Effect of food intake on echocardiographic measurements in healthy elderly.

OBJECTIVE: This study evaluates whether food intake affects systolic and diastolic echocardiographic measurements in healthy seniors. METHODS: Thirty healthy subjects 65-70 years of age were investigated with echocardiography, at fasting and then 30, 90, and 180 min after a meal. RESULTS: After 30 min the biggest changes were seen in left ventricular wall stress and myocardial performance index with a decrease of 45% and 33%, respectively, compared to fasting values. Significant (p < .05) increases also were seen in left ventricular stroke volume, left ventricular cardiac output, left ventricular cardiac index, left ventricular outflow velocity-time integral, peak of early diastolic (E) and late diastolic (A) mitral flow velocities, the E/A ratio, pulsed tissue Doppler peak systolic (s') and early (e') and late (a') diastolic velocities, pulmonary vein peak velocities in systole (S) and diastole (D), mitral annular plane systolic excursion (MAPSE), tricuspid annular plane systolic excursion (TAPSE), and global longitudinal strain (GLS) (increases ranging 6%-19%). After 90 min there remained a decrease in wall stress and myocardial performance index of 31% and 17%, respectively, and smaller, but still significant, changes could be seen in left ventricular stroke volume, left ventricular outflow velocity-time integral, MAPSE (lateral), TAPSE, GLS, and a few pulsed tissue Doppler peak systolic velocities and late diastolic velocities. An increase also could be seen in deceleration time of E-wave (DT). After 180 min, all variables except DT were back at baseline or below. No significant changes were seen in S/D ratio, lateral early diastolic velocity (e' lateral) and E/e'ratio. CONCLUSIONS: This study shows that food intake affects commonly used echocardiographic parameters, both systolic and diastolic, in healthy seniors. With a few exceptions, the changes seen in the older population were less pronounced than previous studies in younger subjects.

Musculoskeletal Benefits from a Physical Activity Program in Primary School are Retained 4 Years after the Program is Terminated.

Daily school physical activity (PA) improves musculoskeletal traits. This study evaluates whether the benefits remain 4 years after the intervention. We followed 45 boys and 36 girls who had had 40 min PA/school day during the nine compulsory school years and 21 boys and 22 girls who had had 60 min PA/school week (reference), with measurements at baseline and 4 years after the program terminated. Bone mineral content (BMC; g) and bone mineral density (BMD; g/cm2) were measured by dual-energy X-ray absorptiometry and knee flexion peak torque relative to total body weight (PTflexTBW) at a speed of 180 degrees/second with a computerized dynamometer. Group differences are presented as mean differences (adjusted for sex and duration of follow-up period) with 95% confidence intervals. The total gain bone mass [mean difference in spine BMC +32.0 g (14.6, 49.4) and in arms BMD of +0.06 g/cm2 (0.02, 0.09)] and gain in muscle strength [mean difference in PTflex180TBW +12.1 (2.0, 22.2)] were greater in the intervention than in the control group. There are still 4 years after the intervention indications of benefits in both bone mass and muscle strength gain. Daily school PA may counteract low bone mass and inferior muscle strength in adult life. ClinicalTrials.gov.NCT000633828 retrospectively registered 2008-11-03.

Physical activity spectrum discriminant analysis-A method to compare detailed patterns between groups.

Investigating physical activity (PA) patterns as a detailed intensity spectrum instead of crude intensity categories have improved the ability to analyze the relationship between measured PA and health variables. The aim of this methodological study was to introduce and investigate the utility of using detailed PA intensity spectrum compared to crude PA intensity categories for comparison of PA between groups and between repeated measures. The study sample consisted of two groups of children, where one group was scheduled for extended physical education (PE) by daily classes while the other group followed usual PE schedule. Accelerometer data was processed into traditional crude PA intensity categories and into detailed PA intensity spectrum. Multivariate partial least squares regression for discriminant analysis (PLS-DA) was applied for PA intensity spectrum group comparison and compared to traditional univariate statistical analysis. Repeated measures were investigated using independent PLS-DA as well as multilevel PLS-DA for paired analysis. While traditional analysis of crude PA intensity categories was unable to find any group differences, multivariate analysis of the PA intensity spectrum identified statistically significant differences. By the extension of multilevel PLS-DA for paired comparison, a clear difference in the PA intensity spectrum was demonstrated between repeated measures. In conclusion, analysis of detailed PA intensity spectrum demonstrates utility for comparing detailed PA data between groups and between repeated measures in interventional and observational research.

