Economic Impact of Obesity

Parallel to rising obesity rates is an increase in costs associated with excess weight. Estimates of future direct (medical) and indirect (nonmedical) costs related to obesity suggest rising expenditures that will impose a significant economic burden to individuals and society as a whole. This article reviews research on direct and indirect medical costs and future economic trends associated with obesity and associated comorbidities. Cost disparities associated with subsets of the population experiencing higher than average rates of obesity are explored. Finally, potential solutions with the highest estimated impact are offered, and future directions are proposed.

Comparison of overweight and obese military-dependent and civilian adolescent girls with loss-of-control eating

OBJECTIVE

Limited data suggest that the children of U.S. service members may be at increased risk for disordered-eating. To date, no study has directly compared adolescent military-dependents to their civilian peers along measures of eating pathology and associated correlates. We, therefore, compared overweight and obese adolescent female military-dependents to their civilian counterparts along measures of eating-related pathology and psychosocial functioning.

METHOD

Adolescent females with a BMI between the 85th and 97th percentiles and who reported loss-of-control eating completed interview and questionnaire assessments of eating-related and general psychopathology.

RESULTS

Twenty-three military-dependents and 105 civilians participated. Controlling for age, race, and BMI-z, military-dependents reported significantly more binge episodes per month (p < 0.01), as well as greater eating-concern, shape-concern, and weight-concern (p's < 0.01) than civilians. Military-dependents also reported more severe depression (p < 0.05).

DISCUSSION

Adolescent female military-dependents may be particularly vulnerable to disordered-eating compared with civilian peers. This potential vulnerability should be considered when assessing military-dependents.

Shared genetic variance between obesity and white matter integrity in Mexican Americans

Obesity is a chronic metabolic disorder that may also lead to reduced white matter integrity, potentially due to shared genetic risk factors. Genetic correlation analyses were conducted in a large cohort of Mexican American families in San Antonio (N = 761, 58% females, ages 18–81 years; 41.3 ± 14.5) from the Genetics of Brain Structure and Function Study. Shared genetic variance was calculated between measures of adiposity [(body mass index (BMI; kg/m²) and waist circumference (WC; in)] and whole-brain and regional measurements of cerebral white matter integrity (fractional anisotropy). Whole-brain average and regional fractional anisotropy values for 10 major white matter tracts were calculated from high angular resolution diffusion tensor imaging data (DTI; 1.7 × 1.7 × 3 mm; 55 directions). Additive genetic factors explained intersubject variance in BMI (heritability, h² = 0.58), WC (h² = 0.57), and FA (h² = 0.49). FA shared significant portions of genetic variance with BMI in the genu (ρG = −0.25), body (ρG = −0.30), and splenium (ρG = −0.26) of the corpus callosum, internal capsule (ρG = −0.29), and thalamic radiation (ρG = −0.31) (all p's = 0.043). The strongest evidence of shared variance was between BMI/WC and FA in the superior fronto-occipital fasciculus (ρG = −0.39, p = 0.020; ρG = −0.39, p = 0.030), which highlights region-specific variation in neural correlates of obesity. This may suggest that increase in obesity and reduced white matter integrity share common genetic risk factors.

Preventing Obesity in the Military Community (POMC): the development of a clinical trials research network

Obesity impacts the U.S. military by affecting the health and readiness of active duty service members and their families. Preventing Obesity in Military Communities (POMC) is a comprehensive research program within Patient Centered Medical Homes (PCMHs) in three Military Training Facilities. This paper describes three pilot randomized controlled trials that target critical high risk periods for unhealthy weight gain from birth to young adulthood: (1) pregnancy and early infancy (POMC-Mother-Baby), (2) adolescence (POMC-Adolescent), and (3) the first tour of duty after boot camp (POMC-Early Career). Each study employs a two-group randomized treatment or prevention program with follow up. POMC offers a unique opportunity to bring together research and clinical expertise in obesity prevention to develop state-of-the-art programs within PCMHs in Military Training Facilities. This research builds on existing infrastructure that is expected to have immediate clinical benefits to DoD and far-reaching potential for ongoing collaborative work. POMC may offer an economical approach for widespread obesity prevention, from conception to young adulthood, in the U.S. military as well as in civilian communities.

Reproducibility of phase rotation STEAM at 3T: focus on glutathione

PURPOSE

The purpose of this study was to determine the reproducibility of a very short echo time (TE) phase rotation stimulated echo acquisition mode (STEAM) sequence at 3T with a focus on the detection of glutathione.

