Plasma homocysteine, but not folate or vitamin B-12, predicts mortality in older people in the United Kingdom.
Dangour AD., Breeze E., Clarke R., Shetty PS., Uauy R., Fletcher AE.
There is uncertainty about the importance of plasma levels of homocysteine, vitamin B-12, and folate for all-cause and cardiovascular disease (CVD) mortality in older people. We examined the associations between plasma levels of folate, vitamin B-12, and homocysteine, and all-cause and CVD mortality among community-dwelling adults aged > or = 75 y living in the United Kingdom. In a population-based prospective cohort study, 853 men and women aged > or = 75 y were examined in 1995-98 as part of the Medical Research Council Trial of Assessment and Management of Older People in the Community. During a median follow-up of 7.6 y (5528 person-years of follow-up), 429 individuals (50.3%) died, including 185 from CVD. Individuals with plasma homocysteine levels in the top one-third compared with the bottom one-third had a 2-fold higher risk of all-cause mortality (hazard ratio, 2.20; 95% CI, 1.76, 2.75; P < 0.001) and CVD mortality (hazard ratio, 1.96; 95% CI, 1.39, 2.78; P < 0.001) after adjustment for age, sex, and other covariates. There was no association of plasma folate or vitamin B-12 levels with mortality. Our results extend previously reported associations of homocysteine with mortality, and the absence of associations of folate and vitamin B-12 with mortality, to the older population.