Polly S. Montgomery

Physical activity is related to quality of life in older adults

BackgroundPhysical activity is associated with health-related quality of life (HRQL) in clinical populations, but less is known whether this relationship exists in older men and women who are healthy. Thus, this study determined if physical activity was related to HRQL in apparently healthy, older subjects.MethodsMeasures were obtained from 112 male and female volunteers (70 ± 8 years, mean ± SD) recruited from media advertisements and flyers around the Norman, Oklahoma area. Data was collected using a medical history questionnaire, HRQL from the Medical Outcomes Survey short form-36 questionnaire, and physical activity level from the Johnson Space Center physical activity scale. Subjects were separated into either a higher physically active group (n = 62) or a lower physically active group (n = 50) according to the physical activity scale.ResultsThe HRQL scores in all eight domains were significantly higher (p < 0.05) in the group reporting higher physical activity. Additionally, the more active group had fewer females (44% vs. 72%, p = 0.033), and lower prevalence of hypertension (39% vs. 60%, p = 0.041) than the low active group. After adjusting for gender and hypertension, the more active group had higher values in the following five HRQL domains: physical function (82 ± 20 vs. 68 ± 21, p = 0.029), role-physical (83 ± 34 vs. 61 ± 36, p = 0.022), bodily pain (83 ± 22 vs. 66 ± 23, p = 0.001), vitality (74 ± 15 vs. 59 ± 16, p = 0.001), and social functioning (92 ± 18 vs. 83 ± 19, p = 0.040). General health, role-emotional, and mental health were not significantly different (p > 0.05) between the two groups.ConclusionHealthy older adults who regularly participated in physical activity of at least moderate intensity for more than one hour per week had higher HRQL measures in both physical and mental domains than those who were less physically active. Therefore, incorporating more physical activity into the lifestyles of sedentary or slightly active older individuals may improve their HRQL.

Efficacy of Quantified Home-Based Exercise and Supervised Exercise in Patients With Intermittent Claudication A Randomized Controlled Trial

Background— This prospective, randomized, controlled clinical trial compared changes in exercise performance and daily ambulatory activity in peripheral artery disease patients with intermittent claudication after a home-based exercise program, a supervised exercise program, and usual-care control. Methods and Results— Of the 119 patients randomized, 29 completed home-based exercise, 33 completed supervised exercise, and 30 completed usual-care control. Both exercise programs consisted of intermittent walking to nearly maximal claudication pain for 12 weeks. Patients wore a step activity monitor during each exercise session. Primary outcome measures included claudication onset time and peak walking time obtained from a treadmill exercise test; secondary outcome measures included daily ambulatory cadences measured during a 7-day monitoring period. Adherence to home-based and supervised exercise was similar (P=0.712) and exceeded 80%. Both exercise programs increased claudication onset time (P<0.001) and peak walking time (P<0.01), whereas only home-based exercise increased daily average cadence (P<0.01). No changes were seen in the control group (P>0.05). The changes in claudication onset time and peak walking time were similar between the 2 exercise groups (P>0.05), whereas the change in daily average cadence was greater with home-based exercise (P<0.05). Conclusions— A home-based exercise program, quantified with a step activity monitor, has high adherence and is efficacious in improving claudication measures similar to a standard supervised exercise program. Furthermore, home-based exercise appears more efficacious in increasing daily ambulatory activity in the community setting than supervised exercise. Clinical Trial Registration— URL: http://www.ClinicalTrials.Gov. Unique identifier: NCT00618670.

Physical Activity Monitoring in Patients With Peripheral Arterial Occlusive Disease

PURPOSE Physical activity is an important variable to measure in patients with peripheral arterial occlusive disease (PAOD) because of this relationship to cardiovascular disease morbidity and mortality. The purposes of this study were to (1) determine the reliability of measures of daily physical activity in PAOD participants using an accelerometer and a pedometer; and (2) assess the validity of both instruments by comparing them against validated physical activity questionnaires. METHODS Forty-three patients with PAOD with a resting ankle/brachial index of 0.63 +/- 0.19 were monitored for 2 consecutive weekdays with an accelerometer and pedometer worn on each hip. The 48-hour monitoring period was repeated approximately 1 week later. RESULTS The daily physical activity values obtained from the accelerometer were similar between the two testing periods, 352 +/- 248 kcal/day vs. 337 +/- 199 kcal/day; P = 0.61, with a reliability coefficient of r = 0.84. The steps obtained from the pedometer during each 2-day period also were similar, 4615 +/- 2839 steps/day vs. 4498 +/- 2768 steps /day; P = 0.75, with a reliability coefficient of r = 0.86. The physical activity values from the accelerometer moderately correlated with the Minnesota Leisure Time Physical Activity Questionnaire, r = 0.33; P < 0.01, and the NASA/Johnson Space Center Physical Activity Scale, r = 0.44; P < 0.001. Similarly, the relationship between the steps obtained from the pedometer and physical Activity and the Minnesota Leisure Time Physical Activity and NASA/Johnson Space Center Physical Activity Scale questionnaires were significant, r = 0.46 and r = 0.51; P < 0.001, respectively. CONCLUSION These findings indicate that an accelerometer and pedometer are two instruments that reliably estimate the physical activity levels of patients with PAOD over 2 consecutive days. Furthermore, the activity questionnaires, suggesting that activity monitoring measures a different component of activities in patients with PAOD with intermittent claudication.

Relationship between free-living daily physical activity and ambulatory measures in older claudicants.

The purpose of this study was to determine the relationship between free-living daily physical activity and ambulatory measurements in peripheral arterial occlusive disease (PAOD) patients with intermittent claudication. Thirty-four older, nonsmoking PAOD patients with intermittent claudication (age = 69.0 ± 6.0 years, ankle/brachial index [ABI] =0.63 ±0.18) were recruited from the Vascular Clinic at the Baltimore Veterans Affairs Medical Center and from radio and newspaper advertisements. Energy expenditure of physical activity (EEPA) was determined by using doubly labeled water and indirect calorimetry techniques. Patients were also characterized on claudication distances and peak oxygen uptake during a graded treadmill test, 6-minute walking distance, weight, body mass index, and percent body fat. The claudication patients were sedentary, as EEPA was 362 ±266 kcal/day. EEPA was related to the 6-minute walk distance (369 ±68 meters; r=0.629, P<0.001), to the number of steps taken during 6 minutes (605 ±99 steps; r=0.485, P=0.008), to the treadmill distance to maximal claudication (313 ±131 meters; r=0.470, P=0.010), and to the time to relief of pain (6:21 ±3:57 min:sec; r=-0.417, P=0.017). None of the other ambulatory and body composition measure ments were correlated with EEPA. In conclusion, a reduction in free-living daily physical activity was associated with a decrease in ambulatory ability and with more severe inter mittent claudication in older PAOD patients.

Step-Monitored Home Exercise Improves Ambulation, Vascular Function, and Inflammation in Symptomatic Patients With Peripheral Artery Disease: A Randomized Controlled Trial

Background This prospective, randomized, controlled clinical trial compared changes in primary outcome measures of claudication onset time (COT) and peak walking time (PWT), and secondary outcomes of submaximal exercise performance, daily ambulatory activity, vascular function, inflammation, and calf muscle hemoglobin oxygen saturation (StO2) in patients with symptomatic peripheral artery disease (PAD) following new exercise training using a step watch (NEXT Step) home‐exercise program, a supervised exercise program, and an attention‐control group. Methods and Results One hundred eighty patients were randomized. The NEXT Step program and the supervised exercise program consisted of intermittent walking to mild‐to‐moderate claudication pain for 12 weeks, whereas the controls performed light resistance training. Change scores for COT (P<0.001), PWT (P<0.001), 6‐minute walk distance (P=0.028), daily average cadence (P=0.011), time to minimum calf muscle StO2 during exercise (P=0.025), large‐artery elasticity index (LAEI) (P=0.012), and high‐sensitivity C‐reactive protein (hsCRP) (P=0.041) were significantly different among the 3 groups. Both the NEXT Step home program and the supervised exercise program demonstrated a significant increase from baseline in COT, PWT, 6‐minute walk distance, daily average cadence, and time to minimum calf StO2. Only the NEXT Step home group had improvements from baseline in LAEI, and hsCRP (P<0.05). Conclusions NEXT Step home exercise utilizing minimal staff supervision has low attrition, high adherence, and is efficacious in improving COT and PWT, as well as secondary outcomes of submaximal exercise performance, daily ambulatory activity, vascular function, inflammation, and calf muscle StO2 in symptomatic patients with PAD. Clinical Trial Registration URL: ClinicalTrials.gov. Unique Identifier: NCT00618670.

