Obesity and dieting associated with opposite changes in white matter expansion in humans
Document Actions
BMI is inversely associated with grey matter density in some basal brain regions in obese subjects, and these changes represent either a marker, a consequence and/or a predisposing factor to whole body fat accretion. White matter expansion in obesity may also be involved in the neuropathogenesis of degenerative brain diseases. To examine the effects of weight gain and weight loss on brain grey and white matter structure, 16 lean and 30 obese healthy subjects underwent magnetic resonance imaging (MRI) during study part I. During part II, 16 obese subjects continued with a very-low-calorie diet for 6 weeks and underwent a second MRI. Voxel-based morphometry (VBM) was used to calculate regional white and grey matter volumes. Compared to lean subjects, obese subjects showed greater white matter volumes in several brain regions, with a positive correlation between white matter volume in basal brain structures and waist-to-hip ratio. This white matter expansion was partially reversed by dieting. By contrast, regional grey matter volumes did not differ significantly in the two study populations and were not affected by dieting. The precise mechanism of the detected white matter expansion remains unclear.
Abstract
