Supiano M A, Hogikyan R V, Morrow L A, Ortiz-Alonso F J, Herman W H, Galecki A T, Halter J B
Department of Internal Medicine, University of Michigan, Ann Arbor.
J Gerontol. 1993 Nov;48(6):M237-43. doi: 10.1093/geronj/48.6.m237.
The purpose of this study was to determine whether age is a predictor of sensitivity to the peripheral effects of insulin on carbohydrate metabolism independent of the potential influences of the level of sympathetic nervous system (SNS) activity and blood pressure (BP).
In 60 human subjects (age range 19-78 years), insulin sensitivity, SI, was determined from glucose and insulin levels obtained during an intravenous glucose tolerance test, and plasma norepinephrine (NE) levels were measured to estimate SNS activity.
There were age-associated increases in plasma NE level (r = .585; p < .001) and mean arterial BP (r = .516; p < .001), and an age-associated decline in SI (r = -.352; p = .04). However, in stepwise multiple regression analysis, body mass index (BMI) and mean arterial BP were the only independent predictors of SI, accounting for 43% of the variance in SI; age, plasma NE level, plasma epinephrine level, and fasting plasma glucose did not enter the model. Although these results suggest an age-associated decline in insulin sensitivity, this decline appears to be associated with BMI and mean arterial BP rather than aging per se. In addition, the age-associated increase in SNS activity was not found to be an independent predictor of insulin sensitivity.
This study demonstrates that in addition to BMI, blood pressure should be considered as another confounding factor in studies of insulin sensitivity in human aging.
本研究的目的是确定年龄是否是胰岛素对碳水化合物代谢外周效应敏感性的预测指标，而不受交感神经系统（SNS）活动水平和血压（BP）潜在影响的干扰。
在60名人类受试者（年龄范围19 - 78岁）中，通过静脉葡萄糖耐量试验期间获得的葡萄糖和胰岛素水平测定胰岛素敏感性（SI），并测量血浆去甲肾上腺素（NE）水平以评估SNS活动。
血浆NE水平（r = 0.585；p < 0.001）和平均动脉压（r = 0.516；p < 0.001）随年龄增加，而SI随年龄下降（r = -0.352；p = 0.04）。然而，在逐步多元回归分析中，体重指数（BMI）和平均动脉压是SI的唯一独立预测指标，占SI变异的43%；年龄、血浆NE水平、血浆肾上腺素水平和空腹血糖未纳入模型。尽管这些结果表明胰岛素敏感性随年龄下降，但这种下降似乎与BMI和平均动脉压有关，而非衰老本身。此外，未发现SNS活动随年龄增加是胰岛素敏感性的独立预测指标。
本研究表明，在人类衰老胰岛素敏感性研究中，除BMI外，血压应被视为另一个混杂因素。
