The influence of type 2 diabetes on serum GH and IGF-I levels in hospitalized Japanese patients

Kentaro Suda; Ryusaku Matsumoto; Hidenori Fukuoka; Genzo Iguchi; Yushi Hirota; Hitoshi Nishizawa; Hironori Bando; Kenichi Yoshida; Yukiko Odake; Michiko Takahashi; Kazuhiko Sakaguchi; Wataru Ogawa; Yutaka Takahashi

doi:10.1016/j.ghir.2016.03.002

The influence of type 2 diabetes on serum GH and IGF-I levels in hospitalized Japanese patients

Growth Horm IGF Res. 2016 Aug:29:4-10. doi: 10.1016/j.ghir.2016.03.002. Epub 2016 Mar 26.

Affiliations

¹ Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Japan.
² Division of Diabetes and Endocrinology, Kobe University Hospital, Japan.
³ Department of Nutrition, Kobe University Hospital, Japan.
⁴ Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Japan. Electronic address: takahash@med.kobe-u.ac.jp.

PMID: 27060213
DOI: 10.1016/j.ghir.2016.03.002

Abstract

Objective: Although serum insulin like growth factor type 1 (IGF-I) levels are negatively correlated with hemoglobin A1c (HbA1c) in patients with type 1 diabetes, this correlation is controversial in patients with type 2 diabetes mellitus (T2DM) because of the influence of multiple factors including insulin secretion and obesity. The aim of this study was to evaluate the influence of T2DM on serum growth hormone (GH) and IGF-I levels in Japanese patients, who exhibited relatively low BMI compared with white patients in the previous studies.

Design: We retrospectively analysed 315 consecutive Japanese hospitalized patients with T2DM. We analysed factors correlated with changes in serum IGF-I levels and those related to diabetes.

Results: The median HbA1c was 8.7% (7.4-10.2) and the median body mass index (BMI) was 26.2kg/m(2) (23.1-29.7), which was relatively low compared with the previous studies. Overall, no correlations was found between serum GH or IGF-I levels and fasting plasma glucose (FPG) or HbA1c; however, when stratified by FPG and HbA1c levels, serum IGF-I levels were significantly lower in patients with FPG≥200mg/dL than in those with FPG<200mg/dL (p=0.039). In addition, serum IGF-I levels were significantly lower in patients with HbA1c≥12% than in those with HbA1c<12% (p=0.046). Multiple linear regression analysis revealed a positive correlation between fasting C-peptide levels and serum IGF-I levels (p=0.040), whereas no correlations was found for BMI, duration of T2DM, FPG levels, or HbA1c. Moreover, patients with improved HbA1c levels during the follow up period showed a significant increase in serum IGF-I levels.

Conclusions: Serum IGF-I levels were significantly decreased in Japanese patients with uncontrolled T2DM, and impaired insulin secretion may be a mechanism underlying this effect. When diagnosing acromegaly in patients with uncontrolled diabetes, these factors should be taken into account.

Keywords: Asian population; Insulin like growth factor type 1; Type 2 diabetes.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Blood Glucose / metabolism*
C-Peptide / metabolism
Diabetes Mellitus, Type 2 / metabolism*
Female
Glycated Hemoglobin / metabolism*
Hospitalization
Human Growth Hormone / metabolism*
Humans
Insulin-Like Growth Factor I / metabolism*
Japan
Linear Models
Male
Middle Aged
Retrospective Studies

Substances

Blood Glucose
C-Peptide
Glycated Hemoglobin A
IGF1 protein, human
hemoglobin A1c protein, human
Human Growth Hormone
Insulin-Like Growth Factor I