Medical and social factors influencing the utilization of healthcare services among older adults in Israel during the COVID-19 lockdown.

Background: The corona virus disease 2019 (COVID-19) pandemic significantly impacted older adults. However, most older communities focused on the medical issues. The aims of this study were to identify the medical and social factors linked with the usage of medical services during the COVID-19 lockdown in Israel. Methods: The study was conducted Over two periods of time from February to April in 2019 (P1), before the COVID-19 and from February to April in 2020 (P2), during the first lockdown. The study was conducted on people aged 65 and older in Israel. The variable statistics were analyzed using frequency tabulation, cross-tabulation frequencies, and t-tests. Two hierarchical logistic regressions were conducted over four steps for each period. Results: The participants (n = 102,303) comprised 64.5% female (65,946) and 35.5% male (36,357) (mean age 80.5, SD- 7.46). It was found that participants who had not subscribed to the supportive community services were 7.47 times more likely to access medical services in P1 and 12.417 times more likely to access medical services during the lockdown. This variable was also found to be a strong predictor in the final model. The most significant variable for predicting the participants' needs during P2 was their previous needs in P1. Other social variables were living in assisted living home and living in community settlements. The presence of 12 diseases in this study did not predict service demand. Conclusion: Community support reduces medical service demands during disasters and provides services for older adults. During pandemics, however, social services need to be expanded and made more easily accessible to older adults.

Health promotion programs in prison: attendance and role in promoting physical activity and subjective health status.

Introduction: Maintaining an inmate's health can serve as a challenge due to unhealthy background, risky behavior, and long imprisonment. This study aimed to analyze the prevalence of participation in health promotion activities among Israeli inmates and its association with their physical activity levels and subjective health status. Methods: A cross-sectional study was designed to examine 522 inmates (429 males, 93 females). The data were collected by trained face-to-face interviewers and self-report questionnaires. Results: Most of the participants (82.37%) did not meet the recommended physical activity level. Half of the participants reported that their physical activity levels decreased since they were in prison compared with 29.50% who reported that their physical activity levels increased. Physical activity and subjective health status were significantly higher among younger male inmates. Furthermore, participation in health-promoting activities was associated with higher levels of physical activity and subjective health status. Discussion: Health promotion activities may play an important role in addressing the challenges of maintaining inmate health. Implications of the findings are further discussed.

Socio-demographic characteristics and their relation to medical service consumption among elderly in Israel during the COVID-19 lockdown in 2020 as compared to the corresponding period in 2019.

PURPOSE: The COVID-19 pandemic has led to the isolation of the population in Israel, including the elderly. The present study aimed to compare the consumption of medical services among adults over the age of 65 in Israel at the time of the first COVID-19 lockdown relative to the corresponding period the year before. METHODS: We conducted a retrospective longitudinal observational quantitative research based on the Natali Healthcare Solutions Israel database of subscribers. Company subscribers over the age of 65 (N = 103,955) were included in the sample (64.5% women) in two time periods, before the COVID-19 outbreak-P1, in 2019, and during the first COVID-19 lockdown- P2 in 2020. Logistic regression was applied to examine service consumption for study variables. RESULTS: The average number of referrals to services was lower during the COVID-19 lockdown period (M = 0.3658, SD = 0.781) compared to the corresponding period in the previous year (M = 0.5402, SD = 0.935). The average number of ambulance orders, doctor home visits and service refusals were higher when compared to the same period in the previous year. During both time periods, women (P1- M = 0.5631, SD = 0.951; P2- M = 0.3846, SD = 0.800) required significantly more (p < .000) services than men (P1- M = 0.5114, SD = 0.910; P2- M = 0.3417, SD = 0.753). Older, widowed people, living in non-Jewish/mixed localities, or in average or below average socioeconomic status localities required relatively more services to those with opposite socio-demographic traits (p < .000). SUMMARY AND CONCLUSIONS: In a large sample of elderly in Israel, findings indicate a decrease in referrals to medical care during the first COVID-19 lockdown period, yet an increase in ambulance orders, doctor visits and service refusals. Socio-demographic characteristics showed a similar effect in both time periods. The period of the first COVID-19 lockdown was characterized by a higher incidence of medical service refusals as compared to the equivalent period in the previous year.

Social Factors Contributing to Healthcare Service Requirements during the First COVID-19 Lockdown among Older Adults.

This study examined social characteristics and their relations to healthcare service demand among older adults during the first COVID-19 lockdown in 2020. The sample was based on a cohort of 103,955 adults over the age of 65. A general index of needs was composed based on healthcare service use data and was predicted in a multi-nominal logistic regression. The frequency of the total needs significantly (p < 0.000) declined while supportive community services (4.9%, 2.0%), living in a community framework (27.0%, 15.2%), and living in a private residence (29.7%, 20.1%) were significantly associated (p < 0.000) with less frequent needs compared to the complementary groups. Supportive communities turned out to be an extremely important service for older adults. Policy makers should consider expanding supportive community services for older adults, as it was shown to have a positive correlation with lower healthcare service use, which might be an indicator of better overall health.

An accurate wearable hydration sensor: Real-world evaluation of practical use.

A wearable body hydration sensor employing photoplethysmographic and galvanic biosensors was field evaluated using 240 human participants with equal numbers of men and women volunteers. Monitoring of water mass loss due to perspiration was performed by medical balance measurements following one of two different treadmill physical exercise regimens over 90 minutes in 15-minute intervals with intervening 10-minute rest periods. Participants wore two different models of the dehydration body monitor device mated to commercially-available smartwatches (Samsung Gear S2 and Samsung Gear Fit2). Device output was recorded by Bluetooth wireless link to a standard smartphone in 20-second blocks. Comparison of the devices with the standard measurement method (change in body mass measured by medical balance) indicated very close agreement between changes in body water mass and device output (percent normalized mean root square error averaged approximately 2% for all participants). Bland-Altman analyses of method agreement indicated that <5% of participant values fell outside of the 95% confidence interval limits of agreement and all measured value differences were normally distributed around the line of equality. The results of this first-ever field trial of a practical, wearable hydration monitor suggests that this device will be a reliable tool to aid in geriatric hydration monitoring and physical training scenarios.

A cross-sectional study on preferred employment settings of final-year nursing students in Israel.

BACKGROUND: Despite the growing demand for community nurses, their number remains relatively low. We examined perceptions of final-year nursing students regarding their preferred work setting after graduation and the factors affecting their choice. METHODS: A cross-sectional survey using a structured questionnaire was developed specifically for this study. The questionnaire was distributed among fourth-year students from all nursing training frameworks across Israel. RESULTS: Of 281 respondents (76.6% women, average age, 29.3 years), most (80.9%) preferred working in hospitals, while 5% preferred community settings; 14% were undecided. Students' knowledge on hospital nurses' tasks was greater compared to their knowledge on community nurses' tasks. Moreover, hospital nurses' tasks were perceived as more important than those of community nurses. The contribution of clinical placement in hospital nursing was perceived as significantly more meaningful than the contribution of clinical placement in community nursing. The vast majority of students (94.3%) stated that they would prefer to undergo a hospital nursing internship. A significant correlation was noted between students' clinical placement, the exposure to community nursing roles, and the perception of the community nurse's role: clinical placements that were perceived as a positive experience led to a more positive perception of community nurses' roles. CONCLUSIONS: Nursing students' perception of community nursing is based upon limited information which does not reflect community nurses' actual role and work.

Feasibility, Safety, and Effectiveness of a Mobile Application in Cardiac Rehabilitation.

BACKGROUND: Cardiac rehabilitation (CR) is underutilized globally despite evidence of clinical benefit. Major obstacles for wider adoption include distance from the rehabilitation center, travel time, and interference with daily routine. Tele-cardiac rehabilitation (tele-CR) can potentially address some of these limitations, enabling patients to exercise in their home environment or community. OBJECTIVES: To evaluate the clinical and physiological outcomes as well as adherence to tele-CR in patients with low cardiovascular risk and to assess exercise capacity, determined by an exercise stress test, using a treadmill before and following the 6-month intervention. METHODS: A total of 22 patients with established coronary artery disease participated in a 6-month tele-CR program. Datos Health (Ramat Gan, Israel), a digital health application and care-team dashboard, was used for remote monitoring, communication, and management of the patients. RESULTS: Following the 6-month tele-CR intervention, there was significant improvement in exercise capacity, assessed by estimated metabolic equivalents with an increase from 10.6 ± 0.5 to 12.3 ± 0.5 (P = 0.002). High-density lipoproteins levels significantly improved, whereas low-density lipoproteins, triglyceride, glycosylated hemoglobin, and systolic and diastolic blood pressure levels were not significantly changed. Exercise adherence was consistent among patients, with more than 63% of patients participating in a moderate intensity exercise program for 150 minutes per week. CONCLUSIONS: Patients who participated in tele-CR adhered to the exercise program and attained clinically significant functional improvement. Tele-CR is a viable option for populations that cannot, or elect not to, participate in center-based CR programs.

[FROM 'REMOTE CARDIAC REHABILITATION' TO CHRONIC DISEASE MANAGEMENT PROGRAMS BY DIGITAL MEANS - REVIEW OF THE NATIONAL PROGRAM AS A MODEL FOR MULTI-DISCIPLINARY DISEASE MANAGEMENT].

INTRODUCTION: Cardiovascular diseases, often accompanied by many background diseases, are the main cause of morbidity and mortality globally. Cardiac rehabilitation programs are a key component of secondary prevention and lack of participation or adherence lead to significantly higher adverse event rates including hospitalization and mortality. Technological means have great potential for improving health care outcomes. Home-cardiac rehabilitation (H-CR) using technology implements the 'patient-centered' approach within the health services. Last year, the Israeli Ministry of Health approved the H-CR program for a low-risk patient and included it into medical coverage of the state. In accordance with the Ministry of Health circular, the H-CR program is implemented at the Sheba Medical Center since November 2018. The program incorporates innovative technology alongside multi-professional care. Implementation of the program enables studies about the methods to put into effect the therapeutic model in other chronic disease management, including home rehabilitation or hospitalization programs, while maintaining patient safety and securing medical information. The purpose of this article is to review the first H-CR program in Israel, its components, benefits, and challenges, as well as, to present the therapeutic model, its competence in multidisciplinary disease management and increased responsiveness to the treatment.

Digital Cardiac Rehabilitation Programs: The Future of Patient-Centered Medicine.

Background: The low participation rate in cardiac rehabilitation programs is the major reason for rehospitalization, morbidity, and mortality. Home-based cardiac rehabilitation by technological means is an essential component of a "patient-centered" approach, which is capable of enhancing the participation rate in rehabilitation programs. Introduction: The aim of this research was to examine attitudes, perceptions, and behavioral intentions toward remote digital cardiac rehabilitation (RDCR) with respect to factors such as age, education, smoking, exercise habits, technological illiteracy, and mobile phone behavior. Materials and Methods: This was a cross-sectional study of 200 adult patients discharged from a hospital after an acute coronary syndrome, cardiac surgery, or percutaneous coronary intervention. All patients answered an anonymous Technology Usage Questionnaire, which examined the relationship between their willingness to participate in the RDCR program and various parameters. The surveys were distributed and completed between July 2017 and November 2017 at the Sheba Medical Center in Israel. Results: Overall, 83% of all participants were interested in participating in the RDCR program. Those with heart failure had a greater interest in the program (100%; p < 0.05), whereas patients after coronary bypass surgery had a lesser interest (71.1%; p < 0.05). The level of attitude toward healthy lifestyle was found to be a significant predictor of willingness to participate in RDCR (odds ratio 2.26; p = 0.01). Sociodemographic characteristics, lifestyle, habits, technological knowledge, age, and gender were not found as significant predictors of interest in RDCR. Conclusions: The RDCR program was acceptable to most cardiac patients, including the elderly population, and could be a potential solution for patients who avoid traditional rehabilitation programs in medical centers.

Comparative accuracy of optical sensor-based wearable system for non-invasive measurement of blood glucose concentration.

