Systemic inflammation has been increasingly related to bipolar disorder -BD- (Tanaka et al. Neurosci Res 2017;115 59-63). Intestinal bacterial translocation has been postulated as one of the causes of this inflammation (Nguyen et al. J Psychiatr Res 2018;99 50-61). A possible pathway is through the lipopolysaccharide, which is presented to CD14 through lipopolysaccharide binding protein (LBP) leading to a release of systemic inflammatory markers like C-reactive protein (CPR) (Funda et al. Infect Immun 2001;69 3772-81).

1) Describe gut permeability in patients with BD through the determination of intestinal inflammatory markers (LBP, sCD14) in plasma; 2) Analyze variables associated with intestinal inflammation.

Cross-sectional study of 38 patients with BD [mean age=45.50 (SD=10.93; range 23-68); males=15 (39.5%)], recruited from mental health outpatient clinics in Oviedo (Spain).

Assessment: Pro-inflammation biomarkers [CRP (mg/dL), Erythrocyte Sedimentation Rate (ESR) (mm/h), Neutrophil/Lymphocyte, Monocyte/Lymphocyte, Platelet/Lymphocyte and Systemic Immune Inflammation Indexes]. Indirect markers of intestinal bacterial translocation [LBP, soluble CD14 (sCD14)]. Dichotomous variables were created for LBP, considering LBP ≥15 μg/dL as increased gut permeability; and for CPR, considering CRP≥0.3 as systemic inflammation. Metabolic syndrome [ATPIII criteria: glucose, HDL, triglycerides (mg/dl), arterial pressure (mmHg), abdominal circumference (cm)], body mass index (BMI) (kg/m2), smoking, cannabis or alcohol use.

Statistical analyses: t-Student test, multiple linear regression analyses.

Average LBP was 14.60 μg/dL (SD=6.4) and 15 patients (39.5%) had increased gut permeability. Moreover, average CPR was 0.40 mg/dL (SD=0.58) and 16 patients (47.1%) showed systemic inflammation. There were no patients with increased levels of sCD14.

Associations were found between LBP and CPR (r=0.357; p=0.032), cannabis use in the last month (t=-2.293; p=0.029), BMI (r=0.433; p=0.008) and abdominal obesity (t=3.006; p=0.005); but no with age or sex.

Subsequently, a multiple linear regression model for LBP was calculated with variables previously mentioned, and age (based on expert criteria). The overall regression was statistically significant (R2=0.49, F=9.273, p<0.001). It was found that CPR, abdominal obesity, and cannabis use in the last month significantly predicted LBP levels (table 1).Table 1.Multiple linear regression analyses to LBP

More than one third of patients with BD had increased gut permeability. Almost 50% had systemic inflammation. Intestinal permeability was directly related to abdominal obesity and systemic inflammation, but inversely related to cannabis use.

None Declared