Metabolic syndrome impairs physical function, health-related quality of life, and peripheral circulation in patients with intermittent claudication

Effects of aerobic and combined training on pain-free walking distance and health-related quality of life in patients with peripheral artery disease: a randomized clinical trial

Background

Decreased walking ability in patients with peripheral arterial disease is often a clinical problem and limits the quality of life and daily activities of these subjects. physical exercise is important in this scenario, as it improves both the daily walking distance and the ability to withstand intermittent claudication related to the limitations of the peripheral disease.

Objectives

Our aim was to compare the effects of two types of exercise training (aerobic training and aerobic training combined with resistance exercises) on pain-free walking distance (PFWD) and health-related quality of life (HRQoL) in a sample composed of patients with peripheral artery disease (PAD).

Methods

Twenty patients with claudication symptoms were randomized to either aerobic control (AC) N= 9, or combined training (CT) N= 8, (24 sixty-minute sessions, twice a week). The total walking distance until onset of pain due to claudication was assessed using the 6-minute walk test and HRQoL was measured using the WHOQOL-bref questionnaire (general and specific domains) at baseline and after training. We used generalized estimating equations (GEE) to assess the differences between groups for the PFWD and HRQoL domains, testing the main group and time effects and their respective interaction effects. P values < 0.05 were considered statistically significant.

Results

Seventeen patients (mean age 63±9 years; 53% male) completed the study. Both groups experienced improvement in claudication, as reflected by a significant increase in PFWD: AC, 149 m to 299 m (P<0.001); CT, 156 m to 253 m (P<0.001). HRQoL domains also improved similarly in both groups (physical capacity, psychological aspects, and self-reported quality of life; P=0.001, P=0.003, and P=0.011 respectively).

Conclusions

Both aerobic and combined training similarly improved PFWD and HRQoL in PAD patients. There are no advantages in adding strength training to conventional aerobic training. This study does not support the conclusion that combined training is a good strategy for these patients when compared with classic training.

Diabetes Is Negatively Associated With Meeting Physical Activity Time-Intensity Guidelines in Patients With Claudication

PURPOSES

We determined the percentage of patients with peripheral artery disease (PAD) and claudication who meet the 2018 physical activity (PA) time-intensity guidelines, and we identified the clinical characteristics associated with the status of meeting the guidelines.

METHODS

Five hundred seventy-two patients were assessed on their daily ambulatory activity for 1 wk with a step activity monitor, and were evaluated on whether or not they achieved 150 min/wk of moderate-intensity PA.

RESULTS

Thirty-one percent (n = 175) of the patients with PAD met the PA time-intensity guidelines and 69% (n = 397) did not. In a final multivariable logistic regression model identifying the independent predictors of meeting the PA time-intensity guidelines from clinical characteristics, diabetes was the only significant variable entered (OR = 0.310: 95% CI, 0.175-0.538; P < .001) and was associated with a 69% lower chance of meeting the guidelines. Patients with diabetes spent less daily time in moderate-intensity ambulatory PA than patients without diabetes (15 ± 13 vs 23 ± 20 min/d; P < .001).

CONCLUSIONS

Thirty-one percent of patients with PAD and claudication met the PA time-intensity guidelines. Furthermore, patients with diabetes were least likely to meet the PA time-intensity guidelines, as they had a 69% lower chance than patients without diabetes. The clinical significance is that PAD patients who have diabetes are particularly susceptible to being physically sedentary, and are therefore prime patients who should be encouraged to increase their daily PA.

Cognitive decrement in older adults with symptomatic peripheral artery disease

Peripheral artery disease (PAD) is highly prevalent, affecting up to 20% of people over 70 years of age. To test the hypothesis that PAD promotes the pathogenesis of vascular cognitive impairment (VCI), we compared cognitive function in older adults with symptomatic PAD and in participants without PAD who had a burden of comorbid conditions. Furthermore, we compared the cognitive function of these groups after adjusting for demographic and clinical characteristics, comorbid conditions, and cardiovascular risk factors. Participants with PAD (age: 69 ± 8 years; n = 58) and those without PAD (age: 62 ± 8 years; n = 30) were assessed on a battery of eight neuropsychological tests. The tests assessed attention and working memory, verbal memory, non-verbal memory, perceptuo-motor speed, and executive function. Participants were further characterized on demographic and clinical characteristics, comorbid conditions, cardiovascular risk factors, and ankle-brachial index. The PAD group had significantly lower neuropsychological scores than the non-PAD control group on all eight tests (P < .01). After adjusting for covariates, significantly worse scores in the PAD group persisted for verbal memory, measured by tests on logical memory-immediate recall (P = .022), and logical memory-delayed recall (P < .001), and for attention and working memory, measured by tests on digits forward (P < .001), and digits backward (P = .003). Participants with symptomatic PAD have substantially lower levels of performance on tests of attention, working memory, and verbal memory than participants without PAD independent of demographic characteristics and comorbid health burdens. These findings provide additional evidence in support of the concept that generalized accelerated vascular aging manifesting as symptomatic PAD in the peripheral circulation also affects the brain promoting the pathogenesis of VCI. These cognitive difficulties may also negatively impact symptomatic patient's ability to understand and adhere to behavioral and medical therapies, creating a vicious cycle. We speculate that more intensive follow-up may be needed to promote adherence to therapies and monitor cognitive decline that may affect care.

Diet is associated with ankle-brachial index, inflammation, and ambulation in patients with intermittent claudication

OBJECTIVE

The aims of this investigation were to determine whether the daily dietary intake of nutrients by patients with peripheral artery disease (PAD) and intermittent claudication (IC) met recommended levels for adults older than 50 years and to determine whether meeting recommended levels of nutrients was associated with ankle-brachial index (ABI), inflammation, and ambulation of patients with PAD and IC.

METHODS

A total of 48 patients were assessed on their dietary intake of 20 nutrients during a 3-day period. Patients were further characterized on demographic variables, comorbid conditions, cardiovascular risk factors, ABI, 6-minute walk distance (6MWD), and high-sensitivity C-reactive protein (hsCRP) concentration.

RESULTS

Few patients met the daily recommended intakes for calcium (4%), fiber (6%), vitamin E (6%), trans fatty acids (13%), vitamin A (15%), total sugars (19%), potassium (23%), sodium (29%), saturated fat (29%), and vitamin C (31%), and none of the patients met the daily recommended intake of vitamin D (0%). Overall, patients met few of the 20 dietary recommendations as the median score was seven recommendations. Only 17 of 48 patients met more than seven of the recommendations. For the ABI regression model adjusted for age, sex, race, smoking, hypertension, dyslipidemia, body mass index, and percentage body fat, the only significant predictor was total sugars (P < .001); patients who did not meet the recommendation had lower ABI values. For the hsCRP-adjusted regression model, the strongest significant predictor was omega-3 polyunsaturated fatty acids (P = .001), indicating that those who did not meet the recommendation had higher hsCRP values. Finally, for the 6MWD-adjusted regression model, folate (P = .011) and dietary score index (P = .014) were significant predictors; those who did not meet the recommendation for folate and those who met 5 or fewer of the 20 recommendations had shorter 6MWD.

CONCLUSIONS

Patients with PAD and IC consume a low-nutrient-dense diet that is deficient in many vitamins, calcium, fruits, and vegetables and contains too much added sugar, saturated and trans fats, and processed foods. In addition, more severe PAD, greater inflammation, and ambulatory dysfunction are independently associated with aspects of a low-nutrient-dense diet, such as too much intake of added sugars, low intake of omega-3 polyunsaturated fatty acids and folate, and meeting the recommended intakes of only five or fewer nutrients.

