Relation of leisure-time physical activity to structural and functional arterial properties of the common carotid artery in male subjects

Association of leisure-time physical activity and sedentary behavior with carotid atherosclerosis morphology: The ARIC carotid-MRI study

Objective

We evaluated the prospective association of midlife leisure-time physical activity (LTPA) and sedentary behavior (SB), and their temporal patterns, with MRI-measured carotid atherosclerotic morphology.

Methods

Participants enrolled in the Carotid MRI substudy (2004-2006) of the Atherosclerosis Risk in Communities (ARIC) Study and with self-reported assessments of LTPA and SB at visits 1 (1987-1989) and 3 (1993-1995) were included in this study. LTPA was ascertained using the ARIC/Baecke physical activity questionnaire and categorized according to the American Heart Association's metric of poor, intermediate, or ideal physical activity. SB, measured as TV viewing frequency, was categorized as high, medium, and low. We used multivariable adjusted linear and logistic regression models to examine the associations between midlife (visit 3 only) and persistent (visit 1 to 3) LTPA and TV viewing with carotid artery plaque burden and components.

Results

Among the 1,582 (mean age: 59 years, 43% male, 18% Black) participants, 45.7%, 21.7%, and 32.6% reported ideal, intermediate, or poor LTPA, respectively. High TV viewing was reported in 33.8% of participants, with 46.4% and 19.8% reporting medium or low TV viewing, respectively. Compared to poor LTPA, ideal LTPA in midlife was not associated with total wall volume (ß=0.01, 95% CI: -0.01, 0.03), maximum carotid wall thickness (ß=0.06, 95% CI: -0.08, 0.21), normalized wall index (ß=-0.01, 95% CI: -0.03, 0.01), or maximum stenosis (ß=-0.11, 95% CI: -1.98, 1.76). Low or middle, compared to high, TV viewing was also not associated with carotid artery measures of plaque burden. Compared to poor LTPA or high TV viewing, ideal LTPA (odds ratio (OR): 0.82, 95% CI: 0.55, 1.23) and low TV viewing (OR=0.90, 95% CI: 0.56, 1.44) was not associated with odds of lipid core presence, respectively.

Conclusion

Overall, this study does not provide strong evidence for an association between LTPA and SB with carotid plaque measures.

Oxidative Stress and Inflammation, Key Targets of Atherosclerotic Plaque Progression and Vulnerability: Potential Impact of Physical Activity

Atherosclerosis, a complex cardiovascular disease, is a leading cause of mortality and morbidity worldwide. Oxidative stress and inflammation are both involved in the development of atherosclerotic plaque as they increase the biological processes associated with this pathology, such as endothelial dysfunction and macrophage recruitment and adhesion. Atherosclerotic plaque rupture leading to major ischemic events is the result of vulnerable plaque progression, which is a result of the detrimental effect of oxidative stress and inflammation on risk factors for atherosclerotic plaque rupture, such as intraplaque hemorrhage, neovascularization, and fibrous cap thickness. Thus, both are key targets for primary and secondary interventions. It is well recognized that chronic physical activity attenuates oxidative stress in healthy subjects via the improvement of antioxidant enzyme capacities and inflammation via the enhancement of anti-inflammatory molecules. Moreover, it was recently shown that chronic physical activity could decrease oxidative stress and inflammation in atherosclerotic patients. The aim of this review is to summarize the role of oxidative stress and inflammation in atherosclerosis and the results of therapeutic interventions targeting them in both preclinical and clinical studies. The effects of chronic physical activity on these two key processes are then reviewed in vulnerable atherosclerotic plaques in both coronary and carotid arteries.

Arterial adaptations in athletes of dynamic and static sports disciplines - a pilot study

BACKGROUND

Structural and functional arterial adaptations with regard to the type and level of training in young athletes are understudied. Our research aimed at evaluating them in two types of exercise (dynamic and static) and two levels of engagement (high and recreational).

METHODS

A total of 76 volunteers formed five groups. Group A included 17 high-level dynamic sports athletes 30·9 ± 6·4 years old, group B 14 recreational ones aged 28·7 ± 6·2 years, group C 15 high-level static sports athletes 26·4 ± 3·9 years old and group D 16 recreational ones, aged 25·8 ± 4·8 years. Fourteen sedentary men 30 ± 3·8 years old formed control group E. Structural indices of left cardiac chambers and thoracic aorta were echographically obtained, as well as common carotid intima-media thickness (cIMT). Furthermore, applanation tonometry was conducted, at rest and during a handgrip strength test, for the acquisition of central arterial pressure parameters, carotid-femoral pulse wave velocity (cfPWV) and total arterial compliance (C_τ ).

RESULTS

No significant differences in structural arterial markers were observed. However, group A obtained the highest handgrip central systolic pressure values (13·1% compared to group D, P<0·05). Resting cfPWV was lower in group B by 13·8% (P<0·05) than C and by 16·7% (P<0·01) than E, whereas C_τ was higher in group Β by 33·3% than C (P<0·05) and by 40·9% than E (P<0·01).

CONCLUSION

Functional arterial exercise-induced adaptations become apparent at an early age, without being in conjunction with structural ones. Recreational dynamic exercise results in the most favourable arterial characteristics.

