Myopathy in hypophosphataemic osteomalacia presenting in adult life

Clinical profiles of treated and untreated adults with hypophosphatasia in the Global HPP Registry

Background

The clinical signs and symptoms of hypophosphatasia (HPP) can manifest during any stage of life. The age at which a patient’s symptoms are reported can impact access to targeted treatment with enzyme replacement therapy (asfotase alfa), as this treatment is indicated for patients with pediatric-onset HPP in most countries. As such, many patients reported to have adult-onset HPP typically do not receive treatment. Comparison of the disease in treated and untreated adult patients is confounded by the approved indication. To avoid this confounding factor, a comparison between baseline disease manifestations prominent among treated versus untreated adult patients was limited to those with pediatric-onset HPP using data collected from the Global HPP Registry. The hypothesis was that treated adults will have a greater disease burden at baseline than untreated adults. The analysis of disease manifestations in adults with adult-onset HPP was conducted separately.

Results

A total of 398 adults with HPP were included; 213 with pediatric-onset (114 treated, 99 untreated) and 141 with adult-onset HPP (2 treated and 139 untreated). The treated, pediatric-onset patients were more likely to have a history of pain (prevalence ratio [PR]: 1.3, 95% confidence interval [CI] 1.1, 1.4), skeletal (PR: 1.3, 95% CI 1.1, 1.6), constitutional/metabolic (PR: 1.7, 95% CI 1.3, 2.0), muscular (PR: 1.8, 95% CI 1.4, 2.1) and neurological (PR: 1.7, 95% CI 1.1, 2.3) manifestations of HPP, and also had poorer measures for health-related quality of life, pain, and disability compared with untreated pediatric-onset patients. In patients with adult-onset HPP, the most frequent signs and symptoms were chronic bone pain (52.5%), dental manifestations (42.6%), fatigue (23.4%), recurrent fractures or pseudofractures (22.0%), and generalized body pain (22.0%).

Conclusions

Along with the more classical skeletal signs and symptoms, pain, muscular, and constitutional/metabolic manifestations are common in adults with HPP, regardless of age of disease onset, highlighting a full spectrum of HPP manifestations.

[Detection of the primary tumor site in tumor-induced osteomalacia by indium-111 octreotide scintigraphy: a case report]

We report a 31-year-old woman with tumor-induced osteomalacia suffering from slowly progressive bilateral muscle weakness predominantly in the proximal muscles and multiple bone pains for the past 2 years. She was unable to walk or raise her arms above the shoulder. We suspected tumor-induced osteomalacia due to decreased serum phosphate and 1alpha, 25 (OH),-vitamin D3 levels, low percentage of tubular reabsorption of phosphate (%TRP), adult onset, and no family history of osteomalacia. Regular imaging examinations could not detect the location of the primary tumor: however, indium-111 octreotide scintigraphy detected the causative primary mesenchymal tumor in the right sole. Pain and muscle weakness improved promptly after tumor resection, and she was able to walk 6 d postoperatively. This is the first case report in Japan describing the detection of the primary tumor site by indium-111 octreotide scintigraphy.

Decreased muscle strength and contents of Mg and Na,K-pumps in chronic alcoholics occur independently of liver cirrhosis

OBJECTIVES

To evaluate the influence of established liver cirrhosis on muscle strength and muscle contents of magnesium (Mg), potassium (K) and sodium, potassium pumps (Na,K-pumps) in chronic alcoholic patients.

DESIGN

An open cross-sectional study.

SETTING AND SUBJECTS

Forty consecutive chronic alcoholics (18 with cirrhosis and 22 without cirrhosis) admitted to the Department of Hepatology, Aarhus University Hospital, Denmark, or to a collaborating alcoholism treatment centre, and 36 healthy control subjects.

MAIN OUTCOME MEASURES

Evaluation of participant's subjective physical ability and measurement of maximum isokinetic muscle strength and muscle mass, as well as measurements of Mg, K and Na,K-pumps in skeletal muscle.