Relationship between metabolic syndrome and trunk muscle quality as well as quantity evaluated by computed tomography

BACKGROUND & AIMS

Metabolic syndrome is a cluster of metabolic abnormalities. Skeletal muscle attenuation and area evaluated by computer tomography (CT) may provide valuable information about patients with metabolic disorder. Therefore, we examined the association between skeletal muscle characteristics and metabolic syndrome, and investigated the combined effect of quantitative and qualitative muscle parameters.

METHODS

In this cross-sectional study, we analyzed 808 middle-aged Japanese subjects. The cross-sectional area of skeletal muscle was evaluated based on CT at the third lumbar vertebrae. The subjects were divided into four groups according to the median levels of skeletal muscle index (SMI) and density (SMD).

RESULTS

Eighty-five men and twenty-two women had metabolic syndrome. In the adjusted model, SMI and SMD had an interaction effect on the number of metabolic syndrome components (p = 0.0398 in men and p = 0.0306 in women). When SMI and SMD were considered as independent variables for multiple regression analysis, SMI (β = -0.155, p = 0.0019 in men and β = -0.295, p < 0.0001 in women) and SMD (β = -0.355, p < 0.0001 in men and β = -0.324, p < 0.0001 in women) were both independently associated with the number of metabolic syndrome components. The subgroup with presence of low SMI and low SMD levels had a significantly higher prevalence of metabolic syndrome than that observed in other groups.

CONCLUSIONS

Therefore, we suggest that not only muscle quantity but also quality is independently associated with metabolic syndrome.

Predictors of health-related quality of life in patients with symptomatic peripheral artery disease

OBJECTIVE

The aim of this study was to identify predictors of baseline measures of health-related quality of life (HRQoL) in symptomatic patients with peripheral artery disease (PAD) from objective markers of severity of PAD, clinical and demographic characteristics, comorbid conditions, cardiovascular risk factors, objectively measured physical activity, and patient-based measures of physical function.

METHODS

HRQoL measurements of 216 symptomatic men and women with PAD were assessed with the Medical Outcomes Study 36-Item Short Form Health Survey. Patients were further characterized on demographic variables, comorbid conditions, cardiovascular risk factors, ankle-brachial index, peak walking time during a maximal treadmill test, 6-minute walk distance, gait speed, ambulatory activity monitored during 1 week, activities of daily living (ADLs), Mini-Mental State Examination questionnaire, and Walking Impairment Questionnaire (WIQ).

RESULTS

For the physical function HRQoL subscale, the significant predictors included WIQ speed score (P < .001), history of stumbling (P < .001), WIQ stair climbing score (P < .001), ADL associated with bathing (P = .001), 6-minute walk distance (P = .004), and daily walking cadence (P = .043). For the role emotional function HRQoL subscale, the significant predictors included a history of stumbling (P < .001), the ADL associated with transferring from a bed to a chair (P < .001), and the WIQ distance score (P = .022).

CONCLUSIONS

Physical and mental subscales of HRQoL in symptomatic patients with PAD are primarily predicted by patient-based physical function rather than by more specific markers of PAD severity and comorbid conditions. The clinical significance is that interventions designed to improve HRQoL should focus on improving the quality of executing functional tasks, such as walking more steadily without stumbling; completing ADLs that are not specific to walking, such as bathing and transferring; and improving patient-based ability to walk various distances and speeds and to climb stairs.

Endothelial Cell Inflammation and Antioxidant Capacity are Associated With 6-Minute Walk Performance in Patients With Symptomatic Peripheral Artery Disease

