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Treatments focuses on symptoms, with genetic counseling recommended.
Treatment consists of maintaining normal levels of calcium, phosphorus, and Vitamin D. Phosphate binders, supplementary Calcium and Vitamin D will be used as required.
Treatment for renal osteodystrophy includes the following:
- calcium and/or native vitamin D supplementation
- restriction of dietary phosphate (especially inorganic phosphate contained in additives)
- phosphate binders such as calcium carbonate, calcium acetate, sevelamer hydrochloride or carbonate, lanthanum carbonate, sucroferric oxyhydroxide, ferric citrate among others
- active forms of vitamin D (calcitriol, alfacalcidol, paricalcitol, maxacalcitol, doxercalciferol, among others)
- cinacalcet
- renal transplantation
- haemodialysis five times a week is thought to be of benefit
- parathyroidectomy for symptomatic medication refractive end stage disease
It was characterized in 1952 by Fuller Albright as "pseudo-pseudohypoparathyroidism" (with hyphen).
Recovery from renal osteodystrophy has been observed following kidney transplantation. Renal osteodystrophy is a chronic condition with a conventional hemodialysis schedule. Nevertheless, it is important to consider that the broader concept of CKD-MBD, which includes renal osteodystrophy, is not only associated with bone disease and increased risk of fractures but also with cardiovascular calcification, poor quality of life and increased morbidity and mortality in CKD patients (the so-called bone-vascular axis). Actually, bone may now be considered a new endocrine organ at the heart of CKD-MBD.
Medical management of OFC consists of Vitamin D treatment, generally alfacalcidol or calcitriol, delivered intravenously. Studies have shown that in cases of OFC caused by either end-stage renal disease or primary hyperparathyoidism, this method is successful not only in treating underlying hyperparathyoidism, but also in causing the regression of brown tumors and other symptoms of OFC.
Almost all who undergo parathyroidectomy experience increased bone density and repair of the skeleton within weeks. Additionally, patients with OFC who have undergone parathyroidectomy begin to show regression of brown tumors within six months. Following parathyroidectomy, hypocalcaemia is common. This results from a combination of suppressed parathyroid glands due to prolonged hypercalcaemia, as well as the need for calcium and phosphate in the mineralization of new bone.
Thirty percent of patients with OFC caused by parathyroid carcinoma who undergo surgery see a local recurrence of symptoms. The post-surgical survival rate hovers around seven years, while patients who do not undergo surgery have a survival rate of around five years.
Treatment depends entirely on the type of hyperparathyroidism encountered.
People with primary hyperparathyroidism who are symptomatic benefit from surgery to remove the parathyroid tumor (parathyroid adenoma). Indications for surgery are as follows:
- Symptomatic hyperparathyroidism
- Asymptomatic hyperparathyroidism with any of the following:
- 24-hour urinary calcium > 400 mg (see Foot Note, below)
- serum calcium > 1 mg/dL above upper limit of normal
- Creatinine clearance > 30% below normal for patient's age
- Bone density > 2.5 standard deviations for below peak (i.e., T-score of -2.5)
- People age < 50
Surgery can rarely result in hypoparathyroidism.
Severe hypocalcaemia, a potentially life-threatening condition, is treated as soon as possible with intravenous calcium (e.g. as calcium gluconate). Generally, a central venous catheter is recommended, as the calcium can irritate peripheral veins and cause phlebitis. In the event of a life-threatening attack of low calcium levels or tetany (prolonged muscle contractions), calcium is administered by intravenous (IV) infusion. Precautions are taken to prevent seizures or larynx spasms. The heart is monitored for abnormal rhythms until the person is stable. When the life-threatening attack has been controlled, treatment continues with medicine taken by mouth as often as four times a day.
Long-term treatment of hypoparathyroidism is with vitamin D analogs and calcium supplementation, but may be ineffective in some due to potential renal damage. The N-terminal fragment of parathyroid hormone (PTH 1-34) has full biological activity. The use of pump delivery of synthetic PTH 1-34 provides the closest approach to physiologic PTH replacement therapy. Injections of recombinant human parathyroid hormone are available as treatment in those with low blood calcium levels.
