慢性盐负荷对成年人血清和尿液中尿调节素水平的影响

Objective: To explore the effects of dietary salt intake on serum and urinary levels through the chronic salt loading intervention. Methods: Eighty adults (18 to 65 years old) were screened from two villages in Liquan and Lantian counties to participate in a 2-week chronic salt intervention, including a 3-day baseline survey, a 7-day low-salt diet, and a 7-day high-salt diet. Uromodulin levels in serum and urine were determined by enzyme-linked immunosorbent assay (ELISA) kits. According to the baseline blood pressure levels, all subjects were divided into normotensive and hypertensive groups. Pearson or Spearman correlation analyzed the associations of 24 h urinary sodium excretions with serum and urinary levels of uromodulin. Results: At the baseline, serum uromodulin in hypertensive subjects was significantly lower than that in normotensive subjects (26.7±9.9 vs. 57.9±9.7 ng/mL, P=0.033). Serum uromodulin levels were significantly lower on a high-salt diet than on a baseline diet [(54.9±8.8 vs. 28.3±4.5) ng/mL, P=0.007]. In addition, daily urinary excretions of uromodulin were lower on a high-salt diet [(28.4±6.6) ng/mL] than on a baseline diet [(282.1±70.0) ng/mL] and on a low-salt diet [(154.1±21.3) ng/mL]. The 24 h urinary sodium excretions were inversely correlated with urinary uromodulin excretions (r=-0.40, P<0.001) on both low-salt and high-salt diets, but not correlated with serum uromodulin levels. Conclusion: Variations in dietary salt intake significantly affect plasma and urine uromodulin levels.