Defective Intestinal Phosphate Absorption in Familial and Non-familial Hypophosphataemia

With an oral phosphate tolerance test a primary defect in intestinal phosphate absorption was found in patients with untreated familial and non-familial hypophosphataemia. It is suggested that this plays a major part in the aetiology of rickets and osteomalacia in these disorders. Vitamin D was shown to have a beneficial effect on intestinal transport of phosphate, though defective absorption was not completely corrected. If intestinal phosphate absorption is normal, oral phosphate supplements will maintain normal plasma phosphate levels even in the presence of a pronounced renal phosphate leak.In familial and non-familial hypophosphataemia the phosphate tolerance test may be a more sensitive index of genetic abnormality than a low plasma phosphate. It may be helpful in distinguishing several syndromes at present classified under non-familial hypophosphataemia, as well as assessing the response to treatment with vitamin D and in investigating intestinal transport of phosphate.     

Parenteral 1,25-dihydroxycholecalciferol in hepatic osteomalacia.

Despite regular long-term parenteral vitamin D2 treatment, four patients with biliary cirrhosis had multiple symptoms of bone disease and bone biopsy specimens showed osteomalacia without osteoporosis. Three patients also had a proximal myopathy. Plasma calcium values (after correction for albumin), phosphorus, magnesium, and serum 25-hydroxy-vitamin D were within normal limits. Treatment with 1,25-dihydroxy-cholecalciferol (1,25-(OH)2D3) relieved symptoms in three of the four patients and improved those in the fourth. Histological examination of bone showed improvement in all four patients, but serum and urinary biochemical changes were not pronounced. We conclude that 1,25-(0H)2D3 treatment has a beneficial effect on bone and muscle in hepatic osteomalacia, either because vitamin D 1-hydroxylation fails in biliary cirrhosis or because hepatic osteomalacia is resistant to vitamin D2 metabolites.     

Severe Hypophosphatemic Osteomalacia Secondary to Fanconi Syndrome Due to Adefovir: A Case Report

ObjectiveGeneralized proximal, type 2, renal tubular acidosis, also known as Fanconi syndrome, is a generalized dysfunction of the proximal renal tubule characterized by impaired reabsorption and increased urinary loss of phosphate and other solutes, such as uric acid, glucose, amino acids, and bicarbonate. Chronic hypophosphatemia is the second most common cause of osteomalacia after vitamin D deficiency in adult patients and can have a heterogeneous presentation, ranging from mild symptoms such as muscle weakness and skeletal pain to more severe presentation, such as disabling myopathy, severe bone and joint pain, difficulty walking, and even bone fractures.MethodsThis report describes a case of severe hypophosphatemic osteomalacia with multiple fragility fractures induced by adefovir, which was worsened and confounded by a previous treatment with zoledronic acid and required prolonged intravenous potassium phosphate administration.ResultsWe highlight the limited diagnostic value of dual X-ray absorptiometry and bone scintigraphy in this challenging diagnosis. Bone metabolism should always be assessed in patients treated with adefovir for early detection of osteomalacia due to Fanconi syndrome.ConclusionAlthough rare, this condition may be life-threatening and mimic other bone metabolic disorders that are treated with drugs that may further impair phosphate balance. (Endocr Pract. 2014;20:e246-e249)     

Signs of steroid myopathy in a group of patients with asthma undergoing continuous steroid therapy

The 35 patients with bronchial asthma undergoing continuous steroid therapy were examined in order to reveal any signs of steroid myopathy. More than 80% of patients complained of muscle weakness. In the physical examination the motor function was correct in the majority of patients. Muscular enzymes and blood electrolytes were normal. EMG has shown typical myopathic changes In over 80% of patients. The diagnosis of subclinical steroid myopathy was based mainly on EMG examination. This myopathy was independent of sex, age, dose an duration of therapy.     

