Childhood Sports Participation Is Associated With Health-Related Quality of Life in Young Men: A Retrospective Cross-Sectional Study

The aim of the study was to examine whether sports participation (SP), engagement in competitive sports (CS), and the type of sport undertaken at the age of 12 are associated with the physical and mental components of health-related quality of life (HRQoL) in young adulthood. The data were collected using questionnaires prior to a compulsory military refresher training course in Finland. The sample consisted of 784 men (mean age 26 years). HRQoL was measured with RAND 36 and childhood SP with a series of questions. Data were analyzed with logistic regression. Higher frequency of SP, participation in district-level CS; performing team, endurance, or extreme sports; and playing yard games in childhood were after adjustments all associated with better HRQoL in early adulthood. The association was mainly found with the mental component, and to a lesser extent with the physical component, of HRQoL. Team (OR 1.43, CI 1.00-2.06) and extreme sports (OR 1.77, CI 1.19-2.63) were associated with better mental HRQoL, while playing yard games (OR 0.62, CI 0.44-0.89) reduced the likelihood for having low physical HRQoL. SP in childhood-in the forms of team or individual sports, but also as informal physical activity, such as playing yard games-is associated with HRQoL in young adulthood.

The Development of Swedish Military Healthcare System: Part II-Re-evaluating the Military and Civilian Healthcare Systems in Crises Through a Dialogue and Study Among Practitioners

Introduction

Historical changes have transformed Sweden from being an offensive to a defensive and collaborative nation with national and international engagement, allowing it to finally achieve the ground for the civilian–military collaboration and the concept of a total defense healthcare. At the same time, with the decreasing number of international and interstate conflicts, and the military’s involvement in national emergencies and humanitarian disaster relief, both the need and the role of the military healthcare system within the civilian society have been challenged. The recent impact of the COVID-19 in the USA and the necessity of military involvement have led health practitioners to anticipate and re-evaluate conditions that might exceed the civilian capacity of their own countries and the need to have collaboration with the military healthcare. This study investigated both these challenges and views from practitioners regarding the benefits of such collaboration and the manner in which it would be initiated.

Material and Method

A primary study was conducted among responsive countries using a questionnaire created using the Nominal Group Technique. Relevant search subjects and keywords were extracted for a systematic review of the literature, according to the PRISMA model.

Results

The 14 countries responding to the questionnaire had either a well-developed military healthcare system or units created in collaboration with the civilian healthcare. The results from the questionnaire and the literature review indicated a need for transfer of military medical knowledge and resources in emergencies to the civilian health components, which in return, facilitated training opportunities for the military staff to maintain their skills and competencies.

Conclusions

As the world witnesses a rapid change in the etiology of disasters and various crises, neither the military nor the civilian healthcare systems can address or manage the outcomes independently. There is an opportunity for both systems to develop future healthcare in collaboration. Rethinking education and training in war and conflict is indisputable. Collaborative educational initiatives in disaster medicine, public health and complex humanitarian emergencies, international humanitarian law, and the Geneva Convention, along with advanced training in competency-based skill sets, should be included in the undergraduate education of health professionals for the benefit of humanity.

Central aortic hemodynamics following acute lower and upper-body exercise in a cold environment among patients with coronary artery disease

Exercise is beneficial to cardiovascular health, evidenced by reduced post-exercise central aortic blood pressure (BP) and wave reflection. We assessed if post-exercise central hemodynamics are modified due to an altered thermal state related to exercise in the cold in patients with coronary artery disease (CAD). CAD patients (n = 11) performed moderate-intensity lower-body exercise (walking at 65–70% of HR_max) and rested in neutral (+ 22 °C) and cold (− 15 °C) conditions. In another protocol, CAD patients (n = 15) performed static (five 1.5 min work cycles, 10–30% of maximal voluntary contraction) and dynamic (three 5 min workloads, 56–80% of HR_max) upper-body exercise at the same temperatures. Both datasets consisted of four 30-min exposures administered in random order. Central aortic BP and augmentation index (AI) were noninvasively assessed via pulse wave analyses prior to and 25 min after these interventions. Lower-body dynamic exercise decreased post-exercise central systolic BP (6–10 mmHg, p < 0.001) and AI (1–6%, p < 0.001) both after cold and neutral and conditions. Dynamic upper-body exercise lowered central systolic BP (2–4 mmHg, p < 0.001) after exposure to both temperatures. In contrast, static upper-body exercise increased central systolic BP after exposure to cold (7 ± 6 mmHg, p < 0.001). Acute dynamic lower and upper-body exercise mainly lowers post-exercise central BP in CAD patients irrespective of the environmental temperature. In contrast, central systolic BP was elevated after static exercise in cold. CAD patients likely benefit from year-round dynamic exercise, but hemodynamic responses following static exercise in a cold environment should be examined further.

Clinical trials.gov: NCT02855905 04/08/2016.

Muscular and cardiorespiratory fitness are associated with health-related quality of life among young adult men

Background

Despite numerous studies providing evidence for positive effects of physical activity and physical fitness, evidence for association between physical fitness and health-related quality of life (HRQoL) in young adults is limited. The aim of the present cross-sectional study was to investigate the association of cardiorespiratory and muscular fitness with HRQoL from the perspective of its physical and mental components among young adult Finnish males.

Methods

The sample consisted of 754 men, with the mean age of 26 years (SD 6.7 years), who participated in the military refresher training. HRQoL was measured using the Finnish RAND 36-item health survey. Cardiorespiratory fitness was determined by a bicycle ergometer test, and muscular fitness by various tests measuring maximal strength and muscular endurance. Logistic regression modelling was used to compare low, moderate and high physical and mental component of HRQoL scores to the respective levels of muscular and cardiorespiratory fitness.

Results

The findings of the adjusted (age, educational level, marital status, employment status, smoking, use of alcohol and BMI) analysis showed that cardiorespiratory and muscular fitness are positively associated with both physical and mental components of HRQoL. In terms of the physical component of HRQoL, even a moderate fitness level was positively associated with better HRQoL. In terms of the mental component of HRQoL, the impact was seen only in the group with the highest fitness level.

Conclusions

The findings suggest a positive contribution of physical fitness to mental health and highlight the importance of both muscular and cardiorespiratory fitness in the promotion of HRQoL. Even lighter forms of physical activity that result in moderate physical fitness could contribute to the physical component of HRQoL. In terms of the mental component of HRQoL, higher levels of physical fitness may be needed to gain higher levels of HRQoL among young males.

Endothelial function in response to exercise in the cold in patients with coronary artery disease

BACKGROUND

Regular long-term physical exercise has favourable effects on endothelial function in patients with coronary artery disease (CAD). However, the effects of an acute exercise bout in the cold on endothelial function are not known.

METHODS

At first, the effects of moderate-intensity aerobic lower-body exercise were assessed in CAD patients (n = 16) in a neutral [+22°C] and cold [-15°C] environment. Secondly, responses to static and dynamic upper-body exercise in a neutral [+22°C] and cold [-15°C] environment were investigated in CAD patients (n = 15). All experiments were performed in a random order. Endothelial function was measured by flow-mediated dilation (FMD) of the brachial artery in response to reactive hyperaemia, before and after the exposures in a neutral environment.

RESULTS

No significant temperature*exercise*condition (pre-post) interaction was observed in FMD% when comparing rest versus aerobic exercise or static versus dynamic upper-body exercise. Relative reactive hyperaemia during FMD protocol, measured by changes in shear rate, was elevated after rest compared to aerobic exercise (p = .001) and after static compared to dynamic upper-body exercise (p < .001). However, no significant temperature*exercise*condition interaction was observed when FMD% was normalized for shear rate.

CONCLUSIONS

Endothelial function to an acute bout of exercise among CAD patients was not modified by the environmental temperature where the exercise was performed. The present findings argue against the hypothesis that exercise in cold environmental conditions impairs endothelial function in patients with CAD.

Cardiorespiratory and muscular fitness in young adult Finnish men between 2003 and 2015

INTRODUCTION

Physical fitness is strongly related to health and may offer valuable information about public health. We investigated trends in physical fitness, leisure-time physical activity (LTPA), and anthropometry of young healthy adult Finnish men in representative population-based samples between 2003 and 2015.

METHODS

Three independent cross-sectional samples of 18- to 35-year-old Finnish men were assessed in 2003 (n = 889), 2008 (n = 803), and 2015 (n = 690). Cardiorespiratory (VO₂ max) and muscular fitness (1-minute sit-ups and push-ups), body mass, and height were measured. Self-reported LTPA was assessed.

RESULTS

After adjusting for age, education, and smoking, cardiorespiratory fitness was higher in 2003 (mean: 43.5, 95%CI: 42.9-44.1 mL/kg/min) compared to 2008 (41.3, 95%CI: 40.7-41.9 mL/kg/min) and 2015 (40.6, 95%CI: 40.0-41.2 mL/kg/min) (P < .001), whereas no difference was observed between 2008 and 2015. The lowest values in muscular fitness were observed in 2003, while no clear trends were further noticed. The adjusted BMI was higher in 2008 (25.1, 95%CI: 24.9-25.4) and 2015 (25.3, 95%CI: 25.3, 95%CI: 25.0-25.6) compared to 2003 (24.5, 95%CI: 24.3-24.8) (P < .005). In 2015, a higher proportion of individuals exercised at least four times per week compared to 2003 and 2008 (P < .05).

CONCLUSION

The decrease in cardiorespiratory fitness that took place between 2003 and 2008 plateaued after 2008. The plateau is in accordance with the previously observed trend of 5-10 years younger Finnish men. Moreover, muscular fitness was for the most part higher in 2008 and 2015 compared to 2003. Efforts directed to promote regular physical activity and improve physical fitness are needed.

High Home Blood Pressure Variability Associates With Exaggerated Blood Pressure Response to Cold Stress

BACKGROUND

Exaggerated sympathetic cardiovascular (CV) reactivity to stress associates with elevated risk for clinical and preclinical end points of CV disease. It would be useful to identify these individuals, preferably from feasible measurements commonly used in health care. Our study examined the association between home blood pressure (BP) variability and cardiac workload response to whole-body cold exposure.

METHODS

Seventy-five men (55-65 years, 46 hypertensive) measured BP at home twice in the morning and evening for a week. We computed systolic home BP variability as SD of daily means and divided the subjects into groups demonstrating either high or low BP variability. They were exposed to whole-body cold exposure (-10 °C, wind 3 m/second, 15 minutes, winter clothes, standing). BP and heart rate were measured at 3-minute intervals during, and 15 minutes before and after the exposure. Rate-pressure product (RPP) was calculated to represent cardiac workload.

RESULTS

Subjects with high systolic home BP variability demonstrated a greater RPP increase in cold conditions compared to those with low BP variability [mean change from baseline (95% CI): 1,850 (1,450 to 2,250) bpm × mm Hg vs. 930 (610, 1,250) bpm × mm Hg, P < 0.01]. This was related to the augmented systolic BP change [31(28, 35) mm Hg vs. 23(20, 26) mm Hg, P < 0.01]. Home BP variability correlated with cold-related RPP (rS = 0.34, P = 0.003) and systolic BP (rS = 0.38, P < 0.001) responses.

CONCLUSIONS

Moderate whole-body cold exposure increased BP and cardiac workload more among those with higher systolic home BP variability, independently of home BP level. Elevated home BP variability may indicate augmented sympathetically mediated vascular reactivity for environmental stressors.

PUBLIC TRIALS REGISTRY NUMBER

Trial Number NCT02007031.

Cross-sectional area of the paraspinal muscles and its association with muscle strength among fighter pilots: a 5-year follow-up

Background

A small cross sectional area (CSA) of the paraspinal muscles may be related to low back pain among military aviators but previous studies have mainly concentrated on spinal disc degeneration. Therefore, the primary aim of the study was to investigate the changes in muscle CSA and composition of the psoas and paraspinal muscles during a 5-year follow up among Finnish Air Force (FINAF) fighter pilots.

Methods

Study population consisted of 26 volunteered FINAF male fighter pilots (age: 20.6 (±0.6) at the baseline). The magnetic resonance imaging (MRI) examinations were collected at baseline and after 5 years of follow-up. CSA and composition of the paraspinal and psoas muscles were obtained at the levels of 3–4 and 4–5 lumbar spine. Maximal isometric strength tests were only performed on one occasion at baseline.

Results

The follow-up comparisons indicated that the mean CSA of the paraspinal muscles increased (p < 0.01) by 8% at L3–4 level and 7% at L4–5 level during the 5-year period. There was no change in muscle composition during the follow-up period. The paraspinal and psoas muscles’ CSA was positively related to overall maximal isometric strength at the baseline. However, there was no association between LBP and muscle composition or CSA.

Conclusions

The paraspinal muscles’ CSA increased among FINAF fighter pilots during the first 5 years of service. This might be explained by physically demanding work and regular physical activity. However, no associations between muscle composition or CSA and low back pain (LBP) experienced were observed after the five-year follow-up.

Good safety practice in a randomized controlled trial (CadColdEx) involving increased cardiac workload in patients with coronary artery disease

Background

Methodological information acknowledging safety of cardiac patients in controlled medical experiments are lacking. The descriptive report presents one good practice for considering safety in a randomized controlled study involving augmented cardiovascular strain among persons with coronary artery disease (CAD).

Methods

The patients were pre-selected by a cardiologist according to strictly defined selection criteria. Further confirmation of eligibility included screening of health. In addition, assessments of physical capacity by a graded bicycle ergometer test were implemented and safety monitored by an exercise physiologist and medical doctor. In this context, an emergency simulation was also carried out. A total of 18 CAD patients each underwent four different experimental interventions where either temperature (+ 22 °C and − 15 °C) and the level of exercise (rest and brisk walking) were employed for 30 min in random order (72 experiments). Baseline (20 min) and follow-up (60 min) measurements were conducted resting at + 22 °C. ECG, and brachial blood pressure were measured and perceived exertion and symptoms of chest pain inquired throughout the experiments. An emergency nurse was responsible for the health monitoring and at least two persons followed the patient throughout the experiment. A medical doctor was available on call for consultation. The termination criteria followed the generally accepted international guidelines for exercise testing and were planned prior to the experiments.

Results

The exercise test simulation revealed risks requiring changes in the study design and emergency response. The cardiovascular responses of the controlled trials were related to irregular HR, ST-depression or post-exercise hypotension. These were expected and the majority could be dealt on site by the research personnel and on call consultation. Only one patient was encouraged to seek for external health care consultation.

Conclusions

Appropriate prospective design is a key to safe implementation of controlled studies involving cardiac patients and stimulation of cardiovascular function. This includes careful selection of participants, sufficient and knowledgeable staff, as well as identifying possible emergency situations and the required responses.

Trial registration

ClinicalTrials ID: NCT02855905.

Cardiovascular responses to cold and submaximal exercise in patients with coronary artery disease

Regular year-round exercise is recommended for patients with coronary artery disease (CAD). However, the combined effects of cold and moderate sustained exercise, both known to increase cardiac workload, on cardiovascular responses are not known. We tested the hypothesis that cardiac workload is increased, and evidence of ischemia would be observed during exercise in the cold in patients with CAD. Sixteen men (59.3 ± 7.0 yr, means ± SD) with stable CAD each underwent 4, 30 min exposures in a randomized order: seated rest and moderate-intensity exercise [walking, 60%-70% of max heart rate (HR)] performed at +22°C and -15°C. Systolic brachial blood pressure (SBP), HR, electrocardiogram (ECG), and skin temperatures were recorded throughout the intervention. Rate pressure product (RPP) and ECG parameters were obtained. The combined effects of cold and submaximal exercise were additive for SBP and RPP and synergistic for HR when compared with rest in a neutral environment. RPP (mmHg·beats/min) was 17% higher during exercise in the cold (18,080 ± 3540) compared with neutral (15,490 ± 2,940) conditions ( P = 0.001). Only a few ST depressions were detected during exercise but without an effect of ambient temperature. The corrected QT interval increased while exercising in the cold compared with neutral temperature ( P = 0.023). Recovery of postexercise blood pressure was similar regardless of temperature. Whole body exposure to cold during submaximal exercise results in higher cardiac workload compared with a neutral environment. Despite the higher RPP, no signs of myocardial ischemia or abnormal ECG responses were observed. The results of this study are useful for planning year-round exercise-based rehabilitation programs for stable CAD patients.

+Gz Exposure and Spinal Injury-Induced Flight Duty Limitations

BACKGROUND

The present study aimed to find out if possible differences in early military flight career +Gz exposure level could predict permanent flight duty limitations (FDL) due to spinal disorders during a pilot's career.

METHODS

The study population consisted of 23 pilots flying with Gz limitation (max limitation ranging from +2 Gz to +5 Gz) due to spinal disorders and 50 experienced (+1000 flight hours) symptomless controls flying actively in operative missions in the Finnish Air Force. Data obtained for all subjects included the level of cumulative Gz exposure measured sortie by sortie with fatigue index (FI) recordings and flight hours during the first 5 yr of the pilot's career.

RESULTS

The mean (± SD) accumulation of FI in the first 5 yr of flying high-performance aircraft was 8.0 ± 1.8 among the pilots in the FDL group and 7.7 ± 1.7 in the non-FDL group. There was no association between flight duty limitations and early career cumulative +Gz exposure level measured with FI or flight hours.

DISCUSSION

According to the present findings, it seems that the amount of cumulative +Gz exposure during the first 5 yr of a military pilot's career is not an individual risk factor for spinal disorders leading to flight duty limitation. Future studies conducted with FI recordings should be addressed to reveal the relationship between the actual level of +Gz exposure and spinal disorders, with a longer follow-up period and larger sample sizes.Honkanen T, Sovelius R, Mäntysaari M, Kyröläinen H, Avela J, Leino TK. +Gz exposure and spinal injury-induced flight duty limitations. Aerosp Med Hum Perform. 2018; 89(6):552-556.

Relationships Between Youth Sports Participation and Mental Health in Young Adulthood Among Finnish Males

Purpose:

To examine whether retrospectively assessed sports participation (SP) and competitive sports (CS) at the age of 12 years is associated with mental health and health behavior in young adulthood among males.

Design:

A cross-sectional study using self-administered questionnaires.

Setting:

Conducted prior to compulsory military refresher training course in Finland allowing geographically representative sample of Finnish young men.

Participants:

Six hundred eighty males aged between 20 and 35 years.

Measures:

Mental well-being was measured with the short version of Warwick-Edinburgh Mental Well-Being Scale and mental distress with 5 items of The Short Form Helalth Survey (SF-36) scale.

Analysis:

Binary logistic regression models.

Results:

Sports participation at the age of 12 was associated with better mental health in young adulthood, with both mental well-being (odds ratio [OR] = 1.86, 95% confidence interval 1.11-3.11) and mental distress (OR = 0.61, 0.41-0.90). Age, years of education, and current physical activity were controlled. Higher level of intensity of SP and the level of CS in childhood were associated with lower level of mental distress in adulthood. No association was found between the level of CS in childhood and mental well-being in adulthood. Further, youth SP seemed to be a risk factor for increased alcohol consumption and use of snuff in adulthood.

Conclusions:

Despite negative outcomes related to health behavior, the findings provide support for the association between youth SP and positive mental health outcomes in adulthood among males.

Feasibility of Gamified Mobile Service Aimed at Physical Activation in Young Men: Population-Based Randomized Controlled Study (MOPO)

Background

The majority of young people do not meet the recommendations on physical activity for health. New innovative ways to motivate young people to adopt a physically active lifestyle are needed.

Objective

The study aimed to study the feasibility of an automated, gamified, tailored Web-based mobile service aimed at physical and social activation among young men.

Methods

A population-based sample of 496 young men (mean age 17.8 years [standard deviation 0.6]) participated in a 6-month randomized controlled trial (MOPO study). Participants were randomized to an intervention (n=250) and a control group (n=246). The intervention group was given a wrist-worn physical activity monitor (Polar Active) with physical activity feedback and access to a gamified Web-based mobile service, providing fitness guidelines, tailored health information, advice of youth services, social networking, and feedback on physical activity. Through the trial, the physical activity of the men in the control group was measured continuously with an otherwise similar monitor but providing only the time of day and no feedback. The primary outcome was the feasibility of the service based on log data and questionnaires. Among completers, we also analyzed the change in anthropometry and fitness between baseline and 6 months and the change over time in weekly time spent in moderate to vigorous physical activity.

Results

Mobile service users considered the various functionalities related to physical activity important. However, compliance of the service was limited, with 161 (64.4%, 161/250) participants visiting the service, 118 (47.2%, 118/250) logging in more than once, and 41 (16.4%, 41/250) more than 5 times. Baseline sedentary time was higher in those who uploaded physical activity data until the end of the trial (P=.02). A total of 187 (74.8%, 187/250) participants in the intervention and 167 (67.9%, 167/246) in the control group participated in the final measurements. There were no differences in the change in anthropometry and fitness from baseline between the groups, whereas waist circumference was reduced in the most inactive men within the intervention group (P=.01). Among completers with valid physical activity data (n=167), there was a borderline difference in the change in mean daily time spent in moderate to vigorous physical activity between the groups (11.9 min vs −9.1 min, P=.055, linear mixed model). Within the intervention group (n=87), baseline vigorous physical activity was inversely associated with change in moderate to vigorous physical activity during the trial (R=−.382, P=.01).

Conclusions

The various functionalities related to physical activity of the gamified tailored mobile service were considered important. However, the compliance was limited. Within the current setup, the mobile service had no effect on anthropometry or fitness, except reduced waist circumference in the most inactive men. Among completers with valid physical activity data, the trial had a borderline positive effect on moderate to vigorous physical activity. Further development is needed to improve the feasibility and adherence of an integrated multifunctional service.

Trial registration

Clinicaltrials.gov NCT01376986; http://clinicaltrials.gov/ct2/show/NCT01376986 (Archived by WebCite at http://www.webcitation.org/6tjdmIroA)

Disordered eating behavior, health and motives to exercise in young men: cross-sectional population-based MOPO study

BACKGROUND

Being overweight is an increasing problem among young people, among whom disordered eating behavior is linked with weight problems as well as unhealthy weight control. The aim of the present study was to investigate whether health factors and motives to exercise differ in young men by the type of disordered eating behavior.

METHODS

The population-based, cross-sectional MOPO study consisted of 2,096 young Finnish men (mean age 17.9, SD 0.7) attending compulsory call-ups for military service in the Oulu area in 2010, 2011, and 2013. They responded to a questionnaire that included two subscales of the Eating Disorder Inventory-3 indicating drive for thinness and bulimic behavior and questions on health, physical activity, and motives to exercise. The association between disordered eating behavior and related factors was analyzed by binary logistic regression.

RESULTS

Altogether, 6.9 % (n = 145) of the men had symptoms of disordered eating, i.e., 5.4 % had a drive for thinness (n = 114) and 3.7 % had bulimic behavior (n = 77). Drive for thinness was associated with a perception of being overweight (OR 3.7; 95 % CI 2.2-6.1), poor self-rated health (2.3; 1.2-4.4), more leisure sitting time (1.1; 1.0-1.2), and body-related exercise motives (body acceptance: 3.0; 1.7-5.2; weight loss: 2.5; 1.4-4.4). Bulimic behavior was positively associated with poor self-rated health (2.6; 1.1-5.8) and several motives to exercise, i.e., due to another person's suggestion (2.8; 1.6-4.8), competitive sports (2.1; 1.2-3.7), body acceptance (2.1; 1.1-3.9), and weight loss (1.9; 1.1-3.3), but inversely associated with health/fitness-related exercise motives (health promotion: 0.3; 0.1-0.5; muscular strength or physical performance: 0.5; 0.2-0.9).

CONCLUSIONS

In young men, disordered eating behavior was associated with being overweight, having poor self-rated health, and having a greater amount of leisure sitting time as well as non-health-related motives to exercise. In order to recognize those at risk for disordered eating behavior, evaluating these factors could be beneficial.

Hypertension Does Not Alter the Increase in Cardiac Baroreflex Sensitivity Caused by Moderate Cold Exposure

Exposure to cold increases blood pressure and may contribute to higher wintertime cardiovascular morbidity and mortality in hypertensive people, but the mechanisms are not well-established. While hypertension does not alter responses of vagally-mediated heart rate variability to cold, it is not known how hypertension modifies baroreflex sensitivity (BRS) and blood pressure variability during cold exposure. Our study assessed this among untreated hypertensive men during short-term exposure comparable to habitual winter time circumstances in subarctic areas. We conducted a population-based recruitment of 24 untreated hypertensive and 17 men without hypertension (age 55–65 years) who underwent a whole-body cold exposure (−10°C, wind 3 m/s, winter clothes, 15 min, standing). Electrocardiogram and continuous blood pressure were measured to compute spectral powers of systolic blood pressure and heart rate variability at low (0.04–0.15 Hz) and high frequency (0.15–0.4 Hz) and spontaneous BRS at low frequency (LF). Comparable increases in BRS were detected in hypertensive men, from 2.6 (2.0, 4.2) to 3.8 (2.5, 5.1) ms/mmHg [median (interquartile range)], and in control group, from 4.3 (2.7, 5.0) to 4.4 (3.1, 7.1) ms/mmHg. Instead, larger increase (p < 0.05) in LF blood pressure variability was observed in control group; response as median (interquartile range): 8 (2, 14) mmHg², compared with hypertensive group [0 (−13, 20) mmHg²]. Untreated hypertension does not disturb cardiovascular protective mechanisms during moderate cold exposure commonly occurring in everyday life. Blunted response of the estimate of peripheral sympathetic modulation may indicate higher tonic sympathetic activity and decreased sympathetic responsiveness to cold in hypertension.

Functional test measures as risk indicators for low back pain among fixed-wing military pilots

PURPOSE

The purpose of this study was to find out the risk value of functional fitness test (FFT) results for low back pain (LBP) among fixed-wing military pilots.

METHODS

A total of 104 male military pilots were recruited for this study. The study was conducted with a self-administered questionnaire and FFT. The functional tests were performed in the beginning of study (baseline). The questionnaire was carried out at the baseline and 5 years later.

