Brain structure predicts risk for obesity

Abstract

The neurobiology of obesity is poorly understood. Here we report findings of a study designed to examine the differences in brain regional gray matter volume in adults recruited as either Obese Prone or Obese Resistant based on self-identification, body mass index, and personal/family weight history. Magnetic resonance imaging was performed in 28 Obese Prone (14 male, 14 female) and 25 Obese Resistant (13 male, 12 female) healthy adults. Voxel-based morphometry was used to identify gray matter volume differences between groups. Gray matter volume was found to be lower in the insula, medial orbitofrontal cortex and cerebellum in Obese Prone, as compared to Obese Resistant individuals. Adjusting for body fat mass did not impact these results. Insula gray matter volume was negatively correlated with leptin concentration and measures of hunger. These findings suggest that individuals at risk for weight gain have structural differences in brain regions known to be important in energy intake regulation, and that these differences, particularly in the insula, may be related to leptin.

Does the brain shrink as the waist expands?

“…These findings parallel the mixed results noted between obesity and learning and memory (Liang et al, 2013). Similarly, only 3 of 7 reports examining the insula showed an association between more atrophy and either higher BMI or more fat mass (Pannacciulli et al, 2006; Smucny et al, 2012; Weise et al, 2013). …”

“…Fifteen studies have examined the association of global or regional brain volumes and adiposity in participants less than 40 years of age (Pannacciulli et al, 2006; Haltia et al, 2007; Miller et al, 2007; Miller et al, 2009; Maayan et al, 2011; Ogura et al, 2011; Brain Development Cooperative Group, 2012; Maudsley et al, 2012; Mueller et al, 2012; Smucny et al, 2012; Ursache et al, 2012; Yokum et al, 2012; Alosco et al, 2013; Melka et al, 2013; Weise et al, 2013). Thirteen of these 15 studies used BMI as a continuous variable or BMI groups, while one study used a quantitative index of fat mass and non-fat mass (Weise et al, 2013).…”

“…Five of 11 studies examining frontal lobes (Pannacciulli et al, 2006; Ogura et al, 2011; Smucny et al, 2012; Alosco et al, 2013; Weise et al, 2013) noted an association between higher BMI and lower GM, also suggesting mixed results. Interestingly, 6 of 9 reports specifically assessing PFC (Pannacciulli et al, 2006; Maayan et al, 2011; Ogura et al, 2011; Smucny et al, 2012; Ursache et al, 2012; Weise et al, 2013) found that higher BMI or fat mass predicted less GM volume.…”

“…Interestingly, 6 of 9 reports specifically assessing PFC (Pannacciulli et al, 2006; Maayan et al, 2011; Ogura et al, 2011; Smucny et al, 2012; Ursache et al, 2012; Weise et al, 2013) found that higher BMI or fat mass predicted less GM volume. Furthermore, Maayan and colleagues (2011), found that obese participants performed markedly worse than lean controls on executive tasks, particularly on a Stroop task, and linked lower frontal volumes with worse executive performance.…”

Propensity to Obesity Impacts the Neuronal Response to Energy Imbalance

“…As we have previously described, subjects were recruited to have a propensity to be resistant to weight gain and obesity (OR) or to be prone to weight gain and obesity (OP) (Schmidt et al, 2012, 2013; Smucny et al, 2012; Cornier et al, 2013; Thomas et al, 2013, 2014). Subjects were 25–40 years of age and were free of significant medical and psychiatric disease, including eating disorders as assessed by screening medical history, physical examination, biochemical testing, and questionnaires [eating attitudes test (Garner et al, 1982) and the Center for Epidemiologic Studies Depression Scale (Radloff, 1977)].…”