RESULTS

Maximum isokinetic muscle strength and muscle mass were equally reduced in patients with and without cirrhosis (P < 0.01 all). In keeping with this, both groups of patients felt equally physically restricted. Muscle Mg was reduced to the same extent in the two groups of patients (by 12 and 9%, P < 0.001, both), whereas the muscle K content was only significantly lower in the cirrhotic patients (10%, P < 0.001). The muscle content of Na,K-pumps was reduced by 14%, (P < 0.01) in the cirrhotic patients and by 8% (P < 0.05) in the noncirrhotic patients.

CONCLUSION

Our alcoholic patients complained of physical disability, had reduced skeletal muscle mass, isokinetic muscle strength, content of muscle Mg and content of Na,K-pumps. There was no difference between patients with and without cirrhosis. It appears that it is the heavy alcohol intake, and not the cirrhosis per se, that is responsible for the observed defects.

Neuromuscular diseases and disorders of the alimentary system

This review outlines the relationship and interaction between neuromuscular diseases and disorders of the alimentary system. Neuromuscular manifestations of gastrointestinal and hepatobiliary diseases are first considered. Such diseases may cause neuromuscular disorders by leading to nutritional deficiency or by more direct mechanisms. The pathogenesis, clinical features, and treatment of these various neuromuscular manifestations are discussed. The impact of disorders of nerve, neuromuscular transmission, and muscle on the alimentary system is then reviewed. The main sequelae are impaired deglutition and gastrointestinal dysmotility. The management of these complications is considered.

RETRACTED: Changes in the supporting muscles of the fractured hip in elderly women

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. The Journal has been made aware of concerns regarding the ethical approval for this study, and the study protocol and data were disputed. Since Dr Sato passed away, the co-authors were contacted about the complaint. Dr Izumi Kondo confirmed that the T score for sufficient 25OHD group in Table 2 was out of range and this was overlooked at the time of writing. He was unable to confirm whether the proper ethical approval was obtained or comment on the study protocol as his role was to advise on the statistical methodology of the revised paper. The other two co-authors did not respond, and one could not be located. This constitutes a violation of our publishing policies and publishing ethics standards.

Reversible muscle weakness in patients with vitamin D deficiency

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Endocrine neuromyopathies

The myopathies associated with endocrine disorders range in clinical presentation from the relatively nonspecific pattern of proximal muscle weakness of glucocorticoid excess states to specific presentations of contractions produced in tetany. All endocrine neuromyopathies emphasize the role of skeletal muscle in protein, carbohydrate, and electrolyte metabolism. Hormonal abnormalities tend to compromise muscle force generation by indirect effects on muscle function. The recognition and effective treatment of all these disorders require the identification of the underlying hormonal imbalances and awareness of general medical problems produced by the endocrine disorders.

Osteomalacic myopathy

A 45-year-old woman reported the development of thigh pain followed within a year by proximal muscle weakness. Clinical findings included short stature, prominent kyphoscoliosis, proximal weakness, and brisk reflexes. Recognition of an increased level of serum alkaline phosphatase and hypophosphatemia led to the diagnosis of osteomalacia. Identification of iron deficiency anemia and hypocholesterolemia implicated previously unrecognized gluten-sensitive enteropathy with associated vitamin D malabsorption as the cause of the osteomalacia. Adherence to a gluten-free diet and treatment with vitamin D2 resulted in weight gain, resolution of pain, and improvement in strength within 3 months. Painful proximal weakness and hyperreflexia may be the initial and primary manifestations of osteomalacia, a readily treatable cause of muscle and bone disease.

[Motor neuron disease: metabolic evaluation]

The authors studied serum and urinary calcium and phosphorus levels, as well as abnormalities on the spine of 30 patients with motor neuron disease. The authors believe in multifactorial aspects in the pathogenesis of motor neuron disease, calling special attention to toxic and metabolic factors.

