Validation of an Automated and Adjustable Blood Pressure System for Use with a Public Health Station.

OBJECTIVE: A new automated and adjustable blood pressure (BP) system has been developed to improve the accuracy of BP measurements on public-use health stations. This self-fitting BP system includes a mechanical cuff that wraps down to the user's arm prior to bladder inflation. The purpose of this study was to validate the adaptable BP system (ABPS) using the current standards from the Association for the Advancement of Medical Instrumentation (AAMI). METHODS: The AAMI/ISO 81060:2013 standards for clinical validation of non-invasive automated arterial BP measurement devices were followed precisely using the same arm sequential method. For each participant, BP was measured over multiple trials by trained observers alternating a reference sphygmomanometer with the ABPS. All study requirements were met with 85 qualifying participants, each with 3 valid paired determinations. RESULTS: The mean difference between ABPS BP and reference BP using all 255 paired determinations was -2.4 ± 7.7 mmHg for systolic and 1.7 ± 5.7 mmHg for diastolic. The standard deviation of the averaged paired determinations per participant was 6.3 mmHg for systolic and 5.2 mmHg for diastolic. Arm circumference measurements had a mean error of -2.1 ± 2.4 cm (R2 = 0.87). A new prediction model for arm circumference was validated using a holdout dataset (R2 = 0.94). CONCLUSION: The results of the study confirm that the ABPS met all benchmarks established by the AAMI. The device accurately measures BP across a wide range of arm circumferences (24-44 cm) and is suitable for use by individuals to self-monitor BP.

Reliability of maximal voluntary muscle strength and power testing in older men.

BACKGROUND: Maximal voluntary muscle strength (MVMS) and leg power are important measures of physical function in older adults. We hypothesized that performing these measures twice within 7-10 days would demonstrate a >5% increase due to learning and familiarization of the testing procedures. METHODS: Data were collected from three studies in older adult men (60-87 years) and were divided into two cohorts defined by study site and type of exercise equipment. MVMS was assessed in 116 participants using the one-repetition maximum method at two separate study visits for the chest press, latissimus pull-down, leg press, leg flexion, and leg extension exercises along with unilateral leg extension power. RESULTS: Test-retest scores were not different and did not exceed 0.8 +/- 9.0% in Cohort 1 or 2.3 +/- 9.8% in Cohort 2, except for leg extension, which improved by 6.6 +/- 14.4% (p <.009) and 3.4 +/- 6.8% (p <.016), respectively. Repeat tests were closely correlated with initial tests (all p <.001). Pearson correlation coefficients ranged from 0.74 for leg extension power to 0.96 for leg press. Coefficients of variation were <10% (4.2%-9.0%) for all exercises except for leg extension power, which was 15.5%. CONCLUSIONS: Our findings demonstrated that test-retest measures of MVMS and power in older adult men do not differ by more than 2.3% except for leg extension, and have relatively low coefficients of variation using data collected from three studies. Moreover, these findings were similar between two study sites using different equipment, which further supports the reliability of MVMS and power testing in older adult men.

Longitudinal change in coronary heart disease risk factors in older runners.

BACKGROUND: it is currently not clear how coronary heart disease (CHD) risk factors change over time in chronic exercisers. Therefore, the purpose of this study is to describe the longitudinal change in CHD risk factors in chronically endurance-trained men and women, and to determine the exercise and nutritional factors associated with those respective changes. METHODS AND RESULTS: ninety-one middle-aged runners (56 male, 35 female) were tested on two occasions approximately 10 years apart (aged 50.8 +/- 8.0 versus 60.0 +/- 7.9 years at respective visits). Body composition, VO2max, blood pressure (BP) and blood chemistries were measured, and the subjects' self-reported training and nutritional history. Data were analysed by factorial analysis of variance (ANOVA) and multivariate step-wise regression. Among the entire sample, training volume decreased (61.1 +/- 28.2 versus 44.7 +/- 24.6 km/week, P<0.05) but nutritional variables did not change. Body fat (16.9 +/- 5.3% for men versus 21.1 +/- 5.3% for women, P<0.05), blood lipids, blood glucose and systolic and diastolic BP all changed negatively over the study duration. These changes occurred similarly in both genders and irrespective of menstrual and hormone replacement status among the women. Lastly, the changes in CHD risk factors were not predicted by change in exercise or nutritional patterns. CONCLUSIONS: despite the maintenance of significant volumes of exercise and the absence of changes in diet, most CHD risk factors demonstrated unfavourable changes over 10 years in chronic men and women runners. However, the absolute values for most CHD risk factors remained better than those reported for sedentary peers of comparable age.

Chronic exercise and skeletal muscle power in older men.

We sought to determine the effects of age and chronic exercise on muscle power in older males. We examined 32 older males 60-74 years of age and grouped as sedentary (CON, n = 11), chronic endurance trained (ET, n = 10), and chronic endurance trained + resistance training (ET + RT, n = 11). Exercise history was obtained by questionnaire. Absolute strength and power measures were obtained by the one-repetition maximum method. Relative strength and power were determined by dividing the absolute measure by the muscle mass involved in the exercise. Total and regional muscle mass was measured by DXA. Absolute and relative leg power were not significantly different among the 3 groups. In contrast, absolute leg press strength was greater in ET + RT compared with CON, and relative leg press strength was greater in ET and ET + RT compared with CON. Chronic running combined with resistance training may therefore enhance absolute and relative muscle strength in older adults, but does not influence muscle power. Endurance exercise may inhibit the ability of resistance exercise to positively influence skeletal muscle power.

Cardiopulmonary responses to eccentric and concentric resistance exercise in older adults.

BACKGROUND: In older ambulatory persons, exercise strategies that are expected to generate beneficial muscle adaptations with low cardiopulmonary demands are needed. OBJECTIVE: We hypothesised that eccentric resistance exercise would be less demanding on the cardiovascular and pulmonary systems than bouts of concentric resistance exercise. DESIGN: The effects of eccentric and concentric resistance exercise were compared during leg squats at a submaximal intensity known to increase muscle mass. SUBJECTS: 19 Older persons (15 women/four men, age 65 +/- 4 years) and 19 young reference controls (10 women/nine men; age 25 +/- 2 years) were enrolled. METHODS: Participants completed eccentric-only and concentric-only exercise bouts 5-7 days apart. RESULTS: Cardiovascular and pulmonary measures were collected from subjects during bouts consisting of three sequential sets of 10 repetitions at 65% of their voluntary concentric 1-repetition maximum force (68+/-16 kg for older participants and 94 +/- 36 kg for young participants). Peak heart rate (119 +/- 10 versus 155 +/- 16 b.p.m.), systolic blood pressure (129 +/- 18 versus 167 +/- 14 mmHg), cardiac index (7.8 +/- 2.0 versus 9.2 +/- 1.5 l/min/m2) and expired ventilation (20.5 +/- 5.7 versus 29.8 +/- 9.1 l/min) were significantly lower during eccentric than during concentric bouts in the older subjects, respectively (P < 0.001 for all comparisons). Similarly, peak heart rate, systolic blood pressure, cardiac index and expired ventilation were significantly lower during eccentric bouts in the young control subjects. CONCLUSIONS: Eccentric resistance exercise produced less cardiopulmonary demands and may be better suited for older persons with low exercise tolerance and at risk of adverse cardiopulmonary events.

Six-week improvements in muscle mass and strength during androgen therapy in older men.

BACKGROUND: The purpose of our study was to assess the early effects of a potent anabolic androgen on muscle mass and strength, lower extremity power, and functional performance in older men. METHODS: Thirty-two men 72 +/- 6 years of age were randomized to receive oxandrolone (10 mg twice daily) or matching placebo in a 2:1 manner for 12 weeks. Total and appendicular lean body mass (LBM) were assessed by dual-energy x-ray absorptiometry (DEXA). Lower extremity muscle volume was determined by magnetic resonance imaging to validate DEXA changes. RESULTS: Total LBM increased by 2.7 +/- 1.6 kg after 6 weeks with oxandrolone (p <.001), which was greater (p <.001) than the decline in LBM (-0.5 +/- 0.9 kg) with placebo. Appendicular LBM increased by 1.2 +/- 0.9 kg after just 6 weeks with oxandrolone (p <.001), which was greater (p <.001) than the decline in LBM (-0.4 +/- 0.5 kg) with placebo. These changes were >90% of the gains in total and appendicular LBM (3.0 +/- 1.5 kg and 1.3 +/- 0.9 kg, respectively) after 12 weeks. Total thigh and hamstring muscle volume increased by 111 +/- 29 mm(3) (p =.001) and 75 +/- 18 mm(3) (p =.001), respectively, after 12 weeks. Maximal strength increased for the leg press 6.3 +/- 5.6% (p =.003), leg curl 6.7 +/- 8.6% (p =.01), chest press 6.9 +/- 6.5% (p =.001), and latissimus pull-down 4.8 +/- 6.3% (p =.009) with oxandrolone after 6 weeks; these increases were different than those with placebo (p <.001) and were 93%, 96%, 74%, and 94% of the respective gains at week 12. There were no improvements in functional measures. CONCLUSION: Treatment with a potent anabolic androgen may produce significant increases in muscle mass and strength after only 6 weeks in healthy older men. However, such treatment did not improve leg muscle power or walking speed.