Lean mass index is positively associated with white matter volumes in several brain regions in children with overweight/obesity

Abstract

Summary Background The relationship of obesity with grey and white matter volumes has been examined in several studies, and the results are decidedly mixed. Objective To investigate the associations of body mass index (BMI), fat mass index (FMI) and lean mass index (LMI) with total and regional grey and white matter volumes. Methods This is a cross‐sectional study involving 100 children (60% boys) with overweight/obesity. T1‐weighted images were acquired using magnetic resonance imaging. Dual energy X‐ray absorptiometry was used to measure body composition. Separate hierarchical regression analyses were performed between predictor variables (BMI, FMI and LMI) and the total brain volumes including sex, years from peak height velocity and parental education as covariates. In addition, FMI was added as a covariate when LMI was the predictor and vice versa. Statistical analyses of imaging data were performed using three whole‐brain voxel‐wise multiple regression models and adjusted by the same covariates. Results LMI was positively associated with white matter in numerous regions and to a lower extent, with grey matter regions. Further, the relationship between LMI, and grey and white matter regions was independent of FMI levels. Conclusions LMI seems to be a positive predictor of regional white matter volumes in children with overweight/obesity.

Differences in Brain Volume between Metabolically Healthy and Unhealthy Overweight and Obese Children: The Role of Fitness

“…Of note, MUO had higher BMI than MHO in this study, which could explain a potential relationship of higher body size with larger brain volumes. However, the difference between groups was small (around 2 km/m 2 ) and BMI did not show associations with gray matter volume in this sample in a previous study [9]. Thus, its confounding effect in this study associations does not appear to be relevant.…”

“…In the last few years, an increased body of evidence has emerged on obesity-related comorbidities and metabolic alterations and their relationship with structural brain abnormalities in children and adolescents [9,[34][35][36]. For instance, Perlaki et al [36] showed that a higher degree of obesity was associated with greater volumes in the amygdala and accumbens, regions involved in the food rewards.…”

“…A recent meta-analysis highlights that obesity and body mass are related to significantly lower gray matter volume in brain areas underlying executive function [8]. Likewise, Gracia-Marco et al [9] investigated the associations of obesity with gray and white matter volumes, concluding that only lean mass index was positively associated with white matter volume and to a lower extent with gray matter volume in certain regions of the brain. However, there is a subset of the population, referred to as metabolically healthy overweight/obesity (abbreviated as MHO to refer to both overweight and obese children with a healthy metabolic profile), who do not have these metabolic abnormalities.…”

Associations of sleep with gray matter volume and their implications for academic achievement, executive function and intelligence in children with overweight/obesity

“…Children with overweight/obesity have been characterized as having poorer sleep behaviors, [25][26][27] and smaller GMV than children with a normal weight. [28][29][30] Furthermore, these children often engage in greater sedentary time (SED) and insufficient physical activity, 31 which may also be associated with poorer sleep behaviors. 32,33 SED and physical activity behaviors coexist with sleep in the 24-hour cycle.…”

The differential relationship of an afterschool physical activity intervention on brain function and cognition in children with obesity and their normal weight peers

“…Additionally, MRI evidence suggests that lean mass index (LMI) among children with overweight or OB is positively associated with regions overlapping white matter tracts, which are related to executive function and planning, emotion and conflict processing, visual processing, attention, memory, and motor function, independent of fat mass index or BMI 43. These data contribute to previously mixed findings in the field of OB with grey and white matter, such that LMI…”