Harvard Medical School
Kotler EB*, Haidar A, Petterway F, Carrington H, Chen Y, Becker K, Plessow F, Thomas JJ, Misra M, Eddy KT, Lawson EA, Holson LM, Breithaupt L*, Lyall AE*
Amanda Lyall, Lauren Briethaupt
Anorexia nervosa (AN) is a low-weight eating disorder (ED) characterized by severe emaciation (BMI<18.5 kg/m^2). Atypical anorexia (At-AN) is similar to AN in terms of psychological diagnostic criteria and behavioral symptomology but differs in that the individual’s BMI is not below 18.5 kg/m^2. Magnetic resonance imaging research has shown that individuals diagnosed with AN have significantly decreased gray matter in the brain when compared to controls.
A common feature of ED is excessive exercise to offset caloric intake. In a nonclinical population, exercise is associated with increased cortical thickness. Yet, few studies have investigated the relationship between exercise and gray matter in individuals with ED.
This study investigates whether there are changes in gray matter measures in females with an ED who exercise compared to healthy controls who exercise. Imaging data were acquired from 57 females with an ED and 32 healthy control females. Cortical thickness, gray matter volume, and surface area were extracted for all participants. For all groups, average weekly hours of vigorous exercise were examined. For AN/at-AN only, average days of driven exercise were also assessed. Group means of gray matter morphometry were compared and controlled for multiple comparisons. The relationship between exercise and gray matter was evaluated using Pearson correlation. The AN and At-AN groups had significantly lower gray matter volumes compared to healthy controls, and no differences were found between the AN and At-AN groups.
Gray matter morphometry was not significantly related to vigorous exercise in the AN, At-AN, or HC group, nor was it related to average days of driven exercise in the AN or At-AN group. Ultimately, no relationships can be drawn from our analyses. This relationship can be further explored using self-report questionnaires that more accurately quantify exercise activity or administering fitness watches.