Untreated Hypertension May Raise Alzheimer Disease Risk in Older Adults

Older adults with untreated hypertension have a significantly higher risk for both Alzheimer dementia and non-Alzheimer dementia, according to study findings published in Neurology.

Researchers used individual participant data from community-based studies from 14 different countries (the United States, Brazil, Australia, China, Japan, Korea, Republic of Congo, Nigeria, Germany, Spain, Italy, France, Sweden, and Greece) to examine how antihypertensive medication use is associated with the risk of developing Alzheimer dementia and non-Alzheimer dementia. Follow-up ranged from 2 to 15 years and participants were aged 60 and older without a dementia diagnosis at baseline.

The main 2 outcomes were Alzheimer dementia and non-Alzheimer dementia, diagnosed using criteria from the National Institute of Neurological and Communicative Diseases- Alzheimer’s Disease and Related Disorders Association for Alzheimer dementia and DSM-IV or DSM-III-R for non-Alzheimer dementia. Participants were analyzed in groups based on hypertension history and antihypertensive use status, consisting of:

• No hypertension history, no baseline antihypertensive use (“healthy control” participants, 35.9%)
• No hypertension history, baseline antihypertensive use (“uncertain hypertension,” 4%); participants from this group were excluded
• Hypertension history, baseline antihypertensive use (“treated hypertension,” 50.7%)
• Hypertension history, no baseline antihypertensive use (“untreated hypertension,” 9.4%)

A total of 31,250 participants (average age at baseline, 72.1; men, 41%) and the average follow-up time was 4.2 years.

Participants with untreated hypertension had a higher risk for Alzheimer dementia (HR, 1.36; 95% CI, 1.013-1.832; P =.0406) compared with healthy control participants and those with treated hypertension (HR, 1.42; 95% CI, 1.075-1.872; P =.0135).

Participants with either treated hypertension (HR, 1.29; 95% CI, 1.029-1.604, P= .0267) or untreated hypertension (HR, 1.69; 95% CI, 1.193-2.403, P= .0032) both had higher risk for non-Alzheimer dementia compared to healthy control participants. The risk for non-Alzheimer dementia was similar between the treated hypertension and untreated hypertension groups.

When analysis was limited to participants with data on greater than 5 years of follow-up, a U-shaped association was found between diastolic blood pressure at baseline and non-Alzheimer dementia risk (P =.0227). Additionally, participants with untreated hypertension had greater risk than those with treated hypertension (HR, 1.71; 95% CI, 1.034-2.841; P =.0366) for vascular dementia, a subgroup of non-Alzheimer dementia.

Study limitations included variability in diagnostic criteria, possibility of baseline cognitive impairment in dementia patients, variable effects of different classes of antihypertensives on risk, and the presence of confounding variables.

“Throughout late life those with treated hypertension had a lower risk of [Alzheimer dementia] compared with those with untreated hypertension, suggesting that antihypertensive use should be part of any [Alzheimer dementia] prevention strategy even in late life,” the researchers concluded.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.