Hypothyroid myopathy as a complication of interferon alpha therapy for chronic hepatitis C virus infection

Uncommon presentation of a common disorder

We report about a young male who presented with generalized muscle stiffness, involving the limb, facial, and paraspinal muscles. The stiffness was severe enough to restrict all his daily activities, progressively increased with movements and also produced recurrent falls. This clinical picture resembled one of stiff person syndrome. As he had hypertrophy of calf muscles and generalized muscle tautness he was evaluated for other disorders which can resemble stiff person syndrome. Investigations revealed severe hypothyroidism with thyroid antibodies being elevated. This case is reported to highlight the fact that myopathy as a presenting manifestation of hypothyroidism can simulate stiff person syndrome. It is essential to identify the condition early as it recovers fully with treatment. Our patient responded well to thyroid replacement therapy and was able to lead a normal life.

Advance in the relationship between thyroid function and liver diseases

Numerous researches have showed that thyroid diseases affect liver function and progression of liver diseases; conversely, liver diseases, especially severe liver disease, can also affect thyroid function. Thyroid function may have changes in patients with chronic viral hepatitis treated with interferon. So physicians should pay more attention to the relationship between thyroid and liver diseases during the course of diagnosis and treatment.

Endocrine and liver interaction: the role of endocrine pathways in NASH

This article reviews evidence that causally links hormonal disorders with hepatobiliary disease, and gives particular focus to nonalcoholic steatohepatitis (NASH). The downstream mechanisms by which endocrine disturbances cause liver disease might be similar to those involved in the development of primary liver disease. Hypothyroidism, for example, might lead to NASH, cirrhosis and potentially liver cancer via the development of hyperlipidemia and obesity. Patients with growth hormone deficiency have a metabolic-syndrome-like phenotype that is also associated with the development of NASH. Polycystic ovary syndrome is a common endocrine disorder that is often associated with insulin resistance, the metabolic syndrome, altered levels of liver enzymes and the development of NASH. Recent findings support a role of dehydroepiandrosterone sulfate deficiency in the development of advanced NASH. In addition, adrenal failure is increasingly reported in patients with end stage liver disease and in patients who have received a liver transplant, which suggests a bidirectional relationship between liver and endocrine functions. Clinicians should, therefore, be aware of the potential role of endocrine disorders in patients with cryptogenic liver disease and of the effects of liver function on the endocrine system.

Chronic autoimmune thyroiditis and rheumatic manifestations

A variety of rheumatic manifestations have been described in association with autoimmune thyroiditis. In the past, most of these manifestations were attributed to the underlying thyroid dysfunction, in particular hypothyroidism. However, a responsibility of the mechanisms involved in the autoimmunity rather than a direct action of thyroid hormones seems supported by the evidences that some rheumatic manifestations may occur even in euthyroid patients, or that they are more frequent in hypothyroid patient with autoimmune thyroiditis than in those without this disease. Rheumatic manifestations could be sometimes attributable to the autoimmune rheumatic diseases frequently associated with autoimmune thyroiditis, such as Sjögren's syndrome, rheumatoid arthritis, systemic lupus erythematosus, or scleroderma. Among the most important or frequent rheumatic manifestations there are a mild non-erosive variety of arthritis, polyarthralgia, myalgia, and sicca syndrome without a true Sjögren's syndrome. Although the possible pathogenesis of these manifestations is not completely established, some hypotheses may be proposed, including a role of autoantibodies characteristics of autoimmune thyroiditis, a possible overlap between autoimmune thyroiditis and some autoimmune rheumatic diseases, and a systemic inflammatory reaction associated with thyroiditis.

Polymyositis-like syndrome in hypothyroidism: review of cases reported over the past twenty-five years

Polymyositis-like syndrome, with proximal muscle weakness and elevation of muscle enzymes, may be a clinical manifestation of hypothyroidism. To define the clinical, biochemical, electromyographic, and pathologic characteristics of patients with this syndrome, we identified and reviewed by MEDLINE all cases reported in the English literature from January 1, 1975 through December 31, 2000. Thirty-two cases were considered. Fifty-nine percent of the patients were male with a mean age of 54.7 +/- 22.6 years, (+/- 1 standard deviation [SD]). Weakness was described in 100% of patients. Other common clinical manifestations were: delayed tendon reflexes with slow relaxation phase (41%), muscle tenderness (25%), and muscle induration (9%). The mean creatine kinase (CK) was 2164 +/- 1954 U/L (+/- 1 SD) and the mean thyroid-stimulating hormone (TSH) was 114.8 +/- 85.6 mIU/L (+/- 1 SD). Fifty percent of patients had electromyography; half of the studies were normal while the other half showed nonspecific myopathic changes. Biopsies were performed in 80% of the patients. The most common findings were type II fiber atrophy, type I fiber hypertrophy, central nuclei disposition, necrosis, increased percentage of type I fibers, and decreased percentage of type II fibers, inflammatory infiltrate and the presence of core-like structures. The characteristics of polymyositis-like syndrome in hypothyroidism did not differ from those of nonspecific hypothyroid myopathy. Clinical judgment alone may not be sufficient to suspect and detect these patients. Serum TSH levels should be routinely determined in all patients with muscle weakness or elevation of creatine kinase.