Christopher J Boos

• MBBS MD Dip IMC FRCP PhD
• Consultant at University Hospital Dorset, Poole

Objective To investigate the differences in clinical and radiographic knee OA markers between injured and uninjured UK service personnel. Methods This study was a cross-sectional analysis, 8 years post-injury, of a prospective cohort study. The Knee Injury and Osteoarthritis Outcome Scores (KOOS), radiographic Kellgren and Lawrence (KL) scores and...

Objective: Knee osteoarthritis (OA) is a leading cause of disability globally, with previous injury a key risk factor. This study investigates the relationship between the risk of progression and incidence of knee radiographic OA (rOA) and pain (KP) with major traumatic injury and identify potential predictors for rOA and KP. Design: The longitudin...

Background Intravenous iron therapy with ferric derisomaltose (FDI) has been shown to improve outcomes in patients with heart failure with reduced ejection fraction (HFrEF) and iron deficiency. However, its effects across different age groups remain unclear. This analysis of the Effectiveness of Intravenous Iron Treatment versus Standard Care in Pa...

Aims Stress echocardiography is widely used to assess patients with chest pain. The clinical value of a positive or negative test result to inform on likely longer-term outcomes when applied in real world practice across a healthcare system has not been previously reported. Methods and Results 5503 patients recruited across 32 UK NHS hospitals bet...

Background/aims Suicidal Ideation (SI) is a risk factor for suicide, a leading cause of death amongst young men globally. In this study we assess whether sustaining a serious physical combat injury is associated with SI and whether leaving service mediates this association. Methods We analysed data from male UK Armed Forces personnel who sustained...

Background Traumatic brain injury (TBI) is common in military campaigns and is a risk factor for dementia. A rme D Ser V ices Tr A uma and Rehabilitatio N Out C om E -TBI (ADVANCE-TBI) aims to ascertain neurological outcomes in UK military personnel with major battlefield trauma, leveraging advances in quantification of axonal breakdown markers lik...

Background Hyperlipidaemia is responsible for 25% of cardiovascular deaths (NHS England 2019). Despite this, the Cardiovascular Disease Prevention Audit (CVDPREVENT) and local data have shown that lipid-lowering therapy in Dorset is in the lowest quartile nationally. Consequently, a nurse-led secondary CVD prevention service was set up to improve l...

Background Heart rate variability (HRV) is a marker of autonomic function. However, the reliability of short‐term HRV measurement in individuals with combat‐related traumatic injury (CRTI) remains undetermined. Methods An intra‐ and inter‐rater reliability study was conducted using a subsample (n = 35) of British servicemen with CRTI enrolled in t...

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 f...

Objective Upper limb (UL) disability in people with UL amputation/s is well reported in the literature, less so for people with lower limb amputation/s. This study aimed to compare UL disability in injured (major trauma) and uninjured UK military personnel, with particular focus on people with upper and lower limb amputation/s. Methods A volunteer...

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...

Background Respiration is a crucial determinant of autonomic balance and heart rate variability (HRV). The comparative effect of spontaneous versus paced breathing on HRV has been almost exclusively explored in healthy adults and never been investigated in an injured military cohort. Objective To examine the effect of spontaneous versus paced brea...

Abstract 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...

Post-Traumatic Growth (PTG) is associated with good cardiovascular health, but the mechanisms of this are poorly understood. This cross-sectional analysis assessed whether factors of PTG (Appreciation of Life (AOL), New Possibilities (NP), Personal Strength (PS), Relating to Others (RTO) and Spiritual Change (SC)) are associated with cardiovascular...

Background and Aims What is the relationship between blood tests for iron deficiency, including anaemia, and the response to intravenous iron in patients with heart failure? Methods In the IRONMAN trial, 1137 patients with heart failure, ejection fraction ≤ 45%, and either serum ferritin < 100 µg/L or transferrin saturation (TSAT) < 20% were rando...

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...

B ackground 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 recruite...

Introduction During combat operations service personnel who sustain combat related traumatic injury (CRTI) are at risk of both direct and indirect injuries to the lungs, including blast lung injury. In this study we aim to investigate the relationship between lung function and CRTI in servicemen deployed to Afghanistan. We hypothesise that eight ye...

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...

In this study, the comparative precision of carotid versus femoral arterial waveforms to measure ultra-short term heart rate variability (HRVUST) following traumatic injury was investigated for the first time. This was an inter-rater reliability study of 50 British servicemen (aged 23–44 years) with non-acute combat-related traumatic injury (CRTI)....

