Epidemiologic study of adrenal gland disorders in Japan

A nationwide epidemiologic study of adrenal disorders was performed in Japan. To cover all the hospitals in Japan, the small-scale hospitals were selected at random, and all the large-scale hospitals were taken into the investigation. Disorders investigated in 1997 were relatively rare disorders, as follows: congenital deficiency of adrenal steroidogenic enzyme (deficiency of 21-hydroxylase, 11beta-hydroxylase, 17alpha-hydroxylase, 3beta-hydroxysteroid dehydrogenase or 18-hydroxylase, and lipoid hyperplasia), congenital Addison's disease, pseudohypoaldosteronism, and 11beta-hydroxysteroid dehydrogenase deficiency. The total number of patients with congenital deficiency of adrenal steroidogenic enzyme from 1992 to 1996 was estimated as 1,462, and 87% of these patients suffered from 21-hydroxylase deficiency. The number of patients with congenital Addison's disease (1992-1996) was estimated at 103. About one-fifth of these patients were female. The causes for these female patients are not attributed to the abnormality of DAX-1 gene, because it causes adrenal insufficiency only in males. Almost all (97.8%) of the rare adrenal diseases were under treatment or under observation. The prognosis was thus found to be quite good, although continuation of the treatment was necessary. Disorders investigated in 1998 were relatively major diseases, as follows: primary aldosteronism, Cushing's syndrome, adrenal preclinical Cushing's syndrome, Addison's disease and pheochromocytoma. The total numbers of patients in Japan in 1997 were estimated as 1,450 for primary aldosteronism, 1,250 for Cushing's syndrome, 290 for adrenal preclinical Cushing's syndrome, 660 for Addison's disease, and 1,030 for pheochromocytoma. In conclusion, for the first time, a reliable national estimation of the prevalence of disorders of adrenal hormones was conducted in this study.