Re-examination of accelerometer data processing and calibration for the assessment of physical activity intensity.

This review re-examines the use of accelerometer and oxygen uptake data for the assessment of activity intensity. Accelerometers capture mechanical work, while oxygen uptake captures the energy cost of this work. Frequency filtering needs to be considered when processing acceleration data. A too restrictive filter attenuates the acceleration signal for walking and, to a higher degree, for running. This measurement error affects shorter (children) more than taller (adults) individuals due to their higher movement frequency. Less restrictive filtering includes more movement-related signals and provides measures that better capture mechanical work, but may include more noise. An optimal filter cut-point is determined where most relevant acceleration signals are included. Further, accelerometer placement affects what part of mechanical work being captured. While the waist placement captures total mechanical work and therefore contributes to measures of activity intensity equivalent by age and stature, the thigh and wrist placements capture more internal work and do not provide equivalent measures. Value calibration of accelerometer measures is usually performed using measured oxygen uptake with the metabolic equivalent of task (MET) as reference measure of activity intensity. However, the use of MET is not stringent and is not a measure of activity intensity equivalent by age and stature. A candidate measure is the mass-specific net oxygen uptake, VO2 net (VO2 tot - VO2 stand). To improve measurement of physical activity intensity using accelerometers, research developments are suggested concerning the processing of accelerometer data, use of energy expenditure as reference for activity intensity, and calibration procedure with absolute versus relative intensity.

Galectin-3 levels relate in children to total body fat, abdominal fat, body fat distribution, and cardiac size.

Galectin-3 has recently been proposed as a novel biomarker for cardiovascular disease in adults. The purpose of this investigation was to assess relationships between galectin-3 levels and total body fat, abdominal fat, body fat distribution, aerobic fitness, blood pressure, left ventricular mass, left atrial size, and increase in body fat over a 2-year period in a population-based sample of children. Our study included 170 children aged 8-11 years. Total fat mass and abdominal fat were measured by dual-energy x-ray absorptiometry (DXA). Body fat distribution was expressed as abdominal fat/total fat mass. Maximal oxygen uptake was assessed by indirect calorimetry during a maximal exercise test and scaled to body mass. Systolic and diastolic blood pressure and pulse pressure were measured. Left atrial size, left ventricular mass, and relative wall thickness were measured by echocardiography. Frozen serum samples were analyzed for galectin-3 by the Proximity Extension Assay technique. A follow-up DXA scan was performed in 152 children 2 years after the baseline exam. Partial correlations, with adjustment for sex and age, between galectin-3 versus body fat measurements indicated weak to moderate relationships. Moreover, left atrial size, left ventricular mass, and relative wall thickness and pulse pressure were also correlated with galectin-3. Neither systolic blood pressure nor maximal oxygen uptake was correlated with galectin-3. There was also a correlation between galectin-3 and increase in total body fat over 2 years, while no such correlations were found for the other fat measurements. CONCLUSION: More body fat and abdominal fat, more abdominal body fat distribution, more left ventricular mass, and increased left atrial size were all associated with higher levels of galectin-3. Increase in total body fat over 2 years was also associated with higher levels of galectin-3. What is Known: • Galectin-3 has been linked to obesity and been proposed to be a novel biomarker for cardiovascular disease in adults. • Information on this subject in children is very scarce. What is New: • The present study demonstrates a relationship between galectin-3 levels and total body fat, abdominal fat, body fat distribution, cardiac size and geometry, and increase in total body fat over 2 years in young children.

School-based study found that physical activity and aerobic fitness predicted increases in total body fat and abdominal fat at a mean age of 9.8 years.

