title: Abnormalities in fasting circulating proinsulin concentration in mild gestational diabetes.
abstract: Fasting plasma proinsulin, insulin and glucose concentrations were measured in ten women with mild gestational diabetes and ten controls matched for race, age (32 +/- 6 vs 31 +/- 6 years), body mass index (28 +/- 8 vs 27 +/- 6) and gestational week (24 +/- 4 vs 25 +/- 4 weeks). There was no significant difference in fasting plasma glucose between these gestational diabetics and their controls (median 4.7, range 3.7-6.0 mmol/l vs 4.5, range 3.4-5.3 mmol/l). The fasting proinsulin levels were significantly higher in the gestational diabetics compared with the controls (median 12.2, range less than 4-14.8 pmol/l vs 5.8, range less than 4-12.8 pmol/l, P less than or equal to 0.02, Wilcoxon Summed Rank Test), while the calculated intact insulin levels (immunoreactive insulin minus proinsulin) were significantly lower (median 14.5, range 6.3-81.8 pmol/l vs 51.6, range 11.7-312 pmol/l, P less than or equal to 0.01). The ratio of proinsulin to calculated intact insulin was significantly higher in the gestational diabetics than the controls (median 0.66, range 0.16-2.04 vs 0.12, range 0.03-0.62), P less than or equal to 0.01). These results demonstrate that gestational diabetics, with normal fasting plasma glucose values, have abnormalities in pancreatic beta-cell secretion, which are likely to be important both in the aetiology of gestational diabetes and non-insulin dependent diabetes.
authors.affiliation: Unit of Metabolic Medicine, St. Mary's Hospital Medical School, Imperial College of Science, Technology and Medicine, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Dornhorst
authors.forename: M
authors.initials: M
authors.lastname: Davies
authors.forename: V
authors.initials: V
authors.lastname: Anyaoku
authors.forename: S M
authors.initials: SM
authors.lastname: Hampton
authors.forename: R S
authors.initials: RS
authors.lastname: Elkeles
authors.forename: R W
authors.initials: RW
authors.lastname: Beard
authors.forename: D G
authors.initials: DG
authors.lastname: Johnston
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005215:Fasting / Q000097:blood; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000097:blood*; D011384:Proinsulin / Q000097:blood*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D011384:Proinsulin