Resting heart rate and the association of physical fitness with carotid artery stiffness

Tracking of Cardiorespiratory Fitness from Childhood to Mid-adulthood

High cardiorespiratory fitness (CRF) in adulthood is important for survival from major chronic diseases and preserving good health. We examined how childhood CRF tracks, or persists, into adulthood. Among a cohort of 748 school children followed over 34 years, we found child CRF correlated with young- (r = 0.30) and mid-adulthood (r = 0.16) CRF.

Prevalent stroke, age of its onset, and post-stroke lifestyle in relation to dementia: A prospective cohort study

INTRODUCTION

The association of age at stroke onset with dementia and the role of post-stroke lifestyle on dementia risk remains unclear.

METHODS

We leveraged data of 496,251 dementia-free participants from UK Biobank and explored the relationship between age at stroke onset and incident dementia. Among 8328 participants with stroke history, we further investigated the association of a healthy lifestyle with risk of dementia.

RESULTS

Participants with stroke history had a higher risk of dementia (hazard ratio [HR], 2.02). The association was stronger among participants with stroke onset at a younger age (≤50: HR, 2.63) compared with those at the age > 50 years (50-60: HR, 2.17; ≥60: HR, 1.58). Among participants with stroke history, a favorable lifestyle was associated with a lower risk of incident dementia.

DISCUSSION

Stroke onset in earlier life stage predicted a higher risk for dementia, but a favorable post-stroke lifestyle may protect against dementia.

Vascular function in hypertension: does gender dimension matter?

Blood pressure and vascular ageing trajectories differ between men and women. These differences develop due to sex-related factors, attributable to sex chromosomes or sex hormones, and due to gender-related factors, mainly related to different sociocultural behaviors. The present review summarizes the relevant facts regarding gender-related differences in vascular function in hypertension. Among sex-related factors, endogenous 17ß-estradiol plays a key role in protecting pre-menopausal women from vascular ageing. However, as vascular ageing (preceding and inducing hypertension) has a steeper increase in women than in men starting already from the third decade, it is likely that gender-related factors play a prominent role, especially in the young. Among gender-related factors, psychological stress (including that one related to gender-based violence and discrimination), depression, some psychological traits, but also low socioeconomic status, are more common in women than men, and their impact on vascular ageing is likely to be greater in women. Men, on the contrary, are more exposed to the vascular adverse consequences of alcohol consumption, as well as of social deprivation, while "toxic masculinity" traits may result in lower adherence to lifestyle and preventive strategies. Unhealthy diet habits are more prevalent in men and smoking is equally prevalent in the two sexes, but have a disproportional negative effect on women's vascular health. In conclusion, given the major and complex role of gender-related factors in driving vascular alterations and blood pressure patterns, gender dimension should be systematically integrated into future research on vascular function and hypertension and to tailor cardiovascular prevention strategies.

Association Between Risk Factors in Childhood and Sex Differences in Prevalence of Carotid Artery Plaques and Intima-Media Thickness in Mid-Adulthood in the Childhood Determinants of Adult Health Study

Background The origins of sex differences in cardiovascular diseases are not well understood. We examined the contribution of childhood risk factors to sex differences in adult carotid artery plaques and intima-media thickness (carotid IMT). Methods and Results Children in the 1985 Australian Schools Health and Fitness Survey were followed up when they were aged 36 to 49 years (2014-19, n=1085-1281). Log binomial and linear regression examined sex differences in adult carotid plaques (n=1089) or carotid IMT (n=1283). Childhood sociodemographic, psychosocial, and biomedical risk factors that might contribute to sex differences in carotid IMT/plaques were examined using purposeful model building with additional adjustment for equivalent adult risk factors in sensitivity analyses. Women less often had carotid plaques (10%) than men (17%). The sex difference in the prevalence of plaques (relative risk [RR] unadjusted 0.59 [95% CI, 0.43 to 0.80]) was reduced by adjustment for childhood school achievement and systolic blood pressure (RR adjusted 0.65 [95% CI, 0.47 to 0.90]). Additional adjustment for adult education and systolic blood pressure further reduced sex difference (RR adjusted 0.72 [95% CI, 0.49 to 1.06]). Women (mean±SD 0.61±0.07) had thinner carotid IMT than men (mean±SD 0.66±0.09). The sex difference in carotid IMT (β unadjusted -0.051 [95% CI, -0.061 to -0.042]) reduced with adjustment for childhood waist circumference and systolic blood pressure (β adjusted -0.047 [95% CI, -0.057 to -0.037]) and further reduced with adjustment for adult waist circumference and systolic blood pressure (β adjusted -0.034 [95% CI, -0.048 to -0.019]). Conclusions Some childhood factors contributed to adult sex differences in plaques and carotid IMT. Prevention strategies across the life course are important to reduce adult sex differences in cardiovascular diseases.

Association of Accelerometer-Measured Sedentary Time and Physical Activity With Risk of Stroke Among US Adults

IMPORTANCE

The amount and intensity of physical activity required to prevent stroke are yet to be fully determined because of previous reliance on self-reporting measures. Furthermore, the association between objectively measured time spent being sedentary as an independent risk factor for stroke is unknown.

OBJECTIVE

To investigate the associations of accelerometer-measured sedentary time and physical activity of varying intensity and duration with the risk of incident stroke.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study involved participants who were enrolled in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study from February 5, 2003, to October 30, 2007. Accelerometer data were collected from 7607 Black and White adults 45 years or older in the contiguous US between May 12, 2009, and January 5, 2013. Data on other races and ethnicities were not collected for scientific and clinical reasons. By design, Black adults and residents of the southeastern US stroke belt and stroke buckle were oversampled. Data were analyzed from May 5, 2020, to November 11, 2021.

EXPOSURES

Sedentary time, light-intensity physical activity (LIPA), and moderate- to vigorous-intensity physical activity (MVPA) were measured using a hip-mounted accelerometer worn for 7 consecutive days and stratified by tertile for the analyses.

MAIN OUTCOMES AND MEASURES

Incident stroke.

RESULTS

Among 7607 participants, the mean (SD) age was 63.4 (8.5) years; 4145 participants (54.5%) were female, 2407 (31.6%) were Black, and 5200 (68.4%) were White. A total of 2523 participants (33.2%) resided in the stroke belt, and 1638 (21.5%) resided in the stroke buckle. Over a mean (SD) of 7.4 (2.5) years of follow-up, 286 incident stroke cases (244 ischemic [85.3%]) occurred. The fully adjusted hazard ratios (HRs) for incident stroke in the highest tertile compared with the lowest tertile were 0.74 (95% CI, 0.53-1.04; P = .08) for LIPA and 0.57 (95% CI, 0.38-0.84; P = .004) for MVPA. Higher sedentary time was associated with a 44% greater risk of incident stroke (HR, 1.44; 95% CI, 0.99-2.07; P = .04). When comparing the highest with the lowest tertile, mean sedentary bout duration was associated with a significantly greater risk of incident stroke (HR, 1.53; 95% CI, 1.10-2.12; P = .008). After adjustment for sedentary time, the highest tertile of unbouted MVPA (shorter bouts [1-9 minutes]) was associated with a significantly lower risk of incident stroke compared with the lowest tertile (HR, 0.62; 95% CI, 0.41-0.94; P = .02); however, bouted MVPA (longer bouts [at least 10 minutes]) was not (HR, 0.78; 95% CI, 0.53-1.15; P = .17). When expressed as continuous variables, sedentary time was positively associated with incident stroke risk (HR per 1-hour/day increase in sedentary time: 1.14; 95% CI, 1.02-1.28; P = .02), and LIPA was negatively associated with incident stroke risk (HR per 1-hour/day increase in LIPA: 0.86; 95% CI, 0.77-0.97; P = .02).

CONCLUSIONS AND RELEVANCE

In this cohort study, objectively measured LIPA, MVPA, and sedentary time were significantly and independently associated with incident stroke risk. Longer sedentary bout duration was also independently associated with an increased risk of incident stroke. These findings suggest that replacing sedentary time with LIPA, or even very short bouts of MVPA, may lower stroke risk, supporting the concept of moving more and sitting less as a beneficial stroke risk reduction strategy among adults.

The independent and joint associations between muscle strength, health variables and cardiovascular disease among adults

OBJECTIVES

We investigated the independent and joint association between muscle strength and health variables according to individual health status among adults.

METHODS

Cross-sectional population-based study comprising 643 adults (39.6 ± 11.1 years, 44.9% men) from Florianópolis, Southern Brazil. Muscle strength was assessed by handgrip strength. Health variables included were systolic (SBP) and diastolic blood pressure (DBP), waist circumference (WC), carotid intima-media thickness (IMT), high-sensitivity C-reactive protein (CRP), total cholesterol (CHOL), HDL cholesterol (HDL-C), triglycerides (TRG), glycated hemoglobin (HbA1c), and insulin resistance index (HOMA-IR). Participants were grouped into three health status categories: 1) healthy (without CVD and risk for CVD); 2) at risk for CVD (obesity, high blood pressure, and hyperglycemia); 3) with CVD. Multiple linear regression adjusted for confounding factors was used.

RESULTS

Muscle strength was inversely associated with IMT (β = -0.02, SE: 0.03), CHOL (β = -0.14, SE: 0.02) and HbA1c (β = -0.01, SE: 0.10), and directly associated with SBP (β = 0.16, SE: 0.06) and WC (β = 0.02, SE: 0.03). Among adults with CVD, muscle strength was inversely associated with IMT (p < 0.05). Higher muscle strength was directly associated with SBP among healthy adults (p < 0.05).

CONCLUSION

The main finding of the present study indicated that among individuals with CVD, muscle strength was associated with lower IMT values.

Risk factors for left ventricular dysfunction in adulthood: role of low birth weight

Aims

This study aimed to determine the relationship of low birth weight (LBW) with adult cardiac structure and function and investigate potential causal pathways.

Methods and results

A population‐based sample of 925 Australians (41.3% male) were followed from childhood (aged 7–15 years) to young adulthood (aged 26–36 years) and mid‐adulthood (aged 36–50 years). Left ventricular (LV) global longitudinal strain (GLS, %), LV mass index (LVMi, g/m^2.7), LV filling pressure (E/e′), and left atrial volume index (g/m²) were measured by transthoracic echocardiography in mid‐adulthood. Birth weight category was self‐reported in young adulthood and classified as low (≤5 lb or ≤2270 g), normal (5–8 lb or 2271–3630 g), and high (>8 lb or >3630 g). Of the 925 participants, 7.5% (n = 69) were classified as LBW. Compared with participants with normal birth weight, those with LBW had 2.01‐fold (95% confidence interval: 1.19, 3.41, P = 0.009) higher risks of impaired GLS (GLS > −18%) and 2.63‐fold (95% confidence interval: 0.89, 7.81, P = 0.08) higher risks of LV hypertrophy (LVMi > 48 g/m^2.7 in men or >44 g/m^2.7 in women) in adulthood, independent of age, sex, and any socio‐economic factors. Participants with LBW significantly increased body fat from childhood to adulthood relative to their peers and had greater levels of triglycerides, fasting glucose, and arterial stiffness in adulthood. These risk factors were the strongest mediators and explained 54% of the LBW effect size on adult GLS and 33% of the LBW effect size on LVMi. The remaining of these associations was independent of any of the measured risk factors.

Conclusions

Low birth weight was associated with impaired cardiac structure and function in mid‐adulthood. This association was only partially explained by known risk factors.

Arterial Stiffness and Hemodynamics in Young Women: The Effects of Oral Contraceptive Intake and Physical Habits

Oral contraceptive (OC) intake seems to be associated with increased central hemodynamics and arterial stiffness. Conversely, physical activity (PA) is known to induce benefits on vascular structure and function, suggesting that the negative effects of the OC pill could be counterbalanced by regular PA. The aim of this cross-sectional study was to determine (1) whether OC intake in young women is associated with higher values of hemodynamic parameters and arterial stiffness and (2) whether these negative effects could be counterbalanced by regular physical activity. Forty-nine young healthy women (21.9 years ± 2.1) were recruited and divided into 4 groups, depending on their hormonal status (OC users: OC+ or non-OC users: OC−) and their physical habits (active/inactive). Assessments of central hemodynamics (central blood pressure, Aix75) and pulse wave velocity (PWV) were performed using applanation tonometry. cBP was higher in OC+ vs. OC−, while PWV was similar between these two groups. No interaction between physical activity and hormonal status was observed for any of these variables. Nevertheless, PWV was lower in young active women compared with age-matched inactive women, suggesting that the positive effect of regular physical exercise on the cardiovascular system is already visible in the first years of women’s adulthood, whatever the hormonal status.

The Effects of Below-Knee Medical Compression Stockings on Pulse Wave Velocity of Young Healthy Volunteers

ABSTRACT

Szolnoky, G, Gavallér, H, Gönczy, A, Bihari, I, Kemény, L, Forster, T, and Nemes, A. The effects of below-knee medical compression stockings on pulse wave velocity of young healthy volunteers. J Strength Cond Res 35(1): 275-279, 2021-The effects of graduated medical compression stockings (MCS) on cardiovascular responses are poorly investigated. A simple study was undertaken to investigate whether the application of below-knee leg MCSs with different pressures could influence aortic pulse wave velocity (PWV) as the gold standard for aortic stiffness measurement evaluated by arteriography. Ten volunteers underwent PWV measurement at baseline, then in below-knee compression class (ccl) 1 (18-21 mm Hg), 2 (23-32 mm Hg) and 3 (34-46 mm Hg) MCSs in a consecutive manner. Baseline PWV (mean value: 7.86 ± 1.70 m·s-1) was significantly reduced by ccl 1 MCSs (mean value: 6.55 ± 0.88 m·s-1, p = 0.04). ccl 2 and ccl 3 stockings also notably decreased baseline PWV (mean values: 6.63 ± 0.65 m·s-1, p = 0.058 and 6.62 ± 1.00 m·s-1, p = 0.067; respectively). The application of low compression MCSs (ccl 1) leads to a significant decrease in PWV indicating a beneficial cardiovascular influence.

Cardiorespiratory Fitness Associates with Cerebral Vessel Pulsatility in a Cohort Enriched with Risk for Alzheimer's Disease

BACKGROUND

There is increasing evidence that vascular disease risk factors contribute to evolution of the dementia syndrome of Alzheimer's disease (AD). One important measure of cerebrovascular health is pulsatility index (PI) which is thought to represent distal vascular resistance, and has previously been reported to be elevated in AD clinical syndrome. Physical inactivity has emerged as an independent risk factor for cardiovascular disease.

OBJECTIVE

This study aims to examine the relationship between a measure of habitual physical activity, cardiorespiratory fitness (CRF), and PI in the large cerebral vessels.

METHODS

Ninety-two cognitively-healthy adults (age = 65.34±5.95, 72% female) enrolled in the Wisconsin Registry for Alzheimer's Prevention participated in this study. Participants underwent 4D flow brain MRI to measure PI in the internal carotid artery (ICA), basilar artery, middle cerebral artery (MCA), and superior sagittal sinus. Participants also completed a self-report physical activity questionnaire. CRF was calculated using a previously-validated equation that incorporates sex, age, body-mass index, resting heart rate, and self-reported physical activity. A series of linear regression models adjusted for age, sex, APOE4 status, and 10-year atherosclerotic cardiovascular disease risk were used to analyze the relationship between CRF and PI.

RESULTS

Inverse associations were found between CRF and mean PI in the inferior ICA (p = .001), superior ICA (p = .035), and basilar artery (p = .040). No other cerebral vessels revealed significant associations between CRF and PI (p≥.228).

CONCLUSIONS

Higher CRF was associated with lower PI in several large cerebral vessels. Since increased pulsatility has been associated with poor brain health and reported in persons with AD, this suggests that aerobic fitness might provide protection against cerebrovascular changes related to the progression of AD clinical syndrome.

Association of heart rate trajectories with the risk of adverse outcomes in a community-based cohort in Taiwan

Heart rate trajectory patterns integrate information regarding multiple heart rate measurements and their changes with time. Different heart rate patterns may exist in one population, and these are associated with different outcomes. Our study investigated the association of adverse outcomes with heart rate trajectory patterns. This was a prospective cohort study based on the Chin-Shan Community Cardiovascular Cohort in Taiwan. A total of 3,015 Chinese community residents aged > 35 years were enrolled in a prospective investigation of cardiovascular risk factors and outcomes from 1990 to 2013.The primary outcome was all-cause mortality, and the secondary outcome was a composite of coronary artery disease and cerebrovascular accidents. The following trajectory patterns were identified: stable, 61%; decreased, 5%; mildly increased, 32%; and markedly increased, 2%. During follow-up (median, 13.9 years), 557 participants died and 217 experienced secondary outcomes. The adjusted hazard ratios of primary and secondary outcomes for participants with a markedly increased trajectory pattern were 1.80 (95% CI [1.18-2.76]) and 1.45 (95% CI [0.67-3.12]), respectively, compared to those for participants with a stable trajectory pattern. A markedly increased heart rate trajectory pattern may be associated with all-cause mortality risks. Heart rate trajectory patterns demonstrated the utility of repeated heart rate measurements for risk assessment.

Factors associated with muscular fitness phenotypes in Australian children: A cross-sectional study

To help inform strategies aimed at increasing muscular fitness levels, we examined factors associated with childhood muscular fitness (strength and power) that preceded the recently observed secular decline. Data were available from a nationally representative sample of Australian children aged 7-15 years in 1985 (n = 8469). Muscular fitness measures included strength (right and left grip, shoulder extension and flexion, and leg strength) and power (standing long jump distance). Anthropometric (adiposity, fat-free mass), cardiorespiratory fitness (CRF), flexibility, speed capability, physical activity (individual and parental), dietary quality and intake (fruit, vegetable, protein) and sociodemographic (area-level socioeconomic status (SES), school type) data were available. Statistical analyses included sex-stratified linear regression. Of all examined factors, measures of adiposity, fat-free mass, CRF, flexibility and speed capability were associated with muscular fitness at levels that met Cohen's threshold for important effects (r-squared = 0.02 to 0.28). These findings highlight the multifactorial relationship between muscular fitness and its determinants. Collectively, these factors were powerful in explaining muscular strength (females: r-squared = 0.32; males: r-squared = 0.41) and muscular power (females: r-squared = 0.36; males: r-squared = 0.42). These findings highlight modifiable and environmental factors that could be targeted to increase childhood muscular fitness.

Factors Associated with Persistently High Muscular Power from Childhood to Adulthood

PURPOSE

Child and adult muscular power have been shown to associate with contemporary cardiometabolic health. Muscular power typically persists (tracks) between childhood and adulthood. Few studies span childhood to adulthood, so we aimed to identify modifiable and environmental factors associated with the persistence or change in muscular power across the life course.

METHODS

Prospective study examining 1938 participants who had their muscular power (standing long jump distance) measured in 1985 as children 7-15 yr old and again 20 yr later in adulthood (26-36 yr old). A selection of objectively measured anthropometric characteristics (adiposity and fat-free mass), cardiorespiratory fitness (CRF), self-reported physical activity, dietary (quality and fruit, vegetable, and protein intake), and sociodemographic data were available at both time points. Muscular power was separated into thirds, and participants were reported as having persistently low, decreasing, persistently moderate, increasing, or persistently high muscular power.

RESULTS

Higher adiposity, lower physical activity, diet quality and socioeconomic status (SES) across the life course, and lower adult CRF were associated with persistently low muscular power. Lower adult protein intake and an increase in adiposity over time were associated with decreasing muscular power. An increase in fat-free mass was associated with a reduced probability of decreasing or persistently high muscular power and an increased probability of increasing muscular power. Higher adult fruit intake was associated with increasing muscular power. Lower adiposity across the life course, higher adult CRF and SES, and higher child protein intake were associated with persistently high muscular power.

CONCLUSION

Healthy weight, good CRF, greater protein intake, and high SES are important correlates of high muscular power maintained from childhood to adulthood.

Physiological, anthropometric parameters, and balance skill response of healthy bankers to fitness training

Sedentary lifestyle as a predisposing factor of chronic diseases like hypertension, diabetes, stroke and obesity is a common phenomenon in the banking job. Studies suggest that fitness training improves health of bankers but has not been established among Ghanaian bankers. This study examined the physiological, anthropometric parameters, and balance skill responses of relatively healthy bankers to fitness training. Twelve bankers aged 28 to 55 years (36.41±7.16 years) in Kumasi completed a 6-month fitness training program (FTP) of 30-min gym workouts and 1-hr swimming per session. Physiological, anthropometric parameters, and balance skill variables assessments were conducted in three trials: pretraining, midtraining and post-FTP. FTP caused significant decrease in pre-post systolic blood pressure (P=0.001), diastolic blood pressure (P=0.000), heart rate (P=0.006), waist circumference (P= 0.007), waist-to-hip ratio (P=0.007), and bone density (P=0.038). There was significance decrease in body mass index (P=0.047) between pre- and midtraining status. Weight significantly decreased among the three trials (P=0.017). Pre-post opened (P=0.043) and closed (P=0.015) eye balance skills increased significantly. Effects of FTP were significantly higher in female (P<0.05). Participants who were at the stage 1 and 2 hypertensions pretraining became normotensive posttraining. Six months FTP has beneficial effects on the physiological, anthropometric parameters, and balance skill of relatively healthy bankers.

The great leap backward: changes in the jumping performance of Australian children aged 11-12-years between 1985 and 2015

Previous data have indicated relative stability over time of paediatric jumping performance, but few data exist since the early 2000s. This study quantified the 30-year secular changes in jumping performance of Australian children aged 11-12-years using data from the Australian Schools Health and Fitness Survey (1985, n = 1967) and Growing Up in Australia's Child Health CheckPoint (2015, n = 1765). Both cohorts measured jumping performance (standing long jump distance), anthropometric and demographic data. Secular changes in jumping performance means and quantiles were examined using multivariable linear and quantile regression. Between 1985 and 2015, jumping performance declined by 16.4 cm or by 11.2% (standardised change 0.66 SD, 95%CI 0.60 to 0.73). Adjustment for body mass reduced the effect by 32%, although the decline remained (absolute change - 11.1 cm, 95%CI -12.5 to -9.7; percent change 7.7%, 95%CI 6.7 to 8.6; standardised change 0.51 SD, 95%CI 0.44 to 0.57). This decline was evident across all quantiles. The jumping performance of Australian children aged 11-12-years has declined between 1985 and 2015, with body mass changes accounting for only part of the decline. Efforts should continue to promote paediatric muscular fitness, reduce adiposity, and aim to reverse this decline in jumping performance.

Racial Differences in the Association Between Nonexercise Estimated Cardiorespiratory Fitness and Incident Stroke

OBJECTIVE

To examine the association between estimated cardiorespiratory fitness (eCRF) and incident stroke by black and white race.

PARTICIPANTS AND METHODS

A total of 24,162 participants from the REasons for Geographic And Racial Differences in Stroke study (13,232 [54.8%] women; 9543 [39.5%] blacks; mean age, 64.6±9.3 years) without stroke at enrollment between January 15, 2003, and October 30, 2007, were followed for incident stroke through March 31, 2016. Baseline eCRF in maximal metabolic equivalents was determined using nonexercise sex-specific algorithms and further grouped into age- and sex-specific tertiles.

RESULTS

Over a mean of 8.3±3.2 years of follow-up, 945 (3.9%) incident strokes occurred (377 in blacks and 568 in whites). The association between eCRF and stroke risk differed significantly by race (P_Interaction<.001). In whites, after adjustment for stroke risk factors and physical functioning score, the hazard ratio of stroke was 0.82 (95% CI, 0.67-1.00) times lower in the middle tertile of eCRF than in the lowest tertile and was 0.54 (95% CI, 0.43-0.69) times lower in the highest tertile of eCRF. The protective effect of higher levels of eCRF on stroke incidence was more pronounced in those 60 years or older among whites. No association between eCRF and stroke risk was observed in blacks.

CONCLUSION

Estimated cardiorespiratory fitness measured using nonexercise equations is a useful predictor of stroke in whites. The lack of an overall association between eCRF and stroke risk in blacks suggests that the assessment of eCRF in blacks may not be helpful in primary stroke prevention.

Vascular characteristics in young women-Effect of extensive endurance training or a sedentary lifestyle

AIM

To explore whether high-level endurance training in early age has an influence on the arterial wall properties in young women.

METHODS

Forty-seven athletes (ATH) and 52 controls (CTR), all 17-25 years of age, were further divided into runners (RUN), whole-body endurance athletes (WBA), sedentary controls (SC) and normally active controls (AC). Two-dimensional ultrasound scanning of the carotid arteries was conducted to determine local common carotid artery (CCA) geometry and wall distensibility. Pulse waves were recorded with a tonometer to determine regional pulse wave velocity (PWV) and pulse pressure waveform.

RESULTS

Carotid-radial PWV was lower in WBA than in RUN (P < .05), indicating higher arterial distensibility along the arm. Mean arterial pressure was lower in ATH than in CTR and in RUN than in WBA (P < .05). Synthesized aortic augmentation index (AI@75) was lower among ATH than among CTR (-12.8 ± 1.6 vs -2.6 ± 1.2%, P < .001) and in WBA than in RUN (-16.4 ± 2.5 vs -10.7 ± 2.0%, P < .05), suggesting a diminished return of reflection waves to the aorta during systole. Carotid-femoral PWV and intima-media thickness (IMT), lumen diameter and radial distensibility of the CCA were similar in ATH and CTR.

CONCLUSION

Elastic artery distensibility and carotid artery IMT are not different in young women with extensive endurance training over several years and in those with sedentary lifestyle. On the other hand, our data suggest that long-term endurance training is associated with potentially favourable peripheral artery adaptation, especially in sports where upper body work is added. This adaptation, if persisting later in life, could contribute to lower cardiovascular risk.

Childhood cardiorespiratory fitness, muscular fitness and adult measures of glucose homeostasis

OBJECTIVES

To assess whether childhood cardiorespiratory fitness (CRF) and muscular fitness phenotypes (strength, power, endurance) predict adult glucose homeostasis measures.

DESIGN

Prospective longitudinal study.

METHODS

Study examining participants who had physical fitness measured in childhood (aged 7-15 years) and who attended follow-up clinics approximately 20 years later and provided a fasting blood sample which was tested for glucose and insulin. Physical fitness measurements included muscular strength (right and left grip, shoulder flexion, shoulder and leg extension), power (standing long jump distance) and endurance (number of push-ups in 30s), and CRF (1.6km run duration). In adulthood, fasting glucose and insulin levels were used to derive glucose homeostasis measures of insulin resistance (HOMA2-IR) and beta cell function (HOMA2-β).

RESULTS

A standard deviation increase in childhood CRF or muscular strength (males) was associated with fasting glucose (CRF: β=-0.06mmol/L), fasting insulin (CRF: β=-0.73mU/L; strength: β=-0.40mU/L), HOMA2-IR (CRF: β=-0.06; strength: β=-0.05) and HOMA2-β (CRF: β=-3.06%; strength: β=-2.62%) in adulthood, independent of the alternative fitness phenotype (all p<0.01). Adjustment for childhood waist circumference reduced the effect by 17-35% for CRF and 0-15% for muscular strength (males) and statistical significance remained for all associations expect between CRF, fasting glucose and HOMA2-β (p>0.06).

CONCLUSIONS

CRF and muscular fitness in childhood were inversely associated with measures of fasting insulin, insulin resistance and beta cell function in adulthood. Childhood CRF and muscular fitness could both be potential independent targets for strategies to help reduce the development of adverse glucose homeostasis.

Childhood Muscular Fitness Phenotypes and Adult Metabolic Syndrome

PURPOSE

The objective of this study is to determine whether childhood muscular fitness phenotypes (strength, endurance, and power) are independently associated with adult metabolic syndrome (MetS).

METHODS

We conducted a longitudinal study including 737 participants who had muscular fitness measures in 1985 when age 9, 12, or 15 yr and attended follow-up in young adulthood 20 yr later when measures of MetS were collected. Childhood measures of muscular fitness included strength (right and left grip, leg, and shoulder extension and flexion), endurance (number of push-ups in 30 s), and power (distance of a standing long jump). A muscular fitness score was created using all individual muscular fitness phenotypes. In adulthood, waist circumference, blood pressure, HDL cholesterol, triglycerides, and glucose were measured. Adult outcomes were MetS defined using the harmonized definition and a continuous MetS risk score.

RESULTS

Participants with childhood muscular strength, muscular power, and combined muscular fitness score in the highest third had significantly lower relative risk (RR) for MetS and a lower continuous MetS score in adulthood independent of cardiorespiratory fitness than those in the lowest third (strength: RR = 0.21 (0.09, 0.49) β = -0.46 (-0.59, -0.34) power: RR = 0.26 (0.12, 0.60), β = -0.36 (-0.49, -0.23) fitness score: RR = 0.20 (0.09, 0.47), β = -0.45 (-0.58, -0.33)). However, adjustment for childhood waist circumference reduced the effect sizes for both adult outcomes by 17%-60%.

CONCLUSION

Phenotypes of childhood muscular fitness can be used to predict adult MetS independent of cardiorespiratory fitness. Although a large proportion of the effect of childhood muscular fitness on adult MetS is potentially being mediated by child waist circumference, these data suggest that promotion of muscular fitness among children might provide additional protection against developing adult MetS.

Weight status, cardiorespiratory fitness and high blood pressure relationship among 5-12-year-old Chinese primary school children

Cardiorespiratory fitness (CRF) and adiposity contribute to high blood pressure (HBP) in adults and children. However, their relative importance as risk factors is unknown. We examined the relationships between weight status, CRF and HBP among Chinese primary school children. A cross-sectional study was conducted with 4926 school children aged 5-12 years. CRF was estimated from a modified Cooper test, body mass index z-scores and weight categories were calculated from objective height and weight measurements and BP was measured using an electronic sphygmomanometer. HBP was defined as >95th percentile based on reference cutoffs for Chinese boys and girls. Generalised Linear Mixed models, adjusting for age, pubertal status and height, were developed for boys and girls to explore the independent and combined associations between fitness, weight status and HBP. Seven hundred and fifty-two (15.3%) children had HBP, with a higher prevalence in obese (40.5% and 45.9% in boys and girls, respectively) and overweight (27.6% and 30.2% in boys and girls, respectively) compared with non-overweight (9.0% and 13.8% in boys and girls, respectively) children. HBP prevalence was lower in boys with higher CRF (odds ratio (OR) for the highest vs lowest CRF quartile in boys 0.64; 95% confidence interval (CI) 0.46-0.89). This association was not seen in girls. With weight status and CRF in the same model, weight status, but not CRF, remained significantly associated with HBP (obesity in boys: OR 4.19; 95% CI 2.63-6.67; in girls: OR 2.49; 95% CI 1.19-5.19). The interaction effect for CRF and weight status was non-significant. Overweight/obesity was significantly associated with HBP among children. There was no evidence of modification of this relationship by CRF.

Combined effects of physical inactivity and acute hyperglycemia on arterial distensibility

Arterial distensibility, an independent predictor of cardiovascular events, is transiently increased with acute hyperglycemia (AHG) in healthy individuals. Whether this response interacts with physical inactivity remains unknown. We examined the effects of short-term bed rest (BR) on the response of carotid artery distensibility (CD) to AHG, and the influence of underlying changes in insulin resistance and blood volume. CD was assessed with ultrasonography before as well as 30 and 120 minutes following ingestion of 75 g of glucose prior to and after 3 days of BR in 15 healthy male volunteers. Plasma insulin/glucose concentrations and blood volumes were concomitantly determined. On day 4 of BR, blood volume was re-established to pre-BR levels by albumin infusion and CD and insulin/glucose concentrations were determined as in the previous experimental days. Basal CD was not affected by BR. AHG increased CD before and after BR but reached a higher peak increment after BR (12% vs 60% at 30 min OGTT, p=0.028). BR also increased the plasma insulin concentration during AHG ( p=0.007). In regression analyses, plasma insulin and glucose concentrations were positively correlated to CD, particularly after BR ( r=0.31, p<0.05). Restoration of the BR-induced loss (5%) in blood volume did not affect the response of CD to AHG. In conclusion, short-term physical inactivity strongly accentuates the initial increase in CD in response to AHG in healthy individuals. This effect is associated with concomitant increases in circulating insulin concentration attributable to early insulin resistance.

Tracking of muscular strength and power from youth to young adulthood: Longitudinal findings from the Childhood Determinants of Adult Health Study

OBJECTIVES

Low muscular fitness levels have previously been reported as an independent risk factor for chronic disease outcomes. Muscular fitness tracking, the ability to maintain levels measured at one point in time to another point in time, was assessed from youth to adulthood to provide insight into whether early identification of low muscular fitness in youth is possible.

DESIGN

Prospective longitudinal study.

METHODS

Study including 623 participants who had muscular fitness measures in 1985 (aged 9, 12 or 15 years) and again 20 years later in young adulthood. Measures of muscular fitness were strength (right and left grip, leg, shoulder extension and flexion measured by dynamometer, and a combined strength score) and power (standing long jump distance).

RESULTS

Strength and power were relatively stable between youth and adulthood; the strongest tracking correlations were observed for the combined strength score (r=0.47, p≤0.001), right grip strength (r=0.43, p≤0.001) and standing long jump (r=0.43, p≤0.001). Youth in the lowest third of muscular fitness had an increased risk of remaining in the lowest third of muscular fitness in adulthood (strength: relative risk (RR)=4.70, 95% confidence interval (CI) (3.19, 6.92); power: RR=4.06 (2.79, 5.90)).

CONCLUSIONS

Youth with low muscular fitness are at increased risk of maintaining a low muscular fitness level into adulthood. These findings warrant investigation into the long term effects of early interventions that focus on improving low muscular fitness levels in youth which could potentially improve adult muscular fitness and reduce future chronic disease outcomes.

Association Between Midlife Cardiorespiratory Fitness and Risk of Stroke

Background and Purpose—

Low cardiorespiratory fitness (CRF) is associated with an increased risk of stroke. However, the extent to which this association is explained by the development of stroke risk factors such as diabetes mellitus, hypertension, and atrial fibrillation is unknown. We evaluated the relationship between midlife CRF and risk of stroke after the age of 65 years, independent of the antecedent risk factor burden.

Methods—

Linking participant data from the Cooper Center Longitudinal Study with Medicare claims files, we studied 19 815 individuals who survived to receive Medicare coverage from 1999 to 2009. CRF estimated at baseline by Balke treadmill time was analyzed as a continuous variable (in metabolic equivalents) and according to age- and sex-specific quintiles (Q1=low CRF). Associations between midlife CRF and stroke hospitalization after the age of 65 years were assessed by applying a proportional hazards recurrent events model to the failure time data with hypertension, diabetes mellitus, and atrial fibrillation as time-dependent covariates.

Results—

After 129 436 person-years of Medicare follow-up, we observed 808 stroke hospitalizations. After adjustment for baseline risk factors, higher midlife CRF was associated with a lower risk of stroke hospitalization (hazard ratio [HR], 0.61; 95% confidence interval [CI], 0.49–0.76; quintiles 4–5 versus 1]. This association remained unchanged after additional adjustment for burden of Medicare-identified stroke risk factors (hypertension, diabetes mellitus, and atrial fibrillation; HR, 0.63; 95% CI, 0.51–0.79; quintiles 4–5 versus 1).

Conclusions—

There is a strong, inverse association between midlife CRF and stroke risk in later life independent of baseline and antecedent burden of risk factors, such as hypertension, diabetes mellitus, and atrial fibrillation.

Submaximal Exercise Systolic Blood Pressure and Heart Rate at 20 Years of Follow-up: Correlates in the Framingham Heart Study

BACKGROUND

Beyond their resting values, exercise responses in blood pressure (BP) and heart rate (HR) may add prognostic information for cardiovascular disease (CVD). In cross-sectional studies, exercise BP and HR responses correlate with CVD risk factors; however, it is unclear which factors influence longitudinal changes in exercise responses over time, which is important for our understanding of the development of CVD.

METHODS AND RESULTS

We assessed BP and HR responses to low-level exercise tests (6-minute Bruce protocol) in 1231 Framingham Offspring participants (55% women) who underwent a routine treadmill test in 1979-1983 (baseline; mean age 39±8 years) that was repeated in 1998-2001 (follow-up; mean age 58±8 years). Adjusting for baseline exercise responses, we related the follow-up exercise responses to baseline CVD risk factors and to their changes between examinations. Compared with men, women had greater rise in exercise systolic (S)BP and HR at 20-year follow-up (both P<0.005). Baseline blood lipid levels, resting SBP and HR, and smoking status were associated with greater exercise SBP at follow-up (all P<0.05). Weight gain across examinations was associated with higher exercise SBP and HR at follow-up (both P<0.0001). Smoking cessation was associated with a 53% reduced risk of attaining the highest quartile of exercise SBP (≥180 mm Hg) at follow-up (P<0.05).

CONCLUSION

An adverse CVD risk factor profile in young adults and its worsening over time were associated with higher SBP and HR responses to low-level exercise in midlife. Maintaining or adopting a healthy risk factor profile may favorably impact the exercise responses over time.

Midlife exercise blood pressure, heart rate, and fitness relate to brain volume 2 decades later

OBJECTIVE

To determine whether poor cardiovascular (CV) fitness and exaggerated exercise blood pressure (BP) and heart rate (HR) were associated with worse brain morphology in later life.

METHODS

Framingham Offspring participants (n = 1,094, 53.9% female) free from dementia and CV disease (CVD) underwent an exercise treadmill test at a mean age of 40 ± 9 years. A second treadmill test and MRI scans of the brain were administered 2 decades later at mean age of 58 ± 8 years.

