, Center for Basic Sciences, Kasturba Medical College , Bejai, Mangalore, Karnataka, India .
authors.forename: Ashish
authors.initials: A
authors.lastname: Agarwal
authors.affiliation: Professor and Head, Department of Biochemistry, Center for Basic Sciences, Kasturba Medical College , Bejai, Mangalore, Karnataka, India .
authors.forename: Poornima Ajay
authors.initials: PA
authors.lastname: Manjrekar
authors.affiliation: Associate Professor, Department of Biochemistry, Center for Basic Sciences, Kasturba Medical College , Bejai, Mangalore, Karnataka, India .
authors.forename: Anupama
authors.initials: A
authors.lastname: Hegde
keywords: Insulin resistance; Neonates; Postnatal life