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 .
Homocysteine-lowering vitamins do not lower plasma S-adenosylhomocysteine in older people with elevated homocysteine concentrations.
Elevated plasma total homocysteine ( tHcy ) is a risk factor for vascular disease but lowering tHcy with B-vitamins , including folate , has generally not reduced vascular events in secondary prevention trials . Elevated plasma S-adenosylhomocysteine ( AdoHcy ) concentration may be a more sensitive indicator of vascular disease than plasma tHcy . However , unlike tHcy , plasma AdoHcy did not correlate with folate concentration in one study indicating that folate supplementation may not lower AdoHcy . Our aim was to determine whether providing B-vitamin supplements to healthy older people with elevated tHcy ( > 13 micromol/l ) affects plasma AdoHcy and S-adenosylmethionine ( AdoMet ) concentrations .  Healthy older participants ( n 276 ; > or = 65 years ) were r and omised to receive a daily supplement containing folate ( 1 mg ) , vitamin B12 ( 500 microg ) and vitamin B6 ( 10 mg ) , or placebo , for 2 years . Of these participants , we selected the first fifty participants in each treatment group and measured plasma AdoHcy and AdoMet . Plasma tHcy was 4.4 ( 95 % CI 3.2 , 5.6 ; P < 0.001 ) micromol/l lower at 2 years in the vitamins group compared with the placebo group . At 2 years , there were no significant differences in plasma AdoMet ( + 4 % ( 95 % CI - 2 , 11 ) ; P = 0.19 ) , AdoHcy ( - 1 % ( 95 % CI - 10 , 8) ; P = 0.61 ) or the AdoMet : AdoHcy ratio ( 0.22 ( 95 % CI - 0.04 , 0.49 ) ; P = 0.10 ) between the two groups . In conclusion , B-vitamin supplementation of older people lowered plasma tHcy but had no effect on plasma AdoMet or AdoHcy concentration . If elevated plasma AdoHcy is detrimental , this may explain why B-vitamins have generally failed to reduce vascular events in clinical trials
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 .