Low serum IGF-I/GH ratio is associated with abnormal glucose tolerance in acromegaly.
OBJECTIVE
Acromegaly is frequently accompanied with impaired glucose tolerance (IGT) and diabetes mellitus (DM). It remains unclear which factors determine the abnormal glucose tolerance status in acromegaly. In addition, diverse actions of GH and IGF-I in regulating glucose metabolism in acromegaly have not yet been well elucidated. The aim of this study was to investigate the factors associated with abnormal glucose tolerance in acromegaly.


METHODS
We conducted a retrospective cross-sectional study that included 48 patients with active acromegaly. The subjects were divided into two groups by the results of 75 g OGTT: normal glucose tolerance (NGT) group (n = 19) and IGT+DM group (n = 29).


RESULTS
Systolic blood pressure (SBP) was significantly higher in the IGT+DM than in the NGT group. Homeostasis model assessment of beta-cell function (HOMA-beta) was significantly decreased in the IGT+DM group compared with the NGT group. Although serum GH or IGF-I levels were not different between the two groups, the IGF-I/GH ratio in the IGT+DM group was significantly lower than that in the NGT group.


CONCLUSIONS
We have shown that a low serum IGF-I/GH ratio was associated with abnormal glucose tolerance in acromegaly. We propose that the IGF-I/GH ratio is a useful marker to understand the metabolic status in acromegaly.
Fukuoka
Hidenori
H
Division of Endocrinology/Metabolism, Neurology and Hematology/Oncology Department of Clinical Molecular Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
Takahashi
Yutaka
Y
Iida
Keiji
K
Kudo
Takumi
T
Nishizawa
Hitoshi
H
Imanaka
Mari
M
Takeno
Ryoko
R
Iguchi
Genzo
G
Takahashi
Kentaro
K
Okimura
Yasuhiko
Y
Kaji
Hidesuke
H
Chihara
Kazuo
K
D000172:Acromegaly / Q000097:blood* / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D000328:Adult; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D001794:Blood Pressure; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000209:etiology; D005260:Female; D018149:Glucose Intolerance / Q000097:blood* / Q000150:complications; D005951:Glucose Tolerance Test; D013006:Growth Hormone / Q000032:analysis / Q000097:blood*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
D015415:Biomarkers; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone