A conceptual framework for managing modifiable risk factors for cardiovascular diseases in Fiji.

AIMS: The current review will look at modifiable lifestyle (physical inactivity, poor nutrition, risky alcohol behavior and cigarette smoking) and cardio-metabolic (obesity, diabetes mellitus, high cholesterol and high blood pressure) cardiovascular disease (CVD) risk factors among Indigenous-Fijian and Indo-Fijian subgroups. A framework for monitoring and managing these risk factors will be presented. METHODS: National health surveys were identified where available. Electronic databases identified sources for filling missing data. The most relevant data were identified, organized and synthesized. RESULTS: Compared to Indo-Fijians, Indigenous-Fijians have higher rates of obesity (17% vs 11%) and hypertension (21% vs 16%), but lower rates of diabetes mellitus (12% vs 21%) and high cholesterol (33% vs 39%). Indigenous-Fijians report higher rates of prescribed physical activity (25% vs 21%), but poorer recommended vegetable intake (48% vs 56%), greater risky alcohol behavior (17% vs 15%) and a much greater prevalence of cigarette smoking (45% vs 24%). Both Indigenous-Fijians and Indo-Fijians report a low prevalence of recommended fruit intake (17% vs 15%). CONCLUSIONS: Fiji is progressing through demographic and epidemiological transitions, including a decline in infectious diseases and improved life expectancy. However, in concert with other developing nations, 'modernization' is accompanied by increased mortality from non-communicable diseases, with CVD being the most prevalent. This transition has been associated with changes to socio-cultural aspects of Fiji, including poor lifestyle choices that may contribute to a cluster of cardio-metabolic conditions which precede CVD.

A boxing-oriented exercise intervention for obese adolescent males: findings from a pilot study.

In New Zealand, obese Maori and Pasifika adolescents are at risk of numerous cardio-metabolic conditions with raising physical activity levels being proposed as a useful intervention. The present study used a mixed method design to explore the effects of a non-contact boxing-oriented training programme designed in terms of improvements to cardio-metabolic variables. Traditional recruitment strategies (media, referrals) were employed, with limited success leading to 3 adolescent boys (14-15 y) participating in the pilot intervention. Exercise sessions included 30 minutes of non-contact boxing training, followed by 30 minutes of progressive resistance training. Participants attended three 1h training sessions each week, for a total of 12 weeks. Physiological variables included anthropometric indices, visceral fat thickness, central blood pressures, central arterial stiffness (augmentation index: AIx), and carotid arterial stiffness (ß). Results revealed that there was no trend for change in body weight (125.5 ± 12.1 kg vs. 126.5 ± 11.0 kg) or BMI (39.3 ± 4.1 kg·m(-2) vs. 39.0 ± 4.6 kg·m(-2)). However, there was a moderate decrease in visceral fat thickness (4.34 ± 2.51 cm vs 3.65 ± 1.11 cm, d = 0.36). There was no change in central pulse pressure (38.7 ± 7.3 mmHg vs. 38.3 ± 5.0 mmHg), however, there was a small improvement in ß (3.01 ± 0.73 vs. 2.87 ± 0.84, d = 0.18). Focus group interview data with participants and their parents were used to explore issues related to motivation to participation. Results revealed participants commented on how the programme has led to new friendships, changes to their physical appearance, and increased physical fitness. Parents commented on increased self-confidence, better performance in school, and a willingness to take part in new activities. In conclusion, it appears participating in the boxing oriented training programme was motivating to participants who engaged and had some physiological benefits in obese adolescent boys of Maori and Pasifika descent. However, despite these positive attributes, poor recruitment rates suggest that future work should focus on identifying the barriers to engagement. Key pointsA boxing-oriented intervention was developed for use with Maori and Pasifika adolescents to improve cardiometabolic risk factors.While results indicate positive benefits of participation in the 60-minute boxing-orientated programme, only three participants were recruited despite intense promotion.Future research should investigate the efficacy of strategies designed to raise intentions to exercise.

Pre-Adolescent Cardio-Metabolic Associations and Correlates: PACMAC methodology and study protocol.