Albright's hereditary osteodystrophy is a form of osteodystrophy, and is classified as the phenotype of pseudohypoparathyroidism type 1A; this is a condition in which the body does not respond to parathyroid hormone.
Types include:
While biochemically similar, type 1 and 2 disease may be distinguished by the differing urinary excretion of cyclic AMP in response to exogenous PTH.
Some sources also refer to a "type 1c".
Pseudohypoparathyroidism is a condition associated primarily with resistance to the parathyroid hormone. Those with the condition have a low serum calcium and high phosphate, but the parathyroid hormone level (PTH) is appropriately high (due to the low level of calcium in the blood). Its pathogenesis has been linked to dysfunctional G Proteins (in particular, Gs alpha subunit). The condition is extremely rare, with an estimated overall prevalence of 7.2/1,000,000 or approximately 1/140000.
Osteodystrophy is any dystrophic growth of the bone. It is defective bone development that is usually attributable to renal disease or to disturbances in calcium and phosphorus metabolism.
One form is renal osteodystrophy.
Prevention of osteomalacia rests on having an adequate intake of vitamin D and calcium. Vitamin D3 Supplementation is often needed due to the scarcity of Vitamin D sources in the modern diet.
Certain medications have been associated with an increase in osteoporosis risk; only glucocorticosteroids and anticonvulsants are classically associated, but evidence is emerging with regard to other drugs.
- Steroid-induced osteoporosis (SIOP) arises due to use of glucocorticoids – analogous to Cushing's syndrome and involving mainly the axial skeleton. The synthetic glucocorticoid prescription drug prednisone is a main candidate after prolonged intake. Some professional guidelines recommend prophylaxis in patients who take the equivalent of more than 30 mg hydrocortisone (7.5 mg of prednisolone), especially when this is in excess of three months. Alternate day use may not prevent this complication.
- Barbiturates, phenytoin and some other enzyme-inducing antiepileptics – these probably accelerate the metabolism of vitamin D.
- L-Thyroxine over-replacement may contribute to osteoporosis, in a similar fashion as thyrotoxicosis does. This can be relevant in subclinical hypothyroidism.
- Several drugs induce hypogonadism, for example aromatase inhibitors used in breast cancer, methotrexate and other antimetabolite drugs, depot progesterone and gonadotropin-releasing hormone agonists.
- Anticoagulants – long-term use of heparin is associated with a decrease in bone density, and warfarin (and related coumarins) have been linked with an increased risk in osteoporotic fracture in long-term use.
- Proton pump inhibitors – these drugs inhibit the production of stomach acid; this is thought to interfere with calcium absorption. Chronic phosphate binding may also occur with aluminium-containing antacids.
- Thiazolidinediones (used for diabetes) – rosiglitazone and possibly pioglitazone, inhibitors of PPARγ, have been linked with an increased risk of osteoporosis and fracture.
- Chronic lithium therapy has been associated with osteoporosis.
Hypoparathyroidism is decreased function of the parathyroid glands with underproduction of parathyroid hormone. This can lead to low levels of calcium in the blood, often causing cramping and twitching of muscles or tetany (involuntary muscle contraction), and several other symptoms. The condition can be inherited, but it is also encountered after thyroid or parathyroid gland surgery, and it can be caused by immune system-related damage as well as a number of rarer causes. The diagnosis is made with blood tests, and other investigations such as genetic testing depending on the results. The treatment of hypoparathyroidism is limited by the fact that there is no exact form of the hormone that can be administered as replacement. However teriparatide, brand name Forteo, a biosimilar peptide to parathyroid hormone, may be given by injection. Calcium replacement or vitamin D can ameliorate the symptoms but can increase the risk of kidney stones and chronic kidney disease.
