A Study on Single Nucleotide Polymorphism of Leptin Receptor and Insulin
Resistance in Gestational Diabetes Mellitus.
Abstract
Objective: To find the association of leptin-receptor gene(LEPR)
polymorphism with gestational diabetes mellitus (GDM) and its role in
altered leptin levels, insulin resistance, and dyslipidemia in GDM.
Design & Setting: This prospective cross-sectional study was conducted
in Justice KS Hegde Hospital, Mangalore, India. 100 GDM patients and 100
gestational age and BMI matched normal glucose tolerant pregnant women
were recruited as cases and controls. Method: Genotyping of
leptin-receptor (LEPR)Gln223Arg was performed by PCR-RFLP. Fasting blood
sugar, leptin, insulin, C-peptide, and lipid profile were performed.
Various insulin-resistance models were constructed using suitable
formulae. Results: No significant association was found between
leptin-receptor gene polymorphism and leptin levels, insulin-resistance
in GDM. However, Odd’s ratio showed that individuals with A allele were
at 1.25 times higher risk of developing GDM. HOMA-B cells significantly
varied among Lep-R genotypes, values being double in AA genotype,
compared to AG, ten times higher in AA compared to GG. The value was
four times higher in AG compared to GG. Conclusion: It could be
concluded from the study that, there are no significant association
between leptin receptor, LEPR Gln223Arg alleles and gestational
diabetes, leptin levels, and insulin resistance. However, subjects with
the ‘G’ allele for LEPR at higher risk of hyperleptinemia. C–peptide
based insulin resistance models were elevated in GDM patients. The study
can establish a cycle of gene polymorphism altering leptin levels, which
in turn can alter insulin secretion and insulin resistance, contributing
to dyslipidemia of pregnancy and gestational diabetes.