Brouhard B H, LaGrone L
Department of Pediatrics, University of Texas Medical Branch, Galveston.
Am J Med. 1990 Oct;89(4):427-31. doi: 10.1016/0002-9343(90)90370-s.
PURPOSE, PATIENTS, AND METHODS: Functional renal reserve in patients with insulin-dependent diabetes mellitus, as determined by the glomerular filtration rate (GFR) response test, is a measure of the capacity of the kidney to increase glomerular filtration in response to the stimulus of a protein meal or amino acid infusion. This 12-month study evaluated the changes in functional renal reserve in eight patients with insulin-dependent diabetes mellitus with nephropathy (micro-albuminuria [greater than or equal to 30 micrograms/minute]) who chronically decreased their dietary protein intake to a mean of 0.6 g/kg/day (Group 1) compared with a group of similar patients (n = 7) who maintained their unusual dietary protein intake (1.0 g/kg/day, Group 2). Patients were evaluated and measurements taken at 3-, 6-, and 12-month intervals. Absolute and percent increases in GFR were calculated from three averaged 1-hour measurements after an 80-g protein test meal.
Although the initial absolute mean rise (14 +/- 12 versus 18 +/- 13 mL/minute/1.73 m2) in GFR and maximal percent rise (16% +/- 16% versus 32% +/- 27%) after the meal did not differ significantly between the two groups, at 12 months, values in the lower protein group increased (27.8 +/- 9.5 mL/minute/1.73 m2 and 54.7% +/- 48.8%), whereas those in the normal protein intake group declined significantly (3.7 +/- 3.6 mL/min-ute/1.73 m2 and 6.5% +/- 6.5%) (p less than 0.05). Both urine urea and microalbuminuria decreased significantly (p less than 0.05) in the low protein group. Unstimulated GFR at the end of 12 months was significantly less (p less than 0.05) in Group 2 (47 +/- 2 mL/minute/1.73 m2) than in Group 1 (71 +/- 21 mL/minute/1.73 m2). The rate of decline in GFR was significantly greater (p less than 0.05) in the normal protein intake group than in the low protein intake group (0.68 +/- 0.4 versus 0.28 +/- 0.15 mL/minute/1.73 m2/month).
This study indicates that sustained dietary protein restriction can help to preserve renal function, decrease albuminuria, and lower the baseline GFR while maintaining functional renal reserve in patients with insulin-dependent diabetes mellitus.
目的、患者与方法：胰岛素依赖型糖尿病患者的功能性肾储备通过肾小球滤过率（GFR）反应试验来测定，它是衡量肾脏在蛋白质餐或氨基酸输注刺激下增加肾小球滤过能力的指标。这项为期12个月的研究评估了8例患有肾病（微量白蛋白尿[≥30微克/分钟]）的胰岛素依赖型糖尿病患者，他们长期将饮食蛋白质摄入量降至平均0.6克/千克/天（第1组），并与一组保持其异常饮食蛋白质摄入量（1.0克/千克/天，第2组）的类似患者（n = 7）进行比较，观察功能性肾储备的变化。患者在3个月、6个月和12个月的间隔期接受评估并进行测量。在一顿80克蛋白质测试餐后，通过三次1小时测量的平均值计算GFR的绝对增加值和百分比增加值。
尽管两组餐后GFR的初始绝对平均升高值（14±12对18±13毫升/分钟/1.73平方米）和最大百分比升高值（16%±16%对32%±27%）无显著差异，但在12个月时，低蛋白组的值升高（27.8±9.5毫升/分钟/1.73平方米和54.7%±48.8%），而正常蛋白质摄入量组的值显著下降（3.7±3.6毫升/分钟/1.73平方米和6.5%±6.5%）（p<0.05）。低蛋白组的尿尿素和微量白蛋白尿均显著下降（p<0.05）。12个月末，第2组（47±2毫升/分钟/1.73平方米）的未受刺激GFR显著低于第1组（71±21毫升/分钟/1.73平方米）（p<0.05）。正常蛋白质摄入量组的GFR下降速率显著高于低蛋白质摄入量组（0.68±0.4对0.28±0.15毫升/分钟/1.73平方米/月）（p<0.05）。
本研究表明，持续的饮食蛋白质限制有助于保护胰岛素依赖型糖尿病患者的肾功能，减少蛋白尿，降低基线GFR，同时维持功能性肾储备。