We determined whether 6-minute walk total distance and pain-free distance were associated with circulating biomarkers of antioxidant capacity and inflammation and with cultured endothelial cell inflammation, oxidative stress, and apoptosis in 251 patients with symptomatic peripheral artery disease (PAD). In multivariate analyses, pain-free distance during the 6-minute walk test was negatively associated with dyslipidemia ( P < .001), chronic kidney disease ( P = .004), and transient transfection, nuclear factor κ-Light-Chain-Enhancer of activated B (NF-κB) cultured endothelial cells ( P = .007) and was positively associated with height ( P = .008). Furthermore, total distance walked during the 6-minute walk test was negatively associated with cultured endothelial cell NF-κB ( P < .001), coronary artery disease ( P = .009), and body mass index ( P = .022) and was positively associated with ankle-brachial index ( P < .001), male sex ( P < .001), and hydroxyl radical antioxidant capacity ( P < .001). The 6-minute walk performance in symptomatic patients with PAD was associated with vascular biomarkers, as walking distances were negatively associated with cultured endothelial cell inflammation and positively associated with circulating antioxidant capacity. The clinical implication is that behavioral interventions designed to alleviate endothelial cell inflammation and increase circulating antioxidant capacity, such as exercise and antioxidant intake, may improve ambulation of patients with PAD during submaximal exercise that is typically performed during daily activities.

Quality of life in patients with intermittent claudication

Background

Intermittent claudication (IC) is a common condition that causes pain in the lower limbs when walking and has been shown to severely impact the quality of life (QoL) of patients. The QoL is therefore often regarded as an important measure in clinical trials investigating intermittent claudication. To date, no consensus exits on the type of life questionnaire to be used. This review aims to examine the QoL questionnaires used in trials investigating peripheral arterial disease (PAD).

Material and methods

A systematic review of randomised clinical trials including a primary analysis of QoL via questionnaire was performed. Trials involving patients with diagnosed PAD were included (either clinically or by questionnaire). Any trial which had QoL as the primary outcome data was included with no limit being placed on the type of questionnaire used.

Results

The search yielded a total of 1845 articles of which 31 were deemed appropriate for inclusion in the review. In total, 14 different QoL questionnaires were used across 31 studies. Of the questionnaires 24.06% were missing at least one domain when reported in the results of the study. Mean standard deviation varied widely based on the domain reported, particularly within the SF36.

Discussion

Despite previous recommendations for Europewide standardisation of quality of life assessment, to date no such tool exists. This review demonstrated that a number of different questionnaires remain in use, that their completion is often inadequate and that further evidence-based guidelines on QoL assessment are required to guide future research.

Clinical impact of exercise in patients with peripheral arterial disease

Increasing prevalence, high morbidity and mortality, and decreased health-related quality of life are hallmarks of peripheral arterial disease. About one-third of peripheral arterial disease patients have intermittent claudication with deleterious effects on everyday activities, such as walking. Exercise training improves peripheral arterial disease symptoms and is recommended as first line therapy for peripheral arterial disease. This review examines the effects of exercise training beyond improvements in walking distance, namely on vascular function, parameters of inflammation, activated hemostasis and oxidative stress, and quality of life. Exercise training not only increases walking distance and physiologic parameters in patients with peripheral arterial disease, but also improves the cardiovascular risk profile by helping patients achieve better control of hypertension, hyperglycemia, obesity and dyslipidemia, thus further reducing cardiovascular risk and the prevalence of coexistent atherosclerotic diseases. American guidelines suggest supervised exercise training, performed for a minimum of 30-45 min, at least three times per week, for at least 12 weeks. Walking is the most studied exercise modality and its efficacy in improving cardiovascular parameters in patients with peripheral arterial disease has been extensively proven. As studies have shown that supervised exercise training improves walking performance, cardiovascular parameters and quality of life in patients with peripheral arterial disease, it should be encouraged and more often prescribed.

Association between gait characteristics and endothelial oxidative stress and inflammation in patients with symptomatic peripheral artery disease