INTRODUCTION: Although cardiovascular disease is typically associated with middle or old age, the atherosclerotic process often initiates early in childhood. The process of atherosclerosis appears to be occurring at an increasing rate, even in pre-adolescents, and has been linked to the childhood obesity epidemic. This study will investigate the relationships between obesity, lifestyle behaviours and cardiometabolic health in pre-pubescent children aged 8-10 years, and investigates whether there are differences in the correlates of cardiometabolic health between Maori and Caucasian children. Details of the methodological aspects of recruitment, inclusion/exclusion criteria, assessments, statistical analyses, dissemination of findings and anticipated impact are described. METHODS AND ANALYSIS: Phase 1: a cross-sectional study design will be used to investigate relationships between obesity, lifestyle behaviours (nutrition, physical activity/fitness, sleep behaviour, psychosocial influences) and cardiometabolic health in a sample of 400 pre-pubescent (8-10 years old) children. Phase 2: in a subgroup (50 Caucasian, 50 Maori children), additional measurements of cardiometabolic health and lifestyle behaviours will be obtained to provide objective and detailed data. General linear models and logistic regression will be used to investigate the strongest correlate of (1) fatness; (2) physical activity; (3) nutritional behaviours and (4) cardiometabolic health. ETHICS AND DISSEMINATION: Ethical approval will be obtained from the New Zealand Health and Disabilities Ethics Committee. The findings from this study will elucidate targets for decreasing obesity and improving cardiometabolic health among preadolescent children in New Zealand. The aim is to ensure an immediate impact by disseminating these findings in an applicable manner via popular media and traditional academic forums. Most importantly, results from the study will be disseminated to participating schools and relevant Maori health entities.

Modifiable cardiovascular disease risk factors among indigenous populations.

Objective. To identify modifiable cardio-metabolic and lifestyle risk factors among indigenous populations from Australia (Aboriginal Australians/Torres Strait Islanders), New Zealand (Maori), and the United States (American Indians and Alaska Natives) that contribute to cardiovascular disease (CVD). Methods. National health surveys were identified where available. Electronic databases identified sources for filling missing data. The most relevant data were identified, organized, and synthesized. Results. Compared to their non-indigenous counterparts, indigenous populations exhibit lower life expectancies and a greater prevalence of CVD. All indigenous populations have higher rates of obesity and diabetes, hypertension is greater for Maori and Aboriginal Australians, and high cholesterol is greater only among American Indians/Alaska Natives. In turn, all indigenous groups exhibit higher rates of smoking and dangerous alcohol behaviour as well as consuming less fruits and vegetables. Aboriginal Australians and American Indians/Alaska Natives also exhibit greater rates of sedentary behaviour. Conclusion. Indigenous groups from Australia, New Zealand, and the United States have a lower life expectancy then their respective non-indigenous counterparts. A higher prevalence of CVD is a major driving force behind this discrepancy. A cluster of modifiable cardio-metabolic risk factors precede CVD, which, in turn, is linked to modifiable lifestyle risk factors.

Validation of oscillometric pulse wave analysis measurements in children.

BACKGROUND: Pulse wave analysis (PWA) has emerged as a noninvasive, valid, reliable, and widely used technique to investigate central blood pressures and systemic arterial wave reflection (augmentation index). The gold-standard technique is tonometry, but this technique can be challenging, especially when used on children. The purpose of this study was to validate oscillometric PWA for use in children. METHODS: Fifty-seven healthy children were recruited for participation. Central blood pressures and peripheral augmentation index (pAIx) were measured objectively using oscillometric (Pulsecor R7) and tonometric (SphygmaCor) devices. All measurements were made during the same visit under standardized conditions between the hours of 8 am and 10 am in the fasted state. RESULTS: Tonometric measurements were unsuccessful on 1 child. Comparisons were made on 56 children (mean age = 9.8±1.0 y; 57% male). A very strong relationship was found between devices for central systolic (r = 0.94; P < 0.001), diastolic (r = 0.99; P < 0.001) and mean (r = 0.96; P < 0.001) blood pressures. However, Bland-Altman analysis indicated a bias toward greater systolic blood pressures with the oscillometric monitor (mean difference = 4.5mm Hg; 95% confidence interval (CI) = -5.16 to -3.89). A good relationship was found for pAIx (r = 0.71; P < 0.001); the mean difference between devices was -1.70% (95% CI = -4.47% to 1.08%), which is not significantly different from zero. CONCLUSIONS: Findings from this study suggest that oscillometric PWA provides valid measures of central blood pressure and arterial wave reflection in children aged 8-10 years.

The Combating Obesity in Maori and Pasifika Adolescent School-Children Study: COMPASS Methodology and Study Protocol.

BACKGROUND: Lifestyle modifications including, physical activity can reduce obesity-related morbidity and subsequent cardiovascular disease in youth. This study will investigate the efficacy of a culturally-sensitive, non-contact, boxing-orientated training program on obesity and related cardio-metabolic conditions in Maori and Pasifika adolescents. Details of the methodological aspects of recruitment, inclusion criteria, randomization, cultural sensitivity, intervention program, assessments, process evaluation, and statistical analyses are described. METHODS: This study will be a community based, New Zealand, randomized control trial (RCT). Male and female obese (body mass index >95(th) percentile) Maori and Pasifika adolescents aged 14-16 years will be recruited and the sample size will be confirmed through a feasibility study. Combating Obesity in Maori and Pasifika Adolescent School-children Study (COMPASS) is a 6-month, theory-based program, conducted 3-times/week in a culturally appropriate setting. Each session includes 40 min boxing-orientated training and 30 min resistance training. Assessments will be made at baseline, 3-months, 6-months, 12-months, and 24-months. Main outcomes include abdominal obesity, endothelial function, and insulin resistance. Other outcomes include arterial stiffness, lipid profile, inflammatory biomarkers, well-being, and aerobic fitness. Control measures include physical activity, sleep behavior, and dietary intake. RESULTS: As a protocol paper there are no specific results to present, our purpose is to share our RCT design with the scientific community. CONCLUSIONS: COMPASS will be used to provide direction for exercise prescription policy in at-risk Maori and Pasifika adolescents.

Does circumferential stress help to explain flow-mediated dilation?

INTRODUCTION: Despite its potential, the validity of the flow-mediated dilation (FMD) test has been questioned because of lack of normalization to the vasodilatory stimulus. The hemodynamic conditions inside blood vessels lead to the development of superficial stress near the vessel walls, which can be divided into 2 categories: (1) circumferential stress (CS) and (2) shear stress (SS). Although SS is thought to be the primary governing stimulus, to the best of our knowledge, the degree to which CS contributes to FMD has not been reported in the literature. PURPOSE: The purpose of this study was to determine the importance of CS to FMD. We defined FMD as the SS-diameter dose-response slope. METHODS: Fourteen physically active, young [mean (SD) age, 26 (5) years], male subjects were tested. Progressive forearm heating and handgrip exercise elicited steady-state increases in shear rate. Hierarchical linear modeling was used to estimate change in diameter with repeated measures of SS and CS nested within each subject. RESULTS: Circumferential stress was found to positively promote FMD in addition to SS (ß = 0.019, P = 0.019). However, the variance explained by CS was less than 1%. CONCLUSIONS: The physiologic significance of CS to FMD was minimal. However, physically active, young men were recruited; it remains to be determined whether CS has a more pronounced effect in subjects exhibiting cardiovascular risk factors.

The effect of estimation and production procedures on running economy in recreational athletes.

OBJECTIVES: Running economy is an important component in any endurance event. However, the influence of effort perception on running economy has yet to be examined. DESIGN: The purpose of this study was to assess the oxygen cost of running (running economy) at identical ratings of perceived exertion (RPE) during estimation (EST) and production (PR) procedures, during treadmill exercise. METHODS: Fourteen, well-trained male participants actively produced (self-regulated) a range of submaximal exercise intensities equating to RPE values 9, 11, 13, 15 and 17, and passively estimated their perception of exertion during an incremental graded-exercise test (GXT). Allometric scaling was used to ensure an appropriate comparison in running economy between conditions. RESULTS: The present study demonstrated that the overall running economy between conditions was statistically similar (p>0.05). A significant interaction was however identified between Conditions and RPE (p<0.001). The interaction revealed that running economy significantly improved during PR but remained fairly consistent during EST between moderate and high perceptions of exertion (RPE 11-17). Despite similarities in running economy between conditions, physiological (oxygen uptake, heart rate, minute ventilation and blood lactate) and physical (running velocity) markers of exercise intensity were significantly higher during EST for equivalent perceptions of exertion (all p<0.05). CONCLUSIONS: Passive estimation procedures may improve running economy and enhance athletic performance when compared to identical perceptions of exertion elicited during active production procedures. Athletes, coaches and physical trainers should consider the perceptual procedures utilised during training to ensure that an athlete trains at the most effective training intensity.

