Serum Insulin, Proinsulin and Proinsulin/Insulin Ratio in Type 2 Diabetic Patients: As an Index of beta-Cell Function or Insulin Resistance.
- Author:
Nan Hee KIM
1
;
Dong Lim KIM
;
Kyung Mook CHOI
;
Sei Hyun BAIK
;
Dong Seop CHOI
Author Information
1. Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea.
- Publication Type:Original Article
- Keywords:
Insulin;
Proinsulin;
beta cell dysfunction;
Insulin resistance
- MeSH:
Aged;
Diabetes Mellitus, Non-Insulin-Dependent/etiology;
Diabetes Mellitus, Non-Insulin-Dependent/blood*;
Female;
Human;
Insulin/blood*;
Insulin Resistance*;
Islets of Langerhans/physiopathology*;
Male;
Middle Age;
Proinsulin/blood*;
Sulfonylurea Compounds/pharmacology
- From:The Korean Journal of Internal Medicine
2000;15(3):195-201
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: Although insulin resistance and decreased insulin secretion are characteristics of established type 2 DM, which of these metabolic abnormalities is the primary determinant of type 2 DM is controversial. It is also not well known how insulin resistance and beta cell dysfunction influence serum insulin, proinsulin, proinsulin/insulin ratio in type 2 DM. METHODS: We compared serum insulin, proinsulin and proinsulin/insulin ratio in type 2 diabetic patients and control subjects. We also investigated the relationship between serum insulin, proinsulin and proinsulin/insulin ratio and several biochemical markers which represent insulin resistance or beta cell function. RESULTS: Insulin, proinsulin and proinsulin/insulin ratio were significantly higher in type 2 DM than control(p < 0.001). In diabetic patients, total insulin level was correlated with urinary albumin excretion rates(r = 0.224, p = 0.025) and body mass index(r = 0.269, p = 0.014). Proinsulin level was correlated with fasting C-peptide(r = 0.43, p = 0.002), postprandial 2 hour blood glucose(r = 0.213, p = 0.05) and triglyceride(r = 0.28, p = 0.022). Proinsulin/insulin ratio was positively correlated with fasting C-peptide(r = 0.236, p = 0.031), fasting blood glucose (r = 0.264, p = 0.015), postprandial 2 hour blood glucose(r = 0.277, p = 0.001) and triglyceride(r = 0.428, p < 0.001). In control subjects, insulin level was correlated with triglyceride(r = 0.366, p = 0.002). Proinsulin/insulin ratio was correlated with age(r = 0.241, p = 0.044). CONCLUSION: The serum levels of insulin and proinsulin seem to be associated with several markers of insulin resistance. Whereas proinsulin/insulin ratio might represent beta cell function rather than insulin resistance. But more studies are needed to clarify the mechanisms of elevated proinsulin/insulin ratio in type 2 DM.
