Glucagon-likepeptide-1secretioninwomenwithgestational diabetesmellitusduringandafterpregnancy

Gestationaldiabetesmellitus(GDM)predispos- eswomentofuturedevelopmentofType2diabetesmellitus (DM2)andthetwoconditionssharesimilarmetabolicalter- ations.Recentobservationssuggestthatadefectiveglucose- stimulatedinsulinsecretionbyglucagon-likepeptide-1(GLP- 1)playsaroleinthepathogenesisofDM2.Whethersucha defect is impaired in GDM remains to be ascertained. Aim: WehavedeterminedGLP-1secretioninresponsetooralglu- cosetolerancetest(OGTT)inGDMandnormalglucosetol- erance (NGT) during and after pregnancy. Materials and methods:100-g-3hOGTTwasperformedin12GDMand16 NGTwomenat27.3±4.1weeksofgestation,fordetermina- tionofplasmaGLP-1,glucose,insulin,andC-peptide.Insulin sensitivity(ISI)andinsulinsecretion(firstandsecondphase); aswellasISI-secretionindex(ISSI)werealsoderived. Results: NGT and GDM women were comparable for age pre-preg- nancy body mass index (BMI) and weight gain. GDM had higher glucose area under the curve (AUC): 27,575.5±3448 vs20,685.88±2715mg/dlmin(p<0.01),butlowerfirst-phase insulinsecretion(993.12±367 vs1376.61±423, p<0.05)and ISSIcomparedtocontrols(3873.23±1185 vs6232.13±1734, p<0.001).WhenweexaminedGLP-1meanlevelsinrelation to mean glycemic values, GLP-1 secretion was inappropri- atelylowwithrespecttomeanglycemicvaluesinGDMcom- paredtoNGT.Atfollow-up,AUCGLP-1wassignificantlylow- erin post-partumGDMcomparedto post-partumNGTwom- en (2542±273 vs 10,092±7367 pmol·l-1·min-1, p<0.05, re- spectively). Conclusions: Our study suggests that GLP-1 se- cretion in GDM women is inadequate for the prevailing glycemic levels both in pregnancy and post partum. More- over,wecannotexcludethatotherimportantaspectsofthe incretineffectmaybeinvolvedinGDMdevelopment. (J.Endocrinol.Invest.34:e287-e290,2011) ©2011,EditriceKurtis