No relation between CMV infection and mortality in the oldest old: results from the Belfrail study

Objective: previous studies have demonstrated an association between cytomegalovirus (CMV) infection and mortality in adults. In this prospective study, it was investigated whether these findings could be confirmed in the oldest old. Methodology: data obtained from a prospective observational cohort study (2008-2012) of 549 community-dwelling persons in Belgium aged 80 and older. Results: seventy-six percent were anti-CMV seropositive of whom 37.5% had an anti-CMV IgG titre in the highest tertile (> 250 IU/ml). After a median time of follow-up of 1,049 days, 127 deaths occurred. Cox proportional hazard models failed to show an association between CMV serostatus and all-cause mortality. Among persons seropositive for CMV, after adjusting for multiple confounders an anti-CMV in the highest tertile was statistically significantly associated with all-cause mortality (hazard ratio: 1.64, 95% confidence interval: 1.08, 2.48). Conclusion: in contrast to previous findings, a positive CMV serostatus was not associated with an increased risk for all-cause mortality in this cohort of very old people. This is probably the result of a survival effect. CMV seropositive subjects with high anti-CMV titres were at higher risk for all-cause mortality compared with other individuals. This may reflect CMV infection reactivation to be more common in the end stages of life.