Abstract: TH-PO156
Bone Mineralization Deficit in Patients on Dialysis: Who Has It and Who Doesn't? What Are the Differences?
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
- Rodrigues, Bruna R., Hospital das Clinicas, Recife, Pernambuco, Brazil
- Gueiros, Ana Paula, Hospital das Clinicas, Recife, Pernambuco, Brazil
- Jorgetti, Vanda, Universidade de Sao Paulo Faculdade de Medicina, Sao Paulo, São Paulo, Brazil
- Gueiros, Jose Edevanilson, Hospital das Clinicas, Recife, Pernambuco, Brazil
Background
Bone mineralization is essential for bone health. Defective bone mineralization can be present both in diseases with high bone turnover, such as mixed disease (MD), and in low bone turnover, in osteomalacia (OM). The objective of this study was to assess the factors associated with defective bone mineralization found in the bone biopsy (BB) of patients on dialysis.
Methods
This was a retrospective, cross-sectional study. The medical records were reviewed of patients on dialysis, who underwent BB, from January 2004 to January 2024. The clinical parameters were: age, sex, time on dialysis, etiology of chronic kidney disease, previous use of aluminum-based chelators, diagnosed with osteoporosis, occurrence of fractures, presence vascular calcification and parathyroidectomy. Laboratory parameters were: total calcium, phosphorus (mg/dL), alkaline phosphatase (ALP) (U/L), intact parathyroid hormone and 25OH vitamin D. The number of times that ALP was above the upper limit of normality (xALP) was used. A transiliac bone biopsy was performed, after double labeling with tetracycline. A comparative analysis was conducted between patients with defective mineralization (Group 1) and patients without (Group 2). Group 1 was made up of patients with MD and OM. Group 2 corresponded to patients with osteitis fibrosa and adynamic bone disease. Univariate and multivariate analyzes were performed to verify factors associated with defective mineralization.
Results
A total of 263 patients were studied, with a median age of 47 years, 87 (33%) of whom belonged to Group 1. Patients in Group 1 differed from those in Group 2 because they had been on dialysis for a longer period of time (years) (10 x 9; p=0.023); they presented lower serum phosphorus (5.1 x 5.9; p<0.001), a higher ALP level (xALP 2.28 x 1.31; p<0.001) and less aluminum toxicity (34.5% x 52.3%; p=0.006). In the multivariate analysis, phosphorus (OR 0.78, 95% CI 0.64 - 0.93; p=0.008) and ALP (xALP OR 1.21.95% CI 1,08 - 1.38; p=0.002) remained independently associated with defective mineralization.
Conclusion
Our results have demonstrated the importance of phosphorus for bone mineralization and have confirmed the role of ALP as a marker for defective mineralization. In this study, aluminum toxicity was not associated with defective mineralization