Lack of C-Peptide Suppression by Exogenous Hyperinsulinemia in Subjects with Symptoms Suggesting Reactive Hypoglycemia

Endocrine Journal

AKIKO SAEKI¹  HIROKO ARII¹  HIROYUKI KUROKI¹  YASUE OMORI¹  KOZO KATSUMORI¹  TARO WASADA¹  SETSU SAITO¹ 

[1] Diabetes Center, Tokyo Women's Medical College

关键词: Reactive hypoglycemia;    Hyperinsulinemic glucose clamp;    C-peptide suppression test;   

DOI  :  10.1507/endocrj.43.639

学科分类：内分泌与代谢学

来源: Japan Endocrine Society

【 摘 要 】

References(27)Cited-By(2)The C-peptide suppression test employing the euglycemic hyperinsulinemic clamp technique has been proposed as a useful diagnostic measure for insulinoma. To examine the specificity of the C- peptide suppression, we applied this test to subjects with symptoms suggesting reactive hypoglycemia. Five subjects studied had never experienced fasting hypoglycemia, and were negative in ultrasound, CT and MRI of the pancreas. Plasma C-peptide was not suppressed by physiological (50-100μU/ml) and supraphysiological (200-500μU/ml) hyperinsulinemia (% of baseline: 97.3±8.6% and 90.6±10.4%, ± SEM, respectively, both NS). Three subjects were re-examined one year later, when their hypoglycemic episodes were noticeably attenuated. No significant suppression was found. Significant suppression was observed when plasma glucose was clamped at 50-60mg/dl in four of five subjects (61.7±11.5%, P<0.05), but one subject responded to neither higher plasma insulin nor low-normal glucose. In contrast, normal glucose tolerance (n=13), IGT (n=12) and obese NIDDM (n=31) subjects showed highly significant suppression during euglycemic and physiological hyperinsulinemia (37.1 ±3.8%, 46.3±5.6%, 39.9±2.6%, respectively, all P<0.001). In conclusion, the results of the present study indicate that a failure of hyperinsulinemic suppression of C-peptide in euglycemia is not specific for insulinoma, and that suppression of C-peptide by insulin at lower plasma glucose levels (50-60mg/dl) would be a better diagnostic test.

【 授权许可】

Unknown