Background Combat-related traumatic injury (CRTI) has been linked to an increased cardiovascular disease (CVD) risk in servicemen returning from military operations. While Heart Rate Variability (HRV) has been established as an objective and non-invasive marker of CVD risk, the long-term impact of unselected CRTI on HRV has not been explored to dat...

Background: The relationship between acute combat-related traumatic injury (CRTI) to coronary flow reserve (CFR) and subclinical cardiovascular risk have not been examined and was the primary aim of this study. Methods and results: UK combat veterans from the ADVANCE cohort study (UK-Afghanistan War 2003-14) with traumatic limb amputations were...

The association between combat-related traumatic injury (CRTI) and bone health is uncertain. A disproportionate number of lower limb amputees from the Iraq and Afghanistan conflicts are diagnosed with osteopenia/osteoporosis, increasing lifetime risk of fragility fracture and challenging traditional osteoporosis treatment paradigms. The aim of this...

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: Th...

Introduction The association between combat-related traumatic injury (CRTI) and bone health is uncertain. A disproportionate number of lower limb amputees from the Afghanistan conflict are diagnosed with osteopenia/osteoporosis, increasing lifetime risk of fragility fracture and challenging traditional osteoporosis treatment paradigms. It was hypot...

Introduction Outcomes of traumatic brain injury (TBI) are highly variable, with cognitive and psychiatric problems often present in survivors, including an increased dementia risk in the long term. Military personnel are at an increased occupational risk of TBI, with high rates of complex polytrauma including TBI characterising the UK campaign in A...

Post-Traumatic Stress Disorder (PTSD) has been identified as an independent risk factor for cardiovascular disease, but the mechanisms of this relationship are not well understood. This study investigates the associations between PTSD symptom clusters (hyperarousal, intrusive thoughts, avoidance behaviours and emotional numbing) and mechanisms of c...

Heart rate variability (HRV) is a non-invasive measure of autonomic function. The relationship between unselected long-term traumatic injury (TI) and HRV has not been investigated. This systematic review examines the impact of non-acute TI (>7 days post-injury) on standard HRV indices in adults. Four electronic databases (CINAHL, Medline, Scopus, a...

Background For patients with heart failure, reduced left ventricular ejection fraction and iron deficiency, intravenous ferric carboxymaltose administration improves quality of life and exercise capacity in the short-term and reduces hospital admissions for heart failure up to 1 year. We aimed to evaluate the longer-term effects of intravenous ferr...

Background Clinical complexity is increasingly prevalent among patients with atrial fibrillation (AF). The ‘Atrial fibrillation Better Care’ (ABC) pathway approach has been proposed to streamline a more holistic and integrated approach to AF care; however, there are limited data on its usefulness among clinically complex patients. We aim to determi...

Heart Rate Variability (HRV) is an indirect measure of autonomic function. Attenuated HRV is linked to worsening health outcomes including Major Adverse Cardiovascular Events (MACE). The relationship between traumatic injury (TI) and HRV has been limitedly studied. This research protocol has been designed to conduct a systematic review of the exist...

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 th...

Background: The long-term psychosocial outcomes of UK armed forces personnel who sustained serious combat injuries during deployment to Afghanistan are largely unknown. We aimed to assess rates of probable post-traumatic stress disorder (PTSD), depression, anxiety, and mental health-associated multimorbidity in a representative sample of serving a...

Aims The 4S-AF classification scheme comprises of four domains: stroke risk (St), symptoms (Sy), severity of atrial fibrillation (AF) burden (Sb), and substrate (Su). We sought to examine the implementation of the 4S-AF scheme in the EORP-AF General Long-Term Registry and compare outcomes in AF patients according to the 4S-AF-led decision-making pr...

Introduction High-altitude (HA) exposure affects heart rate variability (HRV) and has been inconsistently linked to acute mountain sickness (AMS). The influence of increasing HA exposure on ultra-short HRV and its relationship to gold standard HRV measures at HA has not been examined. Methods This was a prospective observational study of adults ag...

Background Epidemiological studies in atrial fibrillation (AF) illustrate that clinical complexity increase the risk of major adverse outcomes. We aimed to describe European AF patients’ clinical phenotypes and analyse the differential clinical course. Methods We performed a hierarchical cluster analysis based on Ward’s Method and Squared Euclidea...

