Statins and dementia: the everlasting debate 

Statins are among the most widely prescribed medications in the realm of cardiology and preventive medicine. It is estimated that more than 200 million people are on statin therapy worldwide, so all issues regarding its safety and possible side effects are of unique importance.

The vast majority of statin users are elderly people suffering form CVD, who are also at high risk of cognitive decline. We have some debatable evidence that statins may alter cognitive performance and pre-dispose old patients to dementia development.

In 2012, the FDA warned that some elderly statin users complained about short term decline in their cognitive functions. 

In 2021, an american imaging study showed that PET scan of the brain of patients on lipophilic statins (atorvastatin, simvastatin, lovastatin, fluvastatin, and pitavastatin) showed a significant decline in metabolism in the brain areas commonly affected by Alzheimer ‘s disease, the most coommon cause of dementia worldwide. From the results of this study, researchers concluded that in patients with mild cognitive impairment and low to moderate serum cholesterol levels at baseline, lipophilic statins were associated with more than double the risk of plunging to dementia over 8-year follow-up in comparison to non-users.

On the other hand, A study published in JACC in 2021, that included more than 18,400 patients who aged 65 years or older, showed that over a five-year follow-up period, people taking statins weren’t more susceptible to dementia than non-users.

Additionally, many researchers think that statins may reduce the risk of cognitive deterioration, by reducing high cholesterol levels,hence exerting a protective role against CV strokes and vascular dementia, in which impaired blood flow to the brain leads to cognitive decline. Furthermore, the anti-inflammatory effects of statins might decrease the risk of developing Alzheimer’s disease.

Interestingly, in December 2021, the results of a systematic review and meta-analysis (of 36 observational studies) published in the European Journal of Preventive Cardiology, showed  that statins were associated with a decreased risk of dementia (OR 0.80 (CI 0.75-0.86) as a whole and  for Alzheimer’s disease, based on the results of 21 studies, the risk was also reduced (OR 0.68 (CI 0.56-0.81), The results were for lipophilic and hydrophilic statins alike, however, more evidence for high-potency statins compared to low-potency statins.

To conclude, The research data regarding the relationship between statins and dementia is mixed, however, it is evident that their benefits tangibly outweigh their risks in people who are highly indicated to take them.

Practical application: 

• You should respect the current voluminous evidence recommending statins and prescribe them as indicated in all patients including elderly patients, however, add inquiry about early symptoms of dementia to your follow up sessions with your elderly patients for early 
• In individualized cases where higher doses of statin are evidently associated with tangible reduction of cognitive functions, we can resort to combinations with ezitimibe and stricter life style modifications to safely decrease statin doses.  
• Hydrophilic statin such as rosuvastatin have a more appealing safety profile in comparison to lipophilic ones (atorvastatin, simvastatin ..) regarding dementia.

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