Elizabeth C. Schroeder

Associations of Health Club Membership with Physical Activity and Cardiovascular Health.

Introduction This study evaluates whether a health club membership is associated with meeting the US physical activity (PA) guidelines and/or favorable cardiovascular health. Methods Using cross-sectional data of health club members (n = 204) and non-members (n = 201) from April to August 2013, this is the first study to our knowledge to examine a health club membership in relation to objectively measured cardiovascular health indicators including resting blood pressure, resting heart rate, body mass index, waist circumference, and cardiorespiratory fitness based on a non-exercise test algorithm. To determine the total PA and sedentary time, this study used a comprehensive PA questionnaire about both aerobic and resistance activities at the health club, as well as lifestyle activities in other settings, which was developed based on the International Physical Activity Questionnaire (IPAQ). Results The odds ratios (95% confidence interval) of meeting either the aerobic, resistance, or both aerobic and resistance PA guidelines for members compared to non-members were 16.5 (9.8–27.6), 10.1 (6.2–16.3), and 13.8 (8.5–22.4), respectively. Significant associations of health club membership with more favorable cardiovascular health outcomes and sedentary behavior were observed for resting heart rate (B: -4.8 b/min, p<0.001), cardiorespiratory fitness (B: 2.1 ml/kg/min, p<0.001), and sedentary time (B: -1.4 hours, p<0.001). Participants with a health club membership of >1 year had more favorable health outcomes, with a smaller waist circumference (men, B: -4.0 cm, p = 0.04; women, B: -3.4 cm, p = 0.06), compared to non-members. Conclusions Health club membership is associated with significantly increased aerobic and resistance physical activity levels and more favorable cardiovascular health outcomes compared to non-members. However, longitudinal, randomized controlled trials would be clearly warranted as cross-sectional data prohibits causal inferences.

Effect of upper body position on arterial stiffness: influence of hydrostatic pressure and autonomic function

Objective: To evaluate changes in arterial stiffness with positional change and whether the stiffness changes are due to hydrostatic pressure alone or if physiological changes in vasoconstriction of the conduit arteries play a role in the modulation of arterial stiffness. Methods: Thirty participants’ (male = 15, 24 ± 4 years) upper bodies were positioned at 0, 45, and 72° angles. Pulse wave velocity (PWV), cardio-ankle vascular index, carotid beta-stiffness index, carotid blood pressure (cBP), and carotid diameters were measured at each position. A gravitational height correction was determined using the vertical fluid column distance (mmHg) between the heart and carotid artery. Carotid beta-stiffness was calibrated using three methods: nonheight corrected cBP of each position, height corrected cBP of each position, and height corrected cBP of the supine position (theoretical model). Low frequency systolic blood pressure variability (LFSAP) was analyzed as a marker of sympathetic activity. Results: PWV and cardio-ankle vascular index increased with position (P < 0.05). Carotid beta-stiffness did not increase if not corrected for hydrostatic pressure. Arterial stiffness indices based on Method 2 were not different from Method 3 (P = 0.65). LFSAP increased in more upright positions (P < 0.05) but diastolic diameter relative to diastolic pressure did not (P > 0.05). Conclusion: Arterial stiffness increases with a more upright body position. Carotid beta-stiffness needs to be calibrated accounting for hydrostatic effects of gravity if measured in a seated position. It is unclear why PWV increased as this increase was independent of blood pressure. No difference between Methods 2 and 3 presumably indicates that the beta-stiffness increases are only pressure dependent, despite the increase in vascular sympathetic modulation.

Measures of adiposity differentially correlate with C-reactive protein among persons with multiple sclerosis

BACKGROUND While MS is considered, in part, an inflammatory disease, the relationship between measures of adiposity and MS have not been well studied. This is important considering the strength of the association between adiposity and inflammation reported in the general population, and the resultant increased risk for cardiovascular and metabolic disease. Evidence demonstrates MS is associated with higher prevalence rates of cardiovascular disease than the general population, which provides an impetus to examine how measures of adiposity and systemic inflammation are related in individuals with MS. OBJECTIVE To examine the association between measures of adiposity and systemic inflammation, specifically using the global marker C-reactive protein (CRP), among persons with MS compared with a control group without MS. METHODS Persons with MS and a control group (n = 33/group) had measures of adiposity (body mass index, total body fat, and trunk fat) correlated and regressed to CRP. RESULTS Differential relationships between CRP and adiposity measures were observed between the MS group and the control group. Within the MS group, when adjusted for sex, age, and physical activity level, only whole body percent fat explained a significant portion of the variance in CRP (adjusted R2 = 0.095, p < 0.05), whereas all of the adiposity measures explained a significant degree of variance within the control group (p < 0.05), with trunk fat mass having the strongest correlation. CONCLUSIONS The differential relationships observed between the MS and control groups suggests that whole body fat may be a more important factor related to whole body inflammation in MS, rather than other adiposity markers, such as BMI or trunk fat. This differential association should be taken into account in future research examining body fatness/obesity and CRP.

Influence of fitness and age on the endothelial response to acute inflammation

What is the central question of the study? What are the effects of age and fitness on the vascular response to acute inflammation in younger and older adults? What is the main finding and its importance? In older adults, cardiorespiratory fitness level has a differential impact on endothelial function after acute inflammation. Compared with older adults with low fitness, older, moderately fit adults have a greater decrease in endothelial function, similar to that of younger adults. These findings have important implications in support of the beneficial effects of higher cardiorespiratory fitness in maintaining vascular reactivity and the ability to respond to stressors.

Resistance training improves cardiovascular health in postmenopausal women

(eg, blood pressure, glucose, total cholesterol) and a wide E vidence has been emerging on the importance of adding a muscle-strengthening component to regular physical activity to improve quality of life; delay the loss of muscle mass and function; and prevent osteoporosis, sarcopenia, and the falls, fractures, and disability that may follow. Menopause and aging may lead to a loss in fitness, decrease in muscle strength and bone mineral density, and a gain in weight, all of which concomitantly increase the risk for many chronic diseases, such as cardiovascular disease. If muscle-strengthening exercise can delay or prevent these diseases in postmenopausal women, this would have important public health implications. Recently, studies have been looking at the effectiveness of resistance training to improve strength and risk factors for cardiovascular disease, such as blood pressure and anthropometric outcomes. Knowing that the reduction in muscle mass and strength may be exacerbated after the loss of estrogen, a few studies have looked at resistance training and cardiovascular health, specifically in postmenopausal women. The study presented by Shaw et al in the current issue of Menopause aimed to investigate if a hypertrophyspecific training program could alleviate some of the detrimental anthropometric and cardiovascular changes often seen in postmenopausal women aged 50 to 79 years. Using a randomized 6-week intervention (resistance training vs control), the authors observed substantial improvements with participants performing resistance training only two times per week for 40 minutes at 67% to 85% of their 1-repetition maximum (1-RM). On completion of the 6-week training program, the individuals in the resistance training group, on average, saw reductions in heart rate ( 5 bpm), systolic blood pressure ( 2 mm Hg), diastolic blood pressure ( 3 mm Hg), waist circumference ( 7 cm), and body fat percentage ( 5%). There were no significant changes noted in the control group. This article provides further evidence that resistance training is beneficial for postmenopausal women to aid in reducing the negative effects of aging and/or menopause on cardiovascular health and anthropometric outcomes. It, however, is evident that there are limitations that should be considered when interpreting the results. First, a more conservative analysis, such as repeated measures analysis of variance with adjustment for the baseline value of each outcome measure, would probably have better captivated the true treatment and time effects. An adjustment for age could have also been considered because it is an important determinant of cardiovascular health outcomes