Endocrine Abstracts

Amiodarone has been used widely for treating resistant tachyarrhythmias in the past three decades. It is an iodinated benzofuran derivative with a structural formula that closely resembles that of thyroid hormones and contains about 37% of organic iodine by weight, from which 10% is deiodinated to yield free iodide. Given the daily maintenance dose of amiodarone between 100–600 mg daily, about 3.5–21 mg of iodide are released into the systemic circulation, equivalent...

Type 1 diabetes (T1D) is part of a group of disorders termed ‘organ-specific autoimmune diseases’, involving destructive inflammation focused on the insulin-producing beta cells in the islet of Langerhans. Patients (frequently children) lose endogenous insulin production and are required to inject insulin several times per day for the remainder of their lives, and, after many years, frequently develop severe life-threatening complications affecting the kidneys, heart...

Osteogenesis imperfecta (OI) is a rare but serious genetic disorder of bone leading to increased fragility and greatly increased susceptibility to fracture. Some patients experience additional problems such as abnormally formed teeth, progressive deafness and scoliosis. The condition is divided into various subtypes with types I and IV being the commonest, type 2 is lethal in utero and type 3 is associated with most disability and deformity. Patients with OI typically h...

The aetiology of thyroid nodules is due to the interaction between genetic and environmental factors. Thyroid nodules are common. Epidemiological studies suggest that 1% of men and 5% of women have thyroid nodules detected clinically and that the frequency increases with age and in iodine-deficient populations. With the increasing use of sensitive imaging techniques, an increasing proportion of thyroid nodules are detected incidentally. Up to 50% of nodules >1 cm detected ...

Pituitary adenomas/ tumours remain the commonest cause of growth hormone deficiency (GHD; indeed recent studies from the UK and Belgium have reported higher than previously estimated prevalence of clinically significant pituitary adenomas). However, the aetiological spectrum of pituitary dysfunction has changed in recent years with endocrinologists increasingly reviewing patients with pituitary dysfunction secondary to radiation injury, traumatic brain injury and subarachnoid ...

Prolactinomas usually present because of reproductive/sexual dysfunction due to the hyperprolactinemia but they may also present because of mass effects. Prolactin (PRL)-secreting microadenomas enlarge in only about 7% of cases, so many can be followed without direct treatment, although sex steroid hormone replacement may be required. Dopamine agonists can normalize PRL levels in over 90% of cases and can reduce tumor size significantly in over 75%, with cabergoline being gene...

A critical aspect of the environment before birth and in infancy is nutrition. It is estimated that 850 m people in the world (820 m in developing countries) are hungry. This has long-term consequences for their later health and economic potential but also for their children. Such figures do not include those people who have unbalanced nutrition, both in terms of macronutrients and micronutrients. An unbalanced diet can lead to ‘malnutrition’ even in those who have a...

Critical illness is associated with dramatic changes in the glucocorticoid axis. These changes occur at all levels of the axis, are most obvious in the increased serum levels of glucocorticoid but also occur within the tissue. Frank impairment of these responses (e.g. in Addison’s disease or with drugs that block adrenal hormone secretion) is associated with an adverse outcome but it has recently been suggested that many critically ill patients develop subtle abnormalitie...

The increase in marrow adipogenesis associated with osteoporosis and age-related osteopenia is well known clinically. However, we are only now beginning to understand the mechanisms that control the differentiation of mesenchymal stem cells to either osteoblasts or adipocytes. Recent work with gene silencing and overexpression has provided insight into critical pathways that determine the fate of these multipotential cells. In vitro and in vivo studies strongly s...

Subclinical thyrotoxicosis, defined as a low serum thyrotrophin (TSH) and normal serum free T4 and T3 concentrations, has been found in up to 3.2% of adults in cross-sectional surveys of thyroid function, of whom 75% have serum TSH concentrations of 0.1 to 0.4 mU/L. If the diagnosis is limited to only those with a serum TSH lower than 0.1 mU/L, the prevalence decreases to 0.7%, with 20% being treated with thyroxine.Thyrotoxicosis is considered overt only...