Kobayashi K, Kobayashi K, Mochizuki M, Matsushita K, Sawanobori E, Ishihara T, Higashida K, Amemiya S
Department of Pediatrics, Yamanashi Medical University, Nakakoma-gun, Japan.
Endocr J. 2000 Mar;47 Suppl:S91-3. doi: 10.1507/endocrj.47.supplmarch_s91.
It has been hypothesized that a decreased amount of the free form of insulin-like growth factor-I (fIGF-I) results in morning hyperglycemia in patients with type 1 diabetes mellitus. In this study, we attempted to clarify the role of fIGF-I in relation to total IGF-I (tIGF-I) and its related peptides or proteins in type 1 diabetes. Forty-seven patients with type 1 diabetes, mean age 13.7 years, were evaluated. Blood samples were obtained for the measurement of BG at 0200, 0400 and 0700, and of insulin, total IGF-I (tIGF-I), fIGF-I, IGFBP-1 and IGFBP-3 at 0700. The SD scores (SDS) were determined for the levels of tIGF-I, flGF-I, IGFBP-1 and IGFBP-3 by using Japanese reference data. The morning increase in BG (deltaBG(4-7)) correlated significantly with fIGF-I SDS (r=-0.352, p=0.0152) and IGFBP-1 SDS (r=0.438, p=0.0021), but did not correlate significantly with the fIGF-I level itself or the ratio of fIGF-I to tIGF-I (f/t IGF-I ratio). Hereupon, the f/t IGF-I ratio correlated positively with fIGF-I SDS (r=0.541, p=0.0003). The mean+/-SD in the f/t IGF-I ratio was 0.94+/-0.43%, and that in fIGF-I SDS was -0.50+/-1.32. The level of IGFBP-I SDS correlated negatively with fIGF-I SDS (r=-0.472, p=0.0008) and insulin (r=-0.365, p=0.0116). We suggest that the morning level of fIGF-I SDS, rather than the fIGF-I level itself, may be a useful marker of decreased insulin-like bioactivity in the dawn phenomenon in type 1 diabetes mellitus.
有假设认为，胰岛素样生长因子-I（fIGF-I）的游离形式量减少会导致1型糖尿病患者出现清晨高血糖。在本研究中，我们试图阐明fIGF-I在1型糖尿病中相对于总IGF-I（tIGF-I）及其相关肽或蛋白质的作用。对47例平均年龄为13.7岁的1型糖尿病患者进行了评估。在凌晨02:00、04:00和07:00采集血样测量血糖（BG），并在07:00测量胰岛素、总IGF-I（tIGF-I）、fIGF-I、IGFBP-1和IGFBP-3。通过使用日本参考数据确定tIGF-I、fIGF-I、IGFBP-1和IGFBP-3水平的标准差评分（SDS）。清晨血糖升高幅度（deltaBG(4 - 7)）与fIGF-I SDS显著相关（r = -0.352，p = 0.0152）和IGFBP-1 SDS显著相关（r = 0.438，p = 0.0021），但与fIGF-I水平本身或fIGF-I与tIGF-I的比值（f/t IGF-I比值）无显著相关性。据此，f/t IGF-I比值与fIGF-I SDS呈正相关（r = 0.541，p = 0.0003）。f/t IGF-I比值的均值±标准差为0.94±0.43%，fIGF-I SDS的均值±标准差为 -0.50±1.32。IGFBP-1 SDS水平与fIGF-I SDS呈负相关（r = -0.472，p = 0.0008），与胰岛素呈负相关（r = -0.365，p = 0.0116）。我们认为，1型糖尿病黎明现象中，清晨fIGF-I SDS水平而非fIGF-I水平本身可能是胰岛素样生物活性降低的有用标志物。
