What is the actual incidence of secondary hypertension in a general population of young male workers compared to hospitalized patients?
The incidence of secondary hypertension in a general population of young hypertensive men is approximately 9.8%, significantly lower than the rates seen in hospitalized cohorts, with chronic glomerular nephritis being the most common cause.
In order to clarify the actual incidence of secondary hypertension in the general population, extensive examinations were performed on 488 hypertensive patients under 40 years old, who were selected from 3313 apparently normal male workers. The incidence of secondary hypertension in this group was 9.8%, and, it was markedly less than that in hospitalized patients (60.9%), which was similar to those reported =already from other hospitals. Twenty-two, cases of chronic glomerular nephritis, four hypertensive patients with high plasma aldosterone and consistently lower plasma renin activity, one of pheochromocytoma, and four of hyperkinetic heart syndrome were found in these apparently normal workers. The percentage of chronic glomerular nephritis was highest among those of secondary hypertensions, and, therefore, the differential diagnosis between essential hypertension and chronic glomerular nephritis was not easy in not a few cases of hospitalized patients. Based on the comparison of clinical and histological findings between essential hypertensives and chronic glomerular nephritic patients, of which diagnosis was established by kidney biopsy, difficulties of clinical differntial diagnosis between both diseases and the importance of kidney biopsy for establishment of the diagnosis was discussed.
Osamu Iimura (Mon,) studied this question.