In the longitudinal study, eighty patients with white coat hypertension were compared with 40 age- and sex-matched normotensives, and with 80 patients with sustained hypertension. The protocol consisted of (a) clinic blood pressure measurements made both by a physician and a nurse, (b) self-monitoring at home, (c) noninvasive ambulatory monitoring, (d) reactivity testing (cold pressor test, mental arithmetic, and isometric exercise) and (e) Korotkoff signal recording. Patients were also tested for early markers of disease (echocardiography and urine albumin).