Treatment in fibrous dysplasia is mainly palliative, and is focused on managing fractures and preventing deformity. There are no medications capable of altering the disease course. Intravenous bisphosphonates may be helpful for treatment of bone pain, but there is no clear evidence that they strengthen bone lesions or prevent fractures. Surgical techniques that are effective in other disorders, such as bone grafting, curettage, and plates and screws, are frequently ineffective in fibrous dysplasia and should be avoided. Intramedullary rods are generally preferred for management of fractures and deformity in the lower extremities. Progressive scoliosis can generally be managed with standard instrumentation and fusion techniques. Surgical management in the craniofacial skeleton is complicated by frequent post-operative FD regrowth, and should focus on correction of functional deformities. Prophylactic optic nerve decompression increases the risk of vision loss and is contraindicated.
Managing endocrinopathies is a critical component of management in FD. All patients with fibrous dysplasia should be evaluated and treated for endocrine diseases associated with McCune–Albright syndrome. In particular untreated growth hormone excess may worsen craniofacial fibrous dysplasia and increase the risk of blindness. Untreated hypophosphatemia increases bone pain and risk of fractures.
High phosphate levels can be avoided with phosphate binders and dietary restriction of phosphate. If the kidneys are operating normally, a saline diuresis can be induced to renally eliminate the excess phosphate. In extreme cases, the blood can be filtered in a process called hemodialysis, removing the excess phosphate.
It is well-known that as kidney function declines, there is a progressive deterioration in mineral homeostasis, with a disruption of normal serum and tissue concentrations of phosphorus and calcium, and changes in circulating levels of hormones. These include parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH) vitamin D; calcidiol), 1,25-dihydroxyvitamin D (1,25(OH)2 vitamin D; calcitriol), and other vitamin D metabolites, fibroblast growth factor 23 (FGF-23), and growth hormone. Beginning in CKD stage 3, the ability of the kidneys to appropriately excrete a phosphate load is diminished, leading to hyperphosphatemia, elevated PTH (secondary hyperparathyroidism), and decreased 1,25(OH)2 vitamin D with associated elevations in the levels of FGF-23. The conversion of 25(OH) vitamin D to 1,25(OH)2 vitamin D is impaired, reducing intestinal calcium absorption and increasing PTH. The kidney fails to respond adequately to PTH, which normally promotes phosphaturia and calcium reabsorption, or to FGF-23, which also enhances phosphate excretion. In addition, there is evidence at the tissue level of a downregulation of vitamin D receptor and of resistance to the actions of PTH. Therapy is generally focused on correcting biochemical and hormonal abnormalities in an effort to limit their consequences.
The mineral and endocrine functions disrupted in CKD are critically important in the regulation of both initial bone formation during growth (bone modeling) and bone structure and function during adulthood (bone remodeling). As a result, bone abnormalities are found almost universally in patients with CKD requiring dialysis (stage 5D), and in the majority of patients with CKD stages 3–5. More recently, there has been an increasing concern of extraskeletal calcification that may result from the deranged mineral and bone metabolism of CKD and from the therapies used to correct these abnormalities.
Numerous cohort studies have shown associations between disorders of mineral metabolism and fractures, cardiovascular disease, and mortality. These observational studies have broadened the focus of CKD-related mineral and bone disorders (MBDs) to include cardiovascular disease (which is the leading cause of death in patients at all stages of CKD). All three of these processes (abnormal mineral metabolism, abnormal bone, and extraskeletal calcification) are closely interrelated and together make a major contribution to the morbidity and mortality of patients with CKD. The traditional definition of renal osteodystrophy did not accurately encompass this more diverse clinical spectrum, based on serum biomarkers, noninvasive imaging, and bone abnormalities. The absence of a generally accepted definition and diagnosis of renal osteodystrophy prompted Kidney Disease: Improving Global Outcomes (KDIGO)] to sponsor a controversies conference, entitled "Definition, Evaluation, and Classification of Renal Osteodystrophy", in 2005. The principal conclusion was that the term "CKD–Mineral and Bone Disorder (CKD–MBD)" should now be used to describe the "broader clinical syndrome encompassing mineral, bone, and calcific cardiovascular abnormalities that develop as a complication of CKD".