AIM: We assessed whether baseline measurements of physical activity, aerobic fitness, body fat and abdominal fat were predictors of changes in body fat measurements over a two-year period. METHODS: The study comprised of 204 children aged 9.8 ± 0.6 years with a normal body mass distribution, who recruited from four schools in middle-class areas of Malmö, Sweden, from 2001 to 2004. Peak oxygen uptake and physical activity were measured at baseline. Body fat was measured by dual-energy X-ray absorptiometry at baseline and two years later. RESULTS: Physical activity, aerobic fitness and total body fat or abdominal fat were predictors of change in total body fat or abdominal fat over a period of two years. Changes in the percentage of body fat were not related to any of the baseline measurements. CONCLUSION: Our two-year follow-up of children with a mean age of 9.8 years at baseline showed that physical activity, aerobic fitness and body fat or abdominal fat predicted changes in total body fat or abdominal fat, but not the percentage of body fat.

The safety of introducing a new generation TAVR device: one departments experience from introducing a second generation repositionable TAVR.

BACKGROUND: In the evolving field of transcatheter aortic valve replacements a new generation of valves have been introduced to clinical practice. With the complexity of the TAVR procedure and the unique aspects of each TAVR device, there is a perceived risk that changing or adding a new valve in a department could lead to a worse outcome for patients, especially during the learning phase. The objective was to study the safety aspect of introducing a second generation repositionable transcatheter valve (Boston Scientific Lotus valve besides Edwards Sapien valve) in a department. METHODS: In a retrospective study, 53 patients receiving the Lotus system, and 47 patients receiving the Sapien system over a period of three years were compared for short-term outcome according to VARC-2 definitions and 1-year survival. RESULTS: Outcome in terms VARC-2 criteria for early safety and clinical efficacy, stroke rate, and survival at 30 days and at 1 year were similar. The Lotus valve had less paravalvular leakage, where 90% had none or trace aortic insufficiency as compared to only 48% for the Sapien system. CONCLUSIONS: Introduction of a new generation valve can be done with early device success and safety, and without jeopardizing the outcome for patients up to one year. We found no adverse effects by changing valve type and observed improved outcome in terms of lower PVL-rates. Both existing and new centers starting a TAVR program can benefit from the use of a new generation device.

Myocardial performance index in female athletes.

BACKGROUND: Long-term intensive training leads to morphological and mechanical changes in the heart generally known as "athlete's heart". Previous studies have suggested that the diastolic and systolic function of the ventricles is unaltered in athletes compared to sedentary. The purpose of this study was to investigate myocardial performance index (MPI) by pulsed wave Doppler (PWD) and by tissue Doppler imaging (TDI) in female elite athletes compared to sedentary controls. METHODS: The study consisted of 32 athletes (mean age 20 ± 2 years) and 34 sedentary controls (mean age 23 ± 2 years). MPI by PWD and TDI were measured in the left (LV) and right ventricle (RV) in both groups. Moreover, comparisons of MPI by the two methods and between the LV and RV within the two groups were made. RESULTS: There were no significant differences in MPI between athletes and controls (p > 0.05), whereas the LV had significantly higher MPI compared to RV (p < 0.001, in athletes and controls). The agreement and the correlation between the two methods measuring MPI showed low agreement and no correlation (athletes RV r = -0.027, LV r = 0.12; controls RV r = 0.20, LV r = 0.30). CONCLUSION: The global function of the LV and RV measured by MPI with PWD and TDI is similar in female athletes compared to sedentary controls. Conversely, both MPI by PWD and by TDI shows a significant difference between the LV and RV. However, the agreement and correlation between conventional methods of measuring MPI by PWD compared to MPI by TDI is very poor in both these populations.

Effect of food intake on myocardial performance index.

BACKGROUND: Myocardial performance index (MPI) has been investigated in a variety of populations, but the effect of food intake has not been evaluated. We assessed whether myocardial performance index is affected by food intake in healthy subjects. METHODS: Twenty-three healthy subjects aged 25.6 ± 4.5 years were investigated. MPI was measured before, 30 min after, and 110 min after a standardized meal. RESULTS: MPI decreased significantly (P < 0.05) from fasting values 30 min after the meal, and had almost returned to baseline after 110 min. MPI decreased from 0.28 ± 0.06 (fasting) to 0.20 ± 0.07 30 min after eating. At 110 min after eating the index value was almost back to the baseline value 0.26 ± 0.06. (P = 0.15). CONCLUSIONS: This study shows that myocardial performance index is affected by food intake in healthy subjects.

Echocardiographic consequences of smoking status in middle-aged subjects.

BACKGROUND: Smoking is known to have many short- and long-term cardiovascular effects. Cardiac index (CI), which is cardiac output indexed to body surface area, is considered to be a valid measure of cardiac performance. We investigated whether there were any differences in CI or other echocardiographic variables between never smokers, ex-smokers, and current smokers in a cardiopulmonary healthy population. METHODS: Subjects (n=355) from a previous population-based respiratory questionnaire survey (never smokers, ex-smokers, and current smokers without significant chronic obstructive lung disease) were examined with echocardiography, and CI (L/min/m2 ) was calculated. RESULTS: Current smokers had a higher CI than never smokers 2.61±0.52 L/min/m2 vs. 2.42±0.49 L/min/m2 (P<.01). Ex-smokers had a nonsignificant, numerically higher value for CI than never smokers 2.54±0.54 L/min/m2 vs. 2.42±0.49 L/min/m2 (P>.05). Smoking status had no significant effect on other echocardiographic variables. CONCLUSION: We conclude that currents smokers without known cardiac disease or significant chronic obstructive lung disease show signs of slightly altered hemodynamics.

Correlation between physical activity, aerobic fitness and body fat against autonomic function profile in children.

AIM: To evaluate correlations between physical activity, VO2PEAK and body fat versus autonomic function in children. METHODS: Children (n = 98) between 10 and 12 years underwent a maximal exercise test (VO2PEAK) and dual-energy X-ray absorptiometry measured body fat. General physical activity, moderate to vigorous physical activity and vigorous physical activity were assessed by accelerometers. Deep breath test with E/I-ratio calculation and a head-up tilt test were performed. The sum of z-scores represented an index score for autonomic function profile and included E/I-ratio plus difference in blood pressure and heart rate between supine and tilted position. Correlation analyses were performed between physical activity parameters, body fat and VO2PEAK versus autonomic function profile. RESULTS: No significant correlations were found between autonomic function profile and physical activity or body fat (p > 0.05). VO2PEAK was correlated with autonomic function profile in boys (r = 0.30, p < 0.05), but not in girls (r = 0.04, NS). One girl and eight boys terminated head-up tilt test prematurely due to intolerance. Minutes of vigorous physical activity per day was lower in these boys compared with those (n = 48) who completed the head-up tilt test (5.1 ± 3.3 vs. 10.4 ± 6.6, p < 0.05). CONCLUSION: Physical activity or body fat was not associated with autonomic function profile. VO2PEAK correlated to autonomic function profile in boys.

A 5-year exercise program in children improves muscle strength without affecting fracture risk.

PURPOSE: High level of physical activity (PA) is associated with great muscle strength and high fracture risk. This prospective controlled population-based study evaluated how a pediatric PA intervention program influenced muscle strength and fracture risk. METHODS: We carried out a school-based exercise intervention program with 200 min of PA per week for 5 years in 335 girls and 408 boys aged 6-9 years at study start. An age-matched control cohort including 756 girls and 782 boys continued with 60 min of PA per week. We registered fractures during the study period and calculated rate ratio. In a sub-sample, including 74 girls and 107 boys in the intervention and 51 girls and 54 boys in the control group, we measured knee flexion and extension strength by a computerized dynamometer and leg composition by dual energy X-ray absorptiometry. Group comparisons were adjusted for differences in age, baseline value for the measured parameter and changes in height. RESULTS: Children in the intervention group had a rate ratio to sustain a fracture of 1.03 (0.78, 1.36) (mean and 95 % confidence interval) (p = 0.79). The annual gain in flexion peak torque muscle strength was greater in both girls (at 60°/s) [1.1 Nm (0.5, 1.8), p < 0.01] and boys (at 180°/s) [0.7 Nm (0.1, 1.2), p < 0.05] in the intervention than in the control group, while leg composition was similar. CONCLUSION: Increased PA during a 5-year period, starting in the pre-pubertal period, improves the gain in muscle strength without affecting the fracture risk.

A seven-year physical activity intervention for children increased gains in bone mass and muscle strength.

AIM: This study evaluated the musculoskeletal effects of increased physical activity on children, starting at six to nine years of age. METHODS: In one school we increased the physical education of 72 girls and 100 boys to 200 minutes per week over seven years. In three other schools, 45 girls and 47 boys continued to receive 60 minutes per week. We measured areal bone mineral density (aBMD) with dual energy X-ray absorptiometry and muscle strength with computerised dynamometer at baseline and after seven years and tibial cortical thickness with peripheral quantitative computed tomography after seven years. RESULTS: Girls in the intervention group gained 0.04 g/cm(2) (0.01-0.08) more total spine aBMD (p < 0.05) and 6.2Nm (1.6, 10.7) more knee flexion strength (p < 0.01) than control group girls and had a 0.1 mm (0.0, 0.3) higher tibial cortical thickness at follow-up (p < 0.05). Boys in the intervention group gained 7.3Nm (0.4, 14.2) more knee extension strength (p < 0.05) and 7.4Nm (2.3, 12.4) more knee flexion strength (p < 0.01) than the control group boys, but their aBMD was no higher than the control group. CONCLUSION: A seven-year, population-based moderately intense exercise intervention enhanced gains in spine bone mass in girls and knee muscle strength in both genders.

A Pediatric Bone Mass Scan has Poor Ability to Predict Peak Bone Mass: An 11-Year Prospective Study in 121 Children.

This 11-year prospective longitudinal study examined how a pre-pubertal pediatric bone mass scan predicts peak bone mass. We measured bone mineral content (BMC; g), bone mineral density (BMD; g/cm(2)), and bone area (cm(2)) in femoral neck, total body and lumbar spine by dual-energy X-ray absorptiometry in a population-based cohort including 65 boys and 56 girls. At baseline all participants were pre-pubertal with a mean age of 8 years (range 6-9), they were re-measured at a mean 11 years (range 10-12) later. The participants were then mean 19 years (range 18-19), an age range that corresponds to peak bone mass in femoral neck in our population. We calculated individual BMC, BMD, and bone size Z scores, using all participants at each measurement as reference and evaluated correlations between the two measurements. Individual Z scores were also stratified in quartiles to register movements between quartiles from pre-pubertal age to peak bone mass. The correlation coefficients (r) between pre-pubertal and young adulthood measurements for femoral neck BMC, BMD, and bone area varied between 0.37 and 0.65. The reached BMC value at age 8 years explained 42 % of the variance in the BMC peak value; the corresponding values for BMD were 31 % and bone area 14 %. Among the participants with femoral neck BMD in the lowest childhood quartile, 52 % had left this quartile at peak bone mass. A pediatric bone scan with a femoral neck BMD value in the lowest quartile had a sensitivity of 47 % [95 % confidence interval (CI) 28, 66] and a specificity of 82 % (95 % CI 72, 89) to identify individuals who would remain in the lowest quartile at peak bone mass. The pre-pubertal femoral neck BMD explained only 31 % of the variance in femoral neck peak bone mass. A pre-pubertal BMD scan in a population-based sample has poor ability to predict individuals who are at risk of low peak bone mass.

Effect of food intake on left ventricular wall stress.

OBJECTIVE: Left ventricular wall stress has been investigated in a variety of populations, but the effect of food intake has not been evaluated. We assessed whether left ventricular wall stress is affected by food intake in healthy subjects. METHODS: Twenty-three healthy subjects aged 25.6 ± 4.5 years were investigated. Meridional end-systolic wall stress (ESS) and circumferential end-systolic wall stress (cESS) were measured before, 30 minutes after, and 110 minutes after a standardised meal. RESULTS: Both ESS and cESS decreased significantly (P < 0.001) from fasting values 30 minutes after the meal, and had not returned to baseline after 110 minutes. ESS decreased from 65 ± 16 kdynes/cm2 (fasting) to 44 ± 12 kdynes/cm2 30 minutes after, and to 58 ± 13 kdynes/cm2 110 minutes after eating. cESS decreased from 98 ± 24 kdynes/cm2 to 67 ± 18 kdynes/cm2 30 minutes after, and to 87 ± 19 kdynes/cm2 110 minutes after the meal. CONCLUSION: This study shows that left ventricular wall stress is affected by food intake in healthy subjects.