Non-invasive biosensors for indirect evaluation of routinely-measured blood components by sweat analysis have broad potential clinical applications. This trial tested a wrist-borne non-invasive glucose monitor (NIGM) to measure blood glucose (BG) levels using photoplethysmographic (PPG) optical sensors. Our aim was to determine the accuracy of the device in comparison with a standard, invasive clinical method for blood glucose monitoring. Adult participants (n = 200) of both sexes from 18 to 75 were recruited for the study. Exclusion criteria: hemophilia and other serious coagulation disorders, impaired venous access, other serious medical conditions. A biosensor was placed on the right wrist of each participant for a non-invasive indirect BG measurement. In parallel, blood from the antecubital vein was collected and glucose levels were assessed with YSI 2300 Bioanalyzer. The measurements were performed twice: before and after food intake, with a 1-h interval between measurements. There were no limitations to food type and quantity. In both anteprandial (ρ = 0.8994, p < 0.0001) and postprandial (ρ =0.9382, p < 0.0001) glucose measurements, NIGM correlated with values obtained by the YSI 2300 reference device - there was no significant difference between the two methods. Plotted on a Parkes Error Grid for Type II diabetes, NIGM readings did not deviate from those of the YSI 2300 in any clinically-significant way, with the majority of correlated readings falling within Parkes zone A. Very few readings fell within Parkes zone B. In anteprandial measurements, the mean bias between methods for all patient volunteers was 3.705 ±â€¯7.838. In postprandial measurements gave a mean bias of 1.362 ±â€¯10.15 for all patient glucose data. The mean absolute relative difference of currently available glucometer models ranges from 5.6% to 20.8%. The NIGM falls in the lower end of this error range at 7.40-7.54%, indicating that PPG-chemochrome sensors are capable of producing results comparable with those of direct measure glucometers. Data presented here demonstrates the reliability and accuracy of the NIGM system as an adjunctive, and perhaps substitutive, non-invasive tool for blood glucose monitoring.

Orange napkins increase food intake and satisfaction with hospital food service: A randomized intervention.

OBJECTIVES: Increased malnutrition risk has been identified in >30% of hospitalized adults in Israel. Because orange has been identified as an appetite stimulant, orange napkins were considered a low-cost enhancement of the meal context. The aim of this study was to assess the effect of an orange napkin on the meal tray on food intake and satisfaction with food service among adults hospitalized in an internal medicine department. METHODS: One hundred and thirty-one patients hospitalized in Internal Medicine Department E, Edith Wolfson Medical Center, Holon, Israel, participated in the study. Patients were randomized to lunch trays with an orange (experimental) or white (control) napkin. Digital imaging was used with the modified Comstock Scale to quantify dietary intake. A validated questionnaire was used to score satisfaction with the hospital's food service. Medical history, anthropometric measures, reason for hospitalization, and meal modifications were extracted from the medical record. RESULTS: Patients in the orange napkin group (n = 66) consumed 17.6% more hospital-provided food than those in the white napkin (control) group (n = 65), driven by the significantly greater proportion of the carbohydrate side dishes and the vegetable dishes consumed. Patients in the orange napkin group also reported significantly greater satisfaction with the hospital's food service. CONCLUSION: The addition of an orange napkin to the meal tray of patients hospitalized in internal medicine departments can increase dietary intake and improve satisfaction with hospital food services. At about 5 cents per piece, the orange napkin is a low-cost, easily implemented strategy to address malnutrition risk in hospitalized adults.

Is an enhanced behaviour change intervention cost-effective compared with physiotherapy for patients with chronic low back pain? Results from a multicentre trial in Israel.

