CalciumNEW2026-08

Clinical risk factors associated with bone biopsy findings in CKD-associated osteoporosis: insights from the Brazilian Registry of Bone Biopsy (REBRABO).

Duque Eduardo J, Lowe Lauren S, Carbonara Cinthia E M, Oliveira Rodrigo B et al. — Archives of osteoporosis

Summary

This study investigated how different clinical factors relate to specific bone problems in people with advanced chronic kidney disease (CKD) who are on dialysis. By analyzing bone biopsy data, researchers identified that factors like age, certain hormone levels, and blood calcium are linked to different types of bone issues, such as abnormal bone mineralization or high bone turnover. These findings can help doctors better understand and manage bone health in CKD patients.

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Key points

Advanced kidney disease can lead to various bone problems, including osteoporosis.
This study identified specific clinical factors linked to different types of bone issues in dialysis patients.
Lower blood calcium levels were associated with abnormal bone mineralization.
Understanding these links can help doctors tailor treatments for bone health in kidney disease.

What the study looked at

**What question did the study ask?** This study aimed to understand which clinical characteristics, such as age, lab results, or dialysis type, are associated with specific types of bone disease in patients with advanced chronic kidney disease (CKD) who require dialysis. Doctors often find it challenging to determine the exact nature of bone problems in these patients without invasive procedures. **How was it studied?** Researchers analyzed data from the Brazilian Registry of Bone Biopsy (REBRABO), a collection of bone samples from patients. They looked at 374 adult patients with advanced CKD on dialysis, examining their bone biopsies to classify bone health (e.g., how quickly bone is breaking down and rebuilding, how well it's mineralized, and its density). These findings were then compared with the patients' demographic and laboratory information. **What did it find?** The study found that different clinical factors were linked to different bone issues. For instance, younger patients on hemodialysis with high levels of certain hormones (PTH and ALP) tended to have faster bone turnover. In contrast, older, frailer patients with lower PTH levels often had low bone volume and slower bone turnover. Importantly, lower blood calcium and phosphate levels were associated with abnormal bone mineralization. This suggests that patient characteristics can offer clues about their underlying bone problems.

Dietary takeaway

This study highlights that maintaining appropriate calcium levels is important for bone health, especially for individuals with advanced kidney disease. While the study focused on patients with chronic kidney disease, it generally reinforces the idea that adequate calcium intake, often from dairy products, leafy greens, or fortified foods, is crucial for proper bone mineralization. However, it's important to remember that this is one study, specifically in a complex patient group, and individual dietary needs should always be discussed with a healthcare provider.

Abstract

UNLABELLED: Chronic kidney disease-associated osteoporosis (CKD-OP) is a highly prevalent-yet frequently underrecognized-condition in patients with advanced CKD. The assessment of bone turnover, mineralization, and volume remains challenging in clinical practice, often requiring bone histomorphometric analysis. Using data from the Brazilian Registry of Bone Biopsies (REBRABO), we identified clinical characteristics associated with these histomorphometric parameters. These findings may help clinicians better characterize the underlying bone phenotype and support a more individualized approach to the diagnosis and management of CKD-associated osteoporosis. PURPOSE: Chronic kidney disease-associated osteoporosis (CKD-OP) is characterized by impaired bone quality, and management of bone fragility in CKD partially relies on evaluating bone turnover (T), mineralization (M), and volume (V), through bone biopsy. However, bone biopsy data from large population-based cohorts are limited, making it challenging to identify clinical parameters that are associated with TMV patterns. METHODS: This cross-sectional study is based on data from the Brazilian Registry of Bone Biopsy (REBRABO) and includes 374 iliac crest bone biopsies from adult patients with CKD5D (median age 51 y), collected between August/15 and December/21. Each biopsy was classified according to bone turnover (low/normal vs. high), mineralization (normal vs. abnormal), and trabecular volume (normal vs. low). Demographic and laboratory parameters were also analyzed. RESULTS: No significant differences in TMV classification were observed based on ethnicity, sex, or diabetes status. Higher turnover was independently associated with younger age, hemodialysis modality, elevated parathyroid hormone (PTH), and alkaline phosphatase (ALP) levels, in a model adjusted for dialysis vintage, prior parathyroidectomy (PTX), and phosphate. Abnormal mineralization was independently associated with age, prior PTX, and lower serum calcium and phosphate, after adjustment for body mass index (BMI), PTH, and ALP. Low trabecular volume was independently associated with older age and lower BMI, in a model adjusted for PTH and history of fractures, and cannot be reliably inferred from biochemical markers. Notably, most patients with adynamic bone also presented with low trabecular volume. CONCLUSION: Our findings suggest that younger patients undergoing hemodialysis with elevated PTH and ALP levels may benefit from a more intensive approach to the management of hyperparathyroidism. In contrast, older and more frail patients with relatively low PTH levels may be more likely to exhibit low bone volume and turnover and could potentially benefit from therapies aimed at stimulating bone formation, such as anabolic agents.

View on PubMed →DOI: 10.1007/s11657-026-01756-z