Pain after combat injury in male UK military personnel deployed to Afghanistan.

BACKGROUND: Chronic pain after injury poses a serious health burden. As a result of advances in medical technology, ever more military personnel survive severe combat injuries, but long-term pain outcomes are unknown. We aimed to assess rates of pain in a representative sample of UK military personnel with and without combat injuries. METHODS: We used data from the ADVANCE cohort study (ISRCTN57285353). Individuals deployed as UK armed forces to Afghanistan were recruited to include those with physical combat injuries, and a frequency-matched uninjured comparison group. Participants completed self-reported questionnaires, including 'overall' pain intensity and self-assessment of post-traumatic stress disorder, anxiety, and depression. RESULTS: A total of 579 participants with combat injury, including 161 with amputations, and 565 uninjured participants were included in the analysis (median 8 yr since injury/deployment). Frequency of moderate or severe pain was 18% (n=202), and was higher in the injured group (n=140, 24%) compared with the uninjured group (n=62, 11%, relative risk: 1.1, 95% confidence interval [CI]: 1.0-1.2, P<0.001), and lower in the amputation injury subgroup (n=31, 19%) compared with the non-amputation injury subgroup (n=109, 26%, relative risk: 0.9, 95% CI: 0.9-1.0, P=0.034). Presence of at least moderate pain was associated with higher rates of post-traumatic stress (RR: 3.7, 95% CI: 2.7-5.0), anxiety (RR: 3.2, 95% CI: 2.4-4.3), and depression (RR: 3.4, 95% CI: 2.7-4.5) after accounting for injury. CONCLUSION: Combat injury, but not amputation, was associated with a higher frequency of moderate to severe pain intensity in this cohort, and pain was associated with adverse mental health outcomes.

Validity of Ultra-Short-Term Heart Rate Variability Derived from Femoral Arterial Pulse Waveform in a British Military Cohort.

Various non-electrocardiogram (ECG) based methods are considered reliable sources of heart rate variability (HRV) measurement. However, the ultra-short recording of a femoral arterial waveform has never been validated against the gold-standard ECG-based 300s HRV and was the aim of this study.A validity study was conducted using a sample from the first follow-up of the longitudinal ADVANCE study UK. The participants were adult servicemen (n = 100); similar in age, rank, and deployment period (Afghanistan 2003-2014). The femoral arterial waveforms (14s) from the pulse wave velocity (PWV) assessment, and ECG (300s) were recorded at rest in the supine position using the Vicorder™ and Bittium Faros™ devices, respectively, in the same session. HRV analysis was performed using Kubios Premium. Resting heart rate (HR) and root mean square of successive differences (RMSSD) were reported. The Bland-Altman %plots were constructed to explore the PWV-ECG agreement in HRV measurement. A further exploratory analysis was conducted across methods and durations.The participants' mean age was 38.0 ± 5.3 years. Both PWV-derived HR (r = 0.85) and RMSSD (rs=0.84) showed strong correlations with their 300s-ECG counterparts (p < 0.001). Mean HR was significantly higher with ECG than PWV (mean bias: -12.71 ± 7.73%, 95%CI: -14.25%, -11.18%). In contrast, the difference in RMSSD between the two methods was non-significant [mean bias: -2.90 ± 37.82% (95%CI: -10.40%, 4.60%)] indicating good agreement. An exploratory analysis of 14s ECG-vs-300s ECG measurement revealed strong agreement in both RMSSD and HR.The 14s PWV-derived RMSSD strongly agrees with the gold-standard (300s-ECG-based) RMSSD at rest. Conversely, HR appears method sensitive.

Post-traumatic growth amongst UK armed forces personnel who were deployed to Afghanistan and the role of combat injury, mental health and pain: the ADVANCE cohort study.

BACKGROUND: Post-traumatic growth (PTG) is a positive psychological consequence of trauma. The aims of this study were to investigate whether combat injury was associated with deployment-related PTG in a cohort of UK military personnel who were deployed to Afghanistan, and whether post-traumatic stress disorder (PTSD), depression and pain mediate this relationship. METHODS: 521 physically injured (n = 138 amputation; n = 383 non-amputation injury) and 514 frequency-matched uninjured personnel completed questionnaires including the deployment-related Post-Traumatic Growth Inventory (DPTGI). DPTGI scores were categorised into tertiles of: no/low (score 0-20), moderate (score 21-34) or a large (35-63) degree of deployment-related PTG. Analysis was completed using generalised structural equation modelling. RESULTS: A large degree of PTG was reported by 28.0% (n = 140) of the uninjured group, 36.9% (n = 196) of the overall injured group, 45.4% (n = 62) of amputee and 34.1% (n = 134) of the non-amputee injured subgroups. Combat injury had a direct effect on reporting a large degree of PTG [Relative risk ratio (RRR) 1.59 (95% confidence interval (CI) 1.17-2.17)] compared to sustaining no injury. Amputation injuries also had a significant direct effect [RRR 2.18 (95% CI 1.24-3.75)], but non-amputation injuries did not [RRR 1.35 (95% CI 0.92-1.93)]. PTSD, depression and pain partially mediate this relationship, though mediation differed depending on the injury subtype. PTSD had a curvilinear relationship with PTG, whilst depression had a negative association and pain had a positive association. CONCLUSIONS: Combat injury, in particular injury resulting in traumatic amputation, is associated with reporting a large degree of PTG.

Relationship between combat-related traumatic injury and its severity to predicted cardiovascular disease risk: ADVANCE cohort study.

BACKGROUND: This study investigated the relationship between combat-related traumatic injury (CRTI) and its severity and predicted cardiovascular disease (CVD) risk. MATERIAL AND METHODS: This was an analysis of comparative 10-year predicted CVD risk (myocardial infarction, stroke or CVD-death) using the QRISK®3 scoring-system among adults recruited into the Armed Services Trauma Rehabilitation Outcome (ADVANCE) cohort study. Participants with CRTI were compared to uninjured servicemen frequency-matched by age, sex, rank, deployment (Afghanistan 2003-2014) and role. Injury severity was quantified using the New Injury Severity Score (NISS). RESULTS: One thousand one hundred forty four adult combat veterans were recruited, consisting of 579 injured (161 amputees) and 565 uninjured men of similar age ethnicity and time from deployment/injury. Significant mental illness (8.5% vs 4.4%; p = 0.006) and erectile dysfunction (11.6% vs 5.8%; p < 0.001) was more common, body mass index (28.1 ± 3.9 vs 27.4 ± 3.4 kg/m2; p = 0.001) higher and systolic blood pressure variability (median [IQR]) (1.7 [1.2-3.0] vs 2.1 [1.2-3.5] mmHg; p = 0.008) lower among the injured versus uninjured respectively. The relative risk (RR) of predicted CVD (versus the population expected risk) was higher (RR:1.67 [IQR 1.16-2.48]) among the injured amputees versus the injured non-amputees (RR:1.60 [1.13-2.43]) and uninjured groups (RR:1.52 [1.12-2.34]; overall p = 0.015). After adjustment for confounders CRTI, worsening injury severity (higher NISS, blast and traumatic amputation) were independently associated with QRISK®3 scores. CONCLUSION: CRTI and its worsening severity were independently associated with increased predicted 10-year CVD risk.

Marching to the Beet: The effect of dietary nitrate supplementation on high altitude exercise performance and adaptation during a military trekking expedition.

PURPOSE: The aim was to investigate the effect of dietary nitrate supplementation (in the form of beetroot juice, BRJ) for 20 days on salivary nitrite (a potential precursor of bioactive nitric oxide), exercise performance and high altitude (HA) acclimatisation in field conditions (hypobaric hypoxia). METHODS: This was a single-blinded randomised control study of 22 healthy adult participants (12 men, 10 women, mean age 28 ± 12 years) across a HA military expedition. Participants were randomised pre-ascent to receive two 70 ml dose per day of either BRJ (~12.5 mmol nitrate per day; n = 11) or non-nitrate calorie matched control (n = 11). Participants ingested supplement doses daily, beginning 3 days prior to departure and continued until the highest sleeping altitude (4800 m) reached on day 17 of the expedition. Data were collected at baseline (44 m altitude), at 2350 m (day 9), 3400 m (day 12) and 4800 m (day 17). RESULTS: BRJ enhanced the salivary levels of nitrite (p = 0.007). There was a significant decrease in peripheral oxygen saturation and there were increases in heart rate, diastolic blood pressure, and rating of perceived exertion with increasing altitude (p=<0.001). Harvard Step Test fitness scores significantly declined at 4800 m in the control group (p = 0.003) compared with baseline. In contrast, there was no decline in fitness scores at 4800 m compared with baseline (p = 0.26) in the BRJ group. Heart rate recovery speed following exercise at 4800 m was significantly prolonged in the control group (p=<0.01) but was unchanged in the BRJ group (p = 0.61). BRJ did not affect the burden of HA illness (p = 1.00). CONCLUSIONS: BRJ increases salivary nitrite levels and ameliorates the decline in fitness at altitude but does not affect the occurrence of HA illness.

The relationship between ambulatory arterial stiffness, inflammation, blood pressure dipping and cardiovascular outcomes.

BACKGROUND: The ambulatory arterial stiffness index (AASI) is an indirect measure of arterial stiffness obtained during ambulatory blood pressuring monitoring (ABPM). Its relationship to nocturnal blood pressure dipping status and major adverse cardiovascular events (MACE) are controversial and its association with vascular inflammation has not been examined. We aimed to investigate the relationship between the AASI, inflammation and nocturnal blood pressure dipping status and its association with MACE. METHODS: Adults (aged 18-80 years) who underwent 24-h ABPM for the diagnosis of hypertension or its control were included. The inflammatory markers measured were the neutrophil-lymphocyte (NLR), platelet-lymphocyte (PLR) and monocyte-lymphocyte ratios (MLR). The primary MACE was a composite of cardiovascular death, acute limb ischaemia, stroke or transient ischaemic attack (TIA) or acute coronary syndrome. RESULTS: A total of 508 patients (51.2% female) aged 58.8 ± 14.0 years were included; 237 (46.7%) were normal-dippers (≥ 10% nocturnal systolic dip), 214 (42.1%) were non-dippers (0-10% dip) and 57 (11.2%) were reverse-dippers (< 0% dip). The AASI was significantly higher among reverse (0.56 ± 0.16) and non-dippers (0.48 ± 0.17) compared with normal dippers (0.39 ± 0.16; p < 0.0001) and correlated with the NLR (r = 0.20; 95% CI 0.11 to 0.29: < 0.0001) and systolic blood pressure dipping % (r = - 0.34; - 0.42 to - 0.26: p < 0.0001). Overall 39 (7.7%) patients had ≥ 1 MACE which included a total of seven cardiovascular deaths and 14 non-fatal strokes/TIAs. The mean follow up was 113.7 ± 64.0 weeks. Increasing NLR, but not AASI or systolic dipping, was independently linked to MACE (overall model Chi-square 60.67; p < 0.0001) and MLR to cardiovascular death or non-fatal stroke/TIA (overall model Chi-square 37.08; p < 0.0001). CONCLUSIONS: In conclusion AASI was associated with blood pressure dipping and chronic inflammation but not independently to MACE. The MLR and NLR were independent predictors of MACE.

Relationship between coronary microvascular dysfunction and left ventricular diastolic function in patients with chest pain and unobstructed coronary arteries.

BACKGROUD: Diastolic dysfunction (DD) is reported to affect up to 35% of the adult general population. The consequence of progressive DD is heart failure with preserved ejection fraction (HFpEF). Coronary microvascular dysfunction (CMD) has been suggested as one of the pathologic mechanisms leading to HFpEF. We investigated whether there was an association between coronary microvascular function and echocardiographic indices of left ventricular diastolic function at rest in patients with chest pain and unobstructed coronary arteries (CPUCA). METHODS: This retrospective observational study recruited patients referred to cardiology clinics assessment of chest pain who subsequently underwent assessment via CT coronary angiogram (CTA). Coronary microvascular dysfunction was determined by myocardial blood flow reserve (MBFR; <2.0) using myocardial contrast echocardiography. Echocardiographic indices of diastolic function (septal mitral annular e'; septal mitral annular E/e', E/A ratio) were measured from baseline transthoracic echocardiogram. RESULTS: 149 patients (52% men) with a mean age 59.7(9.5) years were recruited. Mean (standard deviation) MBFR was 2.2 (0.51). 37% (55/149) had MBFR < 2.0. Median [interquartile range] septal mitral annular e' velocity and septal mitral annular E/e' were 7.6 cm/s [6.2, 8.9] and 9.5 [7.5, 10.8], respectively. Univariate regression analysis showed only age was a significant predictor of increasing septal mitral annular E/e' (ß = +0.20 95% CI 0.13, +0.28, P < .001) but not MBFR. Multivariable analysis also showed no association between these septal mitral annular E/e' and MBFR after adjustment for cardiovascular risk factors. CONCLUSION: There was no relationship found between echocardiographic indices of left ventricular diastolic function and coronary microvascular function at rest.

The association between PTSD and cardiovascular disease and its risk factors in male veterans of the Iraq/Afghanistan conflicts: a systematic review.

Military personnel with Post-Traumatic Stress Disorder (PTSD) can experience high levels of mental and physical health comorbidity, potentially indicating a high level of functional impairment that can impact on both military readiness and later ill-health. There is strong evidence to implicate PTSD as a contributory factor to Cardiovascular Disease (CVD) among serving personnel and veterans. This systematic review focusses on the association between PTSD and cardiovascular disease/risk factors in male, military serving and ex-serving personnel who served in the Iraq/Afghanistan conflicts. PUBMED, MEDLINE, PILOTS, EMBASE, PSYCINFO, and PSYCARTICLES were searched using PRISMA guidelines. Three hundred and forty-three records were identified, of which 20 articles were selected. PTSD was positively associated with the development of CVD, specifically circulatory diseases, including hypertension. PTSD was also positively associated with the following risk factors: elevated heart rate, tobacco use, dyslipidaemia, and obesity. Conflicting data is presented regarding heart rate variability and inflammatory markers. Future studies would benefit from a standardized methodological approach to investigating PTSD and physical health manifestations. It is suggested that clinicians offer health advice for CVD at an earlier age for ex-/serving personnel with PTSD.

Smartphone-Enabled Heart Rate Variability and Acute Mountain Sickness.

INTRODUCTION: The autonomic system and sympathetic activation appears integral in the pathogenesis of acute mountain sickness (AMS) at high altitude (HA), yet a link between heart rate variability (HRV) and AMS has not been convincingly shown. In this study we investigated the utility of the smartphone-derived HRV score to predict and diagnose AMS at HA. METHODS: Twenty-one healthy adults were investigated at baseline at 1400 m and over 10 days during a trek to 5140 m. HRV was recorded using the ithlete HRV device. RESULTS: Acute mountain sickness occurred in 11 subjects (52.4%) at >2650 m. HRV inversely correlated with AMS Scores (r = -0.26; 95% CI, -0.38 to -0.13: P < 0.001). HRV significantly fell at 3700, 4100, and 5140 m versus low altitude. HRV scores were lower in those with both mild (69.7 ± 14.0) and severe AMS (67.1 ± 13.1) versus those without AMS (77.5 ± 13.1; effect size n = 0.043: P = 0.007). The HRV score was weakly predictive of severe AMS (AUC 0.74; 95% CI, 0.58-0.89: P = 0.006). The change (delta) in the HRV Score (compared with baseline at 1400 m) was a moderate diagnostic marker of severe AMS (AUC 0.80; 95% CI, 0.70-0.90; P = 0.0004). A fall in the HRV score of >5 had a sensitivity of 83% and specificity of 60% to identify severe AMS (likelihood ratio 1.9). Baseline HRV at 1400 m was not predictive of either AMS at higher altitudes. CONCLUSIONS: The ithlete HRV score can be used to help in the identification of severe AMS; however, a baseline score is not predictive of future AMS development at HA.

Changes in appetite, energy intake, body composition, and circulating ghrelin constituents during an incremental trekking ascent to high altitude.

PURPOSE: Circulating acylated ghrelin concentrations are associated with altitude-induced anorexia in laboratory environments, but have never been measured at terrestrial altitude. This study examined time course changes in appetite, energy intake, body composition, and ghrelin constituents during a high-altitude trek. METHODS: Twelve participants [age: 28(4) years, BMI 23.0(2.1) kg m-2] completed a 14-day trek in the Himalayas. Energy intake, appetite perceptions, body composition, and circulating acylated, des-acylated, and total ghrelin concentrations were assessed at baseline (113 m, 12 days prior to departure) and at three fixed research camps during the trek (3619 m, day 7; 4600 m, day 10; 5140 m, day 12). RESULTS: Relative to baseline, energy intake was lower at 3619 m (P = 0.038) and 5140 m (P = 0.016) and tended to be lower at 4600 m (P = 0.056). Appetite perceptions were lower at 5140 m (P = 0.027) compared with baseline. Acylated ghrelin concentrations were lower at 3619 m (P = 0.046) and 4600 m (P = 0.038), and tended to be lower at 5140 m (P = 0.070), compared with baseline. Des-acylated ghrelin concentrations did not significantly change during the trek (P = 0.177). Total ghrelin concentrations decreased from baseline to 4600 m (P = 0.045). Skinfold thickness was lower at all points during the trek compared with baseline (P ≤ 0.001) and calf girth decreased incrementally during the trek (P = 0.010). CONCLUSIONS: Changes in plasma acylated and total ghrelin concentrations may contribute to the suppression of appetite and energy intake at altitude, but differences in the time course of these responses suggest that additional factors are also involved. Interventions are required to maintain appetite and energy balance during trekking at terrestrial altitudes.

Markers of physiological stress during exercise under conditions of normoxia, normobaric hypoxia, hypobaric hypoxia, and genuine high altitude.

PURPOSE: To investigate whether there is a differential response at rest and following exercise to conditions of genuine high altitude (GHA), normobaric hypoxia (NH), hypobaric hypoxia (HH), and normobaric normoxia (NN). METHOD: Markers of sympathoadrenal and adrenocortical function [plasma normetanephrine (PNORMET), metanephrine (PMET), cortisol], myocardial injury [highly sensitive cardiac troponin T (hscTnT)], and function [N-terminal brain natriuretic peptide (NT-proBNP)] were evaluated at rest and with exercise under NN, at 3375 m in the Alps (GHA) and at equivalent simulated altitude under NH and HH. Participants cycled for 2 h [15-min warm-up, 105 min at 55% Wmax (maximal workload)] with venous blood samples taken prior (T0), immediately following (T120) and 2-h post-exercise (T240). RESULTS: Exercise in the three hypoxic environments produced a similar pattern of response with the only difference between environments being in relation to PNORMET. Exercise in NN only induced a rise in PNORMET and PMET. CONCLUSION: Biochemical markers that reflect sympathoadrenal, adrenocortical, and myocardial responses to physiological stress demonstrate significant differences in the response to exercise under conditions of normoxia versus hypoxia, while NH and HH appear to induce broadly similar responses to GHA and may, therefore, be reasonable surrogates.

Anticoagulation in atrial fibrillation and chronic heart failure: the risk and drug of choice.

PURPOSE OF REVIEW: This review seeks to provide an evidence-based update on the issue of atrial fibrillation and chronic heart failure with an emphasis on anticoagulation and the expanding use of the novel oral anticoagulants (NOACs). RECENT FINDINGS: There is an increasing appreciation of the important reciprocal relationship between atrial fibrillation and heart failure and the negative prognostic impact that each condition has on the other. There are now four NOACs approved for stroke prevention in atrial fibrillation. There are increasing data to support their use in atrial fibrillation with heart failure, including in patients with nonmechanical or rheumatic valvular disease, and to facilitate direct current cardioversion. The choice of NOAC is heavily dependent on individual patient characteristics. SUMMARY: The use of and indications for NOACs for patients with heart failure and atrial fibrillation are rapidly increasing.

Novel oral anticoagulants and stroke prevention in atrial fibrillation and chronic heart failure.

Heart failure (HF) and atrial fibrillation (AF) frequently coexist and share a reciprocal relationship. The presence of AF increases the propensity to HF and can worsen its severity as well as escalating the risk of stroke. Despite the proven efficacy of vitamin K antagonists and warfarin for stroke prevention in AF, their use is beset by numerous problems. These include their slow onset and offset of action, unpredictability of response, the need for frequent coagulant monitoring and serious concerns around the increased risks of intracranial and major bleeding. Three recently approved novel anticoagulants (dabigatran, rivaroxaban and apixaban) are already challenging warfarin use in AF. They have a predictable therapeutic response and a wide therapeutic range and do not necessitate coagulation monitoring. In this article, the relationship between HF and AF and the mechanisms for their compounded stroke risk are reviewed. The evidence to support the use of these three NOACs amongst patients with AF and HF is further explored.

Rating of perceived exertion and acute mountain sickness during a high-altitude trek.

BACKGROUND: There is a widely held belief that strenuous exercise should be avoided on arrival at high altitude (HA) and during acclimatization. Data from chamber studies are contradictory and the studies are usually of short duration, therefore differing from the "real world." METHODS: We studied 48 trekkers during a 10-d ascent to 16,827 ft (5129 m) in the Cordillera Real area of Bolivia. Borg Rating of Perceived Exertion (RPE) scores were recorded for the hardest perceived exertion during the day after ascents to 12,576, 14,600, and 16,827 ft (3833, 4450, and 5129 m). Heart rate, Spo2, and Lake Louise Score (LLS) were recorded simultaneously. Statistical testing was performed using SPSS 21 software. A P-value of ≤ 0.05 was deemed significant. RESULTS: Acute mountain sickness (AMS) rates were higher after trekking days with higher levels of perceived exertion. The LLS was higher in those with a Borg RPE score ≥ 15 both following exercise (mean LLS 2.6 vs. 1.7) and at rest the following day (mean LLS 2.7 vs. 1.7). Heart rate was higher in those with high Borg RPE scores (80 vs. 87) and oxygen saturations lower at rest (86 vs. 83) the following morning. DISCUSSION: This data lends weight to the advice of moderate exertion during a trek to HA and suggests that reducing perceived exertion may reduce AMS.

Ambulatory arterial stiffness index, mortality, and adverse cardiovascular outcomes; Systematic review and meta-analysis.

The ambulatory arterial stiffness index (AASI) is a novel measure of both blood pressure (BP) variability and arterial stiffness. This systematic review and meta-analysis was designed to evaluate the strength of the association between AASI and mortality and major adverse cardiovascular events (MACE). PubMed, Scopus, CINAHL, Google Scholar. and the Cochrane library were searched for relevant studies to July 31, 2023. Two investigators independently extracted data. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of all included articles. The relationship between baseline AASI and outcomes were examined using relative risk (RR) ratios with 95% confidence intervals (CI) with RevMan web. Thirteen studies were included and representing 28 855 adult patients who were followed up from 2.2 to 15.2 years. A 1-standard deviation (1-SD) increase in AASI was associated with a significant increase in all-cause death (RR 1.12; 95% CI: 0.95-1.32), stroke (RR 1.25; 95% CI: 1.09-1.44), and MACE (RR 1.07; 95% CI: 1.01-1.13; [I2  = 32%]). Higher dichotomized AASI (above vs. below researcher defined cut-offs) was associated with a significant increase in all-cause mortality (RR 1.19; 95% CI: 1.06-1.32), cardiovascular death (RR 1.29; 95% CI: 1.14-1.46), stroke (RR 1.57; 95% CI: 1.33-1.85), and MACE (RR1.29; 95% CI: 1.16-1.44). There was a significant risk of bias in more than 50% of studies with no evidence of significant publication bias. Higher AASI is associated with an increased risk of all-cause and cardiovascular death, stroke, and MACE. Further high-quality studies are warranted to determine reproducible AASI cut-offs to enhance its clinical risk precision.

Validity and reliability of outcome measures to assess dysfunctional breathing: a systematic review.

OBJECTIVE: This study aimed to systematically review the psychometric properties of outcome measures that assess dysfunctional breathing (DB) in adults. METHODS: Studies on developing and evaluating measurement properties to assess DB were included. The study investigated the empirical research published between 1990 and February 2022, with an updated search in May 2023 in the Cochrane Library database of systematic reviews and the Cochrane Central Register of Controlled Trials, the Ovid Medline (full), the Ovid Excerta Medica Database, the Ovid allied and complementary medicines database, the Ebscohost Cumulative Index to Nursing and Allied Health Literature and the Physiotherapy Evidence Database. The included studies' methodological quality was assessed using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) risk of bias checklist. Data analysis and synthesis followed the COSMIN methodology for reviews of outcome measurement instruments. RESULTS: Sixteen studies met the inclusion criteria, and 10 outcome measures were identified. The psychometric properties of these outcome measures were evaluated using COSMIN. The Nijmegen Questionnaire (NQ) is the only outcome measure with 'sufficient' ratings for content validity, internal consistency, reliability and construct validity. All other outcome measures did not report characteristics of content validity in the patients' group. DISCUSSION: The NQ showed high-quality evidence for validity and reliability in assessing DB. Our review suggests that using NQ to evaluate DB in people with bronchial asthma and hyperventilation syndrome is helpful. Further evaluation of the psychometric properties is needed for the remaining outcome measures before considering them for clinical use. PROSPERO REGISTRATION NUMBER: CRD42021274960.

