Tolvaptan use tied to changes in mineral metabolism parameters and increased BMD in polycystic kidney disease

Autosomal-dominant polycystic kidney disease is distinguished by a distinctive bone and mineral phenotype. The impact of Tolvaptan treatment on bone mineral density and mineral metabolism is unknown. Matteo Bargagli, University of Bern, Bern, Switzerland, and colleagues analyzed the Bern ADPKD registry, a prospective observational cohort study.

Changes in mineral metabolism parameters and bone mineral density associated with Tolvaptan treatment were assessed using Multivariable mixed-effects regression models. Mineral metabolism parameters were measured at baseline and every 12 months afterward. Dual-energy X-ray absorptiometry was used to determine the bone mineral density at baseline and after three years.

The analysis included 189 participants (122 without and 67 with subsequent treatment with Tolvaptan).

The study demonstrated the following findings:

• Tolvaptan treatment during follow-up was associated with increased bone mineral density at the femoral neck (β 0.092).
• Tolvaptan treatment, in addition, was associated with higher plasma magnesium (β 0.019), urine pH (β 0.214), bicarbonate (β 0.972), and lower parathyroid hormone (β −0.191), fractional urinary magnesium excretion (β −0.473), and 1,25-(OH)2-Vitamin D3 (β −0.126).

"Among patients with autosomal-dominant polycystic kidney disease, chronic tolvaptan treatment is linked with significant changes in both mineral metabolism and acid-base parameters and increased femoral bone mineral density," the researchers wrote their conclusion.

About autosomal-dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder identified by several cysts growing in the kidney. ADPKD is a progressive disease, and symptoms worsen over time. The common symptoms include pain in the back and sides, kidney cysts, headaches, brain aneurysms, kidney stones, high blood pressure, abnormal heart valves, urinary tract infections, and liver and pancreatic cysts.

ADPKD is the kidneys' most common inherited disorder of the kidneys. It is inherited in a dominant pattern. The condition is most frequently caused by changes in the PKD1 and PKD2 genes and less frequently by changes in the DNAJB11 and GANAB genes.

Reference:

Matteo Bargagli, Andri Vetsch, Manuel A Anderegg, Nasser A Dhayat, Uyen Huynh-Do, Nicolas Faller, Bruno Vogt, Pietro Manuel Ferraro, Daniel G Fuster, Tolvaptan treatment is associated with altered mineral metabolism parameters and increased bone mineral density in ADPKD patients, Nephrology Dialysis Transplantation, 2022;, gfac298, https://doi.org/10.1093/ndt/gfac298