Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan.
Department of Preventive Medicine for Diabetes and Lifestyle-related Diseases, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan.
Endocr J. 2021 Jan 28;68(1):95-102. doi: 10.1507/endocrj.EJ20-0366. Epub 2020 Sep 10.
Japanese Americans living in the United States are genetically identical to Japanese people, but have undergone a rapid and intense westernization of their lifestyle. This study investigated variability in glucagon secretion after glucose loading among Japanese Americans with normal glucose tolerance (NGT) according to obesity status. The 75-g oral glucose tolerance test (OGTT) was performed for 138 Japanese Americans (aged 40-75 years) living in Los Angeles. Plasma glucagon levels measured using the sandwich enzyme-linked immunosorbent assay were compared according to body mass index (BMI) categories among 119 individuals with NGT. The individuals were classified into three categories according to their BMI values: <22 kg/m (n = 37), 22-24.9 kg/m (n = 46), and ≥25 kg/m (n = 36). Fasting plasma glucagon levels and glucagon-area under the curve levels during the OGTT were the highest in the BMI ≥25 kg/m group. Fasting glucagon levels were correlated with BMI (r = 0.399, p < 0.001), fasting insulin levels (r = 0.275, p = 0.003) and the homeostasis model assessment-insulin resistance (r = 0.262, p = 0.004). In conclusion, our findings suggest that fasting hyperglucagonemia is associated with obesity and insulin resistance even during the NGT stage in the Japanese American population.
美国的日裔美国人在基因上与日本人相同，但他们的生活方式已经经历了快速而强烈的西化。本研究根据肥胖状况，调查了具有正常糖耐量（NGT）的日本裔美国人在葡萄糖负荷后胰高血糖素分泌的变异性。对 138 名居住在洛杉矶的日本裔美国人（年龄 40-75 岁）进行了 75g 口服葡萄糖耐量试验（OGTT）。使用夹心酶联免疫吸附试验测量的血浆胰高血糖素水平根据 119 名 NGT 个体的体重指数（BMI）类别进行比较。根据 BMI 值将个体分为三组：<22 kg/m（n = 37）、22-24.9 kg/m（n = 46）和≥25 kg/m（n = 36）。BMI≥25 kg/m 组的空腹血浆胰高血糖素水平和 OGTT 期间胰高血糖素曲线下面积水平最高。空腹胰高血糖素水平与 BMI（r = 0.399，p < 0.001）、空腹胰岛素水平（r = 0.275，p = 0.003）和稳态模型评估-胰岛素抵抗（r = 0.262，p = 0.004）相关。总之，我们的研究结果表明，在日本裔美国人人群中，即使在 NGT 阶段，空腹高胰高血糖素血症与肥胖和胰岛素抵抗有关。