The response to 1,25-dihydroxycholecalciferol and to dihydrotachysterol in adult-onset hypophosphataemic osteomalacia

The biochemical changes observed in a patient with adult-onset hypophosphataemic osteomalacia after three weeks treatment with 1,25-dihydroxycholecalciferol (1,25-(OH)2D3) followed by dihydrotachysterol (DHT) are reported. The treatment with 1,25-(OH)2D3 resulted in restoration of intestinal phosphate absorption to normal with a small rise in plasma phosphate concentration; there was no significant change in tubular reabsorption of phosphate. The tubular reabsorption of bicarbonate, which was initially low, returned almost into the normal range with normalisation of plasma bicarbonate concentration. Aminoaciduria decreased. There were no changes in plasma or urinary calcium but immunoreactive parathyroid hormone (i-PTH) which was initially elevated fell but still remained above the normal range. These changes were maintained after replacing the 1,25-(OH)2D3 treatment with dihydrotachysterol (DHT).

Lipid storage myopathy, ichthyosis, and steatorrhea

A 41-year-old man had ichtyrosis, ectropion, steatorrhea, and slowly progressive proximal limb weakness. Biopsies showed abnormal lipid accumulation in muscle, liver skin, leukocytes, and gastric mucosa. Lipid storage was particularly marked in cultures of skin and muscle, and it increased in subsequent cell generations. By electron microscopy, the lipid globules showed no limiting membranes. The stored lipid was identified by thin-layer chromatography as triglyceride; there was no excess of cholesterol or cholesteryl esters. Muscle carnitine concentration and activities of carnitine palmityltransferase and acid lipase were normal; 14CO2 production from labeled palmitate in leukocytes was not impaired. The excessive accumulation of triglyceride in different tissues and in the progeny of cells in tissue culture suggests a genetic error of lipid metabolism.

Changes in the kinetics of muscle contraction in vitamin D-depleted rats

Using an in situ rat soleus neuromuscular preparation, changes in the muscle contraction kinetics in response to vitamine D depletion were studied. For a single isometric contraction, the time-to-peak tension (Tp) and the time-for-recovery-half-way-to-resting tension (T1/2r) were recorded. For a 150 Hz, 300 msec tetanus, the T1/2r was determined. Animals raised on high-calcium, high-phosphate, vitamin D-depleted diets showed prolongation of all parameters. Repletion of vitamin D returned Tp and T1/2r values to normal. Neither dietary calcium deficiency nor thyroparathyroidectomy produced an prolongation of Tp or T1/2r values. Therefore, based upon the experimental data, it appears that vitamin D or one of its metabolites, independent of any effect on the serum calcium or serum phosphate concentration, is necessary for normal muscle relaxation.

Myoglobin: methods and diagnostic uses

Myoglobin is the oxygen-binding protein characteristic of skeletal and cardiac muscle. With muscle disease or dysfunction, myoglobin may enter the circulation, and after renal clearance, it may also appear in the urine. Therefore, the presence of myoglobinemia and myoglobinuria may serve as indicators of the presence and severity of muscle disease. With newly developed methods of detection, myoglobinemia and myoglobinuria are now recognized as complications of trauma, ischemia, surgery, states of exertion and stress, metabolic abnormalities, inherited enzyme disorders, toxin and drug actions, and inflammatory states. Infarction of the heart muscle also can be detected by myoglobin assay. Persistent myoglobinuric states may be complicated by renal failure and electrolyte imbalance. The diagnosis of myoglobinemia and myoglobinuria can be now confirmed with the use of immunoassay techniques. Although not yet widely available, they offer the possibility of the specificity and sensitivity needed for clinical use.

Primary hyperparathyroidism presenting as a proximal myopathy

A 46-year-old female presented with a three year history of progressive weakness. Asymptomatic apart from proximal myopathy, multi channel screening and radiological features indicated primary hyperparathyroidism with severe metabolic bone disease. Removal of a parathyroid adenoma led to improvement of muscle strength and regression of bony and metabolic changes.

Muscle weakness in osteomalacia

The muscle weakness that frequently accompanies osteomalacia and rickets may arise from a variety of causes. Particularly in patients with muscle weakness, identification of the metabolic disorder is important, since effective treatment is often possible.