Studies of the benefits of supplementation with calcium and vitamin D are conflicting, possibly because most studies did not have people with low dietary intakes. A 2013 review by the USPSTF found insufficient evidence to determine if supplementation with calcium and vitamin D results in greater harm or benefit in men and premenopausal women. The USPSTF did not recommend low dose supplementation (less than 1 g of calcium and 400 IU of vitamin D) in postmenopausal women as there does not appear to be a difference in fracture risk. It is unknown what effect higher doses have. A 2015 review found little data that supplementation of calcium decreases the risk of fractures.
While some meta-analyses have found a benefit of vitamin D supplements combined with calcium for fractures, they did not find a benefit of vitamin D supplements alone.
While supplementation does not appear to affect the risk of death, there is an increased risk of myocardial infarctions with calcium supplementation, kidney stones, and stomach problems.
Vitamin K deficiency is also a risk factor for osteoporotic fractures. The gene gamma-glutamyl carboxylase (GGCX) is dependent on vitamin K. Functional polymorphisms in the gene could attribute to variation in bone metabolism and BMD. Vitamin K2 is also used as a means of treatment for osteoporosis and the polymorphisms of GGCX could explain the individual variation in the response to treatment of vitamin K. Vitamin K supplementation may reduce the risk of fractures in postmenopausal women; however, there is no evidence for men.
Chronic kidney disease–mineral and bone disorder (CKD-MBD) is one of the many complications associated with chronic kidney disease. It represents a systemic disorder of mineral and bone metabolism due to CKD manifested by either one or a combination of the following:
- Abnormalities of calcium, phosphorus (phosphate), parathyroid hormone, or vitamin D metabolism
- Abnormalities in bone turnover, mineralization, volume, linear growth, or strength
- Vascular or other soft-tissue calcification
CKD-MBD explains, at least in part, the high morbidity and mortality of CKD patients, linking kidney and bone disease with cardiovascular complications. It is a matter of discussion whether CKD-MBD may be considered a real syndrome or not.
CKD-MBD broadens the "old" concept of "renal osteodystrophy", which now should be restricted to describing the "bone pathology" associated with CKD. Thus, renal osteodystrophy is currently considered "one" measure of the skeletal component of the systemic disorder of CKD–MBD that is quantifiable by histomorphometry of bone biopsy.
McCune–Albright syndrome is a complex genetic disorder affecting the bone, skin, and endocrine systems. It is a mosaic disease arising from somatic activating mutations in "GNAS", which encodes the alpha-subunit of the Gs G-coupled protein receptor. These mutations lead to constitutive receptor activation.
It was first described in 1937 by Donovan James McCune and Fuller Albright.
Nutritional osteomalacia responds well to administration of 2,000-10,000 IU of vitamin D3 by mouth daily. Vitamin D3 (cholecalciferol) is typically absorbed more readily than vitmin D2 (ergocalciferol). Osteomalacia due to malabsorption may require treatment by injection or daily oral dosing of significant amounts of vitamin D3.
Hypocalcemia is common and can occur unnoticed with no symptoms or, in severe cases, can have dramatic symptoms and be life-threatening. Hypocalcemia can be parathyroid related or vitamin D related. Parathyroid related hypocalcemia includes post-surgical hypoparathyroidism, inherited hypoparathyroidism, pseudohypoparathyroidism, and pseudo-pseudohypoparathyroidism. Post-surgical hypoparathyroidism is the most common form, and can be temporary (due to suppression of tissue after removal of a malfunctioning gland) or permanent, if all parathyroid tissue has been removed. Inherited hypoparathyroidism is rare and is due to a mutation in the calcium sensing receptor. Pseudohypoparathyroidism is maternally inherited and is categorized by hypocalcemia and hyperphosphatemia. Finally, pseudo-pseudohypoparathyroidism is paternally inherited. Patients display normal parathyroid hormone action in the kidney, but exhibit altered parathyroid hormone action in the bone.
Vitamin D related hypocalcemia may be associated with a lack of vitamin D in the diet, a lack of sufficient UV exposure, or disturbances in renal function. Low vitamin D in the body can lead to a lack of calcium absorption and secondary hyperparathyroidism (hypocalcemia and raised parathyroid hormone). Symptoms of hypocalcemia include numbness in fingers and toes, muscle cramps, irritability, impaired mental capacity and muscle twitching.