Heather J.A. Foulds

Dilatation and Dysfunction of the Right Ventricle Immediately After Ultraendurance Exercise Exploratory Insights From Conventional Two-Dimensional and Speckle Tracking Echocardiography

Background— Running an ultramarathon has been shown to have a transient negative effect on right ventricular (RV) and left ventricular (LV) function. Additionally, recent findings suggested that ultraendurance athletes may be more at risk of developing a RV cardiomyopathy. The standard echocardiographic assessment of RV function is problematic; however, the introduction of ultrasonic speckle tracking technology has the potential to yield a comprehensive evaluation of RV longitudinal function, providing new insights into this phenomenon. Thus, the primary aim of this exploratory study was to evaluate comprehensively RV structure and function after a 161-km ultramarathon and establish whether changes in the RV are associated with alterations in LV function. Methods and Results— Myocardial speckle tracking echocardiograms of the RV and LV were obtained before and immediately after a 161-km ultramarathon in 16 healthy adults. Standard echocardiography was used to determine RV size and function and LV eccentricity index. Speckle tracking was used to determine the temporal evaluation of indices of RV and LV function. RV size was significantly increased postrace (RV outflow, 32 to 35 mm, P =0.002; RV inflow, 42 to 45 mm, P =0.027) with an increase in LV eccentricity index (1.03 to 1.13, P =0.006). RV strain (e) was significantly reduced postrace (−27% to −24%, P =0.004), but there was no change in the rates of e. Peak e in all planes of LV motion were reduced postrace (longitudinal, −18.3 to −16.3%, P =0.012; circumferential, −20.2% to −15.7%, P =0.001; radial, 53.4% to 40.3%, P =0.009). Changes in RV size and function correlated with diastolic strain rates in the LV. Conclusions— This exploratory study demonstrates RV dilatation and reduction in function after an ultramarathon. Further research is warranted to elucidate the mechanisms responsible for these findings. It is not clear what clinical impact might result from consecutive bouts of postexercise RV dysfunction.Background— Running an ultramarathon has been shown to have a transient negative effect on right ventricular (RV) and left ventricular (LV) function. Additionally, recent findings suggested that ultraendurance athletes may be more at risk of developing a RV cardiomyopathy. The standard echocardiographic assessment of RV function is problematic; however, the introduction of ultrasonic speckle tracking technology has the potential to yield a comprehensive evaluation of RV longitudinal function, providing new insights into this phenomenon. Thus, the primary aim of this exploratory study was to evaluate comprehensively RV structure and function after a 161-km ultramarathon and establish whether changes in the RV are associated with alterations in LV function. Methods and Results— Myocardial speckle tracking echocardiograms of the RV and LV were obtained before and immediately after a 161-km ultramarathon in 16 healthy adults. Standard echocardiography was used to determine RV size and function and LV eccentricity index. Speckle tracking was used to determine the temporal evaluation of indices of RV and LV function. RV size was significantly increased postrace (RV outflow, 32 to 35 mm, P=0.002; RV inflow, 42 to 45 mm, P=0.027) with an increase in LV eccentricity index (1.03 to 1.13, P=0.006). RV strain (&egr;) was significantly reduced postrace (−27% to −24%, P=0.004), but there was no change in the rates of &egr;. Peak &egr; in all planes of LV motion were reduced postrace (longitudinal, −18.3 to −16.3%, P=0.012; circumferential, −20.2% to −15.7%, P=0.001; radial, 53.4% to 40.3%, P=0.009). Changes in RV size and function correlated with diastolic strain rates in the LV. Conclusions— This exploratory study demonstrates RV dilatation and reduction in function after an ultramarathon. Further research is warranted to elucidate the mechanisms responsible for these findings. It is not clear what clinical impact might result from consecutive bouts of postexercise RV dysfunction.

The relationship between hypertension and obesity across different ethnicities.

Background and objective: Hypertension and obesity are major contributors to cardiovascular disease, and the relationship between these conditions is known to vary among ethnicities. However, this relationship has not previously been examined in aboriginal populations. The present investigation aimed to identify and compare this relationship among white (n = 3566), aboriginal (n = 850), East Asian (n = 446), and South Asian (n = 222) individuals from the province of British Columbia, Canada. Methods: Blood pressure, BMI, and waist circumference were directly measured along with self-reported antihypertensive medication usage. Relative risk ratios were calculated to evaluate the risk of hypertension among individuals of varying BMI and waist circumference measurements. The relative risks of hypertension were compared both within and between four ethnic groups. Results: Greater relative risks for hypertension were observed among individuals with increased BMI or increased waist circumference among all four ethnic groups. Aboriginal individuals appear to experience the greatest increases in relative risk for hypertension with increased BMI or waist circumference compared to other ethnic groups. The differences in the risk of developing hypertension between aboriginal and white populations appear to be largely associated with differences in body composition (i.e., BMI or waist circumference). East Asian and South Asian populations experience greater relative risk for hypertension than white populations at the same level of BMI or waist circumference. Conclusion: Hypertension prevention and treatment strategies among aboriginal, East Asian, and South Asian populations should target reducing fat mass and abdominal fat.

