From the Guidelines
Chronic Kidney Disease (CKD) significantly complicates osteoporosis by increasing the risk of fractures, particularly in patients with advanced CKD stages.
Key Complications
- Increased bone turnover: CKD leads to elevated levels of intact parathyroid hormone (PTH), which is associated with increased bone resorption and turnover, a main feature of bone disease due to hyperparathyroidism 1.
- Abnormal bone metabolism: CKD causes abnormalities in bone metabolism, including decreased bone mineral density (BMD), which increases the risk of fractures 1.
- Osteoporosis diagnosis and treatment: The diagnosis and treatment of osteoporosis in CKD patients are challenging due to the complexity of bone disease in CKD, and the lack of effective treatments that can improve BMD and reduce fracture risk 1.
Diagnostic Approaches
- Bone biopsy: Bone biopsy is the gold standard for diagnosing and classifying renal osteodystrophy, but it is not routinely performed due to its invasive nature 1.
- DXA BMD testing: Dual-energy X-ray absorptiometry (DXA) BMD testing is recommended to assess fracture risk in CKD patients, particularly those with stage G3a to G5D CKD, if the results will impact treatment decisions 1.
Treatment Considerations
- Osteoporosis medications: The use of osteoporosis medications in CKD patients is not well established, and clinical trials have not shown consistent beneficial effects on BMD 1.
- CKD-MBD treatment: Treatment of CKD-mineral and bone disorder (CKD-MBD) focuses on decreasing phosphate levels, maintaining calcium levels, and addressing elevated PTH levels, while avoiding hypercalcemia 1.
From the Research
Complications of Chronic Kidney Disease (CKD) on Osteoporosis
- CKD is associated with the development of mineral bone disorder (MBD), osteoporosis, and fragility fractures 2, 3
- The consequences of CKD-MBD include increased fracture risk, greater morbidity, and mortality 2
- Changes in mineral and humoral metabolism as well as bone structure develop early in the course of CKD, leading to abnormalities in bone turnover, mineralization, volume, linear growth, or strength 2
Pathogenesis of CKD-Associated Osteoporosis
- CKD-induced osteoporosis is a systemic disease characterized by the disruption of mineral, hormone, and vitamin homeostasis that elevates the likelihood of fracture 3
- The pathogenesis of CKD-associated osteoporosis involves the homeostasis and pathways of several components such as parathyroid hormone, calcium, phosphate, vitamin D, fibroblast growth factor, and klotho 3
- Abnormal bone mineralization, remodeling, and turnover are also key factors in the development of CKD-associated osteoporosis 3
Diagnostic Tools and Therapeutic Approaches
- Patients with CKD show higher osteoporosis prevalence, greater fracture rate, increased morbidity and mortality, and an elevated occurrence of hip fracture 3, 4
- Diagnostic tools such as DXA or FRAX can be used to screen fracture risk in CKD patients 2
- Biomarkers such as bALP and iPTH may assist in assessing bone turnover 2
- Therapeutic approaches include lifestyle modifications such as exercise, calcium, and vitamin D supplementation, smoking cessation, and avoidance of excessive alcohol intake 2, 3
- Antiresorptive agents (mainly bisphosphonates) and anabolic agents may be appropriate for CKD patients with osteoporosis, but further studies are needed to assess their safety and efficacy 4, 5
Management and Prevention of CKD-Associated Osteoporosis
- Managing hyperphosphatemia and secondary hyperparathyroidism (SHPT) are crucial in preventing CKD-associated osteoporosis 2
- Understanding the complex pathogenesis of CKD-MBD is essential in improving short- and long-term outcomes 2
- Treatment strategies for CKD-associated osteoporosis should be patient-centered to determine the type of renal osteodystrophy 2
- Further studies are needed to explore more details regarding the underlying pathophysiology and to assess the safety and efficacy of agents for treating CKD-MBD 2, 3, 5