Longitudinal study of blood pressure and white matter hyperintensities - The EVA MRI cohort

Objective: To investigate the relationship between baseline hypertension an d severity of white matter hyperintensities (WMH) at 4-year follow-up in a sample of subjects aged 59 to 71 years old at entry. Methods: Subjects were participants in the Epidemiology of Vascular Ageing study, a longitudinal study on vascular aging and cognitive decline. At 4-year follow-up, 845 sub jects had a cerebral MRI. MRI examinations were read by a single rater to d etermine the severity of WMH, ranging from absent to severe. Hypertension a t each wave of the study was defined as systolic blood pressure greater tha n or equal to 160 mm Hg, diastolic blood pressure greater than or equal to 95 mm Hg, or use of antihypertensive medication. Results: Hypertension at b aseline was significantly associated with an increased risk of having sever e WMH at 4-year follow-up. When taking into account both blood pressure lev els and antihypertensive drug intake, analysis showed that the risk of havi ng severe WMH was significantly reduced in subjects with normal blood press ure taking antihypertensive medication compared with those with high blood pressure taking antihypertensive agents. Cross-sectional relationships betw een hypertension and WMH at 4-year follow-up showed that the frequency of s evere WMH was significantly higher in people who were hypertensive at both baseline and 4-year follow-up than those who were hypertensive only at I-ye ar follow-up. Conclusions: Hypertension is a major risk factor for severe W MH. Subjects taking antihypertensive drugs and who have controlled blood pr essure had a reduced risk of severe WMH. Longitudinal studies are needed to investigate whether reduction of the development of WMH, by treatment and prevention of hypertension, might reduce the subsequent risk of cognitive d eterioration or stroke.