Premium
Association of ghrelin dynamics with beta cell function in Japanese subjects with normal glucose tolerance
Author(s) -
Murai Norimitsu,
Saito Naoko,
Kodama Eriko,
Iida Tatsuya,
Mikura Kentaro,
Imai Hideyuki,
Kaji Mariko,
Hashizume Mai,
Kigawa Yasuyoshi,
Koizumi Go,
Tadokoro Rie,
Sugisawa Chiho,
Endo Kei,
Iizaka Toru,
Saiki Ryo,
Otsuka Fumiko,
Shun Ishibashi,
Nagasaka Shoichiro
Publication year - 2019
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/cen.14073
Subject(s) - ghrelin , medicine , endocrinology , insulin resistance , insulin , homeostasis , hormone
Background Ghrelin is involved in feeding regulation and energy metabolism and is also known to inhibit insulin secretion (β). However, few clinical studies have demonstrated the relationship between β and ghrelin dynamics. This study tested the hypothesis that, in oral glucose tolerance tests (OGTT), ghrelin dynamics are associated with β. Methods Subjects were 1145 healthy individuals <40 years old who tested normal on the 75‐g OGTT. The following indicators and the ghrelin suppression ratio (GSR) during OGTT were calculated: insulin sensitivity (SI) [1/homoeostasis model assessment of insulin resistance, insulin sensitivity index‐Matsuda and 1/fasting insulin (1/FIRI)]; and β [Stumvoll first‐phase index (Stumvoll‐1), Stumvoll second‐phase index and insulinogenic index]. From nine combinations of SI and β, combinations that produce hyperbolic relationships were identified. Results Stumvoll‐1 and 1/FIRI showed a hyperbolic relationship in nonobese subjects, and the product of Stumvoll‐1 and 1/FIRI was used as the disposition index (DI). When analyzed by BMI quartiles, post‐loading glucose and insulin levels at each time point increased from Q1 (low BMI) through Q4 (high BMI), whereas the DI, ghrelin levels at each time point, and GSR decreased from Q1 to Q4. On multivariate and bivariate analysis, GSR and DI were positive and independent, and fasting ghrelin and FIRI were negatively and independently correlated. Conclusions Ghrelin dynamics were associated with beta cell function in subjects with normal glucose tolerance. Glucose intolerance in obesity may be due not only to insulin resistance but also to impaired beta cell function associated with abnormalities of ghrelin dynamics.