Cardiometabolic dysregulation and cognitive decline: potential role of depressive symptoms

BACKGROUND: Previous studies have examined associations of cardiometabolic factors with depression and cognition separately. AIMS: To determine if depressive symptoms mediate the association between cardiometabolic factors and cognitive decline in two community studies. METHODS: Data for the analyses were drawn from the Rotterdam Study, the Netherlands (n = 2940), the Whitehall II study, UK (n = 4469) and the Canadian Longitudinal Study on Aging, Canada (n = 13,720). RESULTS: Mediation analyses suggested a direct association between cardiometabolic factors and cognitive decline and an indirect association through depression: poorer cardiometabolic status at time 1 was associated with a higher level of depressive symptoms at time 2 (standardised regression coefficient 0.07 and 0.06, respectively), which, in turn, was associated with greater cognitive decline between time 2 and time 3 (standardised regression coefficient of -0.15 and -0.41, respectively). CONCLUSIONS: Evidence from three independent cohort studies suggest an association between cardiometabolic dysregulation and cognitive decline and that depressive symptoms tend to precede this decline. KEY MESSAGES: • Cardiometabolic dysregulation and depression might increase cognitive decline. • The association between cardiometabolic dysregulation and cognitive decline might be mediated by depression.