Hypothyroidism in men in industry; a preliminary report on chemical evidence.

Of 2,807 specimens from blood donors and men in industry, 340 or 12 per cent had serum protein-bound iodine values of 4.0 micrograms or less per 100 cc. In a selected group of 610 "white collar" workers, 52 or 8.5 per cent had similar low values. Careful reexamination of a sample of the latter group indicated that at least 75 per cent of them had hypothyroidism needing treatment. Further analysis of the factors producing hypothyroidism and the validation of the incidence found is warranted. If the incidence observed in this study is confirmed, these findings indicate that 6 per cent to 9 per cent, or more than a million middle aged American men have hypothyroidism.