In this third up date of the Cochrane review , there were no differences in effects of homocysteine-lowering interventions in the form of supplements of vitamins B6 , B9 or B12 given alone or in combination comparing with placebo on myocardial infa rct ion , death from any cause or adverse events .
BACKGROUND Cardiovascular disease , which includes coronary artery disease , stroke and peripheral vascular disease , is a leading cause of death worldwide .
Homocysteine is an amino acid with biological functions in methionine metabolism .
A postulated risk factor for cardiovascular disease is an elevated circulating total homocysteine level .
The impact of homocysteine-lowering interventions , given to patients in the form of vitamins B6 , B9 or B12 supplements , on cardiovascular events has been investigated .
This is an up date of a review previously published in 2009 , 2013 , and 2015 .
OBJECTIVES To determine whether homocysteine-lowering interventions , provided to patients with and without pre-existing cardiovascular disease are effective in preventing cardiovascular events , as well as reducing all-cause mortality , and to evaluate their safety .
'Mendelian randomization': can genetic epidemiology contribute to understanding environmental determinants of disease?
Associations between modifiable exposures and disease seen in observational epidemiology are sometimes confounded and thus misleading , despite our best efforts to improve the design and analysis of studies . Mendelian r and omization-the r and om assortment of genes from parents to offspring that occurs during gamete formation and conception-provides one method for assessing the causal nature of some environmental exposures . The association between a disease and a polymorphism that mimics the biological link between a proposed exposure and disease is not generally susceptible to the reverse causation or confounding that may distort interpretations of conventional observational studies . Several examples where the phenotypic effects of polymorphisms are well documented provide encouraging evidence of the explanatory power of Mendelian r and omization and are described . The limitations of the approach include confounding by polymorphisms in linkage disequilibrium with the polymorphism under study , that polymorphisms may have several phenotypic effects associated with disease , the lack of suitable polymorphisms for study ing modifiable exposures of interest , and canalization-the buffering of the effects of genetic variation during development . Nevertheless , Mendelian r and omization provides new opportunities to test causality and demonstrates how investment in the human genome project may contribute to underst and ing and preventing the adverse effects on human health of modifiable exposures
In this third up date of the Cochrane review , there were no differences in effects of homocysteine-lowering interventions in the form of supplements of vitamins B6 , B9 or B12 given alone or in combination comparing with placebo on myocardial infa rct ion , death from any cause or adverse events .
BACKGROUND Cardiovascular disease , which includes coronary artery disease , stroke and peripheral vascular disease , is a leading cause of death worldwide .
Homocysteine is an amino acid with biological functions in methionine metabolism .
A postulated risk factor for cardiovascular disease is an elevated circulating total homocysteine level .
The impact of homocysteine-lowering interventions , given to patients in the form of vitamins B6 , B9 or B12 supplements , on cardiovascular events has been investigated .
This is an up date of a review previously published in 2009 , 2013 , and 2015 .
OBJECTIVES To determine whether homocysteine-lowering interventions , provided to patients with and without pre-existing cardiovascular disease are effective in preventing cardiovascular events , as well as reducing all-cause mortality , and to evaluate their safety .