Kurpad Anura V, Regan Meredith M, Raj Tony, El-Khoury Antoine, Kuriyan Rebecca, Vaz Mario, Chandakudlu Deepak, Venkataswamy Veena G, Borgonha Sudhir, Young Vernon R
Department of Physiology and Nutrition Research Center, St John's Medical College, Bangalore, India.
Am J Clin Nutr. 2002 Aug;76(2):404-12. doi: 10.1093/ajcn/76.2.404.
The mean lysine requirement of healthy Indian subjects was estimated from short-term experimental diet periods to be 29 mg x kg(-1) x d(-1), which is higher than the 1985 FAO/WHO/UNU upper requirement of 12 mg x kg(-1) x d(-1).
Our objective was to confirm our proposed requirement of 29 mg x kg(-1) x d(-1) by extending the diet period to 21 d and by using 4 test lysine intakes (12, 20, 28, and 36 mg x kg(-1) x d(-1)) and a 24-h indicator amino acid oxidation and balance approach.
During two 21-d diet periods, 18 healthy Indian men were randomly assigned to receive 12 and 28 or 20 and 36 mg lysine x kg(-1) x d(-1) as part of an L-amino acid diet. At 1800 on days 6 and 20, [(13)C]leucine was infused over 24 h to assess leucine oxidation and daily leucine balance at each test intake.
Leucine oxidation, balance, and flux did not differ significantly between days 7 and 21. Twenty-four-hour leucine oxidation was lower at lysine intakes of 28 and 36 mg than at 12 and 20 mg. Leucine balances at lysine intakes of 12 and 20 mg were negative and significantly less than equilibrium (P < 0.01) and lower (P < 0.02) than balances at 28 and 36 mg lysine. Two-phase regression analysis indicated a breakpoint at 31 mg lysine x kg(-1) x d(-1) in the relation between lysine intake and 24-h leucine oxidation and balance.
Full adaptation to a low lysine intake occurs within 7 d. The previously proposed tentative mean lysine requirement for Western subjects of 30 mg x kg(-1) x d(-1) is confirmed for healthy Indian adults.
通过短期实验饮食期估计，健康印度受试者的平均赖氨酸需求量为29毫克×千克⁻¹×天⁻¹，这高于1985年粮农组织/世界卫生组织/联合国大学设定的12毫克×千克⁻¹×天⁻¹的上限需求量。
我们的目的是通过将饮食期延长至21天，并使用4种测试赖氨酸摄入量（12、20、28和36毫克×千克⁻¹×天⁻¹）以及24小时指示性氨基酸氧化和平衡方法，来确认我们提出的29毫克×千克⁻¹×天⁻¹的需求量。
在两个21天的饮食期内，18名健康印度男性被随机分配接受12和28或20和36毫克赖氨酸×千克⁻¹×天⁻¹，作为L - 氨基酸饮食的一部分。在第6天和第20天的18:00，持续24小时输注[¹³C]亮氨酸，以评估每种测试摄入量下的亮氨酸氧化和每日亮氨酸平衡。
第7天和第21天之间，亮氨酸氧化、平衡和通量没有显著差异。赖氨酸摄入量为28和36毫克时的24小时亮氨酸氧化低于12和20毫克时。赖氨酸摄入量为12和20毫克时的亮氨酸平衡为负，且显著低于平衡状态（P < 0.01），并且低于赖氨酸摄入量为28和36毫克时的平衡（P < 0.02）。两阶段回归分析表明，在赖氨酸摄入量与24小时亮氨酸氧化和平衡之间存在一个断点，为31毫克赖氨酸×千克⁻¹×天⁻¹。
7天内可完全适应低赖氨酸摄入量。健康印度成年人的平均赖氨酸需求量先前对西方受试者提出的暂定需求量30毫克×千克⁻¹×天⁻¹得到确认。
