Predicting Frontal Lobe H-MRS Metabolite Levels Using Obesity and Metabolic Markers in Individuals with Bipolar Disorder: A Meta-Analysis and Cross-Sectional Study

Abstract

Obesity and related metabolic disorders, such as metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM) impact the brain, particularly in the frontal lobe. Individuals with severe and persistent mental illness (SPMI), such as bipolar disorder (BD), are at greater risk for obesity. We conducted a meta-analysis of previous research testing associations between NAA (N-Acetylaspartate) and obesity. NAA was significantly and negatively associated with BMI (body-mass index) in the frontal lobe only (p = 0.00). Secondly, we ran several multiple regression models using age, sex, status, BMI, waist-to-hip ratio, cholesterols, triglycerides (TGC), glucose, and insulin measured in the frontal lobe. Participants were patients with BD (n = 110) or healthy controls (n = 78). BMI significantly predicted NAA (p = 0.042) and Cr (p = 0.032), and TGC also significantly predicted NAA (p < 0.002) and Cr (p = 0.008).