Thursday, December 14, 2006

Folic Acid And The Heart

Preventing CAD is very important. This is the primary strategy in our fight against CAD. Indentifying coronary risk factors (CRF) is something that any rookie doctor should be able to rattle off without much ado. Hypertension, diabetes, cigaratte smoking, hyperlipidemia, obesity should pop right off the top of the head. However homocysteinemia is the odd one.

I always had trouble understanding homocysteinemia as an important CRF. Even the pathogenesis of homocysteine promoting CAD is difficulty to work out. However, many considered the use of folic acid for lowering serum homocysteine as innocuous enough to accept it without close scrutiny of data, for a long time. Recently much meta-analysis and clinical trials has been undertaken to see if folic acid actually help, indirectly asking if homocysteinemia is actually a CRF?

Dr Lydia A Bazzano, et al. published an article entitled "Effect of folic acid supplementation on risk of cardiovascular diseases. A meta-analysis of randomized controlled trials". JAMA 2006; 296: 2720-2726, which found no diference between those given folic acid and those not on folic acid, again underlining the fact that homocysteinemia is a very controversial CRF.

Having analysed 12 controlled clinical trials with a total of about 16,500 patients make this a very large meta-analysis. However, there is a yet bigger meta-analysis by Oxford on the way. For the moment, use folic acid supplements, if you wish. It is safe without side-effects, but whether you need to or not, is not so easy to answer. I rather suspect, maybe not. Suffice to know that I don't see another large RCT, perhaps only more meta-analysis, with all the shortcomings of meta-analysis.

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