Impact of combined elevations of homocysteine and asymmetric dimethylarginine on all-cause death - The Tanushimaru Study.

BACKGROUND: Both homocysteine (Hcy) and asymmetric dimethylarginine (ADMA) induce endothelial dysfunction. However, the impact of both elevations on all-cause death is not known. We investigated the association between elevations of Hcy or ADMA and all-cause death in a general population. METHODS: A total of 517 subjects (224 men, 293 women; mean age, 62.8 years) were recruited from a population-based survey in 1999 in Tanushimaru, and we measured fasting plasma Hcy and ADMA levels. We followed them up for over 20 years and examined the effect on mortality using Cox proportional hazard regression model. RESULTS: The mean follow-up years were 17.7 (1.8-20.8). In this period, 182 subjects have died (35.2%). The correlation between Hcy and ADMA was high (r=0.194; p<0.001). With Cox regression analysis after adjustments for age and sex, elevated log transformed Hcy levels were significantly associated with all-cause death (p=0.028). When Hcy and ADMA levels were divided into quintiles, the hierarchical model showed the synergistic effect of Hcy and ADMA on all-cause death. CONCLUSIONS: This is the first report that we have measured Hcy and ADMA levels simultaneously in this community-dwelling Japanese, and we demonstrated that combined elevations of Hcy and ADMA had big impact on all-cause death in this epidemiological study.