Association of markers of inflammation and intestinal permeability in suicidal patients with major mood disorders

Abstract

BackgroundPatients with major mood disorders are at high risk of suicidal behavior compared to the general population. Suicide is a public health concern, accounting for around 1.2% of deaths worldwide. Understanding its underlying mechanisms may help identify predictive biomarkers and design novel targeted treatments. Immune dysfunctions, in particular affecting the gut-brain axis, are of interest given their dual involvement in mood disorders and suicidal behavior. We thus explored the possible relationships between suicide attempt (SA) and circulating biomarkers of intestinal permeability and systemic inflammation in patients with major depressive disorder (MDD) or bipolar disorder (BD) with and without a history of SA. Method137 patients with BD and 168 with MDD were included, and among them, 133 had a history of SA and 172 did not. Among them, 104 were males (34%) and 201 females (66%). Depressive symptoms were evaluated using the Inventory of Depressive Symptomatology clinical scale (IDS-C30). Circulating levels of intestinal fatty acid binding protein (IFABP), calprotectin, apolipoprotein E (ApoE), lipopolysaccharides binding protein (LBP), lipopolysaccharides (LPS), soluble beta-2-microglobulin (B2m), and C-reactive protein (CRP), were determined. Multivariate linear regressions were performed according to the gender status given the proportion of the herein studied male and female individuals and the higher propensity of females to experience SA as compared to males. ResultsAfter adjusting for confounding variables, patients in the SA group had significantly higher CRP, and lower IFABP levels in comparison to the NSA group. LimitationsThe unavailability of confounding variables such as dietary habits, should be noted. In addition, the cross-sectional nature of the study hampers the identification of causative effects. ConclusionAlthough preliminary, our observations revealed associations between markers of inflammation and intestinal permeability in patients with suicidal behavior warranting further confirmation in larger cohorts.