RESULTS

The isometric low back endurance test result was associated with physical activity-related LBP experienced 5 years later. Demographic information was not associated with LBP. The prevalence of overall LBP was 71% and the flight-related LBP prevalence was 31% at the baseline.

DISCUSSION

Our findings show that LBP among military pilots is a common problem but it is also associated with tasks other than flying. The functional test results were not associated with flight-related LBP but adequate isometric back endurance may have protective role in LBP caused in physical activities. When trying to find the pilots with increased risk of flight-related LBP, a more sensitive set of tests should be considered.

Profiles of sedentary and non-sedentary young men - a population-based MOPO study

BACKGROUND

Sedentary behavior is associated with poor well-being in youth with adverse trajectories spanning to adulthood. Still, its determinants are poorly known. Our aim was to profile sedentary and non-sedentary young men and to clarify their differences in a population-based setting.

METHODS

A total of 616 men (mean age 17.9, SD 0.6) attending compulsory conscription for military service completed a questionnaire on health, health behavior, socioeconomic situation and media use. They underwent a physical (body composition, muscle and aerobic fitness) and medical examination. Profiles were formed by principal component analysis (PCA).

RESULTS

A total of 30.1 % men were sedentary (daily leisure-time sitting ≥5 h) and 28.9 % non-sedentary (sitting ≤2 h). The sedentary men had more body fat, more depressive symptoms, but lower fitness and life satisfaction than non-sedentary men. However, according to PCA, profiles of unhealthy eating, life-dissatisfaction, and gaming were detected both among sedentary and non-sedentary men, as well as high self-rated PA and motives to exercise.

CONCLUSION

Determinants of sedentary and non-sedentary lifestyles were multiple and partially overlapping. Recognizing individual patterns and underlying factors of the sedentary lifestyle is essential for tailored health promotion and interventions.

Central aortic blood pressure of hypertensive men during short-term cold exposure

BACKGROUND

Short- and long-term exposures to cold increase blood pressure and may explain the higher wintertime cardiovascular morbidity and mortality. Hypertensive subjects may be more susceptible to adverse cold-related cardiovascular health effects. The aim of our study was to assess the effect of short-term cold exposure on central aortic blood pressure among untreated hypertensive men.

METHODS

We conducted a population-based recruitment of 41 hypertensive men and a control group of 20 men without hypertension (aged 55-65 years) who underwent whole-body cold exposure (15-minute exposure to temperature -10 °C, wind 3 m/s, winter clothes). Central aortic blood pressure, augmentation index, and subendocardial viability ratio were measured by radial artery applanation tonometry.

RESULTS

Short-term cold exposure increased the central aortic blood pressure similarly both in both hypertensive men, from 130/93 to 162/107 mm Hg (P < 0.001) and men in the control group, from 114/81 to 142/91 mmHg (P < 0.001). Augmentation index increased by 12% (from 10% to 22%, P < 0.001; and from 16% to 28%, P < 0.001, respectively), whereas subendocardial viability ratio decreased 10% (from 188% to 177%, P = 0.001; and from 203% to 193%, P = 0.01, respectively) during cold exposure in both hypertensive men and control subjects.

CONCLUSIONS

Short-term cold exposure increases central aortic blood pressure and cardiac workload, and myocardial oxygen demand slightly increases in relation to blood supply in untreated hypertensive middle-aged men. Because of the higher baseline blood pressure among hypertensive subjects, the cold-induced rise in central aortic blood pressure may increase the risk of adverse cardiovascular health effects.

Gamified physical activation of young men--a Multidisciplinary Population-Based Randomized Controlled Trial (MOPO study)

BACKGROUND

Inactive and unhealthy lifestyles are common among adolescent men. The planned intervention examines the effectiveness of an interactive, gamified activation method, based on tailored health information, peer networks and participation, on physical activity, health and wellbeing in young men. We hypothesize that following the intervention the physical activation group will have an improved physical activity, as well as self-determined and measured health compared with the controls.

METHODS/DESIGN

Conscription-aged men (18 years) attending compulsory annual call-ups for military service in the city of Oulu in Finland (n = 1500) will be randomized to a 6-months intervention (n = 640) or a control group (n = 640) during the fall 2013. A questionnaire on health, health behaviour, diet and wellbeing is administered in the beginning and end of the intervention. In addition, anthropometric measures (height, weight and waist circumference), body composition, grip strength, heart rate variability and aerobic fitness will be measured. The activation group utilizes an online gamified activation method in combination with communal youth services, objective physical activity measurement, social networking, tailored health information and exercise programs according to baseline activity level and the readiness of changes of each individual. Daily physical activity of the participants is monitored in both the activation and control groups. The activation service rewards improvements in physical activity or reductions in sedentary behaviour. The performance and completion of the military service of the participants will also be followed.

DISCUSSION

The study will provide new information of physical activity, health and health behaviour of young men. Furthermore, a novel model including methods for increasing physical activity among young people is developed and its effects tested through an intervention. This unique gamified service for activating young men can provide a translational model for community use. It can also be utilized as such or tailored to other selected populations or age groups.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01376986.

Sports activity and the use of cigarettes and snus among young males in Finland in 1999-2010

BACKGROUND

Studies of the relationship between sports activity and smoking among adolescents and young adults report contradictory results. We examined the association between sports activity (intensity and type of sport) and the current use of snus (Swedish snuff), cigarette smoking, and the combined use of cigarettes and snus (dual use) among young males in Finland.

METHODS

Data were collected from 16,746 male conscripts who completed a survey during the first days of their conscription during the years 1999-2010 (median age 19 years, response rate 95%). Main outcome measures were self-reported daily/occasional use of snus, cigarette smoking, and dual use. The association between sports activity, type of sport, and several sociodemographic background variables was assessed using logistic regression analysis.

RESULTS

Over the study period (1999-2010), the prevalence of cigarette smoking decreased from 42% to 34%, while snus use increased from 5% to 12%, and dual use increased from 7% to 13% (p < 0.001). Compared with no physical activity, regular competitive sports activity (defined as high-intensity sports activity) was positively associated with use of snus (odds ratio [OR] 10.2; 95% confidence interval [CI]: 7.8-13.5) and negatively with cigarette smoking (OR 0.2; 95% CI: 0.1-0.3). When stratified by type of sport in multivariate models, ice hockey was most strongly associated with snus use (OR 1.6; 95% CI: 1.4-1.9) and dual use (OR 2.0; 95% CI 1.8-2.3) compared with those not playing ice-hockey, followed by other team sports for snus use (OR 1.5; 95% CI: 1.3-1.8) and dual use (OR 1.8; 95% CI: 1.6-2.0) compared with those not participating in other team-sports.

CONCLUSIONS

Our results show a clear association between snus use and intensity and type of training. Team sports were associated with increased use of snus and dual use compared with no participation in team sports. These findings should be acknowledged when planning and implementing preventive strategies.

Unaltered blood coagulation and platelet function in healthy subjects exposed to acute hypoxia

INTRODUCTION

Acute hypoxia has been suspected to cause blood coagulation and platelet activation. Our aim was to study blood coagulation and platelet function during a short hypoxic exposure.

METHODS

Healthy nonsmoking men (N = 10) inhaled a normobaric hypoxic gas mixture containing 8% of oxygen (92% nitrogen) for 7 min via a face mask. Venous blood was collected 5 min before and during the 5 to 7 min of hypoxia exposure (i.e., pretest and hypoxia samples, respectively) while monitoring arterial oxygen saturation (SaO2) with pulse oximetry. Blood sampling was completed in 2 min and the face mask was removed. Venous epinephrine and norepinephrine, complete blood counts, and a panel of coagulation markers were analyzed. Platelet aggregation induced by ristocetin, adenosine diphosphate (ADP), arachidonic acid, and thrombin receptor activating peptide was studied with Multiplate and shear force-dependent functions with PFA-100R (collagen/epinephrine and collagen/ADP cartridges), both assays in whole blood.

RESULTS

During hypoxia, SaO2 declined from 98 to 58% (ranges 97-99% vs. 42-85%), while heart rate increased from 69/min to 94/min (SD 11 vs. SD 13). Venous epinephrine and norepinephrine levels also increased. This short hypoxia induced minor but uniform increases in red cells, reticulocytes, and leukocytes and decreases in platelet counts. Plateletfunctions and prothrombin time, APTT, thrombin time, D-dimer, fibrinogen levels or von Willebrand factor (VWF), antithrombin, factor V (FV) or FVIII activities did not change.

DISCUSSION

Profound acute hypoxia failed to affect blood coagulation or platelet functions in healthy individuals.

Deep breathing improves blunted baroreflex sensitivity even after 30 years of type 1 diabetes

AIMS/HYPOTHESES

Cardiovascular autonomic neuropathy is associated with increased morbidity in patients with type 1 diabetes. Although it is conventionally considered to be an organic, irreversible disorder, we previously demonstrated in patients with short-duration type 1 diabetes that reduced baroreflex sensitivity (BRS) could be corrected by slow, deep breathing, indicating a functional component to the disorder. We have now tested whether autonomic abnormalities in long-term diabetes progress to a stage that cannot be modified by functional manoeuvres, indicating a switch towards predominantly organic dysfunction.

METHODS

We studied 117 patients with a short duration (8.9 ± 0.1 years) and 37 patients with a long duration (33.7 ± 0.5 years) of type 1 diabetes, 73 healthy controls and 12 heart-transplanted participants (surgical heart denervation). An autonomic score was calculated from autonomic function tests. Spectral analysis of heart rate and blood pressure variability, and BRS, were obtained from recordings during normal (15 breaths per min) and slow, deep (six breaths per min) controlled breathing.

RESULTS

BRS was reduced in all patients, but more in patients with a long duration of diabetes or with increasing autonomic involvement, although the effect of duration disappeared after adjustment for age. Slow breathing increased the BRS to the level of the control participants at a normal rate of breathing (15 per min) in all patients except those with an abnormal autonomic score.

CONCLUSIONS/INTERPRETATION

Patients with type 1 diabetes have a blunted BRS that in the majority of patients can be restored by slow breathing, irrespective of disease duration. Even after a long duration of diabetes, the abnormal BRS is at least in part of functional origin.

Early autonomic dysfunction in type 1 diabetes: a reversible disorder?

AIMS/HYPOTHESIS

Cardiac autonomic neuropathy is associated with increased morbidity and mortality rates in patients with type 1 diabetes. The prevalence of early autonomic abnormalities is relatively high compared with the frequency of manifest clinical abnormalities. Thus, early autonomic dysfunction could to some extent be functional and might lead to an organic disease in a subgroup of patients only. If this is true, manoeuvres such as slow deep-breathing, which can improve baroreflex sensitivity (BRS) in normal but not in denervated hearts, could also modify autonomic modulation in patients with type 1 diabetes, despite autonomic dysfunction.

METHODS

We compared 116 type 1 diabetic patients with 36 matched healthy control participants and 12 heart-transplanted participants with surgically denervated hearts. Autonomic function tests and spectral analysis of heart rate and blood pressure variability were performed. BRS was estimated by four methods during controlled (15 breaths per minute) and slow deep-breathing (six breaths per minute), and in supine and standing positions.

RESULTS

Conventional autonomic function tests were normal, but resting spectral variables and BRS were reduced during normal controlled breathing in patients with type 1 diabetes. However, slow deep-breathing improved BRS in patients with type 1 diabetes, but not in patients with surgically denervated hearts. Standing induced similar reductions in BRS in diabetic and control participants.

CONCLUSIONS/INTERPRETATION

Although we found signs of increased sympathetic activity in patients with type 1 diabetes, we also observed a near normalisation of BRS with a simple functional test, indicating that early autonomic derangements are to a large extent functional and potentially correctable by appropriate interventions.

International Physical Activity Questionnaire

PURPOSE

This study was conducted to criterion-validate the short format of International Physical Activity Questionnaire (IPAQ) against health-related fitness.

METHODS

Participants included 951 men, aged 21-43 yr. VO2max by ergometer was used to measure cardiorespiratory fitness. Muscular fitness tests included the number of sit-ups, push-ups, and squats performed during 60 s. Physical activity was assessed from IPAQ by categories for health (health-enhancing physical activity (HEPA)) and by calculating total and vigorous MET-hours per week. The participants were classified in five groups of almost equal size by the IPAQ outcomes. Moreover, the frequency of vigorous activity was assessed by one precoded question (single-item question on leisure-time vigorous physical activity (SIVAQ)).

RESULTS

The mean fitness improved from the first through the fourth IPAQ group. VO2max in the most active IPAQ group, however, was lower than in the fourth group (P < 0.05), both with HEPA categories and vigorous METs as the outcome. In contrast, the weekly frequency of vigorous physical activity showed a positive association with fitness through all six categories. The 65 sedentary (according to SIVAQ) and unfit individuals who belonged to the highest 20% (by IPAQ total METs) were older (30.6 +/- 5.1 vs 28.9 +/- 3.8, P = 0.02), more obese (waist 93 +/- 12 vs 89 +/- 10 cm), more often current smokers (59.4 vs 42.0%; P = 0.03), and less educated (<12 yr of education 70.8 vs 52.0%; P = 0.02), compared with the others in the highest IPAQ group.

CONCLUSIONS

Almost 10% of young men had poor fitness and apparently low physical activity, but they reported very high physical activity by IPAQ. An evident need therefore exists to develop IPAQ further to solve the apparent overreporting by a considerable proportion of sedentary individuals.

Waist circumference and BMI are independently associated with the variation of cardio-respiratory and neuromuscular fitness in young adult men

OBJECTIVE

To test two hypotheses: (1) cardiorespiratory (CRF) and neuromuscular (NMF) fitness is associated with body mass index (BMI) and waist circumference (WC), independent of each other and of leisure-time physical activity; (2) individuals with high CRF and NMF have lower WC for a given BMI, compared with those with low CRF and NMF.

DESIGN

Cross-sectional study.

SETTING

Men participating in refresher training organized by the Finnish Defence Forces.

PARTICIPANTS

A total of 951 men (mean age 29.1, s.d. 4.2 years; BMI 25.3 kg/m(2), s.d. 3.8; WC 91, s.d. 11 cm).

MAIN OUTCOME MEASURES

Body mass index, WC, maximal oxygen uptake (VO(2)max), height of vertical jump, number of push-ups and sit-ups during a 1-min test, static back extension endurance, isometric grip strength, self-reported leisure-time vigorous physical activity. Multiple linear regressions were used to explain the variation in fitness.

RESULTS

Waist circumference had significant (P<0.001) negative association with all test results (standardized beta coefficients from -0.23 to -0.77), except for grip strength. Body mass index had significant negative association with VO(2)max (-0.12; P<0.05), but positive association (P<0.01) with grip strength (0.28), vertical jump (0.21) and push-ups (0.55). For a given BMI, the estimated WC was highest among those with the poorest results for VO(2)max, vertical jump, sit-ups and push-ups.

CONCLUSIONS

Despite stronger isometric grip strength, the functional muscle fitness of the upper body, trunk and lower extremities is impaired in individuals with abdominal obesity. Although the known loss of CRF is a serious consequence of obesity, the deterioration of NMF deserves increased attention.

Hormonal responses to 100 km cross-country skiing during 2 days

AIM

The purposes of this study were to investigate the resting levels and the acute hormonal responses of serum testosterone and cortisol, and with time-resolved immunofluorometric assay of luteinising hormone (LH) and follicle stimulating hormone (FSH), to daily repeated prolonged skiing.

METHODS

Quasi-experimental design: short-term follow-up, (reversal) field trial to investigate the daily responses of blood hormones to repeated 50 km skiing during 2 days in men.

PARTICIPANTS

10 physically active men (34.8+/-9.7 y, 1.82+/-0.05 m, 76.1+/-6.6 kg, BMI: 23.0+/-1.5 kg.m(-2)) participating in the Finlandia Ski Race, covering a total distance of 100 km during 2 days.

MEASURES

venous blood samples were obtained before and after skiing, and after 1 week's recovery, to determine the concentrations of testosterone, LH, FSH and cortisol in the blood.

RESULTS

Testosterone was reduced by over 20% after both days (p=0.016 and 0.002, respectively). LH decreased after the 1( st) race by 37% and after the 2nd race by 44% (p=0.028, both). FSH secretion was stable and cortisol increased 2.2- and 2.6-fold after the races (p<0.001).

CONCLUSIONS

The participants in the 2 days' prolonged skiing exercise went through a period of heavy physical stress. They showed changes in their serum testosterone, LH and cortisol concentrations, which, with the exception of the FSH secretion, alter the acute responses of both the adrenal cortex and the hypothalamus-pituitary-testicular axis. When training or competition programmes are planned it should taken into consideration that daily repeated high intensity prolonged skiing without a recovery day may cause hormonal overreaching.

The Effects of a Four-Day March on the Gonadotrophins and Mood States of Army Officers

The effects of daily repeated prolonged exercise on gonadotrophin levels and mood states were studied in six physically active army officers participating in a 4-day march totaling 185 km. We hypothesized that submaximal daily repeated prolonged exercise may disturb the balance of the hypothalamic-pituitary-testicular axis, which could be determined from the concentrations of serum luteinizing hormone and follicle-stimulating hormone with time-resolved immunofluorometric assay. In addition, the mood states of the men were followed during the exercise period. The results indicate that soldiers who are in good physical condition and are accustomed to marching are capable of marathon walking on 4 successive days while carrying a 10-kg backpack, without any major adverse effects on the function of the hypothalamic-pituitary-testicular axis or mood states. This study indicates that psychological monitoring and physiological measurements could be of value in following responses to daily repeated prolonged psychophysiological stress in field conditions with soldiers.