The pioneer in hemodynamics and pulse-wave analysis, Otto Frank

Arterial pulse-wave velocity is a noninvasive index of arterial distensibility now generally advocated to assess cardiovascular health above-and-beyond merely measuring blood pressure. A host of recent findings supports its use. This evidence draws attention to the fact that vascular stiffness precedes the increase in blood pressure with age and that even nonpharmacological lifestyle interventions can improve distensibility independent of blood pressure. Where do these ingeniously modern ideas come from, and who defined the principles we embrace today? A worthwhile lesson in physiology and exercise in humility is the effort to revisit the origins of these concepts and the man to whom gratitude should be directed.

[Short-term impact of an ambulatory cardiac rehabilitation program on arterial rigidity]

BACKGROUND

If the positive impact of cardiac rehabilitation on metabolic profile and exercise tolerance is well documented in the literature, very few studies evaluated the impact of these rehabilitation programs on arterial rigidity.

PURPOSE

The main objective of this study was to determine if a short and intense 4-week cardiac rehabilitation program could yield a positive impact on arterial rigidity.

METHOD

A cohort study was performed on Leopold Bellan Foundation. All patients referred for cardiac rehabilitation program after an acute event (surgery, technical gesture or acute decompensate heart failure) were included in this study. Our CR program consists of four sessions per week for five weeks (total of 20 sessions) and includes both exercise and health and nutrition education sessions. In addition to clinical and therapeutic data collection, biochemical analysis for carbohydrate and lipid metabolism and exercise capacity measurements, carotid femoral pulse wave velocity (PWV) were measured in a quiet room in the morning of their first and last day prior to any exercise.

RESULTS

One hundred and ninety-eight cardiac patients have participated in this study, of which 79% were male, mean age 60 ± 10, 50 (25%) were diabetic, 103 (52%) were hypertensive, 60 (30%) were current smokers, 98 (50%) had dyslipidemia, and 140 (71%) were referred for cardiac rehabilitation after acute coronary syndrome. Arterial stiffness is defined by a VPWV value greater or equal to 10. At the beginning, 59% of our patients have rigid arteries. After 20 sessions of cardiac rehabilitation, this number is significantly reduced to 51% (P=0.12). Patients with arterial stiffness have accumulated more major cardiovascular risk factors, and have had less exercise capacity than others. However they benefit similarly from the cardiovascular rehabilitation program.

CONCLUSION

In the present study, we observed that arterial stiffness, as reflected by the PWV, tends to decrease after short-term ambulatory cardiac rehabilitation program.

Carotid Stiffness and Physical Activity in Elderly--A Short Report of the SAPALDIA 3 Cohort Study

Introduction

Regular physical activity has been shown to reduce cardiovascular disease risk in the general population. While smaller studies in specified groups (highly trained versus untrained individuals) indicate a certain dose-dependent effect of physical activity on the reduction of carotid stiffness (an indicator of subclinical vascular disease), it is unclear whether this association is present in a representative sample. Thus, we investigated this question cross-sectionally in participants from the population-based Swiss Cohort Study on Air Pollution And Lung and Heart Diseases In Adults (SAPALDIA).

Methods

Self-reported total, moderate and vigorous physical activity and distensibility as a measure of local arterial stiffness among 1636 participants aged 50 to 81 years without clinically manifest diseases were evaluated. Mixed regression models were used to examine associations of physical activity intensity with distensibility.

Results

Vigorous physical activity, but not total nor moderate physical activity, was significantly associated with increased distensibility (= reduced carotid stiffness) in univariate analyses (percent change in the geometric mean and 95% confidence interval per 1 standard deviation increment in vigorous physical activity = 2.54 (0.69; 4.43), p<0.01; in total physical activity = 1.62 (-0.22; 3.50), p = 0.08; in moderate physical activity = 0.70 (-1.12; 2.56), p = 0.45). These associations disappeared when we additionally adjusted for age.

Conclusion

After adjustment for the most important confounders and risk factors, we found no evidence for an association of physical activity with carotid stiffness in the general middle aged to elderly population.

Haemostatic factors, lipoproteins and long-term mortality in a multi-ethnic population of Gujarati, African-Caribbean and European origin

OBJECTIVES

To examine the relations between haemostatic factors and lipoproteins with mortality in British Europeans, African-Caribbeans (AfC) and Gujarati Indians.

METHODS

A prospective cohort study of 331 subjects (40-79 years), followed-up over 26 years for mortality. Apolipoprotein-A1 (Apo-A1), apolipoprotein-B (Apo-B), factor VII coagulant activity (FVIIc), fibrinogen and von Willebrand Factor (vWF) were measured at baseline in 118 Europeans, 100 AfC and 113 Gujaratis. Aortic pulse wave velocity (aPWV) was measured in 174 participants.

RESULTS

147 (44.4%) subjects died during a median of 24 years follow-up with 69 cardiovascular deaths. Women at baseline had higher, and AfC males the lowest FVIIc and Apo-A1 levels. Baseline age-sex and ethnicity adjusted FVIIc levels were higher in those who died (131.0 vs. 117.4%; P = 0.048). In similarly adjusted partial correlations, Apo-A1 was inversely related to arterial stiffness (ρ = -0.23, P = 0.04). Over the 26 years follow-up, participants below the median (i.e. with lower concentration) of FVIIc, Fibrinogen, Apo-B and vWF had better survival rates than those with higher concentrations; those with higher concentrations of Apo-A1 had better survival. In Cox multivariable regression analyses including sex, ethnicity and aPWV, independently increased risk of all-cause mortality came only from SBP (per 5 mmHg); P = 0.011), age (per year); P < 0.0001 and FVIIc at 7% (per 10-unit; HR 1.07 (1.02, 1.12); P = 0.008. Separately, Apo-A1 (HR 0.12 (0.02, 0.75; P = 0.029) was independently associated with a very significant 88% reduction in all-cause mortality.