RESULTS

Poor CV fitness and greater diastolic BP and HR response to exercise at baseline were associated with a smaller total cerebral brain volume (TCBV) almost 2 decades later (all p < 0.05) in multivariable adjusted models; the effect of 1 SD lower fitness was equivalent to approximately 1 additional year of brain aging in individuals free of CVD. In participants with prehypertension or hypertension at baseline, exercise systolic BP was also associated with smaller TCBV (p < 0.05).

CONCLUSION

Our results suggest that lower CV fitness and exaggerated exercise BP and HR responses in middle-aged adults are associated with smaller brain volume nearly 2 decades later. Promotion of midlife CV fitness may be an important step towards ensuring healthy brain aging.

The Association of Resting Heart Rate and Incident Hypertension: The Henry Ford Hospital Exercise Testing (FIT) Project

BACKGROUND

Given that sympathetic tone is associated with hypertension, we sought to determine whether resting heart rate (RHR), as a surrogate for cardiac autonomic function, was associated with incident hypertension.

METHODS

We analyzed 21,873 individuals without a history of hypertension who underwent a clinically indicated exercise stress test. Baseline RHR was assessed prior to testing and was categorized as <70, 70-85, and >85 beats-per-minute (bpm). Incident hypertension was defined by subsequent diagnosis codes for new-onset hypertension from three or more encounters. We tested for effect modification by age (<60 vs. ≥60 years), sex, race, and history of coronary heart disease (CHD).

RESULTS

Mean (±SD) age was 49 (±12) years, 55% were men and 21% were Black. Compared to the lowest RHR (<70 bpm) category, patients in the highest category (>85 bpm) were younger, more likely to be female, heavier, diabetic, and achieve lower metabolic equivalents (METS). Over a median of 4 years follow-up, there were 8,179 cases of incident hypertension. Compared to RHR <70 bpm, persons with RHR >85 bpm had increased risk of hypertension after adjustment for CHD risk factors, baseline blood pressure (BP), and METS (hazard ratio = 1.15 (95% confidence interval 1.08-1.23)). Age was an effect modifier (interaction P = 0.02), whereas sex, race, and CHD were not. In age-stratified analyses the relationship remained significant only in those younger than 60 years.

CONCLUSION

Elevated RHR is an independent risk factor for incident hypertension, particularly in younger persons. Whether lifestyle modification or other strategies to reduce RHR can prevent incident hypertension in high-risk individuals warrants further study.

Factors Affecting Tracking of Blood Pressure from Childhood to Adulthood: The Childhood Determinants of Adult Health Study

OBJECTIVES

To examine the modifiable factors that alter the trajectory of blood pressure (BP) from childhood to adulthood.

STUDY DESIGN

This study investigated the BP of 798 participants (53% female) from the Childhood Determinants of Adult Health Study who had BP measured when aged 9, 12, or 15 years, and at follow-up 20 years later. BP was classified as normal or elevated (prehypertensive or hypertensive) in childhood and adulthood. BP trajectory groups (persistently normal, resolution, incident elevated, persistently elevated) were established according to these classifications. Potentially modifiable factors measured at both examinations included body mass index, fruit and vegetable intake, physical activity, cardiorespiratory fitness, alcohol consumption, smoking, and socioeconomic status.

RESULTS

Spearman correlation coefficients for BP tracking from childhood to adulthood were 0.31 (P < .001) for systolic BP and 0.16 (P < .001) for diastolic BP. Children with elevated BP had a 35% increased risk of elevated BP in adulthood compared with those with normal BP (relative risk 1.35, 95% CI 1.18-1.55, P < .001). Relative to those with persistently elevated BP, participants in the resolution group significantly decreased their body mass index z-score, decreased their alcohol consumption z-score, and increased their vegetable consumption z-score between childhood and adulthood. The proportion of participants with upwardly mobile socioeconomic status was significantly higher in the resolution group (41.2%) compared with the persistently elevated group (27.5%).

CONCLUSIONS

Resolution of elevated BP in the transition from childhood to adulthood appeared to be partially determined by modifiable factors associated with a healthy lifestyle.

Physical fitness and hypertension in a population at risk for cardiovascular disease: the Henry Ford ExercIse Testing (FIT) Project

BACKGROUND

Increased physical fitness is protective against cardiovascular disease. We hypothesized that increased fitness would be inversely associated with hypertension.

METHODS AND RESULTS

We examined the association of fitness with prevalent and incident hypertension in 57 284 participants from The Henry Ford ExercIse Testing (FIT) Project (1991–2009). Fitness was measured during a clinician‐referred treadmill stress test. Incident hypertension was defined as a new diagnosis of hypertension on 3 separate consecutive encounters derived from electronic medical records or administrative claims files. Analyses were performed with logistic regression or Cox proportional hazards models and were adjusted for hypertension risk factors. The mean age overall was 53 years, with 49% women and 29% black. Mean peak metabolic equivalents (METs) achieved was 9.2 (SD, 3.0). Fitness was inversely associated with prevalent hypertension even after adjustment (≥12 METs versus <6 METs; OR: 0.73; 95% CI: 0.67, 0.80). During a median follow‐up period of 4.4 years (interquartile range: 2.2 to 7.7 years), there were 8053 new cases of hypertension (36.4% of 22 109 participants without baseline hypertension). The unadjusted 5‐year cumulative incidences across categories of METs (<6, 6 to 9, 10 to 11, and ≥12) were 49%, 41%, 30%, and 21%. After adjustment, participants achieving ≥12 METs had a 20% lower risk of incident hypertension compared to participants achieving <6 METs (HR: 0.80; 95% CI: 0.72, 0.89). This relationship was preserved across strata of age, sex, race, obesity, resting blood pressure, and diabetes.

CONCLUSIONS

Higher fitness is associated with a lower probability of prevalent and incident hypertension independent of baseline risk factors.

Plasma Renin Activity and Resting Heart Rate in a Population of Community-Dwelling Japanese: The Tanushimaru Study

BACKGROUND

Heart rate is a strong predictor of mortality and development of obesity and diabetes. The renin-angiotensin-aldosterone system plays an important role in blood pressure control and volume homeostasis. Although many studies have indicated the association between aldosterone and hypertension or insulin resistance, epidemiological evidence of the association of heart rate with plasma renin activity (PRA) remains scant. Therefore, we investigated whether heart rate is associated with PRA.

