ASSOCIATIONS OF AGE, BODY MASS INDEX, AND BIOCHEMICAL PARAMETERS WITH BRAIN MORPHOLOGY IN PATIENTS WITH ANOREXIA NERVOSA

INTRODUCTION: Accumulating evidence shows that patients with anorexia nervosa (AN) have globally reduced brain mass, including lower cortical volume and thickness, which largely normalizes following weight restoration. The dynamic underlying mechanisms for these processes are unknown, and how age and severity of emaciation are associated with brain morphology in AN is poorly understood. We investigated associations of age, body mass index (BMI) and biochemical parameters with brain morphology in a large sample of patients in treatment. METHODS: We included 85 patients (94% female) aged 12-48 (mean = 23) years with clinical and quality controlled magnetic resonance imaging (MRI) data. T1-weighted MRI images, clinical characteristics, and biochemical parameters were retrospectively collected from hospital records. Brain morphology was measured using FreeSurfer, and associations were investigated using regression models and correlations. RESULTS: Controlling for BMI, age showed significant associations with brain morphology generally concordant with known typical brain developmental patterns. Controlling for age, BMI showed significant positive associations with cortical volume and thickness. There were no significant interaction effects between age and BMI. None of the biochemical parameters correlated significantly with brain morphology. DISCUSSION: Our findings suggest the presence of normal neurodevelopmental patterns in AN and highlight the value of considering age-related effects on brain morphology. Importantly, we showed that severity of emaciation is related to brain morphology reductions, underscoring the importance of weight restoration. More studies are needed to shed light on potential biochemical mechanisms associated with brain alterations in AN.