Hormonal responses to daily strenuous walking during 4 successive days

The hormonal response to 4 days' walking exercise (totaling 164 km) was examined among 15 healthy males. We hypothesised that submaximal daily, repeated, prolonged exercise may disturb the balance of the adrenal cortex and pituitary-testicular axis, which could be analysed from the concentrations of serum cortisol and testosterone, and with time-resolved immunofluorometric assay (IFMA) of luteinising hormone (LH) and follicle stimulating hormone (FSH). In the adrenal cortex the increased response to acute exercise could be seen after the 1st day. The concentration of testosterone was reduced after the first two exercise sessions and a plateau was reached after the 3rd day of walking. LH decreased during the 2nd and 3rd day by 31% (P = 0.04 and 0.001, respectively) and remained steady on the 4th day. In FSH the suppression was seen all the time after the second exercise session and before the final walk it was reduced by 19% (P = 0.02) compared with the baseline. The acute response of the adrenal cortex and pituitary-gonadal axis (excluding secretion of FSH) disappeared within 4 days of repeated prolonged walking and no dramatic lasting changes occurred despite this major 4-day effort. However, when using the sensitive IFMA, which can detect low concentrations of gonadotropins, secretion of FSH was seen to remain reduced and no stability was seen.

Predictors of abnormal cardiovascular autonomic function measured by frequence domain analysis of heart rate variability and conventional tests in patients with type 1 diabetes

OBJECTIVE

Frequency domain analysis of heart rate variability (HRV) is used to assess cardiovascular autonomic function. There are no prospective data on the sensitivity of its various components to glycemia or other diabetes-related risk factors compared with conventional tests and with other complications of diabetes.

RESEARCH DESIGN AND METHODS

In 1985, possible risk factors of future complications were determined in 115 children with type 1 diabetes. In 1996, the presence of complications (HRV analysis, conventional tests of autonomic function, urinary albumin excretion rate [UAER], and retinopathy) were assessed in 83 of these patients (age 32 +/- 1 years, duration of diabetes 22 +/- 1 years).

RESULTS

Poor glycemic control (measured as lifetime glycemic exposure or HbA1c in 1985) was the most important independent predictor of decreases in all measures of absolute power of HRV (total power [TP] and very low frequency, low frequency [LF], and high frequency [HF] power) and square root of the mean square of R-R interval differences but not of changes of normalized measures or ratios (normalized HF and LF LF/HF). Other significant independent predictors of autonomic dysfunction were late age of onset of diabetes, female sex, and high BMI. To examine the sensitivity of the various tests to glycemia, the patients were divided into tertiles based on lifetime glycemic exposure (A1c months). Glycemic exposure in the tertiles averaged 194 +/- 25 A1c months (20 years of HbA1c 0.8% above normal), 556 +/- 19 A1c months(20 years of HbA1c 2.3% above normal), and 963 +/- 30 A1c months (20 years of HbA1c 4% above normal). Tests of complications that were significantly abnormal in patients already in the lowest tertile and were correlated with glycemia were TP and severity of retinopathy. Of conventional tests, only the ratio of length of R-R intervals during expiration to inspiration (E/I ratio) was significantly related to glycemic exposure, but it required high glycemic exposure (20 years of HbA1c 4% above normal) to be abnormal. UAER was significantly increased only in the highest tertile of glycemic exposure.

CONCLUSIONS

TP and retinopathy score were much more sensitive to antecedent glycemia than conventional tests of autonomic function or UAER and were significantly abnormal in patients exposed to approximately 20 years' duration of an HbA1c 0.8% above normal.

Autoantibodies against oxidized LDL and endothelium-dependent vasodilation in insulin-dependent diabetes mellitus

We determined whether autoantibodies against oxidized LDL are increased in patients with IDDM, and if so, whether they are associated with endothelial dysfunction in vivo. Autoantibodies against oxidized LDL (ratio of antibodies against oxidized vs. native LDL, oxLDLab) were determined in 38 patients with IDDM (HbA(1c) 8.4+/-0.2%), who were clinically free of macrovascular disease, and 33 healthy normolipidemic subjects (HbA(1c) 5.1+/-0.1%, P<0.001 vs. IDDM). The groups had comparable serum total-, LDL- (2. 9+/-0.1 vs. 2.8+/-0.1 mmol/l, IDDM vs. controls), and HDL-cholesterol concentrations. OxLDLab were 1.5-fold higher in the IDDM patients (1.8+/-0.1) than in the normal subjects (1.2+/-0.1, P<0.001). OxLDLab were correlated with age in normal subjects, but not with age, duration of disease, LDL-cholesterol, HbA(1c) or degree of microvascular complications in patients with IDDM. To determine whether oxLDLab are associated with endothelial dysfunction in vivo, blood flow responses to intrabrachial infusions of acetylcholine, sodium nitroprusside and L-NMMA were determined in 23 of the patients with IDDM (age 33+/-1 years, body mass index 24. 3+/-0.6 kg/m(2), HbA(1c) 8.5+/-0.3%) and in the 33 matched normal males. OxLDLab were 41% increased in IDDM (1.7+/-0.2 vs. 1.2+/-0.1, P<0.01). Within the group of IDDM patients, HbA(1c) but not oxLDLab or LDL-cholesterol, was inversely correlated with the forearm blood flow response to acetylcholine (r=-0.51, P<0.02), an endothelium-dependent vasodilator, but not to sodium nitroprusside (r=0.06, NS). These data demonstrate that oxLDLab concentrations are increased in patients with IDDM, but show that chronic hyperglycemia rather than oxLDLab, is associated with impaired endothelium-dependent vasodilation in these patients.

Angiotensinogen gene M235T polymorphism predicts left ventricular hypertrophy in endurance athletes

OBJECTIVES

We studied whether left ventricular mass in athletes associates with polymorphisms in genes encoding components of the renin-angiotensin system.

BACKGROUND

Adaptive left ventricular hypertrophy is a feature of the athlete's heart. However, similarly training athletes develop left ventricular mass to a different extent, suggesting that genetic factors may modulate heart size.

METHODS

We measured left ventricular mass by echocardiography in 50 male and 30 female elite endurance athletes aged 25 +/- 4 (mean +/- SD) years. Deoxyribonucleic acid samples were prepared for genotyping of angiotensinogen (AGT) gene M235T polymorphism, angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and angiotensin II type 1 receptor (AT1) gene A1166C polymorphism.

RESULTS

The AGT gene M235T genotypes were significantly associated with left ventricular mass independently of blood pressure in both genders (p = 0.0036 for pooled data). TT homozygotes had greater mass compared with MM homozygotes in both men (147 +/- 12 g/m vs. 132 +/- 15 g/m, p = 0.032) and women (121 +/- 12 g/m vs. 101 +/- 13 g/m, p = 0.019). There was a gender difference in the relation between myocardial mass and AGT genotype, MT heterozygotes resembling MM homozygotes among women and TT homozygotes among men. The other studied gene polymorphisms were not associated with left ventricular mass.

CONCLUSIONS

Angiotensinogen gene M235T polymorphism is associated with the variability in left ventricular hypertrophy induced by endurance training, with athletes homozygous for the T allele having the largest hearts. We found no association between ACE gene I/D or AT1 gene A1166C polymorphisms and left ventricular mass.

QT interval and QT dispersion in endurance athletes and in power athletes using large doses of anabolic steroids

We measured electrocardiographic repolarization indexes in athletes. Physiologic adaptive cardiac hypertrophy did not increase QT dispersion in endurance athletes despite long QT intervals due to increased vagal tone. In contrast, power athletes taking large doses of anabolic steroids had increased QT dispersion despite short QT intervals, which seems to reflect altered myocardium in the hypertrophied heart.

Impaired endothelium-dependent vasodilation in type 2 diabetes. Relation to LDL size, oxidized LDL, and antioxidants

OBJECTIVE

To search for determinants of endothelial dysfunction in type 2 diabetes.

RESEARCH DESIGN AND METHODS

We performed a comprehensive analysis of cardiovascular risk markers and measured blood flow responses to endothelium-dependent (acetylcholine [ACh] and NG-monomethyl-L-arginine) and -independent (sodium nitroprusside [SNP]) vasoactive agents in 30 nonsmoking men with type 2 diabetes (age 51 +/- 1 years, BMI 27.8 +/- 0.4 kg/m2, HbA1c 7.4 +/- 0.3%) and 12 matched normal control men.