The aim of the study was to determine whether gait characteristics were associated with endothelial cell inflammation, oxidative stress, and apoptosis and with circulating biomarkers of inflammation and antioxidant capacity in older patients with symptomatic peripheral artery disease (PAD). Gait measurements of 231 symptomatic men and women with PAD were assessed during a 4-m walk test. Patients were further characterized on endothelial effects of circulating factors present in the sera using a cell culture-based bioassay on primary human arterial endothelial cells and on circulating inflammatory and vascular biomarkers. In a multivariate regression model for gait speed, the significant independent variables were age (p < 0.001), intercellular cell adhesion molecule-1 (ICAM-1) (p < 0.001), diabetes (p = 0.003), sex (p = 0.003), and history of cerebrovascular accidents (p = 0.021). In multivariate analyses for gait cadence, the significant independent predictors included high-sensitivity C-reactive protein (HsCRP) (p < 0.001), diabetes (p = 0.001), and hypertension (p = 0.001). In a multivariate regression model for gait stride length, the significant independent variables were HsCRP (p < 0.001), age (p < 0.001), ICAM-1 (p < 0.001), hypertension (p = 0.002), cellular reactive oxygen species production (p = 0.007), and sex (p = 0.008). Higher levels of circulating biomarkers of inflammation and endothelial cell oxidative stress were associated with slower gait speed, slower cadence, and shorter stride length in older symptomatic patients with PAD. Additionally, this profile of impaired gait was more evident in older patients, in women, and in those with diabetes, hypertension, and history of cerebrovascular accidents.

Reliability and validity of 6MWT for outpatients with schizophrenia: A preliminary study

Although the 6-minute walk test (6MWT) has been widely used in patients with schizophrenia, there is a lack of scientific evidence about its reliability and validity in this population. The first goal of this study was to explore the test-retest reliability of the 6MWT and to identify the associated parameters that contribute to the variability of the distance walked during the 6MWT in outpatients with schizophrenia. The second goal was to assess the criterion validity of the 6MWT in men with schizophrenia. Fifty one outpatients with schizophrenia participated in the study. To test-retest reliability (men=39; women=12), participants performed the 6MWT twice within 3 days interval. To test criterion validity (men=13), peak oxygen uptake (VO2peak) was measured on a treadmill. For the associated parameters with the distance walked (n=51), medications use, smoking behavior, body and bone composition, and physical activity levels were analyzed. No significant differences between the means of the two 6MWTs were found. The intraclass correlation coefficient was 0.94 indicating good reliability. 6MWT correlated significantly with VO2peak (r=0.67) indicating criterion validity. Height, body fat mass, smoking behavior and minutes of PA/week were significantly associated with the 6MWT. Results suggest that 6MWT shows good reliability for individuals with schizophrenia and good validity for the small sample of male participants in this study.

Increased peripheral vascular disease risk progressively constrains perfusion adaptability in the skeletal muscle microcirculation

To determine the impact of progressive elevations in peripheral vascular disease (PVD) risk on microvascular function, we utilized eight rat models spanning "healthy" to "high PVD risk" and used a multiscale approach to interrogate microvascular function and outcomes: healthy: Sprague-Dawley rats (SDR) and lean Zucker rats (LZR); mild risk: SDR on high-salt diet (HSD) and SDR on high-fructose diet (HFD); moderate risk: reduced renal mass-hypertensive rats (RRM) and spontaneously hypertensive rats (SHR); high risk: obese Zucker rats (OZR) and Dahl salt-sensitive rats (DSS). Vascular reactivity and biochemical analyses demonstrated that even mild elevations in PVD risk severely attenuated nitric oxide (NO) bioavailability and caused progressive shifts in arachidonic acid metabolism, increasing thromboxane A2 levels. With the introduction of hypertension, arteriolar myogenic activation and adrenergic constriction were increased. However, while functional hyperemia and fatigue resistance of in situ skeletal muscle were not impacted with mild or moderate PVD risk, blood oxygen handling suggested an increasingly heterogeneous perfusion within resting and contracting skeletal muscle. Analysis of in situ networks demonstrated an increasingly stable and heterogeneous distribution of perfusion at arteriolar bifurcations with elevated PVD risk, a phenomenon that was manifested first in the distal microcirculation and evolved proximally with increasing risk. The increased perfusion distribution heterogeneity and loss of flexibility throughout the microvascular network, the result of the combined effects on NO bioavailability, arachidonic acid metabolism, myogenic activation, and adrenergic constriction, may represent the most accurate predictor of the skeletal muscle microvasculopathy and poor health outcomes associated with chronic elevations in PVD risk.

