Hyperthyroidism in the Land of Graves: Results of Treatment by Surgery, Radio-iodine and Carbimazole in 837 Cases

A review of the outcome of treatment by subtotal thyroidectomy, radio-iodine and carbimazole of 837 patients with hyperthyroidism seen consecutively over the period 1954--78 inclusive is presented. The age and sex distribution, the male to female ratio, the ABO blood group distribution and the prevalence of pernicious anaemia and diabetes mellitus in these patients was also analysed. Life-table data showed that the five-year and ten-year cumulative relapse rates following a two-year course of carbimazole (n = 162) were 56 per cent and 62 per cent; following surgery (n = 266), 6 per cent and 10 per cent and following radio-iodine (n = 43), 3 per cent and 14 per cent. Five-year and ten-year cumulative hypothyroid rates after surgery were 10 per cent and 18 per cent, and after radio-iodine 10 per cent and 30 per cent. Hypothyroidism did not occur after carbimazole therapy. Of 31 patients who took carbimazole for less than two years (mean 11 months, range 6--19 months), 91 per cent had relapsed at five years. Of 79 patients treated for longer than two years (mean 3.8 years, range 2 1/2--14 years), relapse rates at five and eight years were 49 per cent and 62 per cent. Nine patients (3.4 per cent) suffered permanent vocal cord paralysis and five (1.9 per cent) had permanent hypocalcaemia. The male/female ratio was 9.9 to 1, with a peak female prevalence between 25 and 30 years and a peak male prevalence between 40 and 45 years. The ABO blood group distribution among patients did not differ significantly from the distribution in the general population (chi 2 = 13.4, p = 0.2). Forty-seven patients (5.6 per cent) had diabetes mellitus and thyrotoxicosis whilst two patients (0.23 per cent) had diabetes, thyrotoxicosis and pernicious anaemia.