Controls but Not Patients with Calcium Nephrolithiasis Secrete Less Urinary Uromodulin After Salt Loading
- Bone and Mineral Metabolism: Stones, Calcifications, Case Reports
November 04, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Bone and Mineral Metabolism
- 502 Bone and Mineral Metabolism: Clinical
- Bani Hani, Salar, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Wolf, Matthias Tilmann, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Sakhaee, Khashayar, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
Calcium is the most common constituent of kidney stones. Uromodulin (UMOD) enhances TRPV5 membrane abundance increasing renal Ca2+ absorption thus reducing hypercalciuria. UMOD stimulates Na+absorption via NKCC2 causing hypertension. High salt intake is also risk factor for nephrolithiasis. We hypothesize that a higher urinary UMOD secretion with a high salt diet compensates for the higher stone risk by improving hypercalciuria.
This is a prospective, randomized, cross-over study. Stone-formers and controls were randomized to a control or a high salt diet for 2 days. After washout, the participants received the diet they were not exposed to previously. After each diet, we obtained 24-hour urine and fasting serum studies.
At baseline, there was no significant difference for urinary UMOD secretion between stone-formers and controls. In contrast to our hypothesis, we found that urinary UMOD secretion was significantly reduced after the salt load in controls but not in stone-formers.
There was no lower baseline urine UMOD level in stone-formers. After salt loading, we show lower urinary UMOD secretion in controls but not in stone-formers. As UMOD enhances NKCC2 contributing to hypertension, acute downregulation of UMOD after a salt loading makes physiologically sense.
Salt-loading reduces uUMOD in controls only (P<0.05).