RESULTS

ACh-induced vasodilation was 37% lower in type 2 diabetic (6.1 +/- 0.5) than in normal subjects (9.7 +/- 1.5 ml.dl-1.min-1, P < 0.01), while flows during SNP were similar (9.1 +/- 0.6 vs. 9.9 +/- 1.3 ml.dl-1.min-1, NS). The ratio of endothelium-dependent vs. -independent flow (ACh:SNP ratio) was 31% lower in type 2 diabetic (0.70 +/- 0.05) than in normal subjects (1.10 +/- 0.18, P < 0.01). Total (2.2 +/- 0.4 vs. 1.3 +/- 0.2 mmol/l, P < 0.05), VLDL, and intermediate-density lipoprotein triglycerides were significantly higher, and the mean LDL particle diameter was significantly smaller in type 2 diabetic than in normal subjects. The lag times for LDL oxidation by Cu2+ in vitro were similar in patients with type 2 diabetes (183 +/- 7) and in normal subjects (183 +/- 9 min, NS). Measured and calculated (sum of concentration of individual antioxidants in serum) total peroxyl radical-trapping capacities (TRAPs) were comparable between the groups. In the patients with type 2 diabetes, LDL size was significantly correlated with endothelium-dependent vasodilation (r = 0.43, P < 0.05), serum triglycerides (r = -0.75, P < 0.001), and the lag time for LDL oxidation in vitro (r = 0.38, P < 0.05). HbA1c was inversely correlated with the lag time for LDL oxidation in vitro (r = -0.41, P < 0.05) and TRAP.

CONCLUSIONS

In summary, patients with type 2 diabetes exhibited impaired endothelium-dependent vasodilation in vivo, elevated serum triglycerides, decreased LDL size, and normal antioxidant capacity. Of these parameters, LDL size was significantly correlated with endothelial function.

Serum total renin, an independent marker of the activity and severity of retinopathy in patients with IDDM

BACKGROUND/AIMS

Recent studies have demonstrated marked renin and prorenin concentration gradients between ocular tissues and blood, and local expression of the renin-angiotensin system (RAS) in the eye. The authors determined whether serum total renin, which mostly consists of prorenin, is a marker of the activity and severity of diabetic retinopathy independent of other microvascular complications.

METHODS

Total renin concentrations (TRC) were measured with a time resolved immunofluorometric assay in 38 patients with IDDM (age 34 (SD 7) years, duration of disease 22 (7) years, serum creatinine 95 (15) mumol/l, urinary albumin excretion rate (UAER) 207 (829) micrograms/min, HbA1c 8.5% (1.2%)), and in 13 matched normal subjects. All subjects were carefully characterised with respect to the presence and severity of retinopathy (RP score), nephropathy, and neuropathy using seven different tests of autonomic neuropathy.

RESULTS

Serum TRC was on average twofold higher in IDDM (396 (SE 211) ng/l) than in normal subjects (201 (88) ng/l, p < 0.001). It was nearly twofold higher in patients with preproliferative or active proliferative retinopathy requiring careful follow up or therapy (TRC 596 (268) ng/l, n = 11) compared with those with quiescent proliferative retinopathy after laser treatment (TRC 338 (183) ng/l, p < 0.01, n = 5); moderately severe non-proliferative retinopathy (337 (106) ng/l, p < 0.01, n = 13), no retinopathy, or only minimal non-proliferative retinopathy (270 (43) ng/l, p < 0.001, n = 9). In multiple linear regression analysis, RP score (p < 0.01), but not the UAER or any index of autonomic neuropathy, was an independent determinant of serum TRC, and explained 32% of its variation (R = 0.57, p < 0.005).

CONCLUSIONS

Serum TRC in patients with diabetic retinopathy is increased independent of renal function and autonomic neuropathy especially in those with severe active changes requiring careful follow up or treatment. These findings support the idea that diabetic retinopathy is the most important determinant of serum TRC in patients with IDDM, and that TRC is produced when retinopathy is active.

Mechanisms of altered hemodynamic and metabolic responses to insulin in patients with insulin-dependent diabetes mellitus and autonomic dysfunction

Patients with autonomic neuropathy are more susceptible to insulin-induced hypotension than normal subjects, but the mechanisms are unclear. We quantitated the hemodynamic and metabolic effects of two doses of i.v. insulin (1 and 5 mU/kg.min, 120 min each) and several aspects of autonomic function in 28 patients with insulin-dependent diabetes mellitus (IDDM) and in 7 matched normal subjects under standardized normoglycemic conditions. The autonomic function tests included those predominantly assessing the integrity of vagal heart rate control (the expiration inspiration ratio during deep breathing and high frequency power of heart rate variability) and tests measuring sympathetic nervous function (reflex vasoconstriction to cold and blood pressure responses to standing and handgrip). During hyperinsulinemia, heart rate increased less (2 +/- 1 vs. 6 +/- 2 beats/min; P < 0.04) and diastolic blood pressure fell more (-3.1 +/- 1.2 vs. 0.9 +/- 2.1; P = NS) in the patients with IDDM than in the normal subjects. Forearm vascular resistance decreased significantly in the patients with IDDM [by -7.1 +/- 1.4 mm Hg/(mL/dL.min); P < 0.001 for high vs. low dose insulin], but not in the normal subjects (-0.1 +/- 2.5 mm Hg/(mL/dL.min; P = NS). Reflex vasoconstriction to cold was inversely correlated with the decreases in diastolic (r = -0.51; P < 0.005) and systolic (r = -0.59; P < 0.001) blood pressure and forearm vascular resistance (r = -0.53; P < 0.005), but not with the change in heart rate. The expiration inspiration ratio was, however, directly correlated with the insulin-induced change in heart rate (r = 0.63; P < 0.001), but not with diastolic or systolic blood pressure or forearm vascular resistance. Whole body (48 +/- 2 vs. 67 +/- 5 mumol/kg.min; P < 0.005) and forearm (44 +/- 4 vs. 67 +/- 8 mumol/kg.min; P < 0.05) glucose uptake were significantly lower in the IDDM patients than in the normal subjects. The latter could be attributed to a defect in the forearm glucose arterio-venous difference (1.5 +/- 0.1 vs. 2.2 +/- 0.2 mmol/L, respectively; P < 0.01), but not in blood flow. We conclude that both impaired vagal heart rate control and sympathetic nervous dysfunction exaggerate the hemodynamic effects of insulin in patients with IDDM and could contribute to insulin-induced hypotension.

Changes in autonomic nervous function during the 4-year follow-up in middle-aged diabetic and nondiabetic subjects initially free of coronary heart disease

OBJECTIVES

To study the changes in autonomic nervous function during the 4-year follow-up period in diabetic patients and to investigate factors predicting autonomic nervous dysfunction.

DESIGN

A 4-year follow-up study.

SETTING

At baseline the study subjects without known cardiovascular disease were recruited from a large group of diabetic and nondiabetic subjects selected randomly from a baseline population.

SUBJECTS

Middle-aged control subjects (n = 44), patients with insulin-dependent diabetes mellitus (n = 32) and patients with non-insulin-dependent diabetes mellitus (n = 32) were studied at baseline and after the 4-year follow-up.

INTERVENTIONS

Autonomic nervous function tests and exercise test at baseline and after the 4-year follow-up.

RESULTS

At the baseline, heart rate variation during deep breathing was significantly lower in patients with insulin-dependent diabetes (13.0 +/- 1.2 beats min-1; P < 0.05) and in patients with non-insulin-dependent diabetes (12.9 +/- 1.5 beats min-1; P < 0.05) than in control subjects (16.6 +/- 1.1 beats min-1). At baseline, autonomic nervous function score was significantly higher indicating disturbed autonomic nervous function in patients with insulin-dependent diabetes (1.74 +/- 0.19; P < 0.01) than in control subjects (1.24 +/- 0.14), but the difference was not significant between control subjects and patients with non-insulin-dependent diabetes (1.47 +/- 0.12). During the follow-up, autonomic nervous function score increased in patients with non-insulin-dependent diabetes to 2.00 +/- 0.21 (P < 0.001, as compared to baseline), but did not change in patients with insulin-dependent diabetes (1.77 +/- 0.18) or control subjects (1.22 +/- 0.12). In both diabetic groups, the deterioration of autonomic nervous function score during the 4-year follow-up was associated with poor glycaemic control at baseline. Clinical manifestation of coronary heart disease was found in three (7%) control subjects, 12 (37%; P < 0.001) patients with insulin-dependent diabetes and 11 (34%; P < 0.01) patients with non-insulin-dependent diabetes mellitus at follow-up examination. Autonomic nervous function was more abnormal in those insulin-dependent diabetic patients with coronary heart disease than those without.

CONCLUSIONS

During the 4-year follow-up the impairment in autonomic nervous function occurred mainly in patients with noninsulin-dependent diabetes. Poor glycaemic control appears to be an important determinant of the progression of autonomic nervous dysfunction in diabetes.

Hyperreactivity to nitrovasodilators in forearm vasculature is related to autonomic dysfunction in insulin-dependent diabetes mellitus

BACKGROUND

The link between diabetes and vascular disease is poorly understood. Data regarding endothelial function in vivo in patients with insulin-dependent diabetes mellitus (IDDM) have been inconsistent with in vitro studies demonstrating hyperglycemia-induced impairments in endothelium-dependent vasodilation.

