Homocysteine and the risk of nursing home admission and mortality in older persons

Abstract

This study aimed to investigate whether higher homocysteine and lower vitamin B12 concentrations increase the risk of future nursing home (NH) admission and all-cause mortality in independently living older persons. In total, 1117 independently living participants (mean age=75.1, s.d.=6.4) were included in this prospective sub-study of the Longitudinal Aging Study Amsterdam. EDTA plasma samples, collected in 1995-1996, were analysed for total homocysteine (μmol/l). Time to NH admission was assessed using a follow-up until 2002-2003. In addition, we studied mortality until 1 June 2007. Cox proportional hazards models were used to examine the association between homocysteine in quartiles and risk of NH admission and mortality. During follow-up, 126 persons (11.3%) were admitted to NHs, and 513 persons (45.9%) deceased. In men, no significant associations were observed. In women, after adjustment for confounding, the highest quartile of homocysteine was associated with a significantly higher risk of NH admission compared with the first quartile (hazard ratio (HR)=2.97, 95% confidence interval (CI)=1.36-6.49). Both women in the third and the fourth quartile of homocysteine had a significantly higher mortality risk (HR=1.70, 95% CI=1.08-2.65 and HR=1.91, 95% CI=1.22-3.00, respectively) compared with the first quartile. Vitamin B12 was not related to an increased risk of NH admission and mortality. Elevated plasma homocysteine is associated with an increased risk of NH admission and mortality in older women, but not in older men.