The broad spectrum of statin myopathy: from myalgia to rhabdomyolysis

PURPOSE OF REVIEW: The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) are the cornerstone of therapy for dyslipidemia. A significant portion of patients are not adherent to statin therapy, due to either intolerance from muscle symptoms or fears of myopathy reported in the media. The diagnosis and management of patients with statin-induced myopathy will be reviewed. RECENT FINDINGS: Based on a review of healthy clinical-trial participants, the placebo-corrected incidences of minor muscle pain, myopathy (with significant elevations in creatinine kinase), and rhabdomyolysis are 190, 5, and 1.6 per 100,000 patient years, respectively. More recent prospective observational data yield better, real-world estimates of muscle complaints (>10%) in patients started on high-dose statins. Current data suggest that important patient characteristics, statin-drug pharmacokinetics, and statin-drug interactions play a role in myopathy. Myopathy is more related to statin dose and blood levels than to LDL reductions. Evidence for managing myopathic patients with coenzyme Q10 is not conclusive. SUMMARY: It is important to maintain perspective by looking at the impact of statin myopathy relative to the impact of preventing atherosclerotic complications. The potential benefits of therapy must outweigh the risks. In the case of statin therapy the benefit/risk ratio is overwhelmingly positive.     

Erythroid promoter confines FGF2 expression to the marrow after hematopoietic stem cell gene therapy and leads to enhanced endosteal bone formation

Fibroblast growth factor-2 (FGF2) has been demonstrated to be a promising osteogenic factor for treating osteoporosis. Our earlier study shows that transplantation of mouse Sca-1(+) hematopoietic stem/progenitor cells that are engineered to express a modified FGF2 leads to considerable endosteal/trabecular bone formation, but it also induces adverse effects like hypocalemia and osteomalacia. Here we report that the use of an erythroid specific promoter, β-globin, leads to a 5-fold decrease in the ratio of serum FGF2 to the FGF2 expression in the marrow cavity when compared to the use of a ubiquitous promoter spleen focus-forming virus (SFFV). The confined FGF2 expression promotes considerable trabeculae bone formation in endosteum and does not yield anemia and osteomalacia. The avoidance of anemia in the mice that received Sca1(+) cells transduced with FGF2 driven by the β-globin promoter is likely due to attenuation of high-level serum FGF2-mediated stem cell mobilization observed in the SFFV-FGF2 animals. The prevention of osteomalacia is associated with substantially reduced serum Fgf23/hypophosphatemia, and less pronounced secondary hyperparathyroidism. Our improved stem cell gene therapy strategy represents one step closer to FGF2-based clinical therapy for systemic skeletal augmentation.     

Osteomalacia with Bone Marrow Fibrosis Due to Severe Vitamin D Deficiency After a Gastrointestinal Bypass Operation for Severe Obesity

ObjectiveTo present 5 cases of bone biopsy-proven osteomalacia with marrow fibrosis (in 3 cases) after gastric bypass operation, review the relevant literature, and offer preventive strategies.MethodsWe summarize the clinical presentation, pertinent biochemical and radiologic data, and bone histomorphometric findings in 5 patients, encountered during a period of 17 years, in whom severe vitamin D deficiency developed after a gastrointestinal bypass surgical procedure for morbid obesity.ResultsFive patients (39 to 60 years of age) were seen for evaluation of metabolic bone disease not responding to “usual” therapy after a gastric bypass surgical procedure. All had generalized bone pain and tenderness, muscle weakness, stooping posture, difficulty walking, and waddling gait due to severe proximal muscle weakness for a period of 2 to 5 years. Diagnoses before the referral varied from arthritis and gout to vitamin D deficiency and osteoporosis despite highly suggestive biochemical or radiologic findings (or both) of osteomalacia in each patient, which was confirmed by bone biopsy. After therapy with pharmacologic doses of ergocalciferol (100,000 IU daily) and calcium carbonate (1 to 2.5 g daily), considerable improvements occurred in clinical symptoms and functional status, biochemical indices, bone mineral density, and bone histomorphometric features.ConclusionGastric bypass operations predispose patients to severe vitamin D deficiency and osteomalacia in the absence of pharmacologic doses of vitamin D therapy. In general, the current recommendations are grossly inadequate in this high-risk population, and the clinical presentation is both nonspecific and often misleading. Prospective long-term studies are needed to determine the appropriate vitamin D dose required to prevent osteomalacia in such patients. (Endocr Pract. 2009;15:528-533)     

