Wednesday, July 30, 2008

Statins Prevent You from Getting Dementia?

When you talk about statins, you talk about cholesterol. Well, thing has changed.

A new study suggested that taking statins may help protect against development of dementia in those who are at high risk of dementia.


The study had 1,674 participants and all the participants were free of dementia when entering the study. All participants had cognitive and clinical evaluations performed every 12 to 15 months. 452 participants (27%) took statins at any time during the study.

During this 5-year follow-up, persons who had used statins were about half as likely as those who did not use statins to develop dementia.

However, the result can only establish an association, but not a causal relationship between taking statins and dementia. Even if the preventative effect of statins does exist against dementia, it is not clear if the drugs can be used to treat dementia.

In addition, from the result of the study, we can see that it is possible that cognitive benefits (prevention of dementia) only come with years of statin use.

Some experts suggest that brain permeant (crossing blood-brain-barrier) statins (such as simvastatin) might be far more effective than statins that don't get into the brain (atorvastatin).


In fact, back in 200o, a 6-year-study published in The Lancet already showed such result, that individuals of 50 years and older who were prescribed statins had a substantially lowered risk of developing dementia, no matter they have hyperlipidemia or not; exposed to non-statin lipid-lowering agents or not. The available data do not distinguish between Alzheimer's disease and other forms of dementia.

Difference between these 2 studies: the year 2008 study involved elderly Mexican-Americans; while the year 2000 study involved elderly UK population.


However, as both of the studies are epidemiology studies, the population are not randomized picked, those who taking statins in such studies may be resistant to cognitive decline for reasons other than statin use.

Therefore, for now, it is suggested that people should take statins only for purposes they are originally indicated for, that is: for cholesterol-lowering.

References:
  1. C. Cramer, M. N. Haan, S. Galea, K. M. Langa, and J. D. Kalbfleisch. Use of statins and incidence of dementia and cognitive impairment without dementia in a cohort study. NEUROLOGY 2008; 71: 344-350
  2. H Jick, GL Zornberg, SS Jick, S Seshadri, and DA Drachman. Statins and the risk of dementia. The Lancet 2000; 356:1627-1631

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