Cianciaruso B, Bellizzi V, Minutolo R, Tavera A, Capuano A, Conte G, De Nicola L
Nephrology Division, School of Medicine, I and II University of Naples, Italy.
Miner Electrolyte Metab. 1998;24(4):296-301. doi: 10.1159/000057385.
Experimental studies suggest that salt intake plays a critical role in the progressive glomerular filtration rate (GFR) loss of established renal disease; however, this issue has never been addressed in humans. To this aim, we have retrospectively analyzed the clinical data of patients with chronic renal failure (CRF), in whom a low-protein diet was prescribed, over a period of about 3 years. On the basis of the daily urinary sodium output, the patients were divided into two groups: a group of patients constantly ingesting > 200 mEq NaCl/day (high sodium intake, HSD, n = 30) and a group in which salt intake was < 100 mEq/day (low sodium intake, LSD, n = 27). Patients taking diuretics or ACE inhibitors were excluded. At baseline, the LSD group, as compared to the HSD group, was characterized by significantly lower creatinine clearance (24 +/- 2 vs. 28 +/- 2 ml/min) and higher proteinuria (2.9 +/- 0.3 vs. 1.5 +/- 0.2 g/day). Despite the presence of these risk factors for progression, and a similar control of blood pressure (the average of the mean arterial pressure during follow-up was 111 +/- 2 mm Hg in LSD and 107 +/- 2 mm Hg in HSD), the LSD patients showed a better renal outcome: in this group, as compared to HSD, the GFR decline was lower (0.25 +/- 0.07 vs. 0.51 +/- 0.09 ml/min/month, p < 0.05), and proteinuria did not change while it markedly increased in HSD. During follow-up, LSD patients also ingested a significantly lower amount of protein. This study therefore suggests that efficacious salt restriction in CRF patients improves the outcome of renal disease independent from its antihypertensive effects.
实验研究表明，盐摄入量在已确诊的肾脏疾病患者肾小球滤过率（GFR）进行性下降中起关键作用；然而，这一问题在人类中从未得到解决。为此，我们回顾性分析了约3年期间接受低蛋白饮食治疗的慢性肾衰竭（CRF）患者的临床资料。根据每日尿钠排出量，将患者分为两组：一组患者每日持续摄入>200 mEq氯化钠（高钠摄入，HSD，n = 30），另一组盐摄入量<100 mEq/天（低钠摄入，LSD，n = 27）。服用利尿剂或ACE抑制剂的患者被排除在外。基线时，与HSD组相比，LSD组的特点是肌酐清除率显著降低（24±2 vs. 28±2 ml/分钟），蛋白尿更高（2.9±0.3 vs. 1.5±0.2 g/天）。尽管存在这些疾病进展的危险因素，且血压控制情况相似（随访期间平均动脉压的平均值在LSD组为111±2 mmHg，在HSD组为107±2 mmHg），但LSD组患者的肾脏预后更好：与HSD组相比，该组GFR下降幅度更低（0.25±0.07 vs. 0.51±0.09 ml/分钟/月，p<0.05），蛋白尿没有变化，而HSD组蛋白尿显著增加。随访期间，LSD组患者摄入的蛋白质量也显著更低。因此，本研究表明，CRF患者有效限盐可改善肾脏疾病的预后，这与其降压作用无关。
