Statins` Anti-Alzheimer`s Effects Vary by Sex, Ethnicity, Drug

By Anne Harding

NEW YORK (Reuters Health) - The protective effect of statins against Alzheimer's disease (AD) varies by gender, ethnicity and drug type, new findings show.

"The right type of statin, for the right person, at the right time may provide an inexpensive means to decrease the burden of AD," Dr. Julie Zissimopoulos of the University of Southern California in Los Angeles and her colleagues conclude in their report, published online December 12 in JAMA Neurology.

Investigators have proposed that statins could reduce AD risk by slowing the formation of beta-amyloid peptide, but epidemiological studies and clinical trials have had conflicting results, Dr. Zissimopoulos and her team note.

In the new study, the researchers looked at medical and pharmacy claims for a 20% sample of Medicare beneficiaries from 2006-2013, comparing AD diagnosis rates for 399,979 statin users.

Annual rates of AD diagnosis were 1.72% for women and 1.32% for men from 2009 to 2013. Rates for Hispanic, black, and white women were 2.29%, 2.11%, and 1.64%, respectively. White men had the lowest AD incidence, at 1.23%. Rates for men in general and for women of "other" race were 1.29% and 1.37%, respectively.

For women overall, high statin exposure was associated with a lower AD risk (hazard ratio 0.85). Simvastatin reduced risk in white women (HR 0.86), white men (HR 0.90), Hispanic women (HR 0.82), Hispanic men (0.67) and black women (HR 0.78), but not black men. Atorvastatin was tied to lower AD risk in white women (HR 0.84), black women (HR 0.81), and Hispanic men and women (HR 0.61 and 0.76, respectively). Only white women saw a reduced AD risk with pravastatin and rosuvastatin (HR 0.82 and HR 0.81, respectively). High exposure to any type of statin did not statistically reduce AD risk in black men.

Lipophilic statins, which cross the blood brain barrier, were associated with AD risk in several of the demographic groups in the study, Dr. Zissimopoulos noted, while hydrophilic statins had less universal effects.

Clinicians can't use the current findings to pick the right statin for their patients, Dr. Zissimopoulos told Reuters Health in an interview. "That's something that the clinician needs to talk to their patient about, but it does suggest overall that maybe having a healthier heart and healthier cardiovascular system is going to be beneficial, not only for your cardiovascular system, but beneficial for your brain," she said.

She and her colleagues are also investigating other drugs widely used by older people, such as antihypertensive medications and diabetes drugs, to see whether they may also be associated with reduced AD risk.

"We're also looking at combinations of drugs, because in the older patient population most individuals are not on just one drug, they're on more than one," Dr. Zissimopoulos said. "Thinking about the combination of drugs that people are on and how that affects Alzheimer disease risk is an area that we're currently focusing on."

SOURCE: bit.ly/2hgkNiW

JAMA Neurol 2016.

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