GPs should be cautious about lowering blood pressure too far in patients with low diastolic levels as this is associated with greater progression of brain atrophy, conclude researchers.
The US cohort study included 663 patients (mean age of 57 years) with coronary artery disease, cerebrovascular disease, peripheral artery disease, or an abdominal aortic aneurysm. They grouped the patients into those with low, normal or high diastolic blood pressure (≤70, 71-90, and >90mmHg). They also measured changes in brain parenchymal function, cortical grey matter fraction, and ventricular fraction - indicators of brain atrophy.
Some 97 patients in the group had low diastolic blood pressure at baseline, with 450 and 116 patients with normal and high diastolic blood pressure, respectively. The mean differences in the change in ventricular fraction between low and high diastolic blood pressure was 0.07% and between low and high mean arterial pressure was 0.05%. Patients with higher baseline diastolic and systolic blood pressures that declined over time showed less progression of subcortical atrophy, compared with those with rising levels of blood pressure.
What this means for GPs
The researchers concluded that their data suggested blood pressure lowering was beneficial in patients with high blood pressure, but ‘one should be cautious with further blood pressure lowering in patients who already have a low diastolic blood pressure’.