Apparent prevalence of curable hypertension in the Hypertension Detection and Follow-up Program

Data describing the 5,485 participants in the stepped-care group of the Hypertension Detection and Follow-up Program were reviewed to determine the apparent prevalence of renal parenchymal and reversible, secondary hypertension. The investigation was limited and was not designed to identify all cases of secondary hypertension. Baseline prevalence of proteinuria was 3.6%, pyuria 7.1%, hematuria 5.1%, and elevated serum creatinine level (greater than or equal to 1.7 mg/dL) 2.7%. The combined occurrence of an elevated serum creatinine level plus one or more urinary abnormalities was noted in 0.95%. Initial review of case reports revealed six participants with hypertension secondary to use of birth control pills and three participants with hypertension that was proved to be secondary to renovascular disease. Specific laboratory or historical criteria were used as indications for more intensive investigation in an additional 65 participants. Among these individuals, one participant with renovascular disease and three with possible primary hyperaldosteronism were identified. A rapid-sequence intravenous urogram or radionuclide scan was performed on another subgroup of 62 participants whose hypertension was "poorly" controlled (diastolic BP, greater than or equal to 95 mm Hg). Fifty-nine studies were negative, one was positive, and two were equivocal. These results suggest that the frequency of clinically relevant cases of reversible, secondary hypertension, at least among individuals with mild to moderate elevation of blood pressure, is low.