Renal OsteodystrophyIn healthy adults, bone tissue is continually being rebuilt. The kidneys play an important role in maintaining healthy bones by balancing the blood levels of phosphorus and calcium, two minerals that are essential to bone development. Renal osteodystrophy is a bone disease that occurs when the kidneys malfunction, causing the levels of phosphorus and calcium to become unbalanced. A relatively common complication of kidney disease, renal osteodystrophy affects most dialysis patients.
Causes of Renal OsteodystrophyPhosphorus helps to regulate blood calcium levels, and healthy kidneys remove excess phosphorus from the blood. If the kidneys malfunction, phosphorus levels can become too high, leading to lower calcium levels.
If blood calcium levels become too low, the parathyroid glands will respond by releasing parathyroid hormone (PTH), which draws calcium from the bones to raise blood calcium levels. Over time, the removal of calcium will weaken the bones.
Healthy kidneys also produce calcitriol, a form of vitamin D, to help the body absorb dietary calcium into the blood and the bones. If the kidneys do not produce enough calcitriol, blood calcium levels will drop, PTH levels will increase and more calcium will be removed from the bones.
Symptoms of Renal OsteodystrophyThe bone changes caused by renal osteodystrophy may begin to occur many years before symptoms appear. In adults, the symptoms typically become noticeable only after several years of dialysis. As the bones lose density and weaken, bone and joint pain may develop and frequent fractures may occur.
Diagnosis of Renal OsteodystrophyTo diagnose renal osteodystrophy, a physician may order bloodwork to measure the levels of calcium, phosphorus, PTH and calcitriol in the blood. Additionally, the physician may perform a bone biopsy to evaluate bone density. This procedure involves the removal of a small sample of bone from the hip for analysis under a microscope.
Treatments for Renal OsteodystrophyUsually, a key aspect of renal osteodystrophy treatment is reducing PTH levels to prevent calcium from being withdrawn from the bones. Overactive parathyroid glands may be controlled with dietary changes or medication. In some cases, one or more parathyroid glands may need to be surgically removed. If the kidneys are not producing adequate amounts of calcitriol, synthetic calcitriol can be taken orally or injected, and calcium supplements may be considered.
A tailored treatment plan, which may include dietary changes, supplements, regular exercise and medication, can boost the body's ability to repair bones damaged by renal osteodystrophy.
The renowned nephrology team at Tampa General Hospital provides a full spectrum of treatment options for kidney disease and its complications, including renal osteodystrophy.