INFLUENCE OF DIABETES ON AMBULATION AND INFLAMMATION IN MEN AND WOMEN WITH SYMPTOMATIC PERIPHERAL ARTERY DISEASE

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Diabetes and sex were correlated with ambulation and inflammation in patients with claudication.

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Men with diabetes have worse ambulation than men without diabetes.

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Women with diabetes have greater inflammation than women free of diabetes.

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Men and women with diabetes have evidence for high levels of angiogenic inhibition.

Objective

To determine whether diabetes and sex were factors associated with ambulatory function, endothelial cell inflammation, oxidative stress, and apoptosis, and with circulating biomarkers of inflammation and antioxidant capacity in patients with peripheral artery disease (PAD) and claudication.

Materials/Methods

Ambulatory function of 180 symptomatic men and women with PAD was assessed during a graded maximal treadmill test, 6-minute walk test, and 4-meter walk test. Patients were further characterized on endothelial effects of circulating factors present in the sera using a cell culture-based bioassay on primary human arterial endothelial cells, and on circulating inflammatory and vascular biomarkers.

Results

Men and women with diabetes had greater prevalence (p = 0.007 and p = 0.015, respectively) of coronary artery disease (CAD) than patients without diabetes. To assure that this difference did not influence planned comparisons, the data set was stratified on CAD. Diabetic men with CAD had a lower peak walking time (PWT) during the treadmill test and a slower 4-meter gait speed compared to non-diabetic men with CAD (p < 0.05). Diabetic women with CAD had a lower PWT compared to their non-diabetic counterparts (p < 0.01). Additionally, diabetic men with CAD had higher pigment epithelium-derived factor (p < 0.05) than their non-diabetic counterparts, and diabetic women with CAD had higher leptin (p < 0.01) and interleukin-8 levels (p < 0.05).

Conclusions

In patients with PAD, diabetic men and women with CAD had more severe claudication than their non-diabetic counterparts, as measured by shorter PWT, and the men had further ambulatory impairment manifested by slower 4-meter gait speed. Furthermore, the diabetic patients with CAD had elevations in interleukin-8, leptin, and PEDF.

Effect of cognitive status on exercise performance and quality of life in patients with symptomatic peripheral artery disease

BACKGROUND

We determined whether scores on a cognitive screening measure were associated with the primary outcome measure of peak walking time (PWT) and with secondary outcome measures related to mobility, community-based ambulation, health-related quality of life (QoL), and vascular function in patients with claudication and peripheral artery disease (PAD).

METHODS

Gross cognitive status of 246 PAD patients was assessed with the Mini-Mental State Examination (MMSE) questionnaire. Patients were grouped according to whether they had a perfect MMSE score of 30 points (n = 123) or whether they missed one or more points (n = 123). Patients were characterized on numerous outcomes, including PWT during a treadmill test and QoL.

RESULTS

Compared with the group with the higher MMSE scores, there was a trend for lower PWT in the group with the lower MMSE scores (P = .06) after adjusting for age, sex, race, and education level (model 1), which became significant (380 ± 250 seconds vs 460 ± 270 seconds; P < .05) after adjusting for model 1 plus coronary artery disease, chronic obstructive pulmonary disease, and arthritis (model 2). Multiple domains of QoL were lower (P < .05) in the group with the lower MMSE scores after adjusting for model 1, but only mental health remained lower (75 ± 20% vs 80 ± 5%; P = .02) after further adjustment with model 2.

CONCLUSIONS

In symptomatic patients with PAD, lower cognitive screening scores were associated with greater ambulatory impairment than in patients with higher MMSE scores. Furthermore, worse cognitive status was associated with lower scores in multiple dimensions of health-related QoL, all of which except mental health were explained by the comorbid conditions of coronary artery disease, chronic obstructive pulmonary disease, and arthritis. The clinical significance is that there is a need for enhanced cognitive and mental health screening as potential indicators of poor outcome among symptomatic patients with PAD. Furthermore, patients identified as having worse cognitive status might be in greatest need of intervention to improve ambulation and QoL related to mental health.