CONCLUSIONS

Despite a relatively small sample size, long-term follow-up suggests an independent effect of the prothrombotic state (via FVIIc) and apo-A1 (a constituent of HDL) on mortality.

Ultra-endurance sports have no negative impact on indices of arterial stiffness

PURPOSE

Marathon running has been linked with higher arterial stiffness. Blood pressure is a major contributor to pulse wave velocity (PWV). We examined indices of arterial stiffness with a blood pressure-independent method in marathon runners and ultra-endurance athletes.

METHODS

Male normotensive amateur runners were allocated to three groups according to former participation in competitions: group I (recreational athletes), group II (marathon runners) and group III (ultra-endurance athletes). Indices of arterial stiffness were measured with a non-invasive device (VaSera VS-1500N, Fukuda Denshi, Japan) to determine the cardio-ankle vascular index (CAVI, primary endpoint) and brachial-ankle PWV (baPWV). Lifetime training hours were calculated. Cumulative competitions were expressed as marathon equivalents. Linear regression analysis was performed to determine predictors for CAVI and baPWV.

RESULTS

Measurements of arterial stiffness were performed in 51 subjects (mean age 44.6 ± 1.2 years): group I (n = 16), group II (n = 19) and group III (n = 16). No between-group differences existed in age, anthropometric characteristics and resting BP. CAVI and baPWV were comparable between all groups (P = 0.604 and P = 0.947, respectively). In linear regression analysis, age was the only independent predictor for CAVI (R(2) = 0.239, β = 0.455, P = 0.001). Systolic BP was significantly associated with baPWV (R(2) = 0.225, β = 0.403, P = 0.004).

CONCLUSIONS

In middle-aged normotensive athletes marathon running and ultra-endurance sports had no negative impact on arterial stiffness.

Blood flow restricted exercise and vascular function

It is established that regular aerobic training improves vascular function, for example, endothelium-dependent vasodilatation and arterial stiffness or compliance and thereby constitutes a preventative measure against cardiovascular disease. In contrast, high-intensity resistance training impairs vascular function, while the influence of moderate-intensity resistance training on vascular function is still controversial. However, aerobic training is insufficient to inhibit loss in muscular strength with advancing age; thus, resistance training is recommended to prevent sarcopenia. Recently, several lines of study have provided compelling data showing that exercise and training with blood flow restriction (BFR) leads to muscle hypertrophy and strength increase. As such, BFR training might be a novel means of overcoming the contradiction between aerobic and high-intensity resistance training. Although it is not enough evidence to obtain consensus about impact of BFR training on vascular function, available evidences suggested that BFR training did not change coagulation factors and arterial compliance though with inconsistence results in endothelial function. This paper is a review of the literature on the impact of BFR exercise and training on vascular function, such as endothelial function, arterial compliance, or other potential factors in comparison with those of aerobic and resistance training.

Lactation and maternal subclinical cardiovascular disease among premenopausal women

OBJECTIVE

The objective of the study was to examine the association between lactation and maternal subclinical cardiovascular disease.

STUDY DESIGN

The Women and Infants Study of Healthy Hearts enrolled 607 mothers who delivered a singleton between 1997 and 2002. In 2007, participating mothers underwent measurements of carotid intima-media thickness, lumen diameter, adventitial diameter, and carotid-femoral pulse wave velocity. Multivariable linear and logistic regressions were used to estimate the associations between lactation and subclinical cardiovascular disease.

RESULTS

Compared with mothers who breastfed for 3 or more months after every birth, mothers who never breastfed exhibited a 0.13 mm larger lumen diameter (95% confidence interval, 0.04-0.22) and a 0.12 mm larger adventitial diameter (95% confidence interval, 0.02-0.22) in models adjusting for age, parity, birth outcome, sociodemographic variables, health-related behaviors, family history, gestational weight gain, early adult body mass index, current body mass index, C-reactive protein, blood pressure, cholesterol, triglyceride, high-density lipoprotein, glucose, and insulin levels.

CONCLUSION

Mothers who do not breastfeed have vascular characteristics associated with a greater risk of cardiovascular disease.

Effects of physical activity on cardiovascular disease

Much attention has been directed toward lifestyle modifications as effective means of reducing cardiovascular disease risk. In particular, physical activity has been heavily studied because of its well-known effects on metabolic syndrome, insulin sensitivity, cardiovascular disease risk, and all-cause mortality. However, data regarding the effects of exercise on various stages of the atherosclerosis pathway remain conflicting. The investigators review previously published reports for recent observational and interventional trials investigating the effects of physical activity on markers of (or causal factors for) atherosclerotic burden and vascular disease, including serum lipoproteins, systemic inflammation, thrombosis, coronary artery calcium, and carotid intima-media thickness. In conclusion, the data show a correlation between physical activity and triglyceride reduction, apolipoprotein B reduction, high-density lipoprotein increase, change in low-density lipoprotein particle size, increase in tissue plasminogen activator activity, and decrease in coronary artery calcium. Further research is needed to elucidate the effect of physical activity on inflammatory markers and intima-media thickness.

