Renal Osteodystrophy: Definition, Causes, Facts, Symptoms, Treatment & Diagnosis
Renal Osteodystrophy causes a depletion of bone minerals. Kidney fails to maintain normal level of calcium and phosphorous in blood. The abnormal blood level of calcium and phosphorous causes hormonal changes, which follows demineralization of bone. The disease is observed in patients undergoing regular dialysis. The disease is also known as Mineral and Bone Disorder. In this article, we will study in detail about certain facts, causes, symptoms, and treatments rendered for Renal Osteodystrophy.
How Do We Define Renal Osteodystrophy?
- Renal Osteodystrophy (RD)- Renal Osteodystrophy is a pathological condition of the bone, which tends to occur when the kidneys are unable to maintain adequate levels of calcium and phosphorus in the bloodstream.
- Physiological Cascade-Kidney disease to Osteodystrophy is as follows-
- Kidney maintains normal blood level of phosphorous by removing excess phosphorous.
- Kidney function becomes abnormal following kidney disease and blood phosphorous level increases.
- Increased blood phosphorous level causes decreased serum or blood calcium level.
- Decreased blood calcium causes increased blood level of parathyroid hormone.1
- Increased Parathyroid hormone in circulating blood causes removal of calcium from bone in to blood so as to maintain normal blood level of calcium.
- Removal of calcium from bones causes Osteodystrophy.
- The disease is known as Renal Osteodystrophy because renal disease induces the cascade to cause demineralization of bone.
- Dialysis- Renal Osteodystrophy is quite common in individuals who suffer from kidney disease or are undergoing dialysis.2, 3
- Renal Osteodystrophy tends to be more serious in children as the bones in their body are still in the growth phase.
- Symptoms of Renal Osteodystrophy can be observed in children with kidney diseases even before beginning dialysis.
- Renal Rickets-
- Renal Osteodystrophy slows down growth of bone and may also lead to other deformities of the bone. An example of such deformity is bowed leg where the legs are bent inwards or outwards.
- The skeletal abnormalities are known as Renal Rickets.
- Renal rickets prevents normal development of skeletal system and patient remains of short stature.
- Patient suffering with renal rickets caused by renal osteodystrophy often end up with frequent bone fracture.
Causes of Renal Osteodystrophy
- Calcitriol Deficiency-
- Calcitriol is secreted by normal kidney from Vitamin D.
- Kidney disease often results in calcitriol deficiency as kidney fails to secrete normal quantity of calcitriol.
- Absence of Calcitriol in blood prevents calcium absorption from digested food in intestine.
- Low calcitriol level increases level of parathyroid hormone, which removes calcium and phosphorous from blood resulting in renal osteodystrophy.2
- Renal Osteodystrophy is often observed in patients suffering with hyperparathyroidism.1
- Hyperparathyroidism causes hyperphosphatemia along with hypocalcaemia.
- Low Vitamin D3-
- Both these conditions are as a result of reduced excretion of phosphates by the affected kidney.
- Low vitamin D3 levels are also a result of the inability of the affected kidney to convert vitamin D3 into Calcitriol, which causes further hypocalcaemia.4
- Renal Magnesium Wasting Disease-5
- High excretion of magnesium causes low blood magnesium level in blood, which results in high parathyroid hormone secretion.
- High parathyroid hormone causes hypocalcaemia, which follows demineralization of calcium from bones.
Facts About Renal Osteodystrophy
- Renal Osteodystrophy is a pathological condition of the bone due to failure of the kidneys to maintain adequate levels of calcium and phosphorus.
- This condition is found to be more serious in children and may result in various deformities as stated above.
- Symptoms of Renal Osteodystrophy are not observed in the adult population unless and until an individual has had dialysis for quite a number of years.
- Treatment for Renal Osteodystrophy includes:
- Prescription of Sensipar
- Calcium supplements.
- Appropriate diet
- Regular exercises, which should be supervised in the beginning.
Symptoms Of Renal Osteodystrophy
- Painful Bones
- Joint Pain
- Isolated joint pain or multiple joint pain
- Joint swelling or sign of joint inflammation is absent,
- Joint deformity may be observed if joint pain is associated with fracture of one of the bone of the joint.
- Bone Deformities-
- Renal rickets
- Bowed legs or bent legs
- Frequent fracture
- Short stature and growth retardation
- Muscular Disorder-
- Muscle weakness
- Gait disorder
- Central Nervous System-6
- Hearing loss.
Diagnosis of Renal Osteodystrophy
- Blood Examination-Following blood examination are essential to diagnose osteodystrophy-
- Serum calcium
- Serum phosphorus levels
- Serum or blood level of parathyroid hormone
- Serum level calcitriol
- Bone Biopsy-
- A bone biopsy may be performed to look at the status of the bones.
Treatment For Renal Osteodystrophy
- Sensipar is cinacalcet hydrochloride
- Synthetic Calcitriol-
- In cases where the production of Calcitriol is inadequate, synthetic calcitriol is prescribed as a pills or injection. 6
- Calcium Supplements and Vitamin D
- Over the counter calcium and vitamin D pills are supplemented with calcitriol treatment.6
- Proper Diet
- Avoiding diet rich in phosphorus.
- Avoid food products, which contain phosphorus in high quantity like milk, peas, nuts, and peanut butter.
- Avoiding frequent drinking of cocoa and beer.
- Dialysis is recommended if phosphorous level is too high and not responding to treatment.
- Treat Hyperparathyroidism-
- One of the treatments for Renal Osteodystrophy can be controlling the PTH levels, which averts withdrawal of calcium from bones.
- This medication lowers the PTH levels.
- In case the PTH levels become uncontrollable then the parathyroid glands may have to be removed through surgical procedure.
- Some of the medications that are prescribed to bind the phosphorus and prevent it from absorbing in the blood are Tums, PhosLo and Renagel.
- Regular exercise also plays a vital role as they strengthen the bones in the body but one should consult a physician before beginning any sort of exercise program.
1. Renal osteodystrophy: review of the disease and its treatment.
El-Kishawi AM1, El-Nahas AM.
Saudi J Kidney Dis Transpl. 2006 Sep;17(3):373-82. 1
2. Renal osteodystrophy in chronic renal failure.
Ho LT1, Sprague SM.
Semin Nephrol. 2002 Nov;22(6):488-93. 2
3. The renal bone diseases in children treated with dialysis.
Sanchez CP1, Salusky IB.
Adv Ren Replace Ther. 1996 Jan;3(1):14-23. 3
4. Familial vitamin D deficient osteomalacia and renal osteodystrophy: shaping up the debate.
Saudi J Kidney Dis Transpl. 2010 Jan;21(1):128-30. 4
5. Severe renal osteodystrophy without elevated serum immunoreactive parathyroid hormone concentrations in hypomagnesemia due to renal magnesium wasting.
Zelikovic I, Dabbagh S, Friedman AL, Goelzer ML, Chesney RW.
Pediatrics. 1987 Mar;79(3):403-9. 5
6. Renal osteodystrophy: role of calcimimetics.
Am J Kidney Dis. 2003 Mar;41(3 Suppl 1):S104-7. 6