RT Journal Article SR Electronic T1 Relationship between combat-related traumatic injury and ultrashort term heart rate variability in a UK military cohort: findings from the ADVANCE study JF BMJ Military Health JO BMJ Mil Health FD British Medical Journal Publishing Group SP e002316 DO 10.1136/military-2022-002316 A1 Maqsood, Rabeea A1 Schofield, S A1 Bennett, A N A1 Bull, A MJ A1 Fear, N T A1 Cullinan, P A1 Khattab, A A1 Boos, C J A1 YR 2023 UL http://militaryhealth.bmj.com/content/early/2023/03/28/military-2022-002316.abstract AB Introduction Combat-related traumatic injury (CRTI) has been linked to an increased cardiovascular disease (CVD) risk. The long-term impact of CRTI on heart rate variability (HRV)—a robust CVD risk marker—has not been explored. This study investigated the relationship between CRTI, the mechanism of injury and injury severity on HRV.Methods This was an analysis of baseline data from the ArmeD SerVices TrAuma and RehabilitatioN OutComE (ADVANCE) prospective cohort study. The sample consisted of UK servicemen with CRTI sustained during deployment (Afghanistan, 2003–2014) and an uninjured comparison group who were frequency matched to the injured group based on age, rank, deployment period and role in theatre. Root mean square of successive differences (RMSSD) was measured as a measure of ultrashort term HRV via <16 s continuous recording of the femoral arterial pulse waveform signal (Vicorder). Other measures included injury severity (New Injury Severity Scores (NISS)) and injury mechanism.Results Overall, 862 participants aged 33.9±5.4 years were included, of whom 428 (49.6%) were injured and 434 (50.3%) were uninjured. The mean time from injury/deployment to assessment was 7.91±2.05 years. The median (IQR) NISS for those injured was 12 (6–27) with blast being the predominant injury mechanism (76.8%). The median (IQR) RMSSD was significantly lower in the injured versus the uninjured (39.47 ms (27.77–59.77) vs 46.22 ms (31.14–67.84), p<0.001). Using multiple linear regression (adjusting for age, rank, ethnicity and time from injury), geometric mean ratio (GMR) was reported. CRTI was associated with a 13% lower RMSSD versus the uninjured group (GMR 0.87, 95% CI 0.80–0.94, p<0.001). A higher injury severity (NISS ≥25) (GMR 0.78, 95% CI 0.69–0.89, p<0.001) and blast injury (GMR 0.86, 95% CI 0.79–0.93, p<0.001) were also independently associated with lower RMSSD.Conclusion These results suggest an inverse association between CRTI, higher severity and blast injury with HRV. Longitudinal studies and examination of potential mediating factors in this CRTI-HRV relationship are needed.Data may be obtained from a third party and are not publicly available. Only the authorised authors (RM, CJB, ANB) had access to the data of this study. Given the sensitive nature of the participants, data have not been made widely available. Requests for data will be considered on a case-by-case basis and subject to the UK Ministry of Defence clearance. More information can be found at: https://www.advancestudydmrc.org.uk/.