Brain Connectivity Changes During Short-Term Weight Restoration in Anorexia Nervosa

Researchers analyzed resting-state functional connectivity in young female patients with anorexia nervosa (n=117) and healthy controls (n=117), using network-based statistics and graph-theory measures. They also examined associations with plasma leptin, a marker linked to nutritional status. A subset of 73 patients underwent repeat assessment after inpatient short-term weight restoration; mean BMI increased by 28.0%.

Underweight patients had increased connectivity in cingulo-occipito-cerebellar circuitry compared with controls (p=.0018). This connectivity decreased during weight restoration (p<.001), and the change was negatively associated with plasma leptin (p=.042). Leptin partially mediated the association between BMI increase and connectivity decrease (p=.039). Patients also had higher characteristic path length and assortativity. Path length decreased during restoration (p=.004), while assortativity appeared not to change.

The findings provide longitudinal evidence that some functional-connectome differences may partially normalize during short-term weight restoration. The proposed relationship with leptin is tentative, and the study does not establish that leptin causes the connectivity changes or that these imaging findings should alter clinical care. The authors suggest that persistent assortativity could reflect vulnerability, but this remains speculative.