Gender differences in insulin and C-peptide concentrations at birth using cord blood collection.

Mohammad Shafi Kuchay,Anil Gupta,Mohammad Ashraf Ganie,Kamal Kishor Pandita,Rattan P Kudyar

doi:10.1590/2359-3997000000148

Abstract

To study gender differences in insulin and C-peptide concentrations at birth using cord blood collection. This study was conducted in a maternity hospital, in Jammu province of Jammu and Kashmir, India. All women with pregnancy who were hospitalized for delivery were followed. All pregnant ladies who had no medical condition affecting insulin levels, as per history and routine antenatal blood testing, were included in the study. The test for cord plasma insulin and C-peptide was done in 60 (30 males) full-term (≥ 37 completed weeks) normal delivery babies within 4 hours of the collection of samples using the electro-chemiluminescence immunoassay (ECLIA) on Roche elecsys module immunoassay analyzer. Weight of the babies was taken immediately after birth using digital scales. Cord plasma insulin and C-peptide measured in EDTA were compared between boys and girls and also related to birth weight. Girls were lighter (2,830 ± 37 vs. 3,236 ± 46 g; p = < 0.001) but had higher cord insulin (16.48 ± 4.88 vs. 10.53 ± 4.04 µU/mL; p = < 0.001), and C-peptide (2.47 ± 0.66 vs. 0.834 ± 0.26 ng/mL; p = < 0.001) concentrations than newborn boys. Female newborn babies have higher cord plasma insulin and C-peptide concentrations than male newborns, despite being smaller, suggesting intrinsic insulin resistance in girls.

Highlights

A number of studies suggest that girls are more insulin resistant than boys
It has been argued that this gender difference in insulin resistance may be due to differences in the environment and physical activity in childhood
Shields and cols. were the first to measure cord blood insulin and insulin-like molecules, thereby eliminating the effect of environment and physical activity on insulin resistance. They demonstrated that cord blood insulin, total proinsulin and intact proinsulin concentrations were higher in girls despite being lighter than boys, indicating intrinsic insulin resistance [5]

Summary

INTRODUCTION

A number of studies suggest that girls are more insulin resistant than boys. This has been shown by using intravenous glucose tolerance tests, fasting insulin measurements and euglycemic clamps in children from age 5 years through late childhood, puberty and adolescence. Euglycemic clamp studies of 357 normal children (10-14 years of age) demonstrated significant differences in insulin resistance between boys and girls [1]. A study of 307 children (5 years of age) was unable to explain gender differences by looking at differences in anthropometry and physical activity They observed that girls at five are intrinsically more insulin resistant than boys [3]. This study was designed to demonstrate the differences in cord plasma insulin and C-peptide levels in normal newborn Indian babies, born of normal parents. A 5-mL sample of cord blood of sixty babies born by normal vaginal delivery was collected immediately following delivery of the placenta. This was transferred to potassium EDTA tubes.

RESULTS

DISCUSSION

CONCLUSION