Garca-Estévez Daniel A, Araújo-Vilar David, Saavedra-González Angeles, Fiestras-Janeiro Gloria, Cabezas-Cerrato José
Division of Endocrinology, Hospital Clínico Universitario de Santiago, 15706 Santiago de Compostela, Spain.
Metabolism. 2004 Nov;53(11):1462-6. doi: 10.1016/j.metabol.2004.06.014.
The objective of our research was to identify the mathematical model that would best define the relationship between obesity, insulin resistance (IR), and beta-cell function. Eighty-seven healthy subjects with a wide range of body mass index (BMI) were studied. Insulin sensitivity (IS) was calculated using Bergman's minimal model. Acute insulin response (AIRg) was calculated as the secretion of insulin during the first 10 minutes following a glucose bolus. IS x AIRg was used as an index of insulin-mediated glucose uptake (IMGU). The relationships among BMI, IS, fasting plasma insulin (FPI), and AIRg were studied in linear relationship terms and in terms of the hyperbolic function. Where the best fit was linear, the Jones and Molitoris method was used to investigate whether the 2-line fit was significantly better. The division of the population into BMI quartiles shows that from the third quartile, IS (12.4 +/- 6.0 v 11.0 +/- 6.4 v 4.8 +/- 1.8 v 3.2 +/- 2.0 E-5 min(-1)pmol/L, P < .01) diminishes. Nevertheless, a plateau was established between the last 3 quartiles for IS x AIRg. AIRg related to BMI via a breakpoint of 29.3 kg . m(-2). The best fits for both the BMI/IS and BMI/FPI relationships were hyperbolic. Our data indicate that obesity represents a continuum of IR, with severity increasing as BMI increases. Nevertheless, above a value of 29 kg . m(-2) and despite great increases in adiposity, IS tends to descend slowly. Moreover, there seems to be an IMGU threshold at a BMI value of approximately 27 kg . m(-2), above which an increase in adiposity leads to a greater fall in IS x AIRg. Furthermore, this threshold also appears to affect pancreatic response to a glucose stimulus.
我们研究的目的是确定能够最佳定义肥胖、胰岛素抵抗（IR）和β细胞功能之间关系的数学模型。对87名体重指数（BMI）范围广泛的健康受试者进行了研究。胰岛素敏感性（IS）采用伯格曼最小模型计算。急性胰岛素反应（AIRg）计算为静脉注射葡萄糖后最初10分钟内的胰岛素分泌量。IS×AIRg用作胰岛素介导的葡萄糖摄取（IMGU）指标。以线性关系和双曲线函数形式研究了BMI、IS、空腹血浆胰岛素（FPI）和AIRg之间的关系。在最佳拟合为线性的情况下，采用琼斯和莫利托里斯方法研究二线拟合是否显著更好。将人群分为BMI四分位数显示，从第三个四分位数开始，IS（12.4±6.0对11.0±6.4对4.8±1.8对3.2±2.0 E-5 min⁻¹[pmol/L]⁻¹，P<0.01）降低。然而，在最后三个四分位数之间建立了IS×AIRg的平台期。AIRg与BMI通过29.3 kg·m⁻²的断点相关。BMI/IS和BMI/FPI关系的最佳拟合均为双曲线。我们的数据表明，肥胖代表了IR的连续体，随着BMI增加，严重程度增加。然而，在29 kg·m⁻²以上，尽管肥胖大幅增加，但IS往往缓慢下降。此外，在BMI值约为27 kg·m⁻²处似乎存在一个IMGU阈值，高于该值，肥胖增加会导致IS×AIRg更大幅度下降。此外，该阈值似乎也会影响胰腺对葡萄糖刺激的反应。
