Gender and ethnicity affect protective role of statins against AD
medwireNews: The potential reduction in Alzheimer’s disease (AD) risk afforded by high use of statins varies by statin type, gender, and ethnicity, report researchers.
“This suggests that certain patients facing multiple, otherwise equal statin alternatives for hyperlipidemia treatment, may reduce AD risk by using a particular statin,” explains the team led by Julie Zissimopoulos (University of Southern California, Los Angeles, USA). But they note that the study did not establish causality.
The observational study was based on data from a 20% sample of Medicare beneficiaries from 2006 to 2013, aged 65 years or older with high or low exposure to statins.
The 399,979 study participants included 7794 Black men, 24,484 Black women, 11,200 Hispanic men, 21,458 Hispanic women, 115,059 White men, and 195,181 White women who were matched for age, region, education level, and comorbid conditions.
From 2009 to 2013, 1.72% of women and 1.32% of men were diagnosed with AD annually and White men had the lowest incidence at 1.23%.
Patients with high exposure to statins – at least 50th percentile of days of filled prescriptions in a given year – had a decreased risk for AD, compared with those with low exposure, and this was true for both men and women, with reductions of 12% and 15%, respectively. This was after controlling for potentially confounding factors such as years since hyperlipidemic diagnosis, and diagnoses prior to 2009 of non-AD dementia, acute myocardial infarction, atrial fibrillation, stroke, diabetes, and hypertension.
But the researchers note in JAMA Neurology that the association between statin and AD risk varied across the different ethnicities.
High statin exposure was associated with a reduced risk for AD for Hispanic men, White women and men, and Black women, with hazard ratios of 0.71, 0.86, 0.89, and 0.82, respectively. However, there was no risk reduction for Black men with high versus low statin exposure.
The statins studied included the four most frequently prescribed. Simvastatin was the most commonly used, by 62% of women and 61% of men, followed closely by atorvastatin, whereas pravastatin and rosuvastatin were used less frequently.
High exposure to simvastatin was associated with a lower risk for AD among White, Hispanic, and Black women, with hazard ratios ranging from 0.78 to 0.86, as well as for White and Hispanic men, with hazard ratios of 0.90 and 0.67, respectively.
Atorvastatin was associated with a reduced risk for AD among White women, Black women, and Hispanic women and men, while a reduced risk with pravastatin and rosuvastatin was only seen among White women.
These findings generally support the theory that lipophilic statins (simvastatin, atorvastatin) cross the blood–brain barrier more readily than hydrophilic statins (pravastatin and rosuvastatin), and so may have a stronger association with AD risk, says the team.
But none of the statin types were associated with a reduced risk for AD among Black men, the researchers note, which they explain may be related to the carriage of gene variants that influence drug clearance and increase resistance.
Given the effects of statins on AD, Zissimopoulos and colleagues recommend that physicians consider which statin they prescribe to their patients.
“The right statin type for the right person at the right time may provide a relatively inexpensive means to lessen the burden of AD,” they conclude.
By Lucy Piper
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