High blood pressure (BP) has previously been linked to a higher risk of dementia—but what about low BP?
Researchers out of South Korea explored that very question, sharing their findings in Hypertension.
In the study, more than 4.5 million patients without a history of dementia were analyzed and followed for 5.4 years. Patients were all under the age of 60. All information came from a Korean National Health Insurance Service database.
Forty-five percent of patients were men, and the mean patient age was 67.4 years old. The overall prevalence of hypertension was 58.2%.
After follow-up, the dementia had been reported in 6.6% of patients. Probable Alzheimer disease (AD) and probable vascular dementia (VaD) occurred in 4.8% and 0.8% of patients, respectively.
According to the authors, the risks of developing probable AD and probable VaD were not the same among patients who had lower BP. Age, the use of antihypertensive medications and various comorbidities all appeared to play a significant role.
Also, probable AD risk showed a U-shaped relationship with BP, but the risk of probable VaD declined with lower BP.
Compared with those who did not develop dementia, patients with incident AD or VaD were more inclined to be older, women, less physically active and present with comorbidities.
"This nationwide study of 4.5 million people more than 60 years of age may provide information that can help explain the complex relationship between blood pressure and dementia risk through a variety of analyses," wrote lead author Chan Joo Lee, a specialist with Yonsei University College of Medicine in South Korea, and colleagues.
Read the full study here.