Insulin and Incretin Biology, Hagedorn Research Institute, Novo Nordisk A/S, Gentofte, Denmark.
Clin Endocrinol (Oxf). 2011 Oct;75(4):514-9. doi: 10.1111/j.1365-2265.2011.04084.x.
Fibroblast growth factor (FGF21) is a potent regulator of glucose and lipid metabolism. In rodents, the hepatic expression of FGF21 is controlled by fasting and a circadian regulation, but the physiological role and regulation of FGF21 in humans is not well established. Therefore, the objective of this study was to elucidate the 24-h profiling of plasma FGF21 during a 72-h fast.
After an initial 12-h overnight fast, plasma levels of FGF21 together with circulating levels of glucose, insulin, glucagon and free fatty acids (FFA) were measured every 6 h during a 72-h fast in healthy female volunteers (n = 14).
During the fast, plasma glucose and serum insulin gradually decreased whilst glucagon and FFA levels increased. Mean 24-h plasma FGF21 levels did not increase during the 72-h fast, but, despite large inter-individually variations, a significant circadian rhythm was observed. Thus, during the first day, plasma FGF21 increased from 125 pg/ml (16-142) at 8.30 a.m to peak levels of 224 pg/ml (88-326) at 2.30 a.m (P = 0·0215), the second day from 60 pg/ml (7-74) at 8.30 a.m to 268 pg/ml (103-410) at 2.30 a.m. (P = 0·0010) and the third day from 94 pg/ml (9-146) to 151 pg/ml (87-207) at 2.30 a.m. (P = 0·0049). Cortisol also showed circadian regulation and peaked at 8.30 a.m every day, 6 h after the observed FGF21 peak.
Plasma FGF21 follows a circadian rhythm during a 72-h fast in healthy female subjects. The circadian regulation has a stronger impact on plasma FGF21 than the fasting status over 72-h period.
成纤维细胞生长因子 21(FGF21)是一种调节葡萄糖和脂质代谢的有效物质。在啮齿动物中,FGF21 的肝脏表达受禁食和昼夜节律调节控制,但 FGF21 在人体中的生理作用和调节尚未得到很好的确定。因此,本研究的目的是阐明在 72 小时禁食期间,血浆 FGF21 的 24 小时变化情况。
在初始的 12 小时夜间禁食后,在 72 小时禁食期间,每隔 6 小时测量健康女性志愿者(n=14)的血浆 FGF21 水平以及循环血糖、胰岛素、胰高血糖素和游离脂肪酸(FFA)水平。
在禁食期间,血浆葡萄糖和血清胰岛素逐渐下降,而胰高血糖素和 FFA 水平升高。尽管个体间存在很大差异,但在 72 小时禁食期间,平均 24 小时血浆 FGF21 水平并未增加,但仍观察到明显的昼夜节律。因此,在第一天,血浆 FGF21 从上午 8:30 的 125pg/ml(16-142)增加到凌晨 2:30 的峰值 224pg/ml(88-326)(P=0.0215),在第二天从上午 8:30 的 60pg/ml(7-74)增加到凌晨 2:30 的 268pg/ml(103-410)(P=0.0010),在第三天从上午 8:30 的 94pg/ml(9-146)增加到凌晨 2:30 的 151pg/ml(87-207)(P=0.0049)。皮质醇也呈现昼夜节律调节,每天上午 8:30 达到峰值,比观察到的 FGF21 峰值早 6 小时。
在健康女性受试者的 72 小时禁食期间,血浆 FGF21 遵循昼夜节律。在 72 小时期间,昼夜节律对血浆 FGF21 的影响比禁食状态更强。