Center for Translational Research in Aging and Longevity, Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, AR USA.
Center for Alaska Native Health Research, Institute of Arctic Biology, University of Alaska-Fairbanks, 902 North Koyukuk Drive, Fairbanks, AK 99775-7000 USA.
Nutr Metab (Lond). 2014 Oct 8;11(1):49. doi: 10.1186/1743-7075-11-49. eCollection 2014.
Lysine supplementation may have a positive influence on the regulation of glucose metabolism but it has not been tested in the geriatric population.
We evaluated the impact of acute lysine supplementation using three randomized experimental scenarios: 1) oral glucose alone (control), 2) oral glucose and low-dose lysine (2 grams), and oral glucose and high dose lysine (5 grams) lysine in 7 older (66 ± 1 years/age), overweight/obese (BMI = 28 ± 2 kg/m(2)) individuals.
We utilized a dual tracer technique (i.e., [6,6-(2)H2] glucose primed constant infusion and 1-[(13)C] glucose oral ingestion) during an oral glucose tolerance test (OGTT) to examine differences in hepatic and peripheral insulin sensitivity under all three scenarios.
Post-absorptive plasma glucose and insulin concentrations were not different between the three trials. Similarly, the response of glucose and insulin concentrations during the oral glucose tolerance tests (OGTT) was similar in the three trials. The results of the Matsuda index (ISI/M) were also not different between the three trials. As an index of hepatic insulin sensitivity, there were no significant differences in the endogenous glucose rate of appearance (glucose Ra) for control, 2 g lysine and 5 g lysine (1.2 ± 0.1, 1.1 ± 0.1, 1.3 ± 0.1 mg•kg(-1)•min(-1)), respectively. With respect to peripheral insulin sensitivity, there were no significant differences in the glucose rate of disappearance (glucose Rd) for control, 2 g lysine and 5 g lysine (4.2 ± 0.1, 4.3 ± 0.2, and 4.5 ± 0.4 mg•kg(-1)•min(-1)), respectively.
Previous studies in younger participants have suggested that lysine may have a beneficial effect on glucose metabolism. However, acute lysine supplementation in the older population does not facilitate beneficial changes in glucose Ra or glucose Rd.
赖氨酸补充可能对葡萄糖代谢的调节有积极影响，但尚未在老年人群中进行过测试。
我们评估了三种随机实验方案下急性赖氨酸补充的影响：1）单独口服葡萄糖（对照），2）口服葡萄糖和低剂量赖氨酸（2 克），3）口服葡萄糖和高剂量赖氨酸（5 克）在 7 名老年（66±1 岁/年龄）、超重/肥胖（BMI=28±2kg/m²）个体中。
我们在口服葡萄糖耐量试验（OGTT）期间利用双示踪剂技术（即[6,6-（2）H2]葡萄糖脉冲恒速输注和 1-[(13)C]葡萄糖口服摄入），在所有三种情况下检查肝和外周胰岛素敏感性的差异。
在三个试验中，餐后血浆葡萄糖和胰岛素浓度没有差异。同样，在三个试验中，口服葡萄糖耐量试验（OGTT）期间葡萄糖和胰岛素浓度的反应也相似。Matsuda 指数（ISI/M）的结果在三个试验中也没有差异。作为肝胰岛素敏感性的指标，对照、2 克赖氨酸和 5 克赖氨酸的内源性葡萄糖出现率（glucose Ra）没有显著差异（分别为 1.2±0.1、1.1±0.1 和 1.3±0.1mg·kg⁻¹·min⁻¹）。关于外周胰岛素敏感性，对照、2 克赖氨酸和 5 克赖氨酸的葡萄糖清除率（glucose Rd）没有显著差异（分别为 4.2±0.1、4.3±0.2 和 4.5±0.4mg·kg⁻¹·min⁻¹）。
先前在年轻参与者中的研究表明，赖氨酸可能对葡萄糖代谢有益。然而，老年人群中急性赖氨酸补充并没有促进葡萄糖 Ra 或葡萄糖 Rd 的有益变化。