The relationship between ambulatory arterial stiffness index and incident atrial fibrillation.

BACKGROUND: The ambulatory arterial stiffness index (AASI) is an indirect measure of blood pressure variability and arterial stiffness which are atrial fibrillation (AF) risk factors. The relationship between AASI and AF development has not been previously investigated and was the primary aim of this study. METHODS: This was an observational cohort study of adults (aged 18-85 years) in sinus rhythm, who underwent 24-h ambulatory blood pressure monitoring (ABPM) for the diagnosis of hypertension or its control. RESULTS: Eight hundred and twenty-one patients (49% men) aged 58.7 ± 15.3 years were followed up for a median of 4.0 years (3317 patient-years). In total, 75 patients (9.1%) developed ≥1 AF episode during follow-up. The mean AASI was 0.46 ± 0.17 (median 0.46). AASI values (0.52 ± 0.16 vs. 0.45 ± 0.17; p < .001) and the proportion of AASI values above the median (65.3% vs. 48.4%; p = .005) were greater among the patients who developed AF versus those that did not respectively. AASI significantly correlated with age (r = .49; 95% confidence interval: 0.44-0.54: p < .001). On Kaplan-Meier analysis, higher baseline AASI by median, tertiles, and quartiles were all significantly associated with AF development (X2: 10.13; p < .001). On Cox regression analyses, both a 1-standard deviation increase and AASI > median were independent predictors of AF, but this relationship was no longer significant when age was included in the model. CONCLUSIONS: AASI is an independent predictor of AF development. However, this relationship becomes insignificant after adjustment for age which is higher correlated with AASI.

The Influence of Physical and Mental Health Mediators on the Relationship Between Combat-Related Traumatic Injury and Ultra-Short-Term Heart Rate Variability in a U.K. Military Cohort: A Structural Equation Modeling Approach.

INTRODUCTION: Combat-related traumatic injury (CRTI) adversely affects heart rate variability (HRV). The mediating effect of mental and physical health factors on the relationship between CRTI, its severity and HRV has not been previously studied and investigated. MATERIALS AND METHODS: A cross-sectional mediation analysis of the ArmeD SerVices TrAuma and RehabilitatioN OutComE (ADVANCE) prospective cohort study was performed. The sample consisted of injured and uninjured British male servicemen who were frequency-matched based on their age, rank, role-in-theater, and deployment to Afghanistan (2003-2014). CRTI and injury severity (the New Injury Severity Scores [NISS] [NISS < 25 and NISS ≥ 25]) were included as exposure variables. HRV was quantified using the root mean square of successive differences (RMSSD) obtained using pulse waveform analysis. Depression and anxiety mediators were quantified using the Patient Health Questionnaire and Generalized Anxiety Disorder, respectively. Body mass index and the 6-minute walk test (6MWT) represented physical health measures. Two mediation pathways between exposure and outcome variables were examined in comparison with the uninjured group using structural equation modeling. RESULTS: Of 862 servicemen, 428 were injured and 434 were uninjured with the mean age at assessment of 33.9 ± 5.4 (range 23-59) years. Structural equation modeling revealed that depression, anxiety, and body mass index did not significantly mediate the relationship between injury/injury severity and RMSSD. However, the 6MWT significantly mediated the relationship between CRTI and RMSSD (27% mediation). The indirect effect of 6MWT on the relationship between injury severity (NISS ≥ 25 vs. uninjured) and RMSSD was -0.06 (95% CI: -0.12, -0.00, P < .05). CONCLUSIONS: The findings suggest that greater physical function may improve HRV following CRTI. Longitudinal studies are warranted to further validate these findings.