Apolipoprotein B is related to arterial pulse wave velocity in young adults: the Cardiovascular Risk in Young Finns Study

OBJECTIVE

Limited data are available regarding the relationship of apolipoproteins B (ApoB) and A-1 (ApoA-1) with arterial stiffness. We conducted the present study to determine whether adulthood ApoB and ApoA-1 are related to arterial pulse wave velocity (PWV). Moreover, we examined whether ApoB and ApoA-1 measured in young adulthood are predictive of PWV assessed 6 years later.

METHODS

The study population consisted of 1618 apparently healthy Finnish young adults (aged 30-45 years, 44.9% males) whose apolipoproteins, other cardiovascular risk factors and PWV were measured in 2007. In a sub-sample population, apolipoproteins and other cardiovascular risk factors had also been measured in 2001 (n=1264). PWV measurements were performed using a whole-body impedance cardiography device.

RESULTS

ApoB (p<0.001) and the ApoB/ApoA-1 ratio (p<0.001) were directly associated with PWV. ApoB and the ApoB/ApoA-1 ratio measured in young adulthood were also predictive of PWV measured 6 later (p<0.001 for both). These relations remained significant (p<0.006) in models adjusted for non-lipid risk factors. The areas under the receiver-operating characteristic (ROC) curves (AUC) were similar for ApoB and non-HDL cholesterol (2001: p for AUC comparison=0.15; 2007: p for AUC comparison=0.07) in detecting subjects with increased PWV (PWV≥90th percentile).

CONCLUSION

The present study suggests that elevation of ApoB or non-HDL cholesterol is associated with increased arterial stiffness in young adults.

Effect of regular physical activity on carotid intima-media thickness. Results from a 6-year prospective study in the early stage of hypertension

AIM

To study the effect of leisure-time physical activity on the progression of carotid intima-media thickness (IMT) in the early stage of hypertension.

METHODS

We studied 47 sedentary and 40 physically active young pre-hypertensive or stage 1 hypertensive subjects. IMT was assessed in the common carotid artery, carotid bulb and internal carotid artery at baseline and after 6.5 years.

RESULTS

Cumulative maximum IMT of the three carotid segments (M-MAX, 0.13 ± 0.08 vs 0.10 ± 0.07 mm, p = 0.006) and cumulative mean IMT (m-IMT, 0.11 ± 0.07 vs 0.09 ± 0.06 mm, p = 0.01), adjusted for confounders, increased to a greater degree in the sedentary than the active subjects. Differences in known risk factors explained a large proportion of the observed association. Inclusion of baseline cholesterol in the regression model attenuated the strength of the association for both M-MAX (p = 0.04) and m-IMT (p = 0.049). When also baseline blood pressure, heart rate, and body mass index were taken into account the association with physical activity status remained significant for maximum IMT of internal carotid artery (p = 0.034) and was of borderline significance for M-MAX (p = 0.066).

CONCLUSIONS

Physical activity can delay the progression of carotid IMT in hypertension. This effect is mediated in substantial part by the better risk factor profile in active subjects.

Lifetime vigorous but not light-to-moderate habitual physical activity impacts favorably on carotid stiffness in young adults: the amsterdam growth and health longitudinal study

Higher levels of habitual physical activity favorably impact on arterial stiffness. It is not clear, however, whether lifetime habitual physical activities of different intensities carry the same protective effect and to what extent any such effect is mediated by other biological cardiovascular risk factors. We, therefore, examined longitudinal data on habitual physical activity and cardiovascular risk factors (8 repeated measures between the ages of 13 and 36 years) in 373 subjects in whom stiffness estimates of the carotid artery were assessed at age 36 years using noninvasive ultrasonography. The time spent in habitual physical activities (in minutes per week) throughout the longitudinal period was compared between subjects across tertiles of the following stiffness estimates: beta-stiffness index, distensibility and compliance coefficients, and the Young's elastic modulus. After adjustments for sex, body height, and other lifestyle variables, subjects in the highest tertile of the beta-stiffness index (ie, with stiffer arteries) had spent, on average, throughout the longitudinal period, less time in vigorous (-26.5 [95% CI: -45.9 to -7.1]) but less so in light-to-moderate habitual physical activities (-11.2 [95% CI: -53.5 to 31.1]) as compared with subjects in the lowest tertile. The difference in time spent in vigorous activities was greatly attenuated when further adjusted for blood lipids, cardiorespiratory fitness, fat distribution, resting heart rate, and mean arterial pressure (to -11.2 [95% CI: -29.4 to 7.0]). Similar results were found for the other stiffness estimates. Promoting vigorous intensity physical activities among the healthy young may, therefore, prevent arterial stiffness and related cardiovascular sequelae later in life, partly through its favorable impact on other biological cardiovascular risk factors.

Do carotid artery diameters manifest early evidence of atherosclerosis in women with rheumatoid arthritis?

OBJECTIVE

Given the high incidence of cardiovascular disease (CVD) in patients with rheumatoid arthritis (RA), we examined the associations between RA diagnosis and characteristics and evidence of carotid atherosclerosis. We take a unique approach by evaluating lumen and interadventitial diameters in addition to intima-media thickness and plaque.

METHODS

Ninety-three women with RA were matched with 93 healthy women by age, race, and menopause status. In cross-sectional analyses, we compared common carotid artery measures between groups and examined their relationships with measures of RA severity and activity.