OBJECTIVE: To assess the cost-effectiveness of an enhanced transtheoretical model of behaviour change in conjunction with physiotherapy compared with standard care (physiotherapy) in patients with chronic lower back pain (CLBP). DESIGN: Cost-utility and cost-effectiveness analyses alongside a multicentre controlled trial from a healthcare perspective with a 1-year time horizon. SETTING: The trial was conducted in eight centres within the Sharon district in Israel. PARTICIPANTS: 220 participants aged between 25 and 55 years who suffered from CLBP for a minimum of 3 months were recruited. INTERVENTIONS: The intervention used a model of behaviour change that sought to increase the adherence and implementation of physical activity in conjunction with physiotherapy. The control arm received standard care in the form of physiotherapy. PRIMARY AND SECONDARY MEASURES: The primary outcome was the incremental cost per quality-adjusted life year (QALY) of the intervention arm compared with standard care. The secondary outcome was the incremental cost per Roland-Morris Disability Questionnaire point. RESULTS: The cost per QALY point estimate was 10 645 New Israeli shekels (NIS) (£1737.11). There was an 88% chance the intervention was cost-effective at NIS50 000 per QALY threshold. Excluding training costs, the intervention dominated the control arm, resulting in fewer physiotherapy and physician visits while improving outcomes. CONCLUSIONS: The enhanced transtheoretical model intervention appears to be a very cost-effective intervention leading to improved outcomes for low cost. Given limitations within this study, there is justification for examining the intervention within a larger, long-term randomised controlled trial. TRIAL REGISTRATION NUMBER: NCT01631344; Pre-results.

Outcomes in Distressed Patients With Chronic Low Back Pain: Subgroup Analysis of a Clinical Trial.

Study Design Subgroup analysis of a controlled clinical trial. Background Current evidence suggests that people with chronic low back pain who are distressed may require different interventions than do those who are not distressed. Recently, the enhanced transtheoretical model intervention (ETMI) reported significant improvements in disability and pain and increased physical activity in patients with chronic low back pain compared to physical therapy as usual. Objectives To compare outcomes between ETMI and physical therapy interventions for participants with and without self-reported distress. Methods We tested the interaction between intervention (ETMI versus physical therapy) and distress status (using the Medical Outcomes Study 12-Item Short-Form Health Survey cut point), and performed between-group comparisons on 3 separate outcomes (disability, pain, and physical activity) at 3 and 12 months. Results In the ETMI group, 57 of 108 participants were considered distressed, versus 62 of 106 participants in the physical therapy group. The interaction between intervention and distress at 12 months was significant. Participants improved with both interventions, but the magnitude of change in distressed participants who received ETMI was larger than that in distressed participants who received physical therapy (mean ± SD difference from baseline in disability of 6.1 ± 6.1 in the ETMI group, compared with 3.4 ± 6.7 in the physical therapy group). Conclusion The enhanced transtheoretical model intervention was significantly more effective than physical therapy in participants with distress. The trial was registered in ClinicalTrials.gov (NCT01631344). Level of Evidence Therapy, level 2b. J Orthop Sports Phys Ther 2018;48(6):491-495. Epub 27 Mar 2018. doi:10.2519/jospt.2018.7670.

Increasing Recreational Physical Activity in Patients With Chronic Low Back Pain: A Pragmatic Controlled Clinical Trial.

Study Design Prospective, pragmatic, nonrandomized controlled clinical trial. Background Clinical guidelines recommend physical activity for the treatment of chronic low back pain. But engaging patients in physical activity has proven difficult. Known obstacles to physical activity include low self-efficacy and fear avoidance. Objectives This study tested the effectiveness of an enhanced transtheoretical model intervention (ETMI) aimed at increasing recreational physical activity in patients with chronic low back pain, in comparison to usual physical therapy. Methods Patients (n = 220) referred to physical therapy for chronic low back pain were allocated to ETMI or to a control group. The ETMI was delivered by physical therapists and based on behavior-change principles, combined with increased reassurance, therapeutic alliance, and exposure to reduce fear avoidance. The primary outcome was back pain-related disability (Roland-Morris Disability Questionnaire). Secondary outcomes included pain intensity, mental and physical health, and levels of physical activity. Results Intention-to-treat analysis in 189 patients at 12 months indicated that patients in the ETMI group had significantly lower disability compared to usual physical therapy. The difference in mean change from baseline between the interventions was 2.7 points (95% confidence interval: 0.9, 4.5) on the Roland-Morris Disability Questionnaire. At 12 months, worst pain, physical activity, and physical health were all significantly better in patients receiving ETMI. The average number of sessions was 3.5 for the ETMI group and 5.1 for controls. Conclusion Targeting obstacles to physical activity with an intervention that includes components to address self-efficacy and fear avoidance appears to be more effective than usual physical therapy care in reducing long-term disability. Further research is needed to explore the mechanisms that impact outcomes in this intervention package. Level of Evidence Therapy, level 2b. Registered June 7, 2012 at ClinicalTrials.gov (NCT01631344). J Orthop Sports Phys Ther 2017;47(2):57-66. doi:10.2519/jospt.2017.7057.

