Progression of dementia was slower in patients taking ACE inhibitors, particularly those who had recently started taking them, compared with those not taking them.
New research suggests that angiotensin-converting enzyme (ACE) inhibitors, generally prescribed to treat hypertension, may slow or even reverse the progression of cognitive decline in dementia patients, especially within the first 6 months of use.
The observational case-control study
, published on July 22, 2013, in BMJ Open
, enrolled 361 patients with Alzheimer’s disease, vascular dementia, or a mix of both, to assess the effects of antihypertensive agents on cognitive decline. Using data on patients from 1999 to 2010, researchers in 2 university hospital memory clinics in Canada compared the rates of cognitive decline in dementia patients already receiving centrally acting ACE inhibitors, patients not receiving ACE inhibitors, and patients who had initiated ACE inhibitors during their first 6 months of treatment. To measure the cognitive decline of participants, the Standardised Mini-Mental State Examination (SMMSE) or the Quick Mild Cognitive Impairment (Qmci) screen were administered to patients twice with a 6-month interval.
The results indicated a small but significant difference in the rate of decline in Qmci scores between patients already taking ACE inhibitors and those not receiving the treatment. The median 6-month rate of decline in Qmci scores for patients not receiving ACE inhibitors was 2.1 points, compared with a 1.8 point decline in patients receiving the antihypertensives. The median 6-month decline for SMMSE scores among patients in the ACE inhibitor group was lower than among those in the no treatment group, but the difference was not statistically significant. Patients in their first 6 months of ACE inhibitor treatment, however, improved their SMMSE scores by a median of 1.2 points.
“This is the first study to demonstrate that cognitive scores improve in patients starting on [ACE inhibitors], compared to those already established on maintenance treatment,” the researchers write. “This may have been related to better medication compliance, the effects of improved [blood pressure] control or increased cerebrovascular perfusion after initial treatment.”
The authors conclude that the results confirm an association between ACE inhibitor treatment and a reduced rate of cognitive decline and suggest that the treatment may show more impressive benefits over a longer period of time. “Further study with an appropriately powered randomized trial is needed to confirm these findings and determine if and for how long these effects are sustained,” they write.
However, the authors note that even if future research establishes that treatment with ACE inhibitors significantly slows or even reverses cognitive decline, use of the antihypertensives may not be beneficial to all dementia patients; some recent evidence has suggested that the medications may actually accelerate the progression of dementia and increase the risk of death in certain patients.