RESULTS

Mean age was 53.3 years, and median RA duration was 14 years. Lumen diameter in patients was significantly greater than in healthy women (5.50 vs. 5.19 mm, p < 0.001), as was interadventitial diameter (6.92 vs. 6.61 mm, p < 0.001). Having RA also was independently associated with greater lumen (beta = 0.256, p < 0.01) and interadventitial (beta = 0.261, p < 0.01) diameters, after controlling for cardiovascular risk factors and intima-media thickness. Carotid intima-media thickness (0.70 vs. 0.71 mm) was similar, and the prevalence of carotid plaque in patients (21%) was higher but not statistically different from healthy women (15%). In patients with RA, we found positive associations between methotrexate dose and interadventitial diameter, between hypothyroidism and intima-media thickness, and between hypothyroidism and soluble endothelial adhesion molecule and plaque, independent of cardiovascular risk factors.

CONCLUSIONS

Women with RA have increased carotid artery diameters compared with healthy women. This may reflect premature vascular aging and may be an early indicator of increased cardiovascular risk.

Systemic arterial compliance, systemic vascular resistance, and effective arterial elastance during exercise in endurance-trained men

Systemic arterial compliance (C) and vascular resistance (R) regulate effective arterial elastance (Ea), an index of artery load. Increases in Ea during exercise are due primarily to reductions of C and maintain optimal ventricular-arterial coupling. Because C at rest and left ventricular functional reserve are greater in endurance-trained (ET) compared with sedentary control (SC) humans, we hypothesized that reductions of C and increases in Ea are greater in ET than SC individuals. The aim of this study was to investigate C, R, and Ea during exercise in ET and SC humans. C, R, Ea, and cardiac cycle length (T) were measured at rest and during exercise of 40, 60, and 80% maximal oxygen uptake using Doppler ultrasonography in 12 SC and 13 ET men. C decreased in an exercise intensity-dependent manner in both groups, but its reductions were greater in the ET than SC subjects. Consequently, although C at rest was greater in the ET than SC group, the intergroup difference in C disappeared during exercise. Exercise-related changes in R/T were relatively slight and R/T was lower in the ET than the SC group, both at rest and during exercise. Although Ea at rest was lower in the ET than SC group, there were no intergroup differences in Ea at 40, 60, or 80% maximal oxygen uptake. We conclude that the reductions of C from rest to exercise are more marked in ET than SC humans. This may be related to the exercise-associated disappearance of the difference in Ea between ET and SC humans.

Association between lower-extremity function and arterial compliance in older adults

The purpose was to identify the association between lower-extremity function and arterial compliance in older men and women. Participants included 46 healthy men (n = 18) and women (n = 28) 60 years of age or older. Lower-extremity functional performance was assessed by the summary performance score (SPS) that includes tests of 5 timed repeated chair rises, standing balance, and 4-meter walking velocity. Arterial compliance and arterial pressure were analyzed through pulsewave analysis. Small arterial compliance (3.74 +/- 2.14; mean +/- SD) was related (r = 0.34, P = .028) to SPS (11.09 +/- 1.19) after adjusting for body surface area, hyperlipidemia, and hypertension. Systolic blood pressure (138 +/- 14) also was related to SPS (r = -0.314, P = .040). These results suggest diminished lower-extremity function is associated with decreased small arterial compliance and elevated arterial pressure in older men and women.

Correlação entre resistência carotídea e autonomia funcional de mulheres idosas

Este estudo objetivou correlacionar resistência da artéria carótida e autonomia funcional de idosas. Avaliou-se a resistência da artéria carótida pelo método de ultra-som Doppler e a Autonomia Funcional por testes relacionados a atividades da vida diária (Protocolo GDLAM). Para a descrição dos dados, calculou-se média e desvio padrão, em que a resistência da carótida interna direita obteve respectivamente (0,71 ± 0,07) e o Índice geral de Autonomia Funcional apresentou (30,40 ± 6,31). O coeficiente de correlação de Spearman mostrou forte associação entre as variáveis do estudo (r = 0,998; p = 0,000). Os resultados sugerem que quanto maior o índice de resistência da artéria carótida, maior será a dificuldade de execução das tarefas da vida diária.

Effect of physical activity and muscle morphology on endothelial function and arterial stiffness

Physically active persons have a reduced risk of atherosclerotic disease. Arterial stiffness and endothelial dysfunction are important risk factors for cardiovascular disease. A high proportion of type I (slow-twitch) muscle fibers in skeletal muscle is associated with a favorable cardiovascular risk profile. We tested physical activity and muscle fiber-type distribution as determinants of endothelial function and arterial stiffness in middle-aged men. Fifty-four men (median age 58) who underwent a muscle biopsy in 1984 were re-studied in 2003. Aortic pulse wave velocity (PWV) and pulse wave reflection were assessed by applanation tonometry. Endothelial function was tested by examining the effects of salbutamol and nitroglycerin on pulse wave reflection. In multiple regression analyses aortic PWV (R2=0.51) correlated positively with age (P=0.017), BMI (P=0.001), and systolic blood pressure (P=0.004). A high augmentation index (R2=0.33) was associated with smoking (P<0.001), high LDL cholesterol (P=0.02), and elevated diastolic blood pressure (P=0.03). Impaired endothelial function (R2=0.37) was associated with high age (P=0.04), high LDL cholesterol (P=0.017), high triglycerides (P=0.027), and high physical activity (P=0.005). Muscle fiber-type distribution is not a determinant of arterial stiffness or endothelial function. Impaired endothelial function was observed in physically active men, underlining the need for further research.

