Patients taking statins may have a lesser risk of being diagnosed with Alzheimer’s disease (AD), results from a study show.
However, the degree of risk is linked to the type of statin and level of use as well as the sex, race and ethnicity of the patient, the researchers found.
“The right type of statin for the right person at the right time may provide an inexpensive means to decrease the burden of AD,” they say.
Reporting in JAMA Neurology
(online, 12 December 2016), researchers analysed 399,979 patients on the Medicare register aged over 65 years who were prescribed statins between 2006 and 2008 and whether or not they were then diagnosed with AD between 2008 and 2013. The statins involved in the study were simvastatin, atorvastatin, fluvastatin, lovastatin, pitavastatin, pravastatin or rosuvastatin.
The researchers defined a statin user as anyone with at least two prescription fills of any statin between 2006 and 2012. Patients were classified as either ‘low’ or ‘high’ statin users depending on how many prescriptions for statins they had filled in a given year.
From 2009 to 2013, 1.72% of women and 1.32% of men were diagnosed with AD annually, the data show.
The researchers also noted that AD incidence was higher among Hispanic women (2.29%) and black women (2.11%) compared with white women (1.64%). White men had the lowest incidence of AD (1.23%) compared with the incidence of AD among Hispanic men (1.86%) and black men (1.94%).
They also found that ‘high’ statin users were 10% less likely to have an AD diagnosis from 2008–2013 compared with low users.
When the authors looked at each individual statin, they found that high exposure to simvastatin in particular was associated with a lower risk of AD for white, Hispanic and black women as well as white and Hispanic men.
Atorvastatin was associated with reduced AD risk among white, black, and Hispanic women and Hispanic men, while pravastatin and rosuvastatin were associated with reduced AD risk for white women. There was no reduction in AD risk for black men associated with any statin, the researchers say.
Commenting on the study, Doug Brown, director of research and development at UK charity the Alzheimer’s Society, says previous research into statins and the associated risk of developing dementia has “produced mixed findings”.
“This new study goes some way towards clearing up this confusion by analysing large amounts of existing data of people who use different types of statins over a long period of time.
“[The researchers’] refreshing approach highlights that ‘one size fits all’ is not always a suitable approach to healthcare and this is likely to be the case when it comes to ways people can reduce their risk of dementia,” Brown says.
“However, their data does not provide direct evidence that statins can influence dementia risk – this question will need to be answered by clinical trials.
“The results found cannot yet be applied to the doctor’s surgery, but could be used to improve the design of clinical trials that can help to answer the complicated questions around statin use and dementia risk.”
 Zissimopoulos JM, Barthold D, Brinton RD et al. Sex and race differences in the association between statin use and the incidence of Alzheimer’s disease. JAMA Neurology 2016. doi: 10.1001/jamaneurol.2016.3783