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. Method Data for the analyses were drawn from the Rotterdam Study, the Netherlands (n = 2940) and the Whitehall II study, UK (n = 4469). 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 two independent cohort studies suggest an association between cardiometabolic dysregulation and cognitive decline and that depressive symptoms tend to precede this decline.