Association of hypokalaemia and hypophosphataemia

A prospective study of 13 patients with hypokalaemia due to a variety of causes demonstrated that six had hypophosphataemia. In 10 patients the plasma inorganic phosphate level rose on correction of the hypokalaemia. Before treatment seven patients had an excessive rate of excretion of phosphate relative to creatinine in the urine. Following correction of the hypokalaemia 11 patients had an increase in renal tubular reabsorption of phosphate relative to creatinine. It is suggested that hypokalaemia may be causally related to the hypophosphataemia, and that in chronic potassium depletion this may affect bone mineralization.     

A comparative evaluation of the clinical x-ray picture of uremic osteodystrophy before and after parathyroidectomy]

The authors present the results of clinical, x-ray, and biochemical studies carried out in 51 patients with uremic osteodystrophy, treated with hemodialysis, before and after parathyroidectomy. The patients were divided into 4 groups with various patterns of x-ray symptoms. Patients with x-ray signs of fibrous osteodystrophy made up group 1, the second group consisted of patients with a combination of fibrous osteodystrophy and osteomalacia with secondary hyperparathyrosis predominance; the third group, like the second one, included patients with the mixed form of uremic osteodystrophy, but with the predominance of the osteomalacic syndrome; Group 4 patients had no x-ray signs of bone changes, and the diagnosis of uremic osteodystrophy was confirmed by clinical laboratory evidence. Analysis of the clinical and x-ray data before and after parathyroidectomy has brought the authors to a conclusion that such an intervention was effective only in cases with manifest clinical and x-ray symptoms of fibrous osteodystrophy. In Group 2 patients with the mixed form of uremic osteodystrophy and less manifest osteomalacia as against fibrous osteodystrophy, subtotal or partial parathyroidectomy is advisable only in cases when conservative therapy is of no avail and fibrous dystrophy is progressing. Surgical treatment is contraindicated to patients in whom x-ray signs of osteomalacia predominate over fibrous osteodystrophy in the total picture of uremic osteodystrophy; it may result in a rapid progress of osteomalacia.     

Osteomalacia with Long-term Anticonvulsant Therapy in Epilepsy

The investigation and treatment of osteomalacia are described in four patients with epilepsy treated with long-term anticonvulsant therapy. It is suggested that drug-mediated enzyme induction may be the mechanism responsible by causing a greatly increased inactivation of vitamin D in these patients.     

Hypothyroid myopathy with unusually high serum creatine kinase values

Depending on the degree of hormone deficiency, skeletal muscle involvement may occur in hypothyroidism. Usually, hypothyroid myopathy is associated with creatine kinase values <5,000 U/l. We report a 54-year-old man suffering from increasing fatigability, hoarseness, gait disturbances and a creatine kinase of 9,000 (normal: <80 U/l). He presented with bradyphrenia, macroglossia, dysarthria, myxedema, monoparesis, reduced deep tendon reflexes and stocking-type sensory disturbances. Free triiodthyronine was 0.25 pg/ml (normal: 0.6-1.9 pg/ml), free thyroxine <0.1 ng/dl (normal: 0. 6-1.8 ng/dl) and the thyroid-stimulating hormone >48.0 (normal: 0. 1-4.0 IU). Clinical neurologic examination and electromyography were compatible with myopathy and polyneuropathy. Other causes of myopathy, except hypothyroidism, were excluded. After L-thyroxine therapy (1.7 microg/kg BW/day) during 3 months, the patient's symptoms and signs vanished, except for sensory disturbances, and creatine kinase values and electromyography became normal. Severe hypothyroidism may be associated with highly elevated creatine kinase and myopathy. Adequate therapy leads to complete recovery, including myopathy.     

