Glucagon/insulin ratio in preoperative screening before pancreatic surgery: correlation with hemoglobin A1C in subjects with and without pancreatic cancer.
Role of impaired suppression of glucagon secretion in the pathogenesis of pancreatic cancer-associated diabetes has been suggested. We examined the correlation between glucagon/insulin ratio (G/I) after glucose challenge and hemoglobin A1C (A1C) in subjects with and without pancreatic cancer. Data were gathered from a preoperative screening 75-g oral glucose tolerance test in patients who would eventually undergo pancreatic resection. A multiple linear regression analysis was conducted using the following covariates: age, body mass index, hemoglobin, glucose and insulin levels at the corresponding time points, indices of insulin resistance, duration of diabetes, insulinogenic index, and use of glucose-lowering drugs. In subject group with pancreatic cancer (n = 45), but not in subject group without pancreatic cancer (n = 101), participants with A1C ≥ 6.5 % had significantly higher glucagon levels, lower insulin levels, and higher G/I ratios after the glucose challenge than those of the subjects with A1C <5.7 %. In the multiple linear regression analysis, there was an independent correlation between post-challenge G/I ratio and A1C in both groups. Some of the patients without pancreatic cancer had inappropriately elevated G/I ratios despite A1C <6.5 %. These patients were characterized by lower insulinogenic indices (p = 0.004) and less insulin resistance (p = 0.008). In conclusion, post-challenge G/I ratio independently correlated with A1C in patients with pancreatic cancer. Although significant, the degree of correlation was weakened in the subjects without pancreatic cancer because some had lower insulin secretory reserve compensated by less insulin resistance, resulting in inappropriately elevated G/I ratios relative to A1C.
Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Gangnam-Gu, Seoul, 135-710, Republic of Korea.
Sang-Man
SM
Jin
Seong Ho
SH
Choi
Dong-Wook
DW
Choi
Jin Seok
JS
Heo
Sunghwan
S
Suh
Ji Cheol
JC
Bae
Jae Hyeon
JH
Kim
Myung-Shik
MS
Lee
Kwang-Won
KW
Kim
Moon-Kyu
MK
Lee
D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D002096:C-Peptide / Q000097:blood; D005260:Female; D005934:Glucagon / Q000097:blood*; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000601:surgery*; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000601:surgery; D057234:Preoperative Period
D001786:Blood Glucose; D002096:C-Peptide; D005934:Glucagon; D006442:Glycated Hemoglobin; D007328:Insulin; C517652:hemoglobin A1c protein, human