Brodsky I G, Robbins D C, Hiser E, Fuller S P, Fillyaw M, Devlin J T
Department of Medicine, University of Vermont College of Medicine, Burlington 05405.
J Clin Endocrinol Metab. 1992 Aug;75(2):351-7. doi: 10.1210/jcem.75.2.1639934.
The dietary protein requirements of patients with insulin-dependent diabetes mellitus (IDDM) are unknown. We studied the metabolic adaptation of IDDM patients with early nephropathy to therapeutic, low-protein diets. Six patients were studied at baseline and following 1 and 12 weeks of consuming 0.6 g/kg-1 ideal body weight.day-1 protein. Outcome variables included quadriceps muscle strength, body composition, nitrogen balance, and estimates of whole body protein turnover using an infusion of L-[1-13C]leucine. All subjects experienced decreased muscle strength (6.6% decline in maximal torque, P = 0.05) and increased body fatness (11% increase in fat mass, P = 0.03) with no change in total body weight. This was accompanied by an initial 40% decrease in the rate of whole-body leucine oxidation after 1 week of dietary restriction which returned almost to baseline rates by 12 weeks (P less than 0.001, 1 week vs. 12 weeks). Nitrogen balance remained negative throughout the period of protein restriction. We conclude that IDDM subjects with early nephropathy experience protein undernutrition during the first 3 months of the dietary protein restriction currently recommended for the treatment of nephropathy. This may result, in part, from an inability to conserve essential amino acids from oxidative loss over the time period of the study.
胰岛素依赖型糖尿病（IDDM）患者的膳食蛋白质需求量尚不清楚。我们研究了患有早期肾病的IDDM患者对治疗性低蛋白饮食的代谢适应性。对6名患者在基线时以及在摄入0.6 g/（kg理想体重·天）蛋白质1周和12周后进行了研究。结果变量包括股四头肌力量、身体成分、氮平衡，以及通过输注L-[1-¹³C]亮氨酸对全身蛋白质周转率的评估。所有受试者均出现肌肉力量下降（最大扭矩下降6.6%，P = 0.05）和身体脂肪增加（脂肪量增加11%，P = 0.03），而总体重无变化。这伴随着饮食限制1周后全身亮氨酸氧化率最初下降40%，到12周时几乎恢复到基线水平（1周与12周相比，P < 0.001）。在蛋白质限制期间，氮平衡始终为负。我们得出结论，患有早期肾病的IDDM受试者在目前推荐用于治疗肾病的饮食蛋白质限制的前3个月会出现蛋白质营养不良。这可能部分是由于在研究期间无法从氧化损失中保留必需氨基酸所致。
