The clinical significance of isolated diastolic hypertension

The prevalence of isolated diastolic hypertension (IDH) has been increased in hypertensive subjects with the new 2017 ACC/AHA blood pressure treatment guidelines to 6.5% from 1.3% by the JNC-7 guidelines. However, its clinical significance as a cause of adverse cardiovascular (CV) events especially in older subjects has been debated by several investigators, who have demonstrated no adverse CV effects of untreated IDH, but not by others. It is also more common in the young subjects who are at low CV risk and quite rare in the older subjects, who are at increased CV risk. Treatment of IDH in the older subjects could increase the CV complications due to a J-curve effect and, in addition, could increase the incidence of stroke from further lowering the normal systolic blood pressure (SBP). Very low SBP and DBP cannot be sustained by the cerebral blood flow autoregulation and could lead to cerebral ischemia. In order to get a better perspective of the current status of the treatment of IDH, a review of the English language literature of the available studies was conducted and 12 papers with pertinent information were retrieved. The analysis of results from these studies suggests that IDH is associated with adverse CV events in younger persons and it should be treated. In contrast, the prevalence of IDH is low in older subjects and is not associated with adverse CV events in the majority of cases. Thus, its further lowering should be avoided to prevent further decrease in normal SBP and prevent the onset of adverse CV events. However, the decision to treat IDH in older subjects should be individualized.