The perceptual response to treadmill exercise using the Eston-Parfitt scale and marble dropping task, in children age 7 to 8 years.

This study assessed the nature of the perceived exertion response to treadmill running in 14 healthy 7-8 year-old children, using the Eston-Parfitt (E-P) Ratings of Perceived Exertion (RPE) scale and a marble dropping task. For the E-P scale and the marble dropping task, the relationships between the RPE and work rate were best described as linear (R2 = .96) and curvilinear (R2 = .94), respectively. This study further suggests that individual respiratory-metabolic cues (oxygen uptake: O2, heart rate: HR, ventilation: VE) may significantly influence the overall RPE to varying degrees in young children. The E-P scale provides an intuitively meaningful and valid means of quantifying the overall perception of exertion in young, healthy children during treadmill running. The marble dropping task is a useful secondary measure of perceived exertion, which provides further insight into the nature of the perceived exertion response to exercise in young children.

Prediction of maximal oxygen uptake from submaximal ratings of perceived exertion and heart rate during a continuous exercise test: the efficacy of RPE 13.

This study assessed the utility of a single, continuous exercise protocol in facilitating accurate estimates of maximal oxygen uptake V(O)(2max) from submaximal heart rate (HR) and the ratings of perceived exertion (RPE) in healthy, low-fit women, during cycle ergometry. Eleven women estimated their RPE during a continuous test (1 W 4 s(-1)) to volitional exhaustion (measured V(O)(2max)). Individual gaseous exchange thresholds (GETs) were determined retrospectively. The RPE and HR values prior to and including an RPE 13 and GET were extrapolated against corresponding oxygen uptake to a theoretical maximal RPE (20) and peak RPE (19), and age-predicted HRmax, respectively, to predict V(O)(2max)). There were no significant differences (P > 0.05) between measured (30.9 +/- 6.5 ml kg(-1) min(-1)) and predicted V(O)(2max) from all six methods. Limits of agreement were narrowest and intraclass correlations were highest for predictions of V(O)(2max) from an RPE 13 to peak RPE (19). Prediction of V(O)(2max) from a regression equation using submaximal HR and work rate at an RPE 13 was also not significantly different to actual V(O)(2max) (R( 2 ) = 0.78, SEE = 3.42 ml kg(-1) min(-1), P > 0.05). Accurate predictions of V(O)(2max) may be obtained from a single, continuous, estimation exercise test to a moderate intensity (RPE 13) in low-fit women, particularly when extrapolated to peak terminal RPE (RPE(19)). The RPE is a valuable tool that can be easily employed as an adjunct to HR, and provides supplementary clinical information that is superior to using HR alone.

The perceptual response to exercise of progressively increasing intensity in children aged 7-8 years: validation of a pictorial curvilinear ratings of perceived exertion scale.

This study assessed the validity of the Eston-Parfitt (E-P) curvilinear Ratings of Perceived Exertion (RPE) Scale and a novel marble quantity task to provide estimates of perceived exertion during cycle ergometry. Fifteen children aged 7-8 years performed a discontinuous incremental graded-exercise test, and reported exertional ratings at the end of each minute. Significant increases in physiological and perceptual data were observed with increasing work rate. The relationship between work rate and marbles was curvilinear (mean R(2)=.94), supporting the theoretical justification for the E-P Scale. Strong linear (R(2)=.93) and curvilinear (R(2)=.94) relationships between RPE from the E-P Scale and work rate confirmed the robustness of the E-P Scale. Valid exertional ratings may be obtained using the E-P Scale with young children. The novel marble quantity task offers an alternative method of deriving perceived exertion responses in children.