Renal Osteodystrophy / Chronic Kidney Disease - Mineral and Bone Disorder

What is Renal Osteodystrophy?

Renal osteodystrophy, also referred to as Chronic Kidney Disease - Mineral Bone Disorder (CKD-MBD), is a result of imbalance in calcium, phosphorus, parathyroid hormone and vitamin D levels leading to abnormal bone turn over and calcification of vascular tissue in patients with chronic kidney disease(1^✔ ✔Trusted Source
Renal Osteodystrophy

Go to source).

This condition arises due to low calcium and high phosphorus levels. Progressive kidney disease and damage lead to an inability of the kidneys to produce adequate calcitriol, or active vitamin D, which is necessary for the absorption of calcium from food. As a result of low calcium levels, parathyroid glands are stimulated and levels of parathyroid hormone are elevated(2^✔ ✔Trusted Source
Definition, evaluation, and classification of renal osteodystrophy: a position statement from Kidney Disease: Improving Global Outcomes (KDIGO)

Go to source). This hormone draws calcium from bones and further stimulates vitamin D production to increase intestinal calcium absorption, thereby maintaining optimum blood calcium levels.

Besides, raised serum phosphorus levels occur due to inadequate removal of phosphorus from the body by the kidneys(3^✔ ✔Trusted Source
Hyperphosphatemia of Chronic Kidney Disease

Go to source). Over time with continuous removal of calcium from bones along with high phosphorus levels, bones become weak and brittle and carry high risk of developing fractures.

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This condition is common in patients with existing kidney disease or in patients who are already on dialysis for long period of time. It can occur in both adults and children(4^✔ ✔Trusted Source
Mineral & Bone Disorder in Chronic Kidney Disease

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This disorder is more severe in children because many children do not exhibit any symptoms of kidney disease, but bone damage does occur. There is a high risk of bone deformities, stunted growth, and fractures. Children, as they grow, may develop deformities in their lower legs, such as bending inside or outside. This condition is also known as "renal rickets"(5^✔ ✔Trusted Source
Renal Rickets

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Symptoms and Signs of Renal Osteodystrophy / CKD-Mineral Bone Disorder (MBD)

Patients with Renal Osteodystrophy present with the following symptoms:

• Bone pain
• Joint pain
• Short stature
• Bone deformities
• Increased risk of bone fractures due to weak and brittle bones(1^✔ ✔Trusted Source
  Renal Osteodystrophy
  
  Go to source)

Renal osteodystrophy primarily affects bone health. Patients might experience bone/joint pain, increased tendency of fractures, bone deformities and stunted growth.

Most patients with renal osteodystrophy do not exhibit any symptoms. It affects kidney disease patients and most commonly those who are on dialysis for a few years.

The severity of symptoms is more in children.

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Diagnosis of Renal Osteodystrophy / CKD-Mineral Bone Disorder (MBD)

Renal osteodystrophy or Chronic Kidney Disease- Mineral Bone Disorder is diagnosed by estimating the levels of calcium, phosphorus, parathyroid hormone and calcitriol in the blood. A bone biopsy is done to assess the bone density. Treatment is with diet modification, dialysis and drug therapy(4^✔ ✔Trusted Source
Mineral & Bone Disorder in Chronic Kidney Disease

Go to source).

The classical picture of lab reports in a patient with renal osteodystrophy shows:

• Low calcium levels
• High phosphorus levels
• Raised parathyroid hormone levels
• Low calcitriol levels

A bone biopsy is sometimes useful to check whether the bone cells are building normal bone or not.

Treatment of Renal Osteodystrophy / CKD-Mineral Bone Disorder (MBD)

The main goal of treatment is to achieve balance between calcium and phosphorus levels. For this, the following steps need to be followed:

Maintaining phosphorus levels in the body:

• Foods that contain phosphorus like milk, cheese, beans, dark sodas and beer should be limited(6^✔ ✔Trusted Source
  Phosphorus metabolism in chronic kidney disease
  
  Go to source, 7^✔ ✔Trusted Source
  Dietary phosphorus in bone health and quality of life
  
  Go to source).
• The flow rate or duration of dialysis may have to be increased.
• Drugs like phosphate binders are helpful in lowering phosphorus levels. Calcium carbonate and calcium acetate are some of them.

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Maintaining adequate calcium levels to improve bone health:

• If calcitriol is inadequately produced by the kidney, then supplementation of synthetic calcitriol is required.
• Calcium supplements Calcium Rich Foods are also given to maintain bone health(8^✔ ✔Trusted Source
  Calcium intake and bone mineral density: systematic review and meta-analysis
  
  Go to source).

• If these measures are not helpful in maintaining parathyroid hormone levels, then surgery for removal of parathyroid glands is necessary.