Hyperhomocysteinemia and venous thrombosis: A meta-analysis

Hyperhomocysteinemia is an established risk factor for atherosclerosis and vascular disease. Until the early nineties the relationship with venous thr ombosis was controversial. At this moment ten case-control studies on venou s thrombosis are published. We performed a metaanalysis of these reports. We performed a MEDLINE-search from 1984 through June 1997 on the keywords " homocysteine" or "hyperhomocysteinemia" and "venous thrombosis", which yiel ded ten eligible case-control studies. We found a pooled estimate of the odds ratio of 2.5 (95% CI 1.8-3.5) for a fasting plasma homocysteine concentration above the 95th percentile or mean plus two standard deviations calculated from the distribution of the respe ctive control groups. For the post-methionine increase in homocysteine conc entration we found a pooled estimate of 2.6 (95% CI 1.6-4.4), These data from case-control studies support hyperhomocysteinemia as a risk factor for venous thrombosis. Further research should focus on the pathoph ysiology of this relationship and on the clinical effects of reducing homoc ysteine levels by vitamin supplementation.