Upper limits of physiological cardiac adaptation in ultramarathon runners.

To the Editor: Physiologic left ventricular (LV) hypertrophy is common in endurance-trained athletes ([1][1]). Controversially, a recent report from Japan suggested that a new upper limit for physiological LV hypertrophy might be present in ultramarathon runners ([2][2]). Specifically, in 291 male

Greater prevalence of select chronic conditions among Aboriginal and South Asian participants from an ethnically diverse convenience sample of British Columbians.

Canadians currently experience elevated rates of chronic conditions compared with past populations, and ethnic differences in the experience of select chronic conditions have previously been identified. This investigation examined the prevalence of select chronic conditions among an ethnically diverse convenience sample of British Columbian adults. A sample of adults (≥18 years) from around the province of British Columbia, including Aboriginal (n = 991), European (n = 3650), East Asian (n = 466), and South Asian (n = 228), were evaluated. Individuals reported their personal histories of cardiovascular disease and diabetes, and physical activity behaviour. Direct measures of health status included body mass index, waist circumference, resting blood pressure, and nonfasting blood glucose, total cholesterol, high-density lipoprotein (HDL) cholesterol, and glycosylated hemoglobin A1C. All ethnic groups were found to have high rates of low HDL (>33%), physical inactivity (>31%), hypertension (>16%), and ethnic-specifically defined obesity (>23%) and abdominal obesity (>33%). Aboriginal and South Asian populations generally demonstrated higher rates of select chronic conditions. The implementation of ethnic-specific body composition recommendations further underscores this poorer health status among South Asian populations. Actions to improve chronic condition rates should be undertaken among all ethnic groups, with particular attention to Aboriginal and South Asian populations.

The prevalence of overweight and obesity in British Columbian Aboriginal adults

Overweight and obesity among Aboriginal populations has been a growing challenge within Canada. This investigation aimed to identify the prevalence of overweight and obesity within British Columbian adult Aboriginal populations including both on and off reserve individuals through direct measurement. Further, this study stratified the variations in these rates according to age, gender and geographic region. Weight, height and waist circumference (WC) were measured via standardized procedures, and body mass index (BMI) was calculated. The mean body composition indicators were above recommended for men (BMI = 30.3 ± 5.6 kg m−2; WC = 104.2 ± 14.7 cm) and women (BMI = 30.9 ±  7.2 kg m−2; WC = 99.3 ± 17.1 cm), respectively. Rates of obesity for men and women were similar, 48.4% and 48.7%, respectively, and showed significant increases with age. Abdominal obesity (AO) was significantly greater among female participants, 69.0% compared with 52.7% in men, while both genders also demonstrated significant increases in AO with age. Both obesity and AO rates were found to be significantly greater in the Northern and Interior regions of the province in comparison to the Vancouver/Lower Mainland region. Alarmingly high rates of obesity and AO were observed in this population in men and women at every age and geographic region.

An evaluation of the physical activity and health status of British Columbian Aboriginal populations

Aboriginal people have experienced elevated rates of obesity, diabetes, cardiovascular disease, and other chronic conditions that are disproportionate to the general Canadian population. We sampled British Columbian Aboriginal populations to determine the current health status of this population. A total of 882 Aboriginal adults ≥16 years of age from 25 locations around the province were sampled from 2007-2011. Health measurements evaluated included body mass index, waist circumference, physical activity, smoking behaviours, and resting blood pressure as well as histories of diabetes, cardiovascular disease, and hypertension. Nonfasting measures of blood sugar, total cholesterol, and high-density lipoprotein cholesterol were also recorded. We used logistical regression to quantify variations in diabetes and cardiovascular disease risk factors with age, gender, geographic location, on- and off-reserve and urban-rural areas of residence, smoking, and physical activity behaviour. The prevalence of diabetes, hypertension, and high total cholesterol were found to be greater among males, while females experienced greater rates of abdominal obesity and physical inactivity. Rates of chronic conditions were similar across on- and off-reserve, urban-rural areas, and geographic region residences, though rural, on-reserve, and northern residents experienced greater risk of poor health status. Larger proportions of on-reserve, rural, and interior individuals were found to be more physically inactive. Aboriginal populations still experience substantially poorer health status in comparison with the general population. Initiatives to improve the health of this population are urgently needed addressing all sectors of the Aboriginal population, all geographic regions, and all areas of residence, with special emphasis on rural, on-reserve, and northern populations.

Systemic arterial compliance following ultra-marathon.

