Obesity and lower grey matter volumes in first episode of psychosis-Overlap with neurostructural alterations in bipolar disorders? (SY-18.3)

Abstrakt

AIMS: Many of the neurostructural alterations reported in bipolar disorders (BD) are also found in schizophrenia. This may reflect shared clinical factors, which are present across major psychoses. Obesity is disproportionately frequent in schizophrenia and BD and is associate with smaller brain volumes. Indeed, previous studies have demonstrated effects of obesity on GM volumes in BD. However, no studies have investigated the association between obesity and brain structure in schizophrenia. METHODS: We analyzed MRI scans from 120 patients with first episode psychosis (FEP) and 114 controls. In primary analyses, we performed voxel-based morphometry (VBM) with small volume corrections to regions associated with FEP or obesity in previous meta-analyses. In secondary analyses, we performed whole-brain VBM analyses. RESULTS: In primary analyses, we found association between FEP and lower GM volume in left fronto-temporal regions (pTFCE = 0.008). BMI was associated with lower GM volume in left cerebellum (pTFCE < 0.001). Secondary, whole brain analyses revealed association between FEP and lower GM in the a) cerebellum (pTFCE = 0.004), b) left frontal (pTFCE = 0.024) and c) right temporal cortex (pTFCE = 0.031), whereas BMI was associated with lower GM volume in cerebellum (pTFCE = 0.004). C-reactive protein levels correlated with obesity related neurostructural alterations. CONCLUSION: Higher BMI, which is frequent in FEP, may contribute to cerebellar alterations in schizophrenia, possibly through low grade systemic inflammation. Interestingly, we did not see effects of obesity in regions most frequently associated with BD. It remains to be tested, whether treatment of overweight/obesity and low grade systemic inflammation might improve or preserve brain structure in FEP.