Mühlhauser I, Prange K, Sawicki P T, Bender R, Dworschak A, Schaden W, Berger M
Department of Metabolic Diseases and Nutrition (WHO-Collaborating Centre for Diabetes), Heinrich-Heine University of Düsseldorf, Germany.
Diabetologia. 1996 Feb;39(2):212-9. doi: 10.1007/BF00403965.
The objectives of the study were to assess the effects of moderate sodium restriction on blood pressure in insulin-dependent diabetic (IDDM) patients with nephropathy and high normal or mildly hypertensive blood pressure (primary objective), and to document possible associated changes of exchangeable body sodium, body volumes, components of the renin-angiotensin-aldosterone system, atrial natriuretic peptide, and catecholamines (secondary objective). Sixteen patients with untreated systolic blood pressure > or = 140 < 160 mmHg and/or diastolic blood pressure > or = 85 < 100 mmHg were included in a double-blind, randomized, placebo-controlled trial. After a 4-week run-in period on their usual diet and a 2-week dietary training period to reduce sodium intake to about 90 mmol/day, eight patients received 100 mmol/day sodium supplement (group 2) and eight patients a matching placebo (group 1) for 4 weeks while continuing on the reduced-sodium diet. Patients were examined at weekly intervals. Main response variables were mean values of supine and sitting systolic and diastolic blood pressure as measured in the clinic and by the patients at home. The differences in blood pressure between the beginning and the end of the blinded 4-week study period were calculated and the differences in changes between the two patient groups were regarded as the main outcome parameters. During the blinded 4-week study period, average urinary sodium excretion was 92 +/- 33 (mean +/- SD) mmol/day in group 1 and 199 +/- 52 mmol/day in group 2 (p = 0.0002). The differences in blood pressure changes between the two patient groups were 3.9(-1.2 to 9) mmHg [mean (95% confidence intervals)] for systolic home blood pressure, 0.9(-3.7 to 5.5) mmHg for diastolic home blood pressure, 4.9(-3.3 to 13.1) mmHg for clinic systolic blood pressure and 5.3(1 to 9.7 mmHg, p = 0.02) for clinic diastolic blood pressure. Combining all patients, there were relevant associations between changes of urinary sodium excretion and blood volume (Spearman correlation coefficient r = 0.57), blood pressure and angiotensin II (diastolic: r = -0.7; systolic: r = -0.48), and exchangeable body sodium and renin activity (r = -0.5). In conclusion, in this study of IDDM patients with nephropathy and high normal or mildly hypertensive blood pressure, a difference in sodium intake of about 100 mmol/day for a period of 4 weeks led to a slight reduction of clinic diastolic blood pressure. Studies including larger numbers of patients with various stages of nephropathy and hypertension are needed to definitely clarify the effects of sodium restriction in IDDM.
本研究的目的是评估适度限钠对患有肾病且血压处于高正常或轻度高血压水平的胰岛素依赖型糖尿病（IDDM）患者血压的影响（主要目标），并记录可交换体钠、身体容积、肾素 - 血管紧张素 - 醛固酮系统各组分、心房利钠肽和儿茶酚胺可能的相关变化（次要目标）。16例未经治疗的收缩压≥140＜160 mmHg和/或舒张压≥85＜100 mmHg的患者被纳入一项双盲、随机、安慰剂对照试验。在按照其日常饮食进行4周的导入期以及进行2周的饮食训练期以将钠摄入量减少至约90 mmol/天后，8例患者接受100 mmol/天的钠补充剂（第2组），8例患者接受匹配的安慰剂（第1组），持续4周，同时继续低钠饮食。每周对患者进行检查。主要反应变量是在诊所测量以及患者在家测量的仰卧位和坐位收缩压和舒张压的平均值。计算4周盲法研究期开始和结束时的血压差异，两组患者变化的差异被视为主要结局参数。在4周盲法研究期内，第1组平均尿钠排泄量为92±33（均值±标准差）mmol/天，第2组为199±52 mmol/天（p = 0.0002）。两组患者血压变化的差异为：家庭收缩压3.9（-1.2至9）mmHg [均值（95%置信区间）]，家庭舒张压0.9（-3.7至5.5）mmHg，诊所收缩压4.9（-3.3至13.1）mmHg，诊所舒张压5.3（1至9.7 mmHg，p = 0.02）。综合所有患者，尿钠排泄变化与血容量之间存在显著相关性（Spearman相关系数r = 0.57），血压与血管紧张素II之间存在相关性（舒张压：r = -0.7；收缩压：r = -0.48），可交换体钠与肾素活性之间存在相关性（r = -0.5）。总之，在这项针对患有肾病且血压处于高正常或轻度高血压水平的IDDM患者的研究中，4周内钠摄入量相差约100 mmol/天导致诊所舒张压略有降低。需要开展纳入更多不同肾病和高血压阶段患者的研究，以明确限钠对IDDM的影响。
