Antihypertensive drugs linked with lower dementia risk in older patients
Patients who filled a new prescription for antihypertensive therapy more than three-quarters of the time were 24% less likely to develop dementia than those who rarely filled theirs, according to a seven-year study carried out in Italy among patients ages 65 years and older.
Treatment with antihypertensive drugs is associated with a lower risk of dementia among adults ages 65 years and older, new research suggests.
Researchers assessed outcomes of 215,547 patients in Lombardy, Italy who newly began taking hypertension drugs between 2009 and 2012. Average patient follow-up was 7.3 years. Investigators matched each patient who developed dementia or Alzheimer's disease with five controls by age, sex, and clinical status. Exposure to therapy was based on the proportion of the follow-up period with a filled prescription for an antihypertensive, with very low exposure defined as 25% of days or less, low as 26% to 50% of days, intermediate as 51% to 75%, and high as 75% or more. Findings were published by the Journal of the American College of Cardiology on March 25.
In total, 13,812 patients (mean age 77.5 years; 40% male) developed dementia or Alzheimer's disease from the time they began medication to 2019. Compared to patients in the very low group, patients with low, intermediate, and high exposure to antihypertensive drugs had a 2% (95% CI, 4% to 7%), 12% (95% CI, 6% to 17%), and 24% (95% CI, 19% to 28%) reduction in risk of dementia, respectively. Findings were consistent in both sexes, among patients ages 85 years or older, and frail patients, defined as those with a high mortality risk at one year.
The most frequently prescribed monotherapy was a renin-angiotensin system blocker. The most frequently prescribed two-drug combination was a renin-angiotensin system blocker plus a diuretic agent. "The favorable effect of exposure to antihypertensive treatment in delaying the onset of dementia extended to a considerably more advanced age than that reported by previous studies," the authors noted. Data also showed a significant dementia risk reduction was only seen after two years of therapy, confirming the drugs' benefit takes time to clinically manifest, they said.
"Taken together, these findings confirm and extend the available evidence that antihypertensive drug treatment has a protective effect on the progression of cognitive dysfunction that leads to dementia," the researchers wrote. Limitations to the study include a lack of data on adherence to therapy and that patients already on antihypertensive drug treatment were excluded from the study.
An accompanying editorial highlighted some still unanswered questions, including rates of adherence and actual blood pressure control among patients prescribed antihypertensives and the generalizability of the study's findings. "Future studies are needed to investigate whether the association between [blood pressure] medication and control affects dementia risk in diverse racial populations, some of which may be at a greater risk of dementia than predominantly Caucasian populations are," they concluded.