Neurological Effects of Repeated Blast Exposure in Special Operations Personnel

Exposure to blast overpressure has been a pervasive feature of combat-related injuries. Studies exploring the neurological correlates of repeated low-level blast exposure in career "breachers" demonstrated higher levels of tumor necrosis factor alpha (TNFα) and interleukin (IL)-6 and decreases in IL-10 within brain-derived extracellular vesicles (BDEVs). The current pilot study was initiated in partnership with the U.S. Special Operations Command (USSOCOM) to explore whether neuroinflammation is seen within special operators with prior blast exposure. Data were analyzed from 18 service members (SMs), inclusive of 9 blast-exposed special operators with an extensive career history of repeated blast exposures and 9 controls matched by age and duration of service. Neuroinflammation was assessed utilizing positron emission tomography (PET) imaging with [18F]DPA-714. Serum was acquired to assess inflammatory biomarkers within whole serum and BDEVs. The Blast Exposure Threshold Survey (BETS) was acquired to determine blast history. Both self-report and neurocognitive measures were acquired to assess cognition. Similarity-driven Multi-view Linear Reconstruction (SiMLR) was used for joint analysis of acquired data. Analysis of BDEVs indicated significant positive associations with a generalized blast exposure value (GBEV) derived from the BETS. SiMLR-based analyses of neuroimaging demonstrated exposure-related relationships between GBEV, PET-neuroinflammation, cortical thickness, and volume loss within special operators. Affected brain networks included regions associated with memory retrieval and executive functioning, as well as visual and heteromodal processing. Post hoc assessments of cognitive measures failed to demonstrate significant associations with GBEV. This emerging evidence suggests neuroinflammation may be a key feature of the brain response to blast exposure over a career in operational personnel. The common thread of neuroinflammation observed in blast-exposed populations requires further study.

Counselor Efficiency at Providing Feedback in a Technology-Based Behavioral Weight Loss Intervention: Longitudinal Analysis

BACKGROUND

Feedback for participants' self-monitoring is a crucial and costly component of technology-based weight loss interventions. Detailed examination of interventionist time when reviewing and providing feedback for online self-monitoring data is lacking.

OBJECTIVE

The aim of this study was to longitudinally examine the time counselors spent providing feedback on participant self-monitoring data (ie, diet, physical activity, weight) in a 12-month technology-based weight loss intervention. We hypothesized that counselors would compose feedback for participants more quickly over time.

METHODS

The time the lay counselors (N=10) spent reviewing self-monitoring records and providing feedback to participants via email was longitudinally examined for all counselors across the three years of study implementation. Descriptives were observed for counselor feedback duration across counselors by 12 annual quarters (ie, 3-month periods). Differences in overall duration times by each consecutive annual quarter were analyzed using Wilcoxon-Mann-Whitney tests.

RESULTS

There was a decrease in counselor feedback duration from the first to second quarter (mean 53 to 46 minutes; P<.001), and from the second to third (mean 46 to 30 minutes; P<.001). A trend suggested a decrease from the third to fourth quarter (mean 30 to 26 minutes; P=.053), but no changes were found in subsequent quarters. Consistent with the hypothesis, counselors may be increasing their efficiency in providing feedback; across 12 months, counselors spent less time reviewing participant self-monitoring and composing feedback (decreasing from mean 53 to 26 minutes).

CONCLUSIONS

Counselors used increasingly less time to review online self-monitoring data and compose feedback after the initial 9 months of study implementation. Results inform counselor costs for future technology-based behavioral weight loss interventions. For example, regardless of increasing counselor efficiency, 25-30 minutes per feedback message is a high cost for interventions. One possibility for reducing costs would be generating computer-automated feedback.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02063178; https://clinicaltrials.gov/ct2/show/NCT02063178.

Weight Loss Intervention Impact on the Physical Fitness Test Scores of Air Force Service Members

INTRODUCTION

Overweight and obesity are a major public health concern in the United States, including among active duty military personnel. Approximately 51% of active duty personnel are classified as overweight and 15% are classified as obese. This may impact military readiness. The current study aimed to determine if a weight loss intervention impacted fitness test scores among Air Force personnel.

MATERIALS AND METHODS

From 2014 to 2016, 204 Air Force members with overweight/obesity were randomized into either a Self-paced or counselor-initiated arm in a weight loss program. Study procedures were approved by the Institutional Review Board of the 59th Medical Wing in San Antonio and were acknowledged by the Institutional Review Board at the University of Tennessee Health Science Center. Fitness test scores from before, during, and after the intervention were used to determine if the intervention resulted in improvements in overall fitness test ratings and scores on individual components of the test.

RESULTS

Participants who lost at least 5% of their weight had better fitness ratings during the intervention compared to individuals who did not lose 5%. However, in the overall sample, fitness ratings worsened from preintervention to during the intervention, and from during to postintervention. Participants with overweight had better aerobic scores pre- and postintervention as well as better abdominal circumference scores and better fitness test ratings preintervention, during the intervention and postintervention compared to participants with obesity.

CONCLUSIONS

Behavioral weight management interventions that achieve 5% weight loss may help improve military fitness test ratings.

Dissemination of the Look AHEAD Intensive Lifestyle Intervention in the United States Military: A Randomized Controlled Trial

OBJECTIVE

The purpose of this study, "Fit Blue," was to compare a translation of the Look AHEAD (Action for Heath in Diabetes) intensive lifestyle intervention with a self-paced version of the same intervention among active duty military personnel.

METHODS

Active duty military personnel (N = 248; 49% male, 34% racial minority) with overweight or obesity were randomized to 12-month distance-based (i.e., phone and email) parallel programs, counselor-initiated (CI) condition or self-paced (SP) condition, from 2014 to 2016. Trained lay interventionists were retired military personnel or had extensive familiarity with the military.

RESULTS

The CI condition had greater weight loss at 4 months (CI: mean ± SD = -3.2 ± 3.4 kg; SP: -0.6 ± 2.9 kg; P < 0.0001) and at 12 months (CI: mean ± SD = -1.9 ± 4.1 kg; SP: -0.1 ± 3.8 kg; P < 0.001). Participants in the CI condition also had a greater percent weight loss at both 4 months (CI: 3.5% ± 3.8, SP: 0.6% ± 3.1; P < 0.0001) and 12 months (CI: 2.1% ± 4.7, SP: 0.0% ± 4.0; P < 0.001). In addition, a greater proportion of CI participants lost 5% or more at 4 months (CI: 29.8%, SP: 10.5%; P < 0.001) and at 12 months (CI: 29.5%, SP: 15.6%; P < 0.05).

CONCLUSIONS

The CI behavioral weight loss intervention translated from Look AHEAD was well received and is a promising approach for managing weight in an active duty military population.