METHODS AND RESULTS

We determined whether alterations in neural control of the vascular tone might contribute to blood flow responses to intrabrachial infusions of acetylcholine (ACh), sodium nitroprusside (SNP), and L-N-monomethyl-arginine (L-NMMA) in 22 men with IDDM (12 with normoalbuminuria. HbA1c = 8.6 +/- 0.3%; 10 with macroalbuminuria, HbA1c = 8.6 +/- 0.3%) and 11 matched normal men. Autonomic function was assessed from reflex vasoconstriction to cold, the blood pressure response to standing and hand grip, and heart rate variation, including spectral analysis, during controlled breathing, and the Valsalva maneuver. IDDM with macroalbuminuria exhibited hyperresponsiveness to both ACh and SNP compared with the patients with normoalbuminuria or normal subjects. Reflex sympathetic vasoconstriction to cold was severely impaired in the IDDM patients with macroalbuminuria (-19 +/- 6%) compared with normoalbuminuric patients (-39 +/- 5%, P < .05) and normal subjects (-54 +/- 7%, P < .001). The macroalbuminuric patients also had evidence of autonomic dysfunction during controlled and deep breathing tests and during the Valsalva maneuver. Within the group of IDDM patients, neither the urinary albumin excretion rate nor other parameters such as HbA1c or serum cholesterol correlated with forearm blood flow during the vasoactive drug infusions. There were, however, significant inverse correlations between several measures of both sympathetic and parasympathetic autonomic functions and vascular hyperresponsiveness to SNP and ACh. For example, the Valsalva ratio was inversely correlated with the increase in blood flow in response to infusion of 3 (r = -.74, P < .001) and 10 (r = -.73, P < .001) micrograms/min SNP and 7.5 (r = -.73, P < .001) and 15 (r = -.75, P < .001) micrograms/min ACh.

CONCLUSIONS

These data are consistent with idea that altered neurotransmission is an important determinant of vascular reactivity of diabetic blood vessels to nitrovasodilators in vivo.

Left ventricular mass, geometry, and filling in endurance athletes: association with exercise blood pressure

We studied whether left ventricular (LV) mass and concentricity [relative myocardial volume (RMV)] are associated with exercise blood pressure (BP) in athletes. LV structure and filling were evaluated by Doppler echocardiography and BP in maximal bicycle ergometry and isometric handgrip tests on 32 male endurance athletes and 15 age-matched controls. Indexed LV mass was 145 +/- 14 (SD) g/m in athletes and 93 +/- 20 g/m in controls. Mass was not associated with BP at rest or in low-grade exercise, but with heavier exercise loads this association strengthened in athletes, being maximal at peak exercise (r = 0.65 for mass and 0.58 for indexed mass; P < 0.001). Multivariate analysis indicated that BP at peak exercise accounted for 34% and the amount of training for an additional 11% of the variance in indexed LV mass. RMV was 21% larger in athletes. Only the increase in systolic BP during handgrip explained significantly (19%) the variance in RMV. LV filling velocities were not associated with mass, RMV, or BP. We conclude that in endurance athletes LV mass is associated with BP in heavy dynamic exercise and LV concentricity with BP response in static exercise.

The effects of a 4-day march on the lower extremities and hormonal balance

The functional strength, flexibility, and ranges of motion of the lower extremities, as well as hormonal balance, estimated by urinary excretion of adrenaline and noradrenaline and serum determinations of testosterone and cortisol, were studied with six physically active army officers participating in a 4-day march totaling 185 km. Catecholamine excretion rates showed cumulatively increased sympathoadrenal stress, and the effects on serum testosterone and cortisol concentrations were minor. Also, leg measurements showed no signs of edema, decreases in flexibility, or decreases in functional strength. Most pain (75%) experienced by the subjects was located in the feet and caused by abrasions and blisters. Only a small portion of perceived pains (25%) was associated with muscle soreness. Serum creatine kinase activity was slightly (ca. 400-650%) increased during the marching days. Thus, soldiers who are in good physical condition and are accustomed to marching are able to walk four marathons on successive days, while carrying 10-kg backpacks, without any major adverse effects on the musculature of their lower extremities.

Serious cardiovascular side effects of large doses of anabolic steroids in weight lifters

Pathological cardiovascular manifestations are reported in four male patients, who had taken massive amounts of anabolic steroids while undergoing many years of strength training. One patient was referred because of ventricular fibrillation during exercise, one because of clinically manifest heart failure, and one because of arterial thrombus in his lower left leg. The fourth patient was persuaded to attend for a check-up because of a long history of massive use of anabolic steroids. All four patients had cardiac hypertrophy. Two of the patients had symptoms and signs of heart failure, and one of these two had a massive thrombosis in both right and left ventricles of his heart. After cessation of the use of anabolic steroids in the other patient with heart failure, left ventricular wall thickness reduced quickly from 12 to 10.5 mm, and fractional shortening increased from 14% to 27%. Endomyocardial biopsy revealed increased fibrosis in the myocardium in two of the three cases. HDL-cholesterol was 0.58 mmol.l-1 and 0.35 mmol.l-1 in the two patients still using multiple anabolic steroids at the time of investigation. The cardiovascular findings described in the present paper should warn all physicians and athletes about the possible serious acute and long-term side effects of the massive use of anabolic steroids.

Measurement of myocardial accumulation of 123I-metaiodobenzylguanidine for studying cardiac autonomic neuropathy in diabetes mellitus

The association of myocardial 123I-metaiodobenzylguanidine (MIBG) accumulation and autonomic neuropathy, as well as factors known to affect autonomic nervous function, were studied in a group of 12 diabetic patients representing different degrees of autonomic failure. The early myocardial uptake phase of 123I-MIBG was measured by calculating the peak net influx rate for the first 30 min after the 123I-MIBG injection and by single photon emission computed tomography (SPECT) imaging 1 h after the injection. The retainment of 123I-MIBG in the myocardium was measured using SPECT imaging 6 h after the injection, and myocardial uptake and the myocardium/liver uptake ratio were calculated. The 6-h myocardium/liver uptake ratio of 123I-MIBG was significantly (p < 0.05) lower in the diabetic patients with clinically evident autonomic neuropathy compared with those without autonomic neuropathy. Greater body mass index was associated with lower peak net influx rate and 1-h myocardial uptake of 123I-MIBG, and greater diastolic blood pressure was associated with lower 1-h myocardial uptake of 123I-MIBG, whether or not the patients had diabetic autonomic neuropathy. In conclusion, reduction in the 6-h myocardium/liver uptake ratio of 123I-MIBG is related to diabetic autonomic neuropathy. Because the early 123I-MIBG accumulation in myocardium is reduced in diabetic patients with greater body mass index and diastolic blood pressure, irrespective of autonomic neuropathy, our results encourage the use of the late myocardial accumulation of 123I-MIBG for studying sympathetic neuropathy in the diabetic heart.

Sympathetic reinnervation after acute myocardial infarction

Myocardial infarction produces sympathetic denervation of the necrotic myocardium and noninfarcted myocardium apical to the injury. Proof of sympathetic reinnervation after myocardial infarction has, however, remained elusive. In this study, we investigated whether cardiac sympathetic reinnervation occurs in men recovering from myocardial infarction. I-123 metaiodobenzylguanidine (MIBG), I-123 paraphenylpentadecanoic acid, and Tc-99m sestamibi scintigraphic imaging were conducted in 13 men 3 and 12 months after a first myocardial infarction to determine the extent of denervated myocardium, the size of the infarct, and the size of the myocardium with reduced perfusion, respectively. A defect was determined as regional uptake of < or = 30% of the maximal myocardial activity. The size of the MIBG defect was not significantly different between 3 and 12 months after infarction (17 +/- 8% and 18 +/- 8% of left ventricular mass, respectively). There was also no significant change in the extent of viable but denervated myocardium at 3 and 12 months (average 9 +/- 6% and 10 +/- 5%, respectively). MIBG activity of the infarct zone (expressed as a percentage of MIBG activity of the myocardium with normal perfusion) did not change (17 +/- 13% and 20 +/- 16%), whereas MIBG activity of the periinfarct zone increased during follow-up (32 +/- 11% and 41 +/- 14%, p < 0.01). This was associated with an increase in periinfarct I-123 paraphenylpentadecanoic acid activity (40 +/- 11% and 48 +/- 9%, p < 0.05), but not Tc-99m sestamibi activity (48 +/- 10% and 48 +/- 11%). In conclusion, we did not observe sympathetic reinnervation in the infarct zone between 3 and 12 months after myocardial infarction. However, MIBG activity of the periinfarct zone increased, suggesting partial reinnervation, and this was associated with a recovery of myocardial metabolic activity of the periinfarct zone.