Clinical Interest of Ambulatory Assessment of Physical Activity and Walking Capacity in Peripheral Artery Disease

The purpose of the present review was to provide, for the first time, a comprehensive analysis and synthesis of the available studies that highlighted the clinical interest of the ambulatory assessment of either physical activity (PA) or walking capacity in patients with lower extremity peripheral artery disease (PAD). We identified 96 related articles published up to March 2015 through a computer-assisted search of the MEDLINE, EMBASE, and Web of Science databases. Ambulatory-measured PA or related energy expenditure (EE) in PAD patients was performed in 87 of the 96 included studies. The main clinical interests of these measurements were (a) the assessment of PA/EE pattern; (b) the characterization of walking pattern; and (c) the control of training load during home-based walking programs. Ambulatory-measured walking capacity was performed in the remaining studies, using either Global Positioning System receivers or the Peripheral Arterial Disease Holter Control device. Highlighted clinical interests were (a) the assessment of community-based walking capacity; (b) the use of new outcomes to characterize walking capacity, besides the conventional absolute claudication distance; and (c) the association with the patient's self-perception of walking capacity. This review also provides for the clinicians step-by-step recommendations to specifically assess PA or walking capacity in PAD patients.

Apolipoprotein profiles in subjects with and without peripheral artery disease

We compared plasma apolipoprotein profiles in subjects with peripheral artery disease (PAD) treated with statin medications (n = 21), subjects with PAD who are untreated with statins (n = 18), and control subjects (n = 70). Subjects were assessed on plasma apolipoproteins, medical history, physical examination, ankle-brachial index, and exercise performance using a treadmill test. The percentage of subjects with an abnormal value of apolipoprotein B (ApoB) (≥ 95 mg/dL) was 53% in the PAD group untreated with statins, 29% in the treated PAD group, and 13% in the controls (p < 0.001). The PAD group untreated with statins had higher values for ApoB (p < 0.001), triglycerides (p < 0.01), low-density lipoprotein (LDL)-cholesterol / high-density lipoprotein (HDL)-cholesterol ratio (p < 0.05), and glucose (p < 0.01) than the control group. In contrast, when the statin-treated PAD group was compared with controls, none of the variables were different except that the treated PAD group had lower LDL-cholesterol (p < 0.01) and higher glucose (p < 0.01). Furthermore, the PAD group treated with statins had lower ApoB (p < 0.01), triglycerides (p < 0.001), LDL-cholesterol (p < 0.05), LDL-cholesterol / HDL-cholesterol ratio (p < 0.05), and non-HDL-cholesterol (p < 0.05) than the untreated PAD group. In conclusion, subjects with PAD who are untreated with statin medications have higher levels of ApoB than controls, whereas subjects treated with statins have a more favorable risk profile, characterized by lower ApoB, LDL-C, LDL-C / HDL-C ratio, and non-HDL-C concentrations. Statin therapy may be efficacious for improving apolipoprotein profiles in subjects with PAD and intermittent claudication.

Diabetic women are poor responders to exercise rehabilitation in the treatment of claudication

BACKGROUND

It is not clear whether subgroups of patients with peripheral artery disease (PAD) and claudication respond more favorably to exercise rehabilitation than others. We determined whether sex and diabetes were factors associated with the response to exercise rehabilitation in patients with claudication.

METHODS

Eighty patients were randomized to home-based and supervised exercise programs, and 60 finished with complete exercise intervention data. Exercise consisted of intermittent walking to near maximal claudication pain for 3 months. Primary outcome measures included claudication onset time (COT) and peak walking time. Patients were partitioned into diabetic and nondiabetic groups and then further partitioned by sex to form four groups.

RESULTS

Overall, exercise adherence was high (84%), and there was no significant difference (P > .05) in the amount of exercise completed among the four groups. All groups had significant improvements (P < .05) in COT and peak walking time after exