A new study reviewed the association between statin use and the incidence of Alzheimer’s disease, and it determined that exposure to statins had noticeable effects on the development of the disease.

The results caused new expectations, seeing that Alzheimer’s disease remains without an effective treatment and the development of dedicated molecules for relieving its symptoms will not be available anytime soon. The study was based on Medicare beneficiaries and compared the rates of Alzheimer’s disease diagnosis with statin use.

More than 5 million Americans are living with Alzheimer’s, as reported by the Alzheimer’s Association. Image credit: http://gracevillagelc.com/

Looking for anything that may prevent Alzheimer’s

Researchers from the University of Southern California and the University of Arizona, led by Julie Zissimopoulos, Ph.D., set as an objective to analyze how exposure to statins, drugs designed to treat high cholesterol, and Alzheimer’s disease incidence are related in patients that were registered on Medicare.

Statin use increased by a 50 percent from 2003 to 2012 in people aged 40 or older, given that 93 percent of all Americans using cholesterol medication use statins. It has been determined that cholesterol levels have something to do with beta-amyloid plaques, which are always present in neural tissue whenever the person is diagnosed with Alzheimer’s disease. Random clinical trials in the past failed to provide significant conclusions about how statin use influenced Alzheimer’s disease, while others even suggested that there was a negative association.

“In 2016, Alzheimer’s and other dementias will coast the nation $236 billion,” said the Alzheimer’s Association. mage credit: Medpage Today.

To have a large pool of data for reviewing, researchers took a 20 percent sample of Medicare beneficiaries, taking note of the prescription drugs they used. The sample consisted of 399,979 statin users, where 77 percent were non-Hispanic people and the rest was comprised of Hispanics, blacks, Asians, and native Americans.

The statins analyzed were simvastatin, atorvastatin, pravastatin, and rosuvastatin, and anyone who acquired at least 2 prescriptions for statins between 2006 and 2012 was included in the study sample. The participants were classified by exposure to statins and they were followed for an average of 7.2 years. Notably, the median for the time between statin exposure and being diagnosed with Alzheimer’s was 5.4 years.

Results showed that Hispanic and black women had the highest incidence of Alzheimer’s disease (2.29 and 2.11 percent), while white men had the lowest (1.21 percent.) It was determined that study participants who took a larger amount of statins from 2006 to 2008 had a 10 percent less chance of developing Alzheimer’s in the median period.

“Individuals with high exposure to statins had lower rates of AD compared with individuals with low exposure to statins across all 4 statin types. Those who did not use any statins (omitted from our analytic sample) had an AD incidence of 1.99% over the same period,” wrote the researchers on the study.

Some statins can cross the blood-brain barrier with more ease, which suggests that these drugs can have a higher effect on the incidence of Alzheimer’s which also develops on the brain. The theory is that a reduction in cholesterol levels would lead to a reduced formation of beta-amyloid plaques. Although there is no significant evidence on this matter, researchers aimed at first finding some sort of relation between what makes cholesterol drop and the disease itself.

“The risk of AD is higher among ethnic minorities, and thus these people from diverse racial and ethnic backgrounds face a high burden. Even modest advancements in the treatment and prevention of AD (eg, a drug that can delay the disease’s onset by 1 year) will result in a cost savings of $223 billion in 2050. The right type of statin, for the right person, at the right time may provide an inexpensive means to decrease the burden of AD,” reads the study published on Monday.

Which statins were successful?

The statin simvastatin (Zocor) was linked to a lower risk of Alzheimer’s for women, and white and Hispanic males, while atorvastatin (Lipitor) was better for Hispanic women. Rosuvastatin and pravastatin were only better for white women specifically. In the case of black males, the acquired data sample was too small to determine any link between the risk of developing Alzheimer’s and statin intake. Simvastatin and atorvastatin are classified as lipophilic, the kind that easily crosses the blood-brain barrier, while rosuvastatin and pravastatin are hydrophilic.

“If somebody asks, ‘Should I be taking a statin to prevent Alzheimer’s disease?’ I would say, ‘Well, there are some data that indicate that, but I would rather have you take your statin if your primary physician says you need it for vascular purposes,’ ” stated Dr. Ronald Petersen from the Mayo Clinic Alzheimer’s Disease Research Center as a comment to the study.

Although there were no decisive results suggesting that Alzheimer’s might be cured or prevented using statins, researchers did prove that there is some relation between statins affecting the brain and the development of the disease. The next step is to determine exactly what is it that lipophilic statins do to prevent Alzheimer’s, seeing that all types of statins reduce cholesterol while lipophilic statins appeared to be the most successful in the field.

Source: JAMA Network