Tobacco harm reduction strategies: The case for physical activity

Since the effects of tobacco smoke are so detrimental to health, growing consideration has been given to the development of harm reduction strategies for those smokers who are unable or unwilling to stop using tobacco. The term harm reduction refers to a policy, strategy, or particular intervention that assumes continued use of an undesired behavior and aspires to lower the risk of adverse consequences associated with the continuation of this addictive behavior. Up to this point, tobacco harm reduction interventions have focused on reducing tobacco-related harm through the utilization of innovative tobacco products, reduced tobacco consumption, and pharmaceutical medications. With the possible exception of medicinal nicotine products, these strategies remain unproven and thus far no scientific or medical literature exists to suggest these harm reduction strategies reduce tobacco-related exposure, morbidity, or mortality. Consequently, a need exists for broadening the range of potentially effective harm reduction strategies. This preliminary review suggests that physical activity has the potential to become one such strategy. Of the eight principles that characterize a harm reduction strategy, all are at least partially satisfied by physical activity. Further, emerging evidence indicates that physical activity may delay the occurrence of disease and premature death initiated by tobacco consumption. Significant concerns remain regarding the practicality of physical activity as a harm reduction strategy and the extent to which participation in physical activity may be used to justify continued smoking.

Endothelium-dependent vasodilation and carotid artery wall remodeling in athletes and sedentary subjects

In this study, the relationship between age, carotid artery remodeling, and endothelium-dependent vasodilation is investigated in sedentary subjects and athletes. Thirty-two young and old healthy sedentary subjects and 32 age-matched endurance athletes underwent ultrasonography of the carotid wall for measuring intima-media thickness (IMT) and corrected integrated backscatter (C-IBS), two early indicators of the atherosclerosis process. Endothelium-dependent vasodilation was assessed by intra-brachial acetylcholine (strain-gauge plethysmography), at baseline and during NO sythase inhibitor NG-monomethyl-L-arginine (L-NMMA), and the antioxidant Vitamin C. Response to sodium nitroprusside (SNP) was also evaluated. Independently of trained status, IMT and C-IBS were higher in older than in young individuals (p<0.0001), while response to acetylcholine, but not to SNP, was lower (p<0.0001). Older athletes showed lower IMT, lower C-IBS (p<0.0001), greater response to acetylcholine (p<0.0001), and greater inhibition of acetylcholine by L-NMMA (p<0.001) than older controls. Only in older sedentary individuals, Vitamin C increased response to acetylcholine (p<0.001) and restored the inhibiting effect of L-NMMA (p<0.01). In the whole population maximal acetylcholine-induced vasodilation was inversely related to IMT (r=-0.60, p<0.0001) and to C-IBS (r=-0.56, p<0.0001). In conclusion, regular physical training can attenuate the age-related impairment of endothelium-dependent vasodilation, which is related to an attenuation of the age-induced remodeling of the carotid wall.

Cardiorespiratory Fitness, Physical Activity, and Arterial Stiffness

Poor cardiorespiratory fitness and low physical activity have been identified as determinants of greater arterial stiffness, a mechanism that can partially explain the association of both variables with increased cardiovascular disease. However, the nature of these associations are not clear because cardiorespiratory fitness and physical activity can both mediate and confound the associations of one another with arterial stiffness. This issue was therefore examined in a population-based cohort of young adults. Subjects included 405 young men and women participating in an ongoing longitudinal study, the Northern Ireland Young Hearts Project. Pulse wave velocity was used to determine arterial stiffness in 2 arterial segments (aortoiliac and aortodorsalis pedis) using a noninvasive optical method. Cardiovascular fitness was estimated with a submaximal cycle test of physical work capacity and physical activity was estimated using a modified Baecke questionnaire. Associations were investigated with the use of multiple linear regression models with adjustment for potential confounders and/or intermediate variables. Cardiorespiratory fitness and sports-related physical activity (but not leisure- and work-related physical activity) were inversely associated with arterial stiffness in young adults. The associations between sports-related physical activity and arterial stiffness were strongly mediated by cardiorespiratory fitness, whereas physical activity levels did not disturb the associations between cardiopulmonary fitness and arterial stiffness. These findings suggest that arterial stiffness-related benefits of exercise are most likely to accrue if exercise prescription in young adults targets improvements in cardiorespiratory fitness.

Carotid Stiffness Indicates Risk of Ischemic Stroke and TIA in Patients With Internal Carotid Artery Stenosis

Background and Purpose— Patients with a carotid artery stenosis, including those with an asymptomatic or moderate stenosis, have a considerable risk of ischemic stroke. Identification of risk factors for cerebrovascular disease in these patients may improve risk profiling and guide new treatment strategies. We cross-sectionally investigated whether carotid stiffness is associated with previous ischemic stroke or transient ischemic attack (TIA) in patients with a carotid artery stenosis of at least 50%.

Methods— Patients were selected from the Second Manifestations of ARTerial disease (SMART) study, a cohort study among patients with manifest vascular disease or vascular risk factors. Arterial stiffness, measured as change in lumen diameter of the common carotid arteries during the cardiac cycle, forms part of the vascular screening performed at baseline. The first 420 participants with a stenosis of minimally 50% in at least 1 of the internal carotid arteries measured by duplex scanning were included in this study. Logistic regression analysis was used to determine the relation between arterial stiffness and previous ischemic stroke or TIA.