Hypophosphataemia in Septicaemia: Higher Incidence in Gram-negative Than in Gram-positive Infections

Phosphataemia has been investigated in 54 patients with Gram-negative septicaemias; either absolute (serum phosphate <2 mg./100 ml.) or relative (P./B.U.N. 0·04) hypophosphataemia was found in 69% of all determinations. In 37 patients with Gram-positive septicaemias hypophosphataemia was present in only 24%, many of whom had additional Gram-negative bacteriuria and possible Gram-negative septicaemia suppressed by antibiotics. The mechanism of this phenomenon is not known. This new sign of Gram-negative septicaemia has some diagnostic importance.     

Neuromuscular complications of human immunodeficiency virus infection and antiretroviral therapy.

At least 4 distinct peripheral neuropathy syndromes occur in patients infected with the human immunodeficiency virus. The most common, painful sensory neuropathy, may be related to the viral infection or may be medication induced and is treated symptomatically. The other 3, chronic inflammatory demyelinating polyradiculoneuropathy, mononeuropathy multiplex (some patients), and the progressive polyradiculopathies related to the acquired immunodeficiency syndrome, may all respond to appropriate therapy. Both inflammatory myopathy and zidovudine myopathy also abate with early diagnosis and treatment.     

Oncogenic osteomalacia associated with mesenchymal tumor in the middle cranial fossa: a case report

ABSTRACT: INTRODUCTION: Tumor-induced osteomalacia is a paraneoplastic syndrome of hypophosphatemia. Osteomalacia causes multiple bone fractures and severe pain. CASE PRESENTATION: We report the case of a 57-year-old Japanese man with tumor-induced osteomalacia associated with a middle cranial fossa bone tumor. The tumor was successfully resected by using a middle fossa epidural approach. His phosphate level recovered to a normal range immediately after the surgery. CONCLUSIONS: It is rare that tumor-induced osteomalacia originates from the middle skull base. This report suggests that, if patients have a clinical and biochemical picture suggestive of tumor-induced osteomalacia, it is crucial to perform a meticulous examination to detect the tumor or the lesion responsible for the tumor. The serum level of fibroblast growth factor 23 is the most reliable marker for evaluating the treatment outcome of tumor-induced osteomalacia.     

25-Hydroxycholecalciferol absorption in steatorrhoea and postgastrectomy osteomalacia.

Post-absorption levels of 25-hydroxy vitamin D (25-OHD) after oral administration of 25-hydroxycholecalciferol (25-OHD3) were measured in 11 subjects. Five had presented with steatorrhoea of various causes while six had post-gastrectomy osteomalacia. Post-absorption levels of 25-OHD were low in four of the patients with steatorrhoea but normal in five of those with post-gastrectomy osteomalacia. There was a significant inverse correlation between peak post-absorption 25-OHD levels and faecal fat excretion. All patients with active post-gastrectomy osteomalacia had subnormal baseline plasma 25-OHD levels, which indicates that the condition is due to a deficiency of vitamin D. Only two of the patients with osteomalacia had estimated dietary vitamin D intakes ofer 1-75 microng/day. These findings suggest that an oral 25-OHD absorption test may be a valuable measure of small intestinal function and that poor dietary vitamin D intake rather than impaired absorption of the vitamin may be the major cause of post-gastrectomy osteomalacia.     

Secondary Hyperparathyroidism in Osteomalacia

Twenty-one patients with histologically proved osteomalacia from various causes were investigated for biochemical and radiological evidence of osteomalacia and secondary hyperparathyroidism. Among the 15 who maintained a normal serum calcium, seven had a raised phosphate excretion index, seven had a raised serum alkaline phosphatase, and six had phalangeal erosions. On the other hand, six patients had a subnormal serum calcium; of these, none showed a raised phosphate excretion index, one had a raised serum alkaline phosphatase, and one had erosions. The phosphate excretion index and the alkaline phosphatase were strongly correlated (r = +0·84). It is concluded that this absence of manifest secondary hyperparathyroidism in some patients with osteomalacia is due to failure of an increase in the release of parathyroid hormone. Measurement of phosphaturia does not appear to be a useful means of detecting osteomalacia. Subsequently, the 24-hour (stable) strontium space measurement was found to be the most sensitive single biochemical screening test for osteomalacia.     

Stem cell biotherapy: A new remedy for Trichinella spiralis-induced inflammatory myopathy

Trichinella spiralis (T. spiralis)-induced myopathy is an inflammatory myopathy that is difficult to treat unless the parasite is combated in its early intestinal phase before it reaches the muscles. This study aimed to evaluate the effect of local mesenchymal stem cell (MSC) therapy on T. spiralis-induced inflammatory myopathy in rats. Rats were divided into four groups: Group 1 (non-infected non-treated group); Group 2 (infected non-treated group); Group 3 (infected albendazole (ABZ)-treated group); and Group 4 (infected MSC-treated group). Their muscle status was assessed physiologically with the righting reflex and electromyography (EMG), parasitologically with the total muscle larval count, histopathologically with hematoxylin and eosin and Mallory's trichrome stains, as well as immunohistochemically for myogenin as a marker of muscle regeneration. Additionally, serum muscle enzymes creatine kinase (CK) and lactate dehydrogenase (LDH), as well as muscle matrix metalloproteinases MMP1 and MMP9, were assayed. Finally, the immunological response was assessed by measuring the levels of the muscle inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interferon-gamma (INF-γ), and interleukin-4 (IL-4). Our findings revealed that MSC therapy markedly improved muscle EMG and righting reflex, as well as the histopathological appearance of the muscles, reduced inflammatory cellular infiltrates, and increased myogenin immunostaining. It also reduced serum CK and LDH levels, as well as muscle INF-γ, TNF-α, IL-4, MMP1, and MMP9 levels. However, it had no effect on the total muscle larval count. Accordingly, due to its anti-inflammatory properties and muscle-regenerative effect, MSC therapy could be a promising new remedy for T. spiralis-induced myopathy.     

Midazolam as an adjunctive therapy for capture myopathy in Bar-tailed Godwits (Limosa lapponica baueri) with prognostic indicators

Capture myopathy is a complication of capture and handling in many species of birds and mammals. Muscular necrosis leads to ataxia, paralysis, and pain, whereas metabolic disturbances can result in death. We conducted an opportunistic clinical trial on Bar-tailed Godwits (Limosa lapponica baueri) that developed capture myopathy after a cannon-net capture in New Zealand in October 2008. We assessed the beneficial effects of midazolam, a benzodiazepine with the effects of anxiolysis, muscle relaxation, and sedation, in the adjunctive treatment of capture myopathy. Physical and biochemical parameters were analyzed retrospectively for their potential as indicators for survival until release. Birds (n=16) were treated with subcutaneous fluid therapy, a nonsteroidal anti-inflammatory (meloxicam), gavage feeding, and sling therapy twice daily. The treatment group (n=8) was treated twice daily with intramuscular midazolam injections, 1.5 mg/kg. Surviving godwits were released over 1-9 days, with 6 of 8 treated birds (75%) surviving to release, compared with 3 of 8 controls (38%). Inability to counteract weight loss in captivity was the most significant problem for both groups. Lack of waterproofing and predation were contributing causes of death for at least two godwits after release. Birds treated with midazolam showed subjective benefits including improved tolerance of handling and sling therapy. Clinical parameters (change in body mass, packed cell volume [PCV], plasma creatine kinase [CK], aspartate aminotransferase [AST], total protein, and uric acid [UA] over time) were not statistically different between groups, although peak average values for CK, AST, and UA were lower in the treatment group. Decline in body mass (%), PCV, final plasma UA, and peak plasma CK were the most useful prognostic indicators. Midazolam shows potential as an ancillary treatment for capture myopathy in birds and is worthy of continued study and use.     

Hypercalcaemia,Hypophosphataemia, and Inability to Excrete Hydrogen Ions

Investigation of a patient with hypercalcaemia, hypophosphataemia, and nephrocalcinosis failed to lead to a clear diagnosis. Neither primary hyperparathyroidism nor primary incomplete renal tubular acidosis could explain all the biochemical features, and it seems that more than one fundamental abnormality may have been present.