Rationale against the drug treatment of marginal diastolic systemic hypertension.

T he Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure’ does not recommend drug treatment for uncemplicated hy~rtension when the diastolic blood pressure (BP) is in the range of 90 to 94 mm Hg (marginal hypertension). They advise instead nonpharmaceutical therapy with periodic examinations to detect possible progression of hypertension. Most physicians, however, still use 90 mm Hg as the level at which they will begin treatment with drugs if necessary and at least 2 authorities*,3 emphasize the importance of decreasing BP using drug treatment when needed in all hypertensive patients, including those with diastolic levels as low as 90 mm Hg. This report will review some of the background data concerning the effectiveness of treatment of patients with diastolic BP in the range of 90 to 94 mm Hg. The question is of considerable importance because patients with diastolic BP in this marginal range comprise approximately 40% of the hypertensive population4*” Level of dfssfok blood pressure and coronary heart disease mortality: The leading cause of death in marginal hy~rtension is coronary heart disease, which is 3 times greater than stroke, the second leading cause. However, cardiovascular risk is lower in marginal hypertensive patients compared to patients with higher levels of diastolic BP.h The curve relating diastolic BP and coronary heart disease mortality increases steeply at levels above 100 mm Hgh Anderson7 using 1978 data from the Framingham study, pointed out that the curve flattened out at diastolic BP levers between 70 and 90 mm Hg; that is, there was no increase in coronary heart disease mortality between 70 and 90 mm Hg. No such inflection or “dogleg” in the curve was seen with respect to systolic BP where coronary heart disease mortality increased continuously from the lowest levels. This inflection in the diastolic curve was not recognized before because of the previous practice of drawing a smooth linear regression curve, which will never disclose a dogleg. This author has been informed by Dr. A. D’Agastino of the Framingham study that their most recent, still unpublished data also show a dogleg or J-shaped diastolic curve. Furthermore, 4 other epidemiologic studiesR also show in the unsmoothed curves relating diastolic BP