Changes in Clinical Characteristics and Drug Treatment of Hypertension Over 40 Years at the Dunedin Hypertension Clinic

Abstract

The clinical characteristics of the 4,170 hypertensive patients referred to the Dunedin Clinic from 1950 to 1989 have been compared for eight successive 5-year periods. A gradual decrease in the severity of referred hypertension and an increase in the proportion of patients already on treatment at the time of referral (currently 50%) were noted. For male patients, mean ± SD initial lying blood pressure was 179 ± 27/116 ± 19 mm Hg in 1950–1954 and 158 ± 25/91 ± 14 mm Hg in 1985–1989. Corresponding prevalence data for target organ damage among male patients were retinal grade 3 or 4, 49% and 3%; cardiomegaly on chest radiograph, 60% and 26%; electrocardiogram left ventricle strain pattern, 28% and 3%; and serum urea levels > 10 mmol/L, 16% and 5%, respectively. For women there was a similar trend. The number of patients on drugs in each of nine categories and the percent use of each drug category for each year during 1950–1989 was recovered from computerized data files. The percentage peak usage of ganglion blockers was in 1950–1958, adrenergic neuron blockers in 1963–1970, centrally acting drugs in 1965–1968, diuretics in 1960–1982, β-blockers in 1974–1987, α-blockers in 1980–1987, and angiotensin converting enzyme inhibitors and calcium antagonists in 1989. The diuretics have been the most enduring drugs, followed by the β-blockers.