[Fluid and sodium balance during exercise--standpoint].

During exercise certain metabolic and physiological processes influence fluid and electrolyte balance. Fluid loss, mostly through sweating, that is not properly compensated for by drinking, may result in dehydration. Clinical manifestations of dehydration depend on the amount of fluid lost. The more severe the level of dehydration is, the greater the reduction in physical and cognitive performance. It is recommended to drink water frequently and in small amounts. In order to encourage drinking, the fluid should be cool, palatable, readily available, and not carbonated. During exercise the ability of the kidney to excrete water is restricted, and therefore, there is a risk of hyperhydration and hyponatremia, mainly under conditions of overdrinking. Sodium loss through sweating and the development of hyponatremia will primarily occur during strenuous exercise lasting more than 4 hours. Symptoms of hyponatremia will generally appear at sodium concentrations below 130 mmol/l. In order to avoid hyponatremia one must avoid overdrinking, and during prolonged physical activity (> 4 hours) sodium intake must match the amount lost by sweating. Proper electrolyte and carbohydrate consumption through a normal diet is preferable to sport beverages or exogenous sodium supplements. In order to avoid dehydration, on one hand, and hyponatremia due to hyperhydration, on the other hand, the amount of fluid consumed should complement the amount of fluid lost during exercise. Given that there is intra- (depending on the type of activity and environmental conditions) and interindividual variability in the rate of fluid and salt loss, fluid and salt intake should be determined on an individual basis, as outlined in this standpoint.

[Tolerance to heat in burnt patients].

Body temperature regulated within the homeostatic range, is essential for the stability of the "milieu intérieur" and for maintaining intact body functioning. Those individuals in the population who cannot adapt to heat stress and whose body temperature will rise earlier and at a higher rate than expected under predetermined conditions are considered as 'heat intolerant". Patients with deep burns are intolerant to heat because of the injured dermis and the destruction of the imbedded eccrine sweat glands and the peripheral vascular bed and its post-synaptic innervations, which common treatment with split-thickness skin grafts cannot restore. Thus, the extent of the inability to regulate body temperature is associated with the percent of the burnt area - the Larger the affected area, the lower is the ability to thermoregulate. The cumulative data suggest that the state of heat intolerance in deep-burnt patients is a persisting condition and cannot be alleviated by heat acclimation.

Physical exercise enhances hepatic insulin signaling and inhibits phosphoenolpyruvate carboxykinase activity in diabetes-prone Psammomys obesus.

We have shown that physical exercise enhances insulin sensitivity of skeletal muscle in diabetes-prone Psammomys-obesus. In this study, we examined the effect of physical exercise on the liver of these animals. Three groups of animals were exposed to a 4-week protocol; high-energy diet (CH), high-energy diet and exercising (EH), and low-energy diet (CL). Different groups were studied either in a fed state or after an overnight fast, 30 minutes after intraperitoneal (IP) injection of 1 U insulin. Hepatic phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) activity was measured. Insulin signaling response was examined after insulin injection in the fast state by analyzing tyrosine phosphorylation of insulin receptor (IR) and the association between insulin receptor substrate-1 (IRS-1) and IRS-2 with phosphatidylinositol 3 kinase (PI3-K). After 4 weeks, none of the EH animals became diabetic, whereas all the CH animals became diabetic. PEPCK activity in the fed state was higher in the CH group compared with the CL and EH groups (480 +/- 28 nmol/min/mg protein, 280 +/- 30 nmol/min/mg protein, and 208 +/- 13 nmol/min/mg protein, respectively) (P < .02). G6Pase activity was higher in the CH and EH groups compared with the CL group (261 +/- 54 nmol/min/mg protein, 251 +/- 34 nmol/min/mg protein, and 75 +/- 32 nmol/min/mg protein, respectively) (P < .01). After insulin administration in the fast state, tyrosine phosphorylation of IR and association of IRS-2 with PI3-K were higher in the EH and CL groups than in the CH group. We conclude that exercise improves in vivo hepatic insulin sensitivity in diabetes-prone Psammomys-obesus.

