Proinsulin Response during Oral Glucose Tolerance Test in Offspring of Patients with Type 2 Diabetes

Lee, Ji Hyun; You, Sung Soo; Park, Kyoung Chan; Ryoo, Hun Mo; Yoon, Hyun Dae; Shon, Ho Sang

Original Article

Diabetes Monit 2002;3(4):315-325.

제2형 당뇨병 환자의 직계자녀에서의 경구 당부하 검사시 혈청 프로인슐린 분비반응

이지현, 유성수, 박경찬, 류헌모, 윤현대, 손호상

Proinsulin Response during Oral Glucose Tolerance Test in Offspring of Patients with Type 2 Diabetes

Ji Hyun Lee, Sung Soo You, Kyoung Chan Park, Hun Mo Ryoo, Hyun Dae Yoon, Ho Sang Shon

Abstract

Background
An elevated proinsulin concentration reflects abnormal proinsulin processing and could indicate abnormal insulin secretion. Recent data suggest that proinsulin is elevated disproportionately in subjects with type 2 diabetes and impaired glucose tolerance. So an elevated proinsulin level was interpreted as an early indicator of beta-cell dysfunction. First-degree relatives of patients with type 2 diabetes are at high risk of developing diabetes. There are many studies showing decreases in insulin secretion or abnormal secretion in nondiabetic relatives of subjects with type 2 diabetes. We examined the proinsulin level and the ratio of proinsulin/total insulin in first-degree relatives of patients with type 2 diabetes. Methods: We investigated proinsulin and insulin responses during an oral glucose tolerance test in twenty-five male offspring of patients with type 2 diabetes and twenty-three age- and sex-matched controls. We measured clinical and biochemical parameters, height, weight, body mass index, blood pressure and lipid profile. Results: There were no differences in serum glucose and true insulin concentrations between the offspring and the control group during the oral glucose tolerance test. The proinsulin concentration was gradually increased as time ensued and the offspring`s value tended to be lower than the control groups during the oral glucose tolerance test. The proinsulin to total insulin ratio was similar between the offspring and control groups during the oral glucose tolerance test and the ratio was gradually increased as time ensued. Conclusion: Young offspring of patients with type 2 diabetes, who have a high risk of developing diabetes, do not exhibit elevated levels of fasting or glucose-stimulated proinsulin as long as they are in a normal glucose tolerance state.

Key Words: Proinsulin, Offspring, OGTT, Type 2 DM