The influence of obesity on arterial compliance in adult men and women

The objective of this study was to determine whether differences in large and small arterial compliance existed among normal weight, overweight, and obese older men and women, and whether large and small arterial compliance were associated with abdominal, hip, and subcutaneous fat distribution. A total of 134 individuals who were 40 years of age and older (age = 62 ± 11 years; mean ± SD) were grouped into normal weight (BMI: 18.5—24.9 kg/m2; n = 33), overweight (BMI: 25.0—29.9 kg/m2; n = 48), or obese (BMI: ≥30.0 kg/m2; n = 53) categories. The hemodynamic and arterial compliance measurements were obtained using the HDI/PulseWave CR-2000 CardioVascular Profiling System (Hypertension Diagnostics, Inc). Body mass index, nine-site sum of skinfolds, and circumference measures around the hip and waist were used for analysis. Large and small arterial compliance was lower (p < 0.001) in the obese group (12.4 ± 4.8 ml/mmHg × 10 vs 4.6 ± 2.5 ml/mmHg × 100, respectively) than the normal weight (16.2 ± 4.9 ml/mmHg × 10 vs 5.5 ± 2.7 ml/mmHg × 100) and overweight (15.2 ± 4.3 ml/mmHg × 10 vs 5.0 ± 2.2 ml/mmHg × 100) groups. This difference remained (p < 0.001) after adjusting for body surface area, sex, hyperlipidemia, and hypertension. Additionally, large arterial compliance correlated (p < 0.05) with sum of skinfolds (r = — 0.209), while small arterial compliance correlated with hip circumference (r = — 0.189). Arterial compliance measures were not related (p > 0.05) to waist circumference or waist-to-hip ratio. In conclusion, obesity was associated with a decrease in large and small arterial compliance independent of conventional risk factors. Additionally, subcutaneous fat and fat around the hips were inversely related to arterial compliance.

Relationship Between Free-Living Daily Physical Activity and Peripheral Circulation in Patients with Intermittent Claudication:

The purpose of this study was to determine the relationship between free-living daily physical activity and peripheral circulation under resting, reactive hyperemia, and maximal exercise conditions in peripheral arterial occlusive disease (PAOD) patients with intermittent claudication. Sixty-one PAOD patients (age=70 ±6 years, ankle/brachial index [ABI] =0.57 ±0.24) were recruited from the Vascular Clinic at the Baltimore Veterans Affairs Medical Center and from radio and newspaper advertise ments. Free-living daily physical activity was measured as the energy expenditure of physical activity (EEPA), determined from doubly labeled water and indirect calorimetry. Patients also were characterized on ankle/brachial index, calf blood flow, calf transcutaneous oxygen tension (TcPO2), and calf transcutaneous heating power (TcHP). ABI and calf blood flow served as markers of the macrocirculation of the lower extremity, while TcPO2 and TcHP served as markers of the microcirculation. The clau dication patients were sedentary, reflected by a mean EEPA value of 486 ±274 kcal/day. EEPA was related to calf TcHP at rest (282 ±24 mW; r=-0.413, p=0.002), after postoc clusion reactive hyperemia (275 ±22 mW; r=-0.381, p=0.004), and after maximal exercise (276 ±20 mW; r=-0.461, p<0.001). ABI, calf blood flow, and calf TcPO2 were not related to EEPA under any condition. In conclusion, higher levels of free-living daily physical activity were associated with better microcirculation of the calf musculature in older PAOD patients with intermittent claudication.

Comparison of Three Blood Pressure Methods Used for Determining Ankle/Brachial Index in Patients with Intermittent Claudication

