Subclinical abnormalities of glucose metabolism in Brazilian women with a history of gestational diabetes mellitus.
BACKGROUND
To evaluate insulin release and insulin sensitivity in women with prior gestational diabetes mellitus (GDM) to gain a better understanding of type 2 diabetes pathogenesis.


METHODS
GDM women were individually matched for age, body mass index, and waist/hip ratio with those who were normal glucose tolerant in a previous pregnancy (NGT). All women presented with normal glucose tolerance. Twenty pairs were submitted to the oral glucose tolerance test (OGTT) with plasma glucose, insulin, and C-peptide determinations. Of the 20 pairs, 18 participated in hyperglycemic (10.0 mmol/l) clamp experiments with frequent plasma glucose and insulin determinations, allowing us to calculate first- and second-phase insulin release and the insulin sensitivity index. GDM and NGT women were compared using Student's t-test, the Mann-Whitney U-test, Friedman's non-parametric test, and the two proportion test for independent groups.


RESULTS
GDM women showed higher glycosylated hemoglobin values; at OGTT, they showed late insulin peak with increased plasma insulin levels only during the second hour, and a similar plasma C-peptide response despite a higher plasma glucose curve; during hyperglycemic clamp procedures, they showed similar biphasic insulin release and insulin sensitivity index. Considering that a woman with previous GDM had a defect in insulin release and/or insulin sensitivity, if its magnitude was at least 25% lower than that of the matched NGT woman, 43.8% showed impairment of first-phase insulin release and 55.6% insulin resistance.


CONCLUSIONS
GDM women showed some degree of glucose intolerance. It is therefore necessary to follow them for a longer time.
Pimenta
Walkyria P
WP
Division of Internal Medicine, Botucatu School of Medicine, Sao Paulo State University, Brazil. wpimenta@fmb.unesp.br
Calderon
Iracema M P
IM
Cruz
Ney S
NS
Santos
Maria Luiza
ML
Aragon
Flávio F
FF
Padovani
Carlos Roberto
CR
D000328:Adult; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism*; D001824:Body Constitution; D015992:Body Mass Index; D001938:Brazil; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology* / Q000378:metabolism; D016640:Diabetes, Gestational / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D005215:Fasting; D005260:Female; D015309:Glucose Clamp Technique; D018149:Glucose Intolerance / Q000097:blood / Q000453:epidemiology* / Q000378:metabolism; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D011247:Pregnancy; D012307:Risk Factors
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin