Generality
Osteomalacia is a metabolic pathology affecting the bones, from which it removes minerals, making them more susceptible to pain, malformations and fractures. We are therefore talking about a demineralising metabolic osteopathy, characterized by the presence of non-calcified osteoid tissue to a greater than normal extent.
Causes
Osteomalacia is typical of adults, while when the mineralization defect affects the growing skeleton (children) we speak more correctly of rickets. The causes of these diseases are to be found in the alterations in the metabolism of vitamin D, calcium and Once, the primary cause of rickets and osteomalacia was to be found in the dietary deficiency of vitamin D; today, thanks to the improvement of socio-economic conditions, dietary deficiencies have become rare (vegetarians are a little more at risk, even if an "adequate sun exposure can easily fill this deficit).
Apart from insufficient dietary intake, specific vitamin D deficiencies may develop due to little or no exposure to the sun, or to insufficient renal or hepatic activity (chronic liver disease, chronic renal failure).Furthermore, being a fat-soluble vitamin, the intestinal absorption of vitamin D is compromised by all conditions in which steatorrhea is recorded, ie an excessive presence of fats in the stool, a sign of insufficient absorption of the same (eg celiac disease, pancreatic insufficiency, diverticulosis, Crohn's disease, gastric and small bowel resection operations),
Among the minerals most represented in bone, a prominent role is played by calcium and phosphorus, which gathering in hydroxyapatite crystals give the bones the characteristic hardness, well known to all. In the article dedicated to calcium metabolism, we have seen as the balance of the mineral in the organism, as well as that of phosphorus, essentially depends on the activity of some organs, first of all the intestine, the kidney, the skin and the parathyroid glands. Vitamin D, on the other hand, increases the absorption of these minerals in the intestine and reduces their urinary excretion,
Osteomalacia can therefore arise due to an "altered availability of vitamin D, calcium or phosphorus, also following the" prolonged intake of drugs that alter its metabolism, such as anticonvulsants (phenytoin, carbamazepine, phenobarbital, primidone), some drugs against HIV, and antacids based on aluminum hydroxide.
Diagnosis
In the blood of a patient suffering from osteomalacia it is possible to find low levels of calcium and / or phosphorus, associated with markers of enhanced osteoblastic activity, such as the increase in alkaline phosphatase and osteocalcin (we briefly recall how osteoblasts are the cells responsible for construction of the bone matrix). It may also be useful to perform specific tests, such as the measurement of serum transaminases, azotemia and creatinine clearance, to assess the health of the liver and kidney in the event of suspected liver or kidney disease. In case of suspected celiac disease or malabsorption disease, the sorbitol breath test, or the measurement of specific blood antibodies, may be useful, while the diagnosis of liver failure involves the measurement of trypsin, fat or elastase in the stool.
The diagnosis can be confirmed by radiographic investigations, where - in the presence of osteomalacia - the typical Looser-Milkmann pseudofractures are highlighted.
Symptoms
In the onset stages of the disease, the patient generally does not complain of any symptoms, while laboratory investigations can highlight the risk of osteomalacia from the earliest stages. As the disease progresses, the affected individual may complain of bone and muscle pain; symptoms are often described as dull bone pain, generally affecting the lower spine, pelvis, hips, legs or legs. ribs. Bone pain is typically exacerbated by light pressure on the bones and movement. Often, a thin fracture line is noted in radiographic findings in areas where the pain is most intense. In addition, musculoskeletal pain may be accompanied by a decrease in tone and muscle strength, with an uncertain and hesitant gait, and poor resistance to walking.The risk of suffering bone micro-fractures, even spontaneous ones, increases, as anticipated, especially in the aforementioned areas.
Care and treatment
If osteomalacia has arisen due to reduced sun exposure and / or an insufficient dietary intake of vitamin D, correcting the plasma levels of this vitamin through specific dietary supplements is the best therapeutic option. Generally, people suffering from osteomalacia take vitamin D supplements (ergocalciferol) orally, for a period ranging from a few weeks to several months; only in some cases, for example when the absorption of vitamin D in the intestine is compromised, or for practical reasons , is given by intravenous injection. The dosage and duration of treatment must be carefully calibrated based on the changes in the patient's clinical, biochemical and radiological picture, but also on the basis of the drugs taken or particular concomitant conditions (vitamin D in high doses is for example contraindicated in the presence of kidney stones, hypercalcemia, hypercalciuria, primary hyperparathyroidism or drug therapy such as digoxin and thiazide diuretics). Periodic checks of the calcium level will be able to extinguish any intoxications from overdosing of vitamin D in the bud, signaled by symptoms such as gastro-intestinal disorders, weight loss, irritability, low-grade fever, dry skin with flaking, vascular and especially renal calcifications.
Alongside the specific vitamin D supplementation, if the phosphorus and calcium levels in the blood are particularly low, it is also possible to replenish these minerals. Finally, if osteomalacia were the consequence of other diseases, such as those in the liver or kidney, treating the underlying pathology that generates the metabolism of the vitamin can help to improve the signs and symptoms of osteomalacia. In these cases, moreover, it is essential to administer the deficient forms of active vitamin D (calcifediol in case of hepatic insufficiency, calcitriol in case of renal insufficiency). Finally, in the presence of "exocrine insufficiency of the pancreas associated with osteomalacia, it is necessary to intervene with" adequate replacement therapy based on pig pancreatic extracts (pancreatin, creon, pancrease).
