Elana Kotler

Pronouns

Rank

Research Staff

Institution

Harvard Medical School

Department

Psychiatry

Authors

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*

Principal Investigator

Amanda Lyall, Lauren Briethaupt

Categories:

Examining the Relationship Between Exercise and Gray Matter Morphometry in Females with Eating Disorders

Abstract

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.

Research Context

Eating disorders, like Anorexia Nervosa, are known to affect women at a significantly higher rate than men. Although the behavioral manifestations of this illness have been widely studied, there is a need for more impactful research investigating the relationship between eating disorders and the brain. Understanding the influence of malnutrition on female neurobiology, especially when it is still developing, is imperative. Since exercise is often a pathologic symptom of eating disorders like anorexia, its effects on a brain that is already malnourished should be explored. The purpose of this analysis is to gain insight into that relationship with an exclusive focus on changes to gray matter. When it comes to the female population, specifically those who are of adolescent and young adult age, considering these relationships can yield important results to consider for both diagnosis and treatment.