Objective The association between combat-related traumatic injury (CRTI) and cardiovascular risk is uncertain. This study aimed to investigate the association between CRTI and both metabolic syndrome (MetS) and arterial stiffness. Methods This was a prospective observational cohort study consisting of 579 male adult UK combat veterans (UK-Afghanis...

Introduction: The relationship between combat-related traumatic injury (CRTI) and cardiovascular risk is uncertain. Available data are largely derived from small retrospective or cross sectional studies. Hypothesis: This study was designed to investigate, prospectively, the link between CRTI and both metabolic syndrome (MetS) and arterial stiffness...

Background It is important to evaluate whether a new treatment for heart failure with reduced ejection fraction (HFrEF) provides additive benefit to background foundational treatments. As such, we aimed to evaluate the efficacy and safety of empagliflozin in patients with HFrEF in addition to baseline treatment with specific doses and combinations...

Aims Stress echocardiography is widely used to identify obstructive coronary artery disease (CAD). High accuracy is reported in expert hands but is dependent on operator training and image quality. The EVAREST study provides UK-wide data to evaluate real-world performance and accuracy of stress echocardiography. Methods and results Participants un...

Background: The ambulatory arterial stiffness index (AASI) obtained during ambulatory blood pressure monitoring (ABPM) has been cited as an independent predictor of major adverse cardiovascular events (MACEs) including cardiovascular death, stroke and worsening chronic kidney disease (CKD) among mixed-sex adult populations. This study aimed to det...

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 co...

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...

Purpose This study investigated the effect of carbohydrate supplementation on substrate oxidation during exercise in hypoxia after pre-exercise breakfast consumption and omission. Methods Eleven men walked in normobaric hypoxia (FiO2 ~11.7%) for 90-min at 50% of hypoxic V[Combining Dot Above]O2max. Participants were supplemented with a carbohydr...

Introduction: Low energy availability (EA) may impede adaptation to exercise, suppressing reproductive function and bone turnover. Exercise energy expenditure (EEE) measurements lack definition and consistency. This study aimed to compare EA measured from moderate and vigorous physical activity from accelerometry (EEEmpva) with EA from total physi...

Introduction The Afghanistan war (2003–2014) was a unique period in military medicine. Many service personnel survived injuries of a severity that would have been fatal at any other time in history; the long-term health outcomes of such injuries are unknown. The A rme D Ser V ices Tr A uma and Rehabilitatio N Out C om E (ADVANCE) study aims to dete...

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 asso...

Introduction: There is evidence that intermittent hypoxic exposure (IHE) may improve high altitude (HA) performance. In this study, the effects of short-term IHE through voluntary apnea training on HA-related symptoms, including acute mountain sickness (AMS), were examined for the first time. Methods: Forty healthy adults were randomized to a self...

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Background and objectives: Cardiovascular disease (CVD) is a leading cause of death among military veterans with several reports suggesting a link between combat and related traumatic injury (TI) to an increased CVD risk. The aim of this paper is to conduct a widespread systematic review and meta-analysis of the relationship between military comba...

Purpose The purpose of experiment one was to determine the appetite, acylated ghrelin and energy intake response to breakfast consumption and omission in hypoxia and normoxia. Experiment two aimed to determine the appetite, acylated ghrelin and energy intake response to carbohydrate supplementation after both breakfast consumption and omission in h...

Aims In recent years, stroke prevention in patients with atrial fibrillation (AF) has radically changed, with increasing use of non-vitamin K antagonist oral anticoagulants (NOACs). Contemporary European data on AF thromboprophylaxis are needed. Methods and results We report 1-year follow-up data from the EURObservational Research Programme in Atri...

Aims In recent years, stroke prevention in patients with atrial fibrillation (AF) has radically changed, with increasing use of non-vitamin K antagonist oral anticoagulants (NOACs). Contemporary European data on AF thromboprophylaxis are needed. Methods and results We report 1-year follow-up data from the EURObservational Research Programme in Atri...

Purpose: This study compared the co-ingestion of glucose and fructose on exogenous and endogenous substrate oxidation during prolonged exercise at terrestrial high altitude (HA) versus sea level, in women. Method: Five women completed two bouts of cycling at the same relative workload (55% Wmax) for 120 minutes on acute exposure to HA (3375m) an...

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 Diseas...

The recent Iraq and Afghanistan conflicts represent a unique time in UK battlefield medicine; with more service personnel surviving complex traumas than any previous time. During these recent conflicts, approximately 830 UK service personnel were very seriously or seriously injured, and over 9000 were aero-medially evacuated. Little is known about...

Introduction: There is conflicting data at sea-level to suggest that Paced Breathing (PB) versus Spontaneous Breathing (SB) during short-term Heart Rate Variability (HRV) measurement improves data reliability. Aim: This study sought to examine the effects of SB versus PB on HRV, at High Altitude (HA). Materials and Methods: This was a prospective o...

The relationship between autonomic function and recovery following prolonged arduous exercise in women has not been examined. We undertook an exploratory study that aimed to examine the temporal change in linear and nonlinear measures of heart rate variability (HRV) following prolonged arduous exercise in the form of first all‐female (mean age 32.7...

Introduction Whilst the link between physical factors and risk of high altitude (HA)-related illness and acute mountain sickness (AMS) have been extensively explored, the influence of psychological factors has been less well examined. In this study we aimed to investigate the relationship between ‘anxiety and AMS risk during a progressive ascent to...

Anonymised data file for the study. (CSV)

The binding of high-mobility group box-1 (HMGB-1) to the membrane receptor for advanced glycation end-products (mRAGE) is a key early mediator of non-infectious inflammation and its triggers include ischaemia/hypoxia. The effects of acute hypoxia on soluble RAGE (sRAGE) are unknown. Fourteen healthy adults (50% women; 26.6+/-3.8 years) were assesse...

Aims Contemporary data regarding atrial fibrillation (AF) management and current use of oral anticoagulants (OACs) for stroke prevention are needed. Methodsand results The EURObservational Research Programme on AF (EORP-AF) Long-Term General Registry analysed consecutive AF patients presenting to cardiologists in 250 centres from 27 European countr...

Background: High altitude (HA) exposure can lead to changes in resting heart rate variability (HRV), which may be linked to acute mountain sickness (AMS) development. Compared with traditional HRV measures, non-linear HRV appears to offer incremental and prognostic data, yet its utility and relationship to AMS have been barely examined at HA. This...

Introduction: Aldosterone decreases at high altitude (HA) but the effect of hypoxia on angiotensin-converting enzyme (ACE), a key step in the renin-angiotensin-aldosterone system, is unclear. Methods: We investigated the effects of exercise and acute normobaric hypoxia (NH, ~11.0% FiO2) on nine participants and six controls undertaking the same...

Postural control and joint position sense are essential for safely undertaking leisure and professional activities, particularly at high altitude. We tested whether exposure to a 12-day trek with a gradual ascent to high altitude impairs postural control and joint position sense. This was a repeated measures observational study of 12 military servi...

Participant AMS occurrence at all altitudes. (DOCX)

SpO2 at different altitudes. (DOCX)

Centre of pressure velocity in the medial-lateral direction at different altitudes. (DOCX)

SRT Scores at different altitudes. (DOCX)

Number of subjects with abnormal and normal results for the Sharpened Romberg Test (SRT) and with or without acute mountain sickness (AMS)†. (DOCX)

Relative error of knee joint position sense at different altitudes. (DOCX)

Absolute error of knee joint position sense at different altitudes. (DOCX)

Variable error of knee joint position sense at different altitudes. (DOCX)

Purpose: Heat adaptation (HA) is critical to performance and health in a hot environment. Transition from short-term heat acclimatisation (STHA) to long-term heat acclimatisation (LTHA) is characterised by decreased autonomic disturbance and increased protection from thermal injury. A standard heat tolerance test (HTT) is recommended for validatin...

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 participan...

Methods: HRV (5-minute single lead ECG) was measured in 63 healthy adults (41 men and 22 women) aged 18-56 years at sea level (SL) and during a HA trek at 3619m, 4600m and 5140m respectively. The main effects of altitude (SL, 3619, 4600 and 5140m) and sex (men vs women) and their potential interaction were assessed using a Factorial Repeated Measu...

Background: Although calcific aortic valve disease (CAVD) is associated with coronary atherosclerosis, it is not known whether early CAVD is associated with coronary microcirculatory dysfunction (CMD). We sought to investigate the relationship between myocardial blood flow reserve (MBFR) - a measure of CMD, and early CAVD in the absence of obstruc...

PurposeTo 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], my...

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...