INFLUENCE OF ISOLATED DIASTOLIC HYPERTENSION IDENTIFIED BY AMBULATORYBLOOD-PRESSURE ON TARGET ORGAN DAMAGE

Clinical decisions and controlled studies in regard to hypertension ha ve long emphasized the casual diastolic blood pressure (DBP). The infl uence of superimposition of high systolic blood pressure (SEP) on the target organ damage has been less studied. To assess the role of isola ted diastolic hypertension without interference of superimposition of systolic hypertension, 171 subjects with normal blood pressure, isolat ed diastolic hypertension (SEP < 140 and DBP greater than or equal to 90 mmHg) isolated systolic hypertension (SEP greater than or equal to 140 and DBP < 90 mmHg) or combined hypertension (SEP greater than or e qual to 140 and DBP greater than or equal to 90 mmHg) determined by me an 24-h ambulatory blood pressure were compared in relation to target organ damage including ECG abnormality related to hypertension, cardia c enlargement by chest X-ray, proteinuria and retinopathy. The inciden ce of target organ damage was lower in subjects with normal BP than in the other three groups. The incidence of target organ damage was almo st significantly higher in patients with isolated systolic hypertensio n than in those with isolated diastolic hypertension. No significant d ifference in the incidence of complications existed between patients w ith isolated systolic and combined hypertension. These findings demons trate that the severity of hypertensive complications is more closely related to mean ambulatory SEP than mean ambulatory DBP. The level of systolic BP is important for predicting the severity of target organ d amage in patients with high diastolic BP, because there is a significa nt difference in the incidence of target organ damage between isolated diastolic hypertension and combined hypertension.