Insulin resistance has no impact on ghrelin suppression in pregnancy

Abstract

Ghrelin is reduced in various states of insulin resistance. The aim of this study was to examine the relationship between ghrelin and glucose metabolism during pregnancy - a natural insulin-resistant state - in women with normal glucose tolerance (NGT), impaired glucose tolerance (IGT) or gestational diabetes mellitus (GDM) and potential changes 3 months after delivery. A total of 54 women, 37 pregnant and with various degrees of insulin resistance and 24 postpartum (PP, seven of them also studied during pregnancy) were studied. Ghrelin plasma concentrations at fasting and 60′ following glucose loading (75 g-2 h-oral glucose tolerance test), area under the curve of plasma glucose (G-AUCOGTT) and insulin sensitivity [homeostatic model assessment (HOMA) and oral glucose sensitivity index (OGIS) indices, respectively] were determined. Both baseline and 60′ ghrelin concentrations were to a comparable degree (∼ by 65%) suppressed in NGT, IGT and GDM as compared to the PP group (the latter being indistinguishable from NGT regarding glucose tolerance and insulin sensitivity). In all women studied both during and after pregnancy, ghrelin levels rose from pregnancy to PP (mean increase 313.8%; P < 0.03). There was no correlation between baseline ghrelin and insulin sensitivity as estimated from both baseline (HOMA) and dynamic (OGTT:OGIS) glucose and insulin data. Ghrelin is substantially decreased during pregnancy, but glucose-induced ghrelin suppression is preserved at a lower level. There is apparently no relation to the degree of insulin resistance. © 2007 Blackwell Publishing Ltd.