A 3-year school-based exercise intervention improves muscle strength - a prospective controlled population-based study in 223 children.

BACKGROUND: Intense physical activity (PA) improves muscle strength in children, but it remains uncertain whether moderately intense PA in a population-based cohort of children confers these benefits. METHODS: We included children aged 6-9 years in four schools where the intervention school increased the school curriculum of PA from 60 minutes/week to 40 minutes/school day while the control schools continued with 60 minutes/week for three years. We measured muscle strength, as isokinetic Peak Torque (PT) (Nm) of the knee flexors in the right leg at speeds of 60°/second and 180°/second, at baseline and at follow-up, in 47 girls and 76 boys in the intervention group and 46 girls and 54 boys in the control group and then calculated annual changes in muscle strength. Data are provided as means with 95% confidence intervals. RESULTS: Girls in the intervention group had 1.0 Nm (0.13, 1.9) and boys 1.9 Nm (0.9, 2.9) greater annual gain in knee flexor PT at 60°/second, than girls and boys in the control group. Boys in the intervention group also had 1.5 Nm (0.5, 2.5) greater annual gain in knee flexors PT at 180°/second than boys in the control group. CONCLUSION: A 3-year moderately intense PA intervention program within the school curriculum enhances muscle strength in both girls and boys.

Vortex formation time in female athletes.

Regular, vigorous physical activity can have a significant impact on cardiac function, leading to cardiac morphological alterations that may be challenging to distinguish from pathological changes. Therefore, new screening methods are needed to accurately differentiate between adaptive changes and pathological alterations in athletes. Vortex formation time (VFT) is an emerging method that shows potential in this regard, as it involves the formation of a rotating vortex ring in the left ventricle during the early filling phase of diastole. In this study, we investigated the difference in VFT between two groups of women: professional handball players and healthy middle-aged female athletes, along with their corresponding control groups. By using echocardiography-Doppler analysis of the heart, VFT was calculated based on the left ventricular ejection fraction, the ratio between the end-diastolic volume and the diameter of the mitral annulus, and the ratio of the atrial contraction volume to the total inflow via the mitral valve. The study reveals a significant increase in VFT in both professional handball players and middle-aged female athletes compared to their respective control groups. Moreover, statistically significant differences between handball players and middle-aged female athletes were observed, indicating that the level of physical activity may affect the VFT. These results suggest that VFT could be a promising screening tool for identifying cardiac adaptations due to long-term vigorous training, potentially enabling more accurate diagnoses of cardiac morphological alterations in athletes.

A 5-year exercise program in pre- and peripubertal children improves bone mass and bone size without affecting fracture risk.

We studied the effect in children of an exercise intervention program on fracture rates and skeletal traits. Fractures were registered for 5 years in a population-based prospective controlled exercise intervention study that included children aged 6-9 years at study start, 446 boys and 362 girls in the intervention group and 807 boys and 780 girls in the control group. Intervention subjects received 40 min/school day of physical education and controls, 60 min/week. In 73 boys and 48 girls in the intervention group and 52 boys and 48 girls in the control group, bone mineral density (BMD, g/cm(2)) and bone area (mm(2)) were followed annually by dual-energy X-ray absorptiometry, after which annual changes were calculated. At follow-up we also assessed trabecular and cortical volumetric BMD (g/cm(3)) and bone structure by peripheral computed tomography in the tibia and radius. There were 20.0 fractures/1,000 person-years in the intervention group and 18.5 fractures/1,000 person-years in the control group, resulting in a rate ratio of 1.08 (0.79-1.47) (mean and 95 % CI). The gain in spine BMD was higher in both girls (difference 0.01 g/cm(2), 0.005-0.019) and boys (difference 0.01 g/cm(2), 0.001-0.008) in the intervention group. Intervention girls also had higher gain in femoral neck area (difference 0.04 mm(2), 0.005-0.083) and at follow-up larger tibial bone mineral content (difference 0.18 g, 0.015-0.35), larger tibial cortical area (difference 17 mm(2), 2.4-31.3), and larger radial cross-sectional area (difference 11.0 mm(2), 0.63-21.40). As increased exercise improves bone mass and in girls bone size without affecting fracture risk, society ought to encourage exercise during growth.