METHODS

Ten healthy subjects were scanned on two separate visits. Spectra were acquired from voxels placed in the anterior and posterior cingulates. Reproducibility was assessed using mean coefficients of variation (CVs) and mean absolute differences (ADs), and reliability was assessed using standard error of measurement (SEM) and intraclass correlations (ICCs). Phantoms containing glutathione and metabolites with overlapping resonances were scanned to test the validity of glutathione quantification.

RESULTS

Excellent reproducibility as illustrated by CVs ≤8.3% and ADs ≤11.6% for both regions was obtained for glutathione and other commonly reported metabolites. Reproducibility measures for γ-aminobutyric acid and glutamine were good overall with CVs ranging from 6.4%-10.5% and ADs ranging from 8.6%-15.5% for both regions. Glutathione absolute and relative reliability were very good (SEMs ≤9.9%) and fair (ICCs = 0.42-0.51), respectively. Phantom studies demonstrated the ability to accurately detect glutathione from other metabolites with overlapping resonances with great precision (R(2)  = 0.99).

CONCLUSION

A very short TE phase rotation STEAM sequence proved reproducible for metabolites difficult to quantify but important for the study of psychiatric and neurological illness.

Spatial memory deficits in a virtual reality eight-arm radial maze in schizophrenia

Learning and memory impairments are present in schizophrenia (SZ) throughout the illness course and predict psychosocial function. Abnormalities in prefrontal and hippocampal function are thought to contribute to SZ deficits. The radial arm maze (RAM) is a test of spatial learning and memory in rodents that relies on intact prefrontal and hippocampal function. The goal of the present study was to investigate spatial learning in SZ using a virtual RAM. Thirty-three subjects with SZ and thirty-nine healthy controls (HC) performed ten trials of a virtual RAM task. Subjects attempted to learn to retrieve four rewards each located in separate arms. As expected, subjects with SZ used more time and traveled more distance to retrieve rewards, made more reference (RM) and working memory (WM) errors, and retrieved fewer rewards than HC. It is important to note that the SZ group did learn but did not reach the level of HC. Whereas RM errors decreased across trials in the SZ group, WM errors did not. There were no significant relationships between psychiatric symptom severity and maze performance. To our knowledge, use of a virtual 8-arm radial maze task in SZ to assess spatial learning is novel. Impaired virtual RAM performance in SZ is consistent with studies that examined RAM performance in animal models of SZ. Results provide further support for compromised prefrontal and hippocampal function underlying WM and RM deficits in SZ. The virtual RAM task could help bridge preclinical and clinical research for testing novel drug treatments of SZ.

Neural changes associated with relational learning in schizophrenia

Relational learning, which is learning the relationship among items, is impaired in schizophrenia but can be improved with training. This study investigated neural changes with functional magnetic resonance imaging before and after training on a relational learning task in schizophrenia and healthy control subjects. Despite their acquiring similar relational learning performance, the groups exhibited different neural activation patterns before and following training. Controls engaged regions within the relational learning network that included frontal, parietal, and medial temporal lobe, before and following training. Controls also exhibited activation reductions in region and spatial extent with relational learning proficiency, a commonly observed phenomenon in successful learning. In contrast, subjects with schizophrenia displayed no positive activations compared with the control condition before training. After training, subjects with schizophrenia displayed bilateral inferior parietal region activation as predicted. Contrary to hypothesis, hippocampal activation was not observed following training in schizophrenia. These findings suggest that the parietal lobe may be receptive to cognitive training interventions and that successful relational learning may be achieved in schizophrenia through the use of alternative extrahippocampal brain regions.

White matter alterations in deficit schizophrenia

Schizophrenia can be classified into two separate syndromes: deficit and nondeficit. Primary, enduring negative symptoms are used to define the deficit form of the illness, which is believed to have a unique neurobiological substrate. Previous research suggests that an aberrant prefrontal-thalamic-parietal network underlies deficit schizophrenia. In this study we conducted diffusion tensor imaging (DTI) fiber tracking to assess the integrity of the superior longitudinal fasciculus (SLF), the major white matter tract that connects prefrontal and parietal cortical regions, in deficit and nondeficit people with schizophrenia. We also used proton magnetic resonance spectroscopy (1H-MRS) to assess neurochemistry in the left middle prefrontal and left inferior parietal cortical regions. A total of 20 subjects with schizophrenia (10 deficit and 10 nondeficit) and 11 healthy subjects participated in this study. Results revealed reduced fractional anisotropy (FA), an index of white matter integrity, in the right hemisphere SLF and frontal white matter in the deficit subjects. There were no differences in MRS metabolite concentrations among groups. To our knowledge, this is the first DTI study to show compromised integrity of the major white matter tract that connects frontal and parietal regions in deficit schizophrenia. These findings provide further support for altered frontal-parietal network in deficit schizophrenia.