Oxidative stress is associated with greater mortality in older women living in the community

OBJECTIVES: To determine whether oxidative stress, as implied by oxidative damage to proteins, is associated with greater mortality in older women living in the community. DESIGN: Longitudinal. SETTING: Women's Health and Aging Study I, Baltimore, Maryland. PARTICIPANTS: Seven hundred forty-six moderately to severely disabled women, aged 65 and older, with baseline measures of serum protein carbonyls. MEASUREMENTS: Serum protein carbonyls, which consist of chemically stable aldehyde and ketone groups produced on protein side chains when they are oxidized, were measured using enzyme-linked immunosorbent assay. Multivariate logistic regression was used to adjust for potential confounders. RESULTS: During 5 years of follow-up, 202 (27.1%) participants died. Geometric mean serum protein carbonyls were 0.091 nmol/mg in women who died and 0.083 nmol/mg in those who survived (P=.02). Log_e protein carbonyls (nmol/mg) were associated with greater risk of mortality (hazards ratio=1.34, 95% confidence interval=1.01-1.79, P=.04) in a multivariate Cox proportional hazards model adjusting for age, current smoking, and body mass index. CONCLUSION: Greater oxidative stress, as indicated by elevated serum protein carbonyl concentrations, was associated with greater risk of death in older women living in the community who were moderately to severely disabled. Prevention of oxidative stress may reduce the risk of mortality.