Abstract: TH-PO141
Magnesium-Sensitive Changes in Serum Calciprotein Crystallization Test (T50): A Post Hoc Analysis from a Randomized Controlled Trial
Session Information
- CKD-MBD: Clinical
October 24, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Bone and Mineral Metabolism
- 502 Bone and Mineral Metabolism: Clinical
Authors
- Bressendorff, Iain Oshoj, Herlev Hospital, Herlev, Hovedstaden, Denmark
- Cejka, Daniel, Ordensklinikum Linz GmbH Elisabethinen, Linz, Oberösterreich, Austria
- Pasch, Andreas, Calciscon AG, Biel, Switzerland
- Schou, Morten, Herlev Hospital, Herlev, Hovedstaden, Denmark
- Brandi, Lisbet, Nordsjaellands Hospital, Hillerød, Hovedstaden, Denmark
- Hansen, Ditte, Herlev Hospital, Herlev, Hovedstaden, Denmark
Background
Serum calciprotein crystallization test (T50) associates with risk of cardiovascular and all-cause mortality in end-stage kidney disease. We have previously demonstrated that increasing dialysate Mg also prolongs T50. We hypothesized that there is an inter-patient variability in responses in T50 to increases in plasma Mg with putatively “Mg sensitive“ and “Mg resistant“ patients.
Methods
Post-hoc analysis of a previous randomized controlled trial of increasing dialysate Mg from 0.5 mmol/L to 1.0 mmol/L. Based on in vitro data, we expected an increase in T50 of 20 min for every 0.1 mmol/L increase in plasma Mg. We plotted changes in T50 and plasma Mg for subjects randomized to dialysate Mg of 1.0 mmol/L to identify subjects with changes as expected (Mg-sensitive) or changes less than expected (Mg-resistant). We also plotted individual measurements of T50 and plasma Mg to visually inspect associations between the two.
Results
Among the 28 subjects analyzed, 13 (46%) were characterized as Mg-sensitive and 15 (54%) were characterized as Mg-resistant. Visual inspection of T50 plotted against plasma Mg showed linear associations for Mg-sensitive individuals versus scattered associations for Mg-resistant individuals. Mg-sensitive individuals had significantly lower baseline T50 and fetuin-A, but no differences in plasma magnesium, phosphate, ionized calcium, bicarbonate, or albumin. Mg-sensitive individuals had significantly greater increases in T50 during high dialysate Mg of 1.0 mmol/L compared to Mg-resistant individuals despite similar increases in plasma Mg.
Conclusion
Patients with end-stage kidney disease have differential responses to T50 despite similar levels of plasma Mg, suggesting that some patients may benefit more than others from a targeted increase in plasma Mg. This suggests an opportunity for personalization of treatments targeting T50.