Endocrine Abstracts

Introduction: Gestational diabetes mellitus (GDM) is an important co-morbidity of pregnancy, with insulin resistance a key contributor in its underlying pathology. Relaxin is a hormone considered crucial for mediating adaptations deemed vital for maintenance of pregnancy. Evidence has suggested that levels of plasma relaxin may be positively correlated with insulin sensitivity. This led us to hypothesize that relaxin may play a role in the pathogenesis of insulin resistance in women with gestational diabetes. The aim of this study was to assess levels of plasma relaxin in women with GDM compared to a control group of healthy pregnant women in the third trimester of pregnancy.

Design and methods: Twenty-six GDM subjects and 27 healthy controls were recruited, matched for gestation week and age. A blood sample was obtained from all participants to determine plasma relaxin levels during the 3rd trimester of pregnancy. Additional data including age, gestation term and HbA1c was collected. A Mann – Whitney U test was used for statistical analysis between the two groups. The study was ethically approved by the Proportionate Review Sub-Committee of North Wales REC. Plasma relaxin was measured by ELISA using kit provided by R and D Systems Europe Ltd.

Results: Plasma relaxin levels in the GDM group were higher compared to the healthy control group (median relaxin concentration 667.5 pg/ml (range=190–2,450 pg/ml) in GDM group vs 439 pg/ml (range=112–1,185 pg/ml) in control group), although this did not reach statistical significance (P=0.15).

Conclusion: Plasma relaxin levels were found to be higher in women with GDM although not statistically significant. Increased relaxin levels in GDM may be a result of the body’s compensatory mechanism to overcome increased insulin resistance present in this group. More studies are required to understand whether relaxin plays a role in the pathogenesis of gestational diabetes and insulin resistance.