Hypoglycaemia in Clinical Diabetes

222 HYPOGLYCAEMIA IN PREGNANCYTable 10.2 Summary of studies examining counterregulatory responses to hypoglycaemia in womenwith pre-gestational diabetesReferenceGestationat time ofstudyControl groupBloodglucose nadirduring studyResultsnDiamondet al.,1992Nisellet al.,1994Rosennet al.,1996Björklundet al.,1998aBjörklundet al.,1998b21–37 weeks Non-pregnant,non-diabeticage matchedwomenLasttrimester,and 8–12weekspost-partumNon-pregnant(1);24–28 (2);32–34 (3)30–34 weeks(1);5–13 monthspostnatal(2)Acted as owncontrolsNon-diabetic,age-matched.Cases werealso studiedon 3occasionsi.e. acted asown controlsActed as owncontrols2.5 mmol/l No glucagon response incases.Epinephrine releasesuppressed in cases; cf.controls.Lower blood glucose forepinephrine and growthhormone release incases; cf. controls3.2 mmol/l No glucagon or cortisolresponse at either timepoint.Similar increases inepinephrine andnorepinephrine onboth occasions3.3 mmol/l Reduced epinephrineresponse in cases; cf.controls at all studytimes.Reduced epinephrineresponse in casesduring pregnancy; cf.pre-pregnancy.Growth hormone responsesreduced in pregnancy incases and controls; cf.pre-pregnancy2.3 mmol/l Epinephrine responsesimilar in pregnancy andpostnatal.Dehydroepiandrosteroneincreased more rapidlyand less sustainedduring pregnancy.Growth hormone responsesreduced in pregnancy30–34 weeks No controls 2.3 mmol/l Increase in placentalgrowth hormone, but nochanges in otherplacental hormonesduring hypoglycaemia9 type 1cases;7 controls8 pregestationaltype 1patients;1 gestational17 type 1cases;10 controls1010