The standard noninvasive test to assess the severity of peripheral arterial occlusive disease (PAOD) is the ankle/brachial systolic blood pressure index (ABI). While ankle systolic blood pressure is obtained by the Doppler ultrasound technique, brachial systolic blood pressure can be obtained by the Doppler, auscultatory, or oscillometric (Dinamap 1846 SX) methods. The purpose was to determine whether the three methods yielded similar brachial systolic blood pressure values, and consequently similar ABI values, in PAOD patients with intermittent claudication. Fifty patients who had a history of inter mittent claudication of 2.3 ±2.0 blocks for a duration of 5.7 ±5.8 years were recruited. Following 10 minutes of supine rest, brachial systolic blood pressure was measured in the right arm by the three techniques in a randomized order, and ankle systolic blood pressure (87.3 ±28.9 mmHg) was measured in the more symptomatic leg with the Doppler technique. Brachial systolic blood pressure was not significantly different (p=0.954) among the Doppler (128.5 ±18.4 mmHg), auscultatory (128.4 ±17.4 mmHg), and oscillometric (128.2 ± 17.1 mmHg) methods. Corresponding ABI values also were similar (p=0.922) among the three respective methods (0.68 ±0.22, 0.68 ±0.22, and 0.68 ±0.21), indicating that ABI did not vary according to the technique used to obtain brachial systolic blood pressure. It is concluded that the accuracy of deter mining ABI in PAOD patients with intermittent claudication was minimally affected by the method chosen to obtain brachial systolic blood pressure.

Calf muscle hemoglobin oxygen saturation characteristics and exercise performance in patients with intermittent claudication

PURPOSE This study was conducted to determine the association between the characteristics of calf muscle hemoglobin oxygen saturation (StO(2)) and exercise performance in patients with intermittent claudication. METHODS The study comprised 39 patients with peripheral arterial disease limited by intermittent claudication. Patients were characterized on calf muscle StO(2) before, during, and after a graded treadmill test, as well as on demographic and cardiovascular risk factors, ankle-brachial index (ABI), ischemic window, initial claudication distance (ICD), and absolute claudication distance (ACD). RESULTS Calf muscle StO(2) decreased 72%, from 55% +/- 18% (mean +/- SD) saturation at rest to the minimum value of 17% +/- 19% saturation attained 459 +/- 380 seconds after the initiation of exercise. After exercise, recovery half-time of calf muscle StO(2) was attained at 129 +/- 98 seconds, whereas full recovery to the resting value was reached at 225 +/- 140 seconds. After adjusting for sex, race, and grouping according to the initial decline constant in calf muscle StO(2) during exercise, the exercise time to minimum calf muscle StO(2) was correlated with the ischemic window (r = -0.493, P = .002), ICD (r = 0.339, P = .043), and ACD (r = 0.680, P < .001). After treadmill exercise, the recovery half-time of calf muscle StO(2) was correlated with the ischemic window (r = 0.531, P < .001), ICD (r = -0.598, P < .001), and ACD (r = -0.491, P = .003). CONCLUSION In patients limited by intermittent claudication, shorter ICD and ACD values are associated with reaching a minimum value in calf muscle StO(2) sooner during treadmill exercise and with having a delayed recovery in calf muscle StO(2) after exercise.

The relationship between history of falling and physical function in subjects with peripheral arterial disease.

The purpose of this study was to determine whether peripheral arterial disease (PAD) subjects with a history of falling had more impaired physical function than their non-falling counterparts. A total of 120 PAD subjects (26%) who had fallen over the past year and 346 PAD subjects (74%) who had not fallen were evaluated. Additionally, subjects were characterized on physical function, consisting of balance, strength, ambulatory function, and monitored physical activity, as well as PAD-specific measures of ankle/brachial pressure index (ABPI) and treadmill claudication distances. Full-tandem stance time was 19% shorter (p ≤ 0.001) in the fallers than in the non-fallers (7.2 ± 0.3 vs 8.9 ± 0.1 s; mean ± SEM), and the self-reported ability to climb stairs was 36% lower (27 ± 4 vs 42 ± 2%). Furthermore, the fallers were 126% more likely (p ≤ 0.001) to report ambulatory stumbling and unsteadiness, took 14% longer (p = 0.022) to perform five sequential sit-to-stand transfers using an armless chair, covered 16% shorter distance (p ≤ 0.001) during a 6-min walk test, and were 25% less physically active than the non-fallers. The groups had similar ABPI and treadmill claudication distances (p ≤ 0.05). A history of falling was independently related to the self-reported ability to climb stairs, the full-tandem stance time, self-reported ambulatory stumbling and unsteadiness, and daily physical activity (multiple R = 0.47, p ≤ 0.001). In conclusion, impairments in multiple domains of physical function were associated with a history of falling in PAD subjects with intermittent claudication. Furthermore, the link between poor physical function and falling was independent of PAD severity.