Clinical outcome and microvascular blood flow in VAC® - and Sorbalgon® -treated peri-vascular infected wounds in the groin after vascular surgery - an early interim analysis.

Vacuum-assisted wound closure (VAC(®)) therapy is considered to be superior to conventional dressings in the treatment of peri-vascular groin infections after vascular surgery at our department. Therefore, we performed an early interim analysis of the clinical outcomes in these seriously ill patients at risk of amputation and death. Patients were randomised to either VAC(®) (n = 5) or Sorbalgon(®) (n = 5; best alternative treatment) therapy after surgical debridement. Non-invasive, laser Doppler perfusion imaging (LDPI) studies of the skin adjacent to the undressed wound were performed after 14 days of wound treatment. There was no difference in LDPI values in VAC(®) versus Sorbalgon(®) treated patients (P = 0·46). One patient in the VAC(®) group suffered from two re-bleeding episodes, leading to vascular resection and transfemoral amputation and in the Sorbalgon(®) group two had a complete wound healing time of more than 4 months and one had a visible interposition bypass graft in the groin after 1 month of treatment. No patient died of the groin infection. Although not statistically proven, fewer wound treatment failures were recorded in the VAC(®) group, justifying this early interim analysis. LDPI studies were feasible.

Physiological Demands and Characteristics of Movement During Simulated Combat.

INTRODUCTION: Military tasks place considerable physiological demands on the soldier. It is therefore important to know the energy expenditure of soldiers while solving tasks in different environments. The purpose of this study was to describe the cardiorespiratory demands of certain movements and activities on ground combat soldiers during military field operations using body sensors and simulated combat. MATERIALS AND METHODS: Movement characteristics and cardiorespiratory responses were assessed in 42 soldiers (three women) in the Swedish Army. The different posts assessed were commander, combat engineer, driver, and gunner. The military field exercises examined were urban operations and retrograde operations in rough terrain. Measurements included (1) body mass, (2) heart rate (HR) including maximal (HRmax), (3) velocity, (4) accelerations/decelerations, and (5) distance moved. Maximal aerobic capacity (V̇O2peak, mL·kg-1·min-1) was tested in a laboratory setting when wearing combat gear and body armor. RESULTS: There was a weak positive correlation (r = 0.41 and 0.28, both P < .05) between VO2peak and percentage of time over 40% and 50% of maximal aerobic capacity during simulated combat. No differences were found for the different posts in time spent over 40% or 50% of maximal aerobic capacity and 76% of their HRmax (P > .05). Wearing combat gear and additional load while solving tasks resulted in mean HR varying between 98 and 111 beats·min-1, corresponding with 50-57% of the soldiers HRmax. Studying all exercises, mean HR was 105 ± 11 beats min-1, 54 ± 5% of HRmax corresponding to light work intensity. Soldiers performed between 2.8 and 4.9 accelerations/min in the different exercises. A significant correlation between V̇O2peak (mL kg-1 min-1) and acceleration and m/min were found, implying that soldiers with good aerobic capacity were able to cope better with tasks requiring quick movements. CONCLUSION: Conducting military operations in urban terrain and retrograde operations in rough terrain strains ground combat soldiers' cardiorespiratory system, with work intensities close to 40% of maximal aerobic capacity in 15-33% of mission time. Tasks with external load carriage include change of direction, accelerations, bounds, and jumping over obstacles, and physical fitness tests should replicate this. Findings in this study also add objective data to the physiological demands of work performed by combat soldiers while conducting urban operations and retrograde operations in rough terrain. These findings could be used to develop a model for classifying work demands for ground combat forces.