METHODS

A total of 1,943 subjects were enrolled, who underwent a health examination in Tanushimaru in 2009. Plasma renin and aldosterone concentrations were measured by radioimmunoassay. PRA and the homeostasis model assessment (HOMA) were used by natural-log transformed. Resting heart rate was measured using electrocardiography.

RESULTS

We divided the subjects into four groups by heart rate (<60/min, 60-69/min, 70-79/min, ≥80/ min), and analyzed an association between PRA and heart rate by analysis of covariance after adjustments for age and sex. The adjusted mean PRA and HOMA index showed a significant trend (P < 0.01) as higher heart rate, although there was no significant trend between aldosterone and heart rate (P = 0.26). In multiple linear regression analysis adjusted for age, sex, systolic blood pressure, HOMA index, and hypertensive medication, PRA was positively and strongly associated with elevated heart rate (P < 0.01).

CONCLUSIONS

This epidemiological study demonstrated that PRA, but not aldosterone, is significantly and positively associated with higher resting heart rate in a general population.

Vigorous physical activity and carotid distensibility in young and mid-aged adults

Although physical activity (PA) improves arterial distensibility, it is unclear which type of activity is most beneficial. We aimed to examine the association of different types of PA with carotid distensibility (CD) and the mechanisms involved. Data included 4503 Australians and Finns aged 26-45 years. Physical activity was measured by pedometers and was self-reported. CD was measured using ultrasound. Other measurements included resting heart rate (RHR), cardiorespiratory fitness (CRF), blood pressure, biomarkers and anthropometry. Steps/day were correlated with RHR (Australian men r = -0.10, women r = - 0.14; Finnish men r = -0.15, women r = -0.11; P<0.01), CRF and biochemical markers, but not with CD. Self-reported vigorous leisure-time activity was more strongly correlated with RHR (Australian men r = -0.23, women r = -0.19; Finnish men r = -0.20, women r = -0.13; P < 0.001) and CRF, and was correlated with CD (Australian men r = 0.07; Finnish men r = 0.07, women r = 0.08; P < 0.05). This relationship of vigorous leisure-time activity with CD was mediated by RHR independently of potential confounders. In summary, vigorous leisure-time PA but not total or less intensive PA was associated with arterial distensibility in young to mid-aged adults. Promotion of vigorous PA is therefore recommended among this population. RHR was a key intermediary factor explaining the relationship between vigorous PA and arterial distensibility.

Taking the pulse of aging: mapping pulse pressure and elasticity in cerebral arteries with optical methods

Cerebrovascular support is crucial for healthy cognitive and brain aging. Arterial stiffening is a cause of reduced brain blood flow, a predictor of cognitive decline, and a risk factor for cerebrovascular accidents and Alzheimer's disease. Arterial health is influenced by lifestyle factors, such as cardiorespiratory fitness (CRF). We investigated new noninvasive optical measures of cerebrovascular health, which provide estimates of arterial pulse parameters (pulse pressure, transit time, and compliance/elasticity) within specific cerebral arteries and cortical regions, and low-resolution maps of large superficial cerebral arteries. We studied naturally occurring variability in these parameters in adults (aged 55-87), and found that these indices of cerebrovascular health are negatively correlated with age and positively with CRF and gray and white matter volumes. Further, regional pulse transit time predicts specific neuropsychological performance.

Physical activity and resting pulse rate in older adults: findings from a randomized controlled trial

BACKGROUND

Elevated resting pulse rate (RPR) is a well-recognized risk factor for adverse outcomes. Epidemiological evidence supports the beneficial effects of regular exercise for lowering RPR, but studies are mainly confined to persons younger than 65 years. We set out to evaluate the utility of a physical activity (PA) intervention for slowing RPR among older adults.

METHODS

A total of 424 seniors (ages 70-89 years) were randomized to a moderate intensity PA intervention or an education-based "successful aging" health program. Resting pulse rate was assessed at baseline, 6 months, and 12 months. Longitudinal differences in RPR were evaluated between treatment groups using generalized estimating equation models, reporting unstandardized β coefficients with robust SEs.

RESULTS

Increased frequency and duration of aerobic training were observed for the PA group at 6 and 12 months as compared with the successful aging group (P < .001). In both groups, RPR remained unchanged over the course of the 12-month study period (P = .67). No significant improvement was observed (β [SE] = 0.58 [0.88]; P = .51) for RPR when treatment groups were compared using the generalized estimating equation method. Comparable results were found after omitting participants with a pacemaker, cardiac arrhythmia, or who were receiving β-blockers.

CONCLUSIONS

Twelve months of moderate intensity aerobic training did not improve RPR among older adults. Additional studies are needed to determine whether PA of longer duration and/or greater intensity can slow RPR in older persons.

The cross-sectional association of sitting time with carotid artery stiffness in young adults

OBJECTIVES

Physical activity is negatively associated with arterial stiffness. However, the relationship between sedentary behaviour and arterial stiffness is poorly understood. In this study, we aimed to investigate the association of sedentary behaviour with arterial stiffness among young adults.

DESIGN

Cross-sectional.

SETTING

34 study clinics across Australia during 2004-2006.

PARTICIPANTS

2328 participants (49.4% male) aged 26-36 years who were followed up from a nationally representative sample of Australian schoolchildren in 1985.

MEASUREMENTS

Arterial stiffness was measured by carotid ultrasound. Sitting time per weekday and weekend day, and physical activity were self-reported by questionnaire. Cardiorespiratory fitness was estimated as physical work capacity at a heart rate of 170 bpm. Anthropometry, blood pressure, resting heart rate and blood biochemistry were measured. Potential confounders, including strength training, education, smoking, diet, alcohol consumption and parity, were self-reported. Rank correlation was used for analysis.

RESULTS

Sitting time per weekend day, but not per weekday, was correlated with arterial stiffness (males r=0.11 p<0.01, females r=0.08, p<0.05) and cardiorespiratory fitness (males r = -0.14, females r = -0.08, p<0.05), and also with fatness and resting heart rate. One additional hour of sitting per weekend day was associated with 5.6% (males p=0.046) and 8.6% (females p=0.05) higher risk of having metabolic syndrome. These associations were independent of physical activity and other potential confounders. The association of sitting time per weekend day with arterial stiffness was not mediated by resting heart rate, fatness or metabolic syndrome.

CONCLUSIONS

Our study demonstrates a positive association of sitting time with arterial stiffness. The greater role of sitting time per weekend day in prediction of arterial stiffness and cardiometabolic risk than that of sitting time per weekday may be due to better reflection of discretionary sitting behaviour.