Assessment of heat tolerance for post exertional heat stroke individuals.

BACKGROUND: The aim of this study was to evaluate the heat tolerance test, which was performed by individuals with high risk for heat injuries, for exposure duration and climatic conditions. MATERIAL/METHODS: Nineteen young (19+/-1 yr) post heat stroke males performed 2 separate tolerance tests consisting of identical treadmill walking (5km.h-1, 2% grade) for 120 min during hot (40 degrees C, 40%RH) and comfort (20 degrees C, 50%RH) climate conditions. Physiological monitoring included rectal temperature (Tre), heart rate (HR), skin temperature and sweat rate (msw). Concomitantly, strain evaluation was assessed by the physiological strain index (PSI) and the cumulative heat strain index (CHSI). RESULTS: 14 subjects were categorized as heat tolerant (HT) and 5 subjects as heat intolerant (HI). The comfort tolerance test was found as irrelevant for heat intolerance assessment. PSI after 60 min (PSI60) was unable to predict PSI after 120 min (PSI120) whereas there was not a high enough correlation between CHSI60 and CHSI120. CONCLUSIONS: It was concluded that tolerance to heat must be tested during heat stress and the test duration cannot be shorter than 120 min.

Hydration status measurement by radio frequency absorptiometry in young athletes--a new method and preliminary results.

A new method for non-invasive measurement of the human state of hydration is presented. This method is based on frequency-dependent absorptiometry of radio-waves passing through tissues. A device utilizing this method was constructed and applied to 12 young (24 +/- 1) male volunteers, who were dehydrated for 1-2.5% of their weight by performance of a physical effort (two 30 min bouts of treadmill walking/running at 2, 3, 4, 5, 6 and 7 mph, 5 min at each speed, separated by 10 min rest), under moderate heat stress (40 degrees C, 40% RH). Hypohydration level was determined by body weight measurements taken before each session, after 30 min and at the end of each session. Concomitantly, measurements of radio frequency (RF) absorption were taken. Each volunteer underwent the heat stress exercise twice: one in which no drinking was permitted, and another with free drinking. A correlation (R2 = 0.734) between weight loss and a change in the radio-waves absorption pattern was observed in most of the volunteers, in both hypo and euhydration sessions. Further work to establish the reproducibility and validity of the RF methodology in larger and different populations, i.e., females, other age groups and different health conditions, is already being researched.

Human ACE I/D polymorphism is associated with individual differences in exercise heat tolerance.

We hypothesized that there is an association between the angiotensin I-converting enzyme (ACE) insertion (I)/deletion (D) polymorphism with the variability in exercise heat tolerance in humans. Fifty-eight Caucasian men were exposed to a 2-h exercise heat-tolerance test. We analyzed the association between their heat-tolerance levels with the ACE DD (n = 25) and I+ (n = 33) genotypes and with various anthropometrical parameters and aerobic fitness. It was found that the relative changes in body core temperature, heat storage, and heart rate during the 120-min exposure to exercise heat stress was consistently lower in the I+ genotype group compared with the DD genotype group (0.8 +/- 0.2 vs. 1 +/- 0.1 degrees C, P < 0.05; 17.7 +/- 1.8 vs. 19.8 +/- 1.3 W/M(2), P < 0.05; and 33 +/- 7 vs. 44 +/- 5 beats/min, respectively, P = 0.06). No significant association was found between heat strain response and the anthropometrical measurements or aerobic fitness in the various genotype groups. We suggest that the ACE I+ polymorphism may be considered as a possible candidate marker for increased heat tolerance.