There is a growing interest in training for and competing in race distances that exceed the marathon; however, little is known regarding the vascular effects of participation in such prolonged events, which last multiple consecutive hours. There exists some evidence that cardiovascular function may be impaired following extreme prolonged exercise, but at present, only cardiac function has been specifically examined following exposure to this nature of exercise. The primary purpose of this study was to characterize the acute effects of participation in an ultra-marathon on resting systemic arterial compliance. Arterial compliance and various resting cardiovascular indices were collected at rest from 26 healthy ultra-marathon competitors using applanation tonometry (HDI CR-2000) before and after participation in a mountain trail running foot race ranging from 120-195 km which required between 20-40 continuous hours (31.2±6.8 h) to complete. There was no significant change in small artery compliance from baseline to post race follow-up (8.5±3.4-7.7±8.2 mL/mmHgx100, p=0.65), but large artery compliance decreased from 16.1±4.4 to 13.5±3.8 mL/mmHgx10 (p=0.003). Participation in extreme endurance exercise of prolonged duration was associated with acute reductions in large artery compliance, but the time course of this effect remains to be elucidated.

The blood pressure and hypertension experience among North American Indigenous populations.

Hypertension is becoming increasingly prevalent among western societies. However, different ethnic groups appear to be affected unequally. This systematic review sought to evaluate blood pressure and hypertension among North American Indigenous populations. Electronic databases (e.g. MEDLINE and EMBASE) were searched and citations cross-referenced. Articles including blood pressure or hypertension among Indigenous populations specifically were included. A total of 1213 unique articles were identified, with 141 included in the final review. Hypertension rates ranged from 19.2% among Inuit/Alaskan natives to 33.9% among First Nations/American Indians, and have increased since pre1980. Overall, hypertension rates were lower among Indigenous populations compared with general populations (23.5 vs. 31.2%), although average blood pressures were similar (123.3/75.1 vs. 124.9/75.2 mmHg). Limited information regarding Indigenous children/youth identified 11.4% hypertension rates, with average blood pressures of 106.7/60.2 mmHg. These findings indicate that current rates of hypertension may actually be lower among Indigenous populations than the general population.

A review of the cardiometabolic risk experience among Canadian Métis populations.

Cardiometabolic risk is a growing concern in Western society in which rates of cardiovascular disease, diabetes, and obesity are on the rise. Aboriginal populations currently experience unequal burdens of these chronic conditions. However, limited information regarding the experience of cardiometabolic risk among Métis populations is available. This review sought to evaluate the cardiometabolic risk experience among Métis populations in Canada. Canadas Métis population currently experiences greater burdens of chronic conditions including metabolic syndrome, diabetes, obesity, and cardiovascular disease than that of the non-Aboriginal population. Métis populations also experience poorer life expectancy, education, and employment attainments, and reduced access to health care services compared with non-Aboriginal populations. Interventions addressing the deficiencies in sociodemographic, lifestyle, and social determinants among the Métis population might help combat rising experiences of chronic diseases faced by these people. Though the burden of chronic conditions, sociodemographic, lifestyle challenges, and social determinants of health among Métis populations are generally less than that of First Nations populations, Métis people experience these health challenges and influencing factors are generally more similar to that of First Nations than non-Aboriginal peoples. Subsequently, Métis populations need to be included in plans and strategies to reduce chronic conditions among Aboriginal populations. In conclusion, Métis populations experience greater burden of cardiometabolic risk and its components than the general Canadian population.

A segmental evaluation of arterial stiffness before and after prolonged strenuous exercise

We aimed to investigate the effects of a single session of prolonged strenuous exercise (PSE) on arterial stiffness by measuring pulse wave velocity (PWV) before and after competition in an ultramarathon. A total of 20 routine ultramarathon competitors (UM) completed baseline and postrace evaluation of central PWV (cPWV), upper-limb PWV (uPWV), and lower-limb PWV (lPWV) using carotid artery - femoral artery, carotid artery - finger, and femoral artery - toe segments, respectively. Fourteen additional age- and gender-matched normally active participants (NA) took part in the identical baseline evaluation but did not participate in the race. Average ultramarathon completion time was 30 h 47 min. Mean arterial blood pressure was reduced after exercise (before exercise (pre), 92 ± 7 mm Hg; after exercise (post), 84 ± 7 mm Hg; P < 0.001), whereas heart rate was increased (pre, 57 ± 10 beats·min(-1); post, 73 ± 12 beats·min(-1); P < 0.001). Also, lPWV (pre, 11.8 ± 3.6 m·s(-1); post, 9.6 ± 2.6 m·s(-1); P < 0.05) and uPWV (pre, 5.0 ± 0.53 m·s(-1); post, 4.4 ± 0.8 m·s(-1); P < 0.01) were reduced after exercise. No change in cPWV occurred (pre, 4.1 ± 0.8 m·s(-1); post, 3.9 ± 1.3 m·s(-1); P = 0.55). At baseline, the NA group had significantly increased cPWV in comparison with the UM group (UM, 4.1 ± 0.8 m·s(-1); NA, 7.4 ± 1.3 m·s(-1); P < 0.001). Acute participation in PSE influenced peripheral but not central arterial stiffness. Those who routinely participate in PSE have reduced central arterial stiffness as compared with normally active, age- and gender-matched controls.