Results— The risk of ischemic stroke or TIA in the highest quartile (stiffest arteries) relative to the lowest quartile was 2.1 (95% CI, 1.1 to 4.1). These findings were adjusted for age, sex, systolic blood pressure, minimal diameter of the carotid artery, and degree of carotid artery stenosis.

Conclusion— In patients with a ≥50% carotid artery stenosis, increased common carotid stiffness is associated with previous ischemic stroke and TIA. Measurement of carotid stiffness may improve selection of high-risk patients eligible for carotid endarterectomy and may guide new treatment strategies.

Alcohol consumption and arterial stiffness in men

OBJECTIVE

Moderate alcohol consumption has been proposed to be anti-atherogenic and protect against coronary heart disease. Arterial stiffness provides a summary measure of atherosclerotic arterial damage and cardiovascular risk. A vascular protective effect of moderate alcohol consumption would be reflected in an inverse association between alcohol intake and aortic stiffness.

DESIGN

A cross-sectional study.

SETTING

The male population of Utrecht.

PARTICIPANTS

Of 370 men, aged 40-80 years, alcohol intake was calculated from a standardized questionnaire and aortic stiffness was non-invasively assessed by pulse-wave velocity (PWV) measurement of the aorta.

RESULTS

There were no non-drinkers; therefore the group consuming 0-3 glasses of alcoholic beverage per week was chosen as the reference group in the analyses. Those drinking 4-10, 11-21 and 22-58 glasses of alcoholic beverage per week had a -0.77 m/s (95% confidence interval, -1.26 to -0.28), -0.57 m/s (95% confidence interval, -1.07 to -0.08) and -0.14 m/s (95% confidence interval, -0.65 to 0.36) difference in mean PWV compared with those drinking 0-3 glasses per week. Adjustment for factors that correlated with PWV or alcohol consumption did not change the strength of the association.

CONCLUSION

Among men aged 40-80 years there is a J-shaped association between alcohol consumption and PWV. This further supports a decreased risk of cardiovascular disease with moderate alcohol consumption.

The Role of Exercise in the Treatment of Cardiovascular Disease Associated with Type 2 Diabetes Mellitus

The role of exercise training in the prevention and treatment of type 2 diabetes mellitus has been studied extensively over the past two decades. Although the primary treatment aim for patients with type 2 diabetes is metabolic control, the morbidity and mortality associated with the disease is more a function of cardiovascular disease. As exercise is associated with favourable reductions in the risk for cardiovascular disease in other high-risk populations, here we explore the role of exercise in the treatment of cardiovascular maladaptations associated with type 2 diabetes. The cardiovascular adaptation to type 2 diabetes is characterised by hypertrophy, stiffening and loss of functional reserve. Clinically, the cardiovascular adaptations to the diabetic state are associated with an increased risk for cardiovascular disease. Functionally, these adaptations have been shown to contribute to a reduced exercise capacity, which may explain the reduced cardiovascular fitness observed in this population. Exercise training is associated with improved exercise capacity in various populations, including type 2 diabetes. Several structural and functional adaptations within the cardiovascular system following exercise training could explain these findings, such as reductions in ventricular and vascular structural hypertrophy and compliance coupled with increased functional reserve. Although these cardiovascular adaptations to aerobic exercise training have been well documented in older populations with similar decrements in cardiovascular fitness and function, they have yet to be examined in patients with type 2 diabetes. For this reason, we contend that exercise training may be an excellent therapeutic adjunct in the treatment of diabetic cardiovascular disease.

Association between behavior-dependent cardiovascular risk factors and asymptomatic carotid atherosclerosis in a general population

BACKGROUND AND PURPOSE

Physical inactivity and unfavorable dietary and lifestyle patterns are related to cardiovascular disease and premature death. Their relationship to atherosclerosis of the carotid arteries and subsequent stroke is unclear. The objective of this study was to investigate the association between those behavioral cardiovascular risk factors and asymptomatic atherosclerosis of the carotid arteries in a population of former East Germany.

METHODS

The Study of Health in Pomerania (SHIP) is a cross-sectional survey in northeast Germany. In 1632 individuals aged 45 to 70 years, high-resolution B-mode ultrasound was used to assess the mean intima-media thickness of the right and left common carotid arteries. Carotid plaques and stenosis were recorded. Physical activity, dietary patterns, and cardiovascular risk factors were assessed in interviews with the use of standardized scales. Physically active participants with optimal dietary patterns were classified in the optimal lifestyle group, and those inactive with unfavorable diet were classified in the unfavorable group.

RESULTS

After adjustment for sex and age, significant decreasing trends were found for both intima-media thickness and severe asymptomatic atherosclerosis from unfavorable to optimal lifestyle patterns in never smokers but not in smokers. Regression analysis revealed an increased risk of severe asymptomatic atherosclerosis in subjects with an unfavorable lifestyle pattern compared with those with an optimal pattern (odds ratio 2.68; 95% CI, 1.13 to 6.37), following a significant linear trend.

CONCLUSIONS

Physical activity and optimal diet are associated with reduced risk of early atherosclerosis in subjects who never smoked, while no benefit of an otherwise optimal lifestyle is observed in smokers.

Regular aerobic exercise and the age-related increase in carotid artery intima-media thickness in healthy men

Carotid artery intima-media thickness (IMT), an independent risk factor for stroke, increases with age. Habitual exercise is associated with a lower prevalence of stroke, but it is unclear whether this protective effect could be mediated through a favorable influence on carotid IMT. We examined this possibility using both cross-sectional and intervention approaches. First, 137 healthy men (age 18-77 yr) who were either sedentary or endurance trained were studied. In both groups, carotid IMT and IMT-to-lumen ratio were progressively higher with age (P < 0.05). There were no significant differences in measures of carotid IMT between sedentary and endurance-trained men at any age. Carotid systolic blood pressure increased progressively with age and was related to carotid IMT (r = 0.63, P < 0.01). Second, 18 healthy sedentary subjects (54 +/- 2 yr) were studied before and after 3 mo of endurance training. Carotid IMT, IMT/lumen ratio, and carotid systolic blood pressure did not change with exercise intervention. Our results do not support the hypothesis that regular aerobic exercise exerts its protective effect against stroke by attenuating the age-related increase in carotid IMT. This lack of effect on carotid IMT may be due to the apparent inability of habitual exercise to prevent or reduce the age-associated elevation in carotid distending pressure.

Intima-media thickness: a new tool for diagnosis and treatment of cardiovascular risk

Increased intima-media thickness (IMT) is a non-invasive marker of early arterial wall alteration, which is easily assessed in the carotid artery by B-mode ultrasound, and more and more widely used in clinical research. Methods of IMT measurement can be categorized by two approaches: (i) measurement at multiple extracranial carotid sites in near and far walls and (ii) computerized measurement restricted to the far wall of the distal common carotid artery. Because IMT reflects global cardiovascular risk, its normal value might be better defined in terms of increased risk rather than in terms of statistical distribution within a healthy population. The available epidemiological data indicate that increased IMT (at or above 1 mm) represents a risk of myocardial infarction and/or cerebrovascular disease. Close relationships have been shown between: (i) most traditional cardiovascular risk factors; (ii) certain emerging risk factors such as lipoproteins, psychosocial status, plasma viscosity, or hyperhomocysteinemia; and (iii) various cardiovascular or organ damages such as white matter lesion of the brain, left ventricular hypertrophy, microalbuminuria or decreased ankle to brachial systolic pressure index. Thus, IMT gives a comprehensive picture of the alterations caused by multiple risk factors over time on arterial walls. Prospective primary and secondary prevention studies have also shown that increased IMT is a powerful predictor of coronary and cerebrovascular complications (risk ratio from 2 to 6) with a higher predictive value when IMT is measured at multiple extracranial carotid sites than solely in the distal common carotid artery. Therapeutic double-blind trials have shown that lipid-lowering drugs, such as resin and overall statines, and to a lesser extent antihypertensive drugs, such as calcium antagonists, may have a beneficial effect on IMT progression in asymptomatic or in coronary patients. However, methodological standardization of IMT measurement still needs to be implemented before routine measurement of IMT can be proposed in clinical practice as a diagnostic tool for stratifying cardiovascular risk in primary prevention and for aggressive treatment decision. It can be anticipated however, that the presence of increased carotid IMT in one individual with intermediate cardiovascular risk would lead to his classification into the high-risk category and thus influence the aggressiveness of risk factor modifications.

Influence of leisure time physical activity and television watching on atherosclerosis risk factors in the NHLBI Family Heart Study

Physical activity favorably influences atherosclerosis risk factors but only a few studies in adults considered the time watching television (TV) as a measure of physical inactivity. We therefore determined in a population-based sample of 1778 subjects from the NHLBI Family Heart Study (FHS) whether leisure time physical activity and TV watching have independent or interactive associations with cardiovascular disease risk factors and carotid artery intima-media wall thickness (IMT). Subjects were free from diabetes mellitus and clinically-ascertained coronary artery disease and did not take lipid-lowering or antihypertensive drugs. Only 0.7 and 1.3% of the variance in leisure time physical activity in women and men, respectively, was explained by the amount of TV watching. Leisure time physical activity had a clearly favorable, and TV watching an unfavorable association with anthropometric measurements (BMI (body mass index), waist girth, waist-hip ratio, subscapular and triceps skinfold thickness). The odds ratio (95% CI) of being overweight was 0.41 (0.28-0.62) in women and 0.69 (0.46-1.04) in men in the highest quartile of leisure time physical activity compared to the lowest quartile. The odds ratio increased for increasing quartiles of TV watching to 2.12 (1.45-3.10) in women and 1.61 (1.07-2.43) in men. Watching TV only 1 h per day in women with a BMI of 30 kg/m2 and doing about 75 min of moderate exercise per week was associated with a BMI 1.8 kg/m2 lower than in women watching TV 3 h per day and doing the same amount of exercise. Those with twice the amount of moderate exercise and watching TV 1 h per day had a BMI 0.45 kg/m2 lower. Furthermore, leisure time physical activity was negatively associated with concentrations of triglycerides and positively with HDL cholesterol in both genders. TV watching was significantly positively associated with triglycerides and slightly negatively with HDL cholesterol in men. The observed associations of leisure time physical activity and TV watching with atherosclerosis risk factors were independent from each other. Finally, we analyzed the relation between leisure time physical activity, TV watching and the degree of IMT of the carotid arteries. Neither of these two measures was significantly associated with IMT. In summary, TV watching, in addition to leisure time physical activity, shows an independent association with obesity-related anthropometric measurements, HDL and triglycerides. Decreasing the amount of TV watching might be effective as a first step in reducing atherosclerosis risk factors, especially overweight.