Introduction:
Renal osteodystrophy is a broad term encompassing all biochemical and skeletal manifestations in patients with chronic kidney disease or end-stage renal disease. Perturbed serum levels of calcium, phosphorus, parathyroid hormone, and vitamin D, along with their effects on mineralization, bone turnover, and extraskeletal mineralization, are all important components of this condition. These abnormalities are reported to occur most likely at a glomerular filtration rate less than 60 milliliters per minute per 1.73 meter square.
What Is Renal Osteodystrophy?
Renal osteodystrophy is a type of metabolic bone disease that occurs in patients with chronic renal failure characterized by a lack of bone mineralization due to electrolyte and endocrine abnormalities. Patients exhibit osteomalacia (softening of bones), osteonecrosis (bone death by no blood supply), and pathologic fractures (fractures occurring due to weakened bone in areas of disease). Renal osteodystrophy as an end-stage renal disease complication; has influenced changes in patient treatment protocols and dialysis regimens. There are two kinds of renal osteodystrophy.
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Conditions of high bone turnover, such as osteitis fibrosis and hyperparathyroidism.
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Conditions of low bone turnover, such as adynamic bone disease or heavy metal-induced osteomalacia.
What Are the Causes and Types of Renal Osteodystrophy?
Bone growth occurs in childhood. In adulthood, bones are constantly in a state of turnover and renewal. Old bone tissue is destroyed and replaced by new tissue. Too fast or too slow bone turnover can lead to renal osteodystrophy. The chronic kidney is the main factor responsible for renal osteodystrophy. Renal disease disrupts mineral and hormone ranges and regular bone turnover. Increased or decreased bone turnover can weaken the bones.
There are four main types of renal osteodystrophy:
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Osteitis Fibrosis- Bone tissue breaks down too quickly, resulting in excessive parathyroid hormone levels (hyperparathyroidism).
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Osteomalacia- Bone tissue breaks down, but no new bone is formed, and it becomes spongy and weak. Osteomalacia can lead to low vitamin D levels, heavy metal toxicity, and overproduction of FGF23 (fibroblast growth factor which regulates phosphate reabsorption)in certain cancers.
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Adynamic Bone Disease- Bone tissue does not regenerate naturally. This condition is the result of low parathyroid hormone levels.
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Mixed Renal Osteodystrophy- Includes signs of osteitis fibrosis and osteomalacia.
What Are the Risk Factors for Renal Osteodystrophy?
The risk factors for renal osteodystrophy are as follows:
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Overweight.
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Diabetes mellitus (increased blood sugar).
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Family history of chronic kidney disease.
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Heart disease.
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Hypertension (increased blood pressure).
What Are the Symptoms of Renal Osteodystrophy?
The main symptoms are fractures and bone pain. Many people with early forms of the disease may exhibit no symptoms at all. Given below are some of the symptoms that people with renal osteodystrophy may experience:
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Weakness.
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Bone pain.
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Pathologic fracture.
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Skeletal deformity.
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Symptoms of hypocalcemia, such as muscle spasms, cramps, and seizures.
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Abdominal pain.
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Muscle cramps.
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Dyspnea, otherwise known as shortness of breath..
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Convulsions.
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Altered mental status.
When to Get Help for Renal Osteodystrophy?
In chronic kidney disease, consult the doctor if suffering from bone pain. This can be a sign of renal osteodystrophy. People with chronic kidney disease do not realize they have chronic kidney disease until it has advanced. Regular checkups by a doctor can help detect kidney disease early. Early detection allows steps to be taken to slow progression.
How Is Renal Osteodystrophy Diagnosed?
The doctor will check the symptoms along with medical and family history. A physical examination may also be performed. Tests that health care providers use to diagnose this condition include:
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Blood Test- This includes tests for calcium, phosphorus, vitamin D, and parathyroid hormone measurements. Blood tests can also measure other markers that help with bone turnover (regeneration), such as alkaline phosphatase. In chronic kidney disease, doctors regularly do blood tests to check for changes in these levels.
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Bone Biopsy- A biopsy removes a small sample of tissue for analysis in the laboratory. A bone biopsy can help providers confirm bone density and structure but is rarely used.
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Bone Density Test- Also called a DEXA scan (dual-energy X-ray absorptiometry), this test measures bone strength and risk of fracture.
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Imaging Test- X-rays, CT scans (computed tomography), and MRIs (medical resonance imaging) help doctors assess the bone changes. Physicians also use CT scans and echocardiograms to visualize calcifications within blood vessels.
What Is the Treatment of Renal Osteodystrophy?
Treatment depends on the amount of bone damage and kidney disease, also whether bone turnover is low or high. The main types of treatment are:
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Dietary Changes- Doctors may recommend a low-phosphorus diet. This includes restricting processed and packaged foods, which often have high levels of added phosphorus. In the case of advanced kidney disease, there may be a need to need to limit foods that are naturally high in phosphorus.
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Medicines and Dietary Supplements- These help balance mineral and hormone levels. These include calcium and vitamin-D supplements, parathyroid hormone-lowering drugs, and phosphorus binders. Physicians may recommend non-calcium phosphorus binders to lower phosphate levels without increasing calcium levels. In the case of persistently high calcium levels, there is a low bone turnover rate and adynamic bone disease.
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Parathyroid Surgery- Surgery is an option when other treatments are ineffective. This includes removing one or more parathyroid glands (parathyroidectomy). Surgeons usually leave at least one parathyroid gland intact. This may help reduce parathyroid levels and prevent akinetic bone disease.
What Are the Complications of Renal Osteodystrophy?
There is no cure other than a kidney transplant. People with chronic kidney disease gradually lose kidney function. Many progress to renal failure or dialysis. Renal osteodystrophy is a common complication of chronic kidney disease and many people with chronic kidney disease also develop heart disease. It is the leading cause of mortality in patients with renal failure. Children with kidney disease may experience growth retardation due to renal osteodystrophy. It can also cause a skeletal deformity known as rickets. This is childhood osteomalacia.
How to Prevent Renal Osteodystrophy?
Renal osteodystrophy cannot be prevented, but the treatment of chronic kidney disease can slow its progression. The following points may help slow its progression:
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Take the medication on time.
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Follow the prescribed diet properly.
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Complete the dialysis treatment.
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Exercise.
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Smoking cessation.
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Drinking less alcohol can also help.
Conclusion:
Renal osteodystrophy is a common complication of chronic kidney disease that weakens the bones. It is caused by changes in the levels of minerals and hormones in the blood. The main symptoms are bone pain and fractures. There is no cure other than a kidney transplant. Dietary changes, medications, and surgery can help slow its progression. This condition cannot be cured, but steps can be taken to slow its progression and maintain quality of life.
