Cross-sectional and longitudinal association between homocysteine, vitamin B12 and physical performance in older persons.

Background/objectives: Decreases in physical performance are associated with multiple negative health outcomes. The objective of this study was to examine whether high plasma homocysteine and low serum vitamin B12 are independent risk factors for lower physical performance, both cross-sectionally and longitudinally.
Subjects/methods: This study was performed in persons aged ≥65 years of the LASA (Longitudinal Aging Study Amsterdam), an ongoing cohort study. Blood was collected in 1995/1996 (n=1352). Physical performance was assessed in 1995/1996 and in 1998/1999 using three tests: the walking test, the chair stands test and the tandem stand (n=901-1155).
Results: After adjustment for confounding, women in the highest quartile of homocysteine had a significantly lower physical performance than did those in the lowest quartile in the cross-sectional analyses (β=-0.93, s.e.=0.34, P<0.01). This association was borderline statistically significant in the longitudinal analyses (β=-0.69, s.e.=0.35, P=0.05). After additional adjustment for serum vitamin B12, both associations were statistically significant (P<0.05). For vitamin B12 in women, and for homocysteine and vitamin B12 in men, the observed associations were less consistent.
Conclusions: High plasma homocysteine is an independent risk factor for lower physical performance in older women. The association between vitamin B12 and physical performance is less clear.