[Evaluation of insulin secretion and insulin resistance by hyperglycemic clamp in Graves disease patients with impaired glucose tolerance].
OBJECTIVE
To investigate the state of insulin secretion and insulin resistance in patients of Graves disease (GD) with impaired glucose tolerance (IGT) by hyperglycemic clamp.


METHODS
Six cases of Graves disease with IGT were selected as GD + IGT group and ten healthy volunteers as normal control group (NC group). All the subjects were required to fast for 12 hours and then underwent hyperglycemic clamp to assay insulin secretion and insulin sensitivity. Glutamic acid decarboxylase antibody (GAD-A) was tested in all the subjects.


RESULTS
Insulin secretion in GD + IGT group was significantly higher than that in NC group. The 1st phase insulin secretion (1PH) was (636.31 +/- 105.54) mIU/L vs (233.56 +/- 21.33) mIU/L, P = 0.001. The 2nd phase insulin secretion (2PH) was (146.68 +/- 25.00) mIU/L vs (67.06 +/- 6.23) mIU/L, P = 0.03. The maximal insulin secretion during 120 - 150 minutes (Ins(120 - 150)) was (195.05 +/- 32.94) mIU/L vs (87.64 +/- 9.78) mIU/L, P = 0.04. The hyperglycemic clamp insulin sensitivity index (average glucose metabolic rate during 120 - 150 minutes/Ins(120 - 150)) was significantly lower in GD + IGT group than that in NC group (11.52 +/- 1.90 vs 21.72 +/- 3.25, P = 0.04). GAD-A was negative in all subjects.


CONCLUSIONS
Cases of GD with IGT show significant insulin resistance with compensated elevated insulin secretion.
Liang
Zhen
Z
Department of Endocrinology, The Shenzhen Affiliated Hospital of Southern Medical University, Shenzhen 518035, China.
Luo
Guo-chun
GC
Hu
Qing-hong
QH
Li
Ming-zheng
MZ
Chen
Nan
N
Yan
De-wen
DW
Chai
Jie
J
Chen
Ze-long
ZL
Li
Hai-yan
HY
Ou
Hui-ting
HT
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D015309:Glucose Clamp Technique; D018149:Glucose Intolerance / Q000097:blood* / Q000378:metabolism; D005951:Glucose Tolerance Test / Q000379:methods; D006111:Graves Disease / Q000097:blood / Q000378:metabolism / Q000503:physiopathology*; D006801:Humans; D007328:Insulin / Q000097:blood* / Q000378:metabolism; D007333:Insulin Resistance; D007515:Islets of Langerhans / Q000378:metabolism; D008297:Male; D008875:Middle Aged
D001786:Blood Glucose; D007328:Insulin