Depressive symptoms in older people with metabolic syndrome: is there a relationship with inflammation?

To investigate if there is a higher prevalence of depressive symptoms in older people with metabolic syndrome (MetS) compared with those without and whether dedpressive symptoms are independently associated to MetS and its single components and to the inflammatory markers.

Physical parameters, standard blood analytes, high sensitivity C-reactive protein (hsCRP) and erythrocyte sedimentation rate (ESR) were assessed. Fifteen-item Geriatric Depression Scale and mini mental state examination (MMSE) were administered.

One hundred thirty-three subjects were enrolled. MetS patients (57) exhibited higher prevalence of depressive symptoms (p < 0.0001), worse cognitive function (p < 0.0001), and higher levels of ESR and hsCRP were higher (p < 0.0001). The univariate analysis showed a linear strong correlation of depressive symptoms (p < 0.0001) with the MMSE score (r = -0.422), body mass index (r = 0.414), MetS (r = 0.582), number of MetS components (r = 0.663), fasting blood glucose (r = 0.565), ESR (r = 0.565), hsCRP (r = 0.745), central obesity (r = 0.269; p = 0.002), and high-density lipoprotein cholesterol (r = -0.241; p = 0.005). However, the multivariate analysis showed that only age (B = -0.093; p = 0.032), MetS (B = 1.446; p = 0.025), fasting blood glucose (B = 0.039; p = 0.005), and hsCRP (B = 7.649; p < 0.0001) were independently associated with depressive symptoms.

MetS and inflammation are independently associated with depressive symptoms in older people. Inflammation may explain cognitive decline too. Further investigations are needed to better understand the direction of these associations and to determine whether these can be reversible.