No abstract

Iodine kinetic studies were performed serially in 15 patients taking 300 mg amiodarone/day for 6 months to assess the biological significance of the high iodine content of the drug. Urinary inorganic iodide excretion increased from 0.25 +/- 0.03 (+/- SE) mumol/mmol creatinine before treatment to over 7 mumol/mmol during therapy. Thyroid iodide clearance fell from 5.93 +/- 0.82 ml/min to less than 0.5 ml/min, while plasma inorganic iodide rose from 0.05 +/- 0.01 mumol/liter to approximately 2.2 mumol/liter during treatment. Thyroid absolute iodide uptake rose from 16.3 +/- 2.7 to 54.6 +/- 5.7 nmol/h after 6 weeks of therapy (P less than 0.001). Thereafter, it progressively declined, but it was still significantly elevated (32.0 +/- 4.3 nmol/h) after 24 weeks (P less than 0.01). The calculated daily excretion of inorganic iodide rose to over 80 mumol during the study, accounting for about 10% of amiodarone iodine. During this time, the patients all had the characteristic plasma thyroid hormone changes associated with amiodarone therapy, i.e. increased T4, free T4, and rT3 and decreased T3, while remaining clinically euthyroid. The massive increase in available inorganic iodide during amiodarone treatment is probably responsible for the induction of both the hypothyroidism and the thyrotoxicosis that can occur in patients receiving the drug.

SUMMARY The response to the subcutaneous injection of glucagon (1 mg) has been studied as a test of the ability of the pituitary to secrete ACTH and growth hormone (GH). Tests have been performed on fifteen normal subjects or patients with unrelated conditions, nine patients with pituitary tumours and seventeen with acromegaly. It is suggested that a normal response is a peak level of 5 ng/ml or more of GH (standard NIH GH 1216C) and either a rise of plasma cortisol measured by competitive protein binding of at least 4 μg/100 ml or a peak level of 7 μg/100 ml. In seventeen patients the responses were compared with those obtained in the insulin hypoglycaemia test and there was good agreement. Measurement of plasma ACTH showed that the response is at pituitary and not adrenal cortical level. Peak responses of ACTH and GH were obtrained at 150 min and of cortisol at 180 min. Plasma glucagon concentrations were falling steadily by this time although still above the control level. The mechanism of action of glucagon is not clear but does not appear to be related to fall of blood sugar. The subcutaneous injection of glucagon is not without side effects; about half the patients were nauseated and nine vomited. Nevertheless we believe that a subcutaneous glucagon test is of value for testing the pituitary reserve of ACTH and GH in situations where insulin hypoglycaemia cannot be used.

Pupillary adaptation to darkness was studied in 63 children and adolescents with Type 1 diabetes using a simple portable pupillometer. Results were compared with those in a group of age-related non-diabetic children and expressed as the ratio of the pupil diameter to the iris diameter (pupil diameter %). In the diabetic patients the pupil diameter % was 61.1 +/- 5.8 (44.4-71.9) % compared with 64.2 +/- 4.1 (53.2-72.6) % in the control subjects (p less than 0.001). Abnormal pupillary adaptation to darkness was found more commonly than abnormal heart rate variation in response to a variety of stimuli in the diabetic patients. Pupillary adaptation to darkness may be useful as an indicator of subclinical autonomic neuropathy in diabetic children.

Summary.Pituitary responsiveness to thyrotrophin releasing hormone (TRH) and luteinizing hormone releasing hormone (LHRH) was studied in thirty one male diabetics, of whom sixteen were insulin-dependent and fifteen on oral ant• agents. Ten age-matched controls were also studied. TRH and LHRH were simultaneously administered intravenously, each in a small dose of 10 ~tg followed two hours later by 190 ~tg and 90 ~tg respectively. Basal hormone levels were measured in a further group of thirty six patients (twelve on insulin, twelve on oral agents and twelve on dietary restrictions alone).Higher thyrotrophin (TSH) response was observed following the small dose of TRH in the patients treated with oral agents than in the control subjects. The response of prolactin was lower in patients treated with oral agents compared with those treated with insulin. There was no difference in plasma 73 and T 4 levels in the patients treated with insulin or oral agents. Significantly higher basal growth hormone (GH) levels were observed in the diabetics. The insulin-dependent group showed a more marked response of GH to TRH/LHRH. No response was observed in the controls. Plasma testosterone levels were significantly lower in the oral agent group (13.8 nmol/1) than in the insulin group (19.4 nmol/1), patients on dietary restrictions (18.4 nmol/1) and the control subjects (19.0 nmol/1). The LH response to the smaller dose of LHRH was impaired in patients on insulin and oral agents. There was a significant difference in FSH response between impotent and sexually normal patients.

No abstract

One hundred and sixty-four patients with Graves' disease were treated with low-dose radioiodine (2 mCi), with a mean follow up of 4 1/2 years. At this time 74 (45%) were euthyroid having had a single dose, with a total of 131 (80%) being controlled with one or more doses. Three (2%) were still toxic but their mean follow up was only 3 years. Thirty (18%) were rendered hypothyroid, two-thirds of these after a single dose of 2 mCi 131I. The one-year incidence of hypothyroidism was 6%, with an incidence at 6 years of 20%. Previous surgery, medical treatment and thyroid antibody status appeared to have no influence on the outcome.

Two postal questionnaire surveys of facilities and staff available to hospital physicians responsible for the care of adults with diabetes in the United Kingdom have been carried out under the auspices of the British Diabetic Association. These surveys, in 1982-83 and 1990, achieved 92% and 94% responses, respectively, giving information on around 95% of UK health districts or their equivalent. Levels of provision and the use of existing facilities had, in general, improved over that time though several important deficiencies still remain. Respondents providing out-of-hours clinics and combined clinics with other specialties increased as did the availability of dietetic advice in outpatient clinics. Although the proportion of respondents reporting no specialist diabetes nursing assistance fell from 53% to 14%, this still left 29 reporting none at all. Access to blood glucose and HbA1 results, facilities for retinal examination, and access to photocoagulation had all improved but there was little change in the availability of adequate examination and educational facilities although this may have been due to a rise in expectations. Chiropodial care was less readily available in 1990 with 17% of respondents (compared with 11%) reporting a complete lack in the clinic. A recommendation that no locality should be without at least one physician with a special interest in diabetes was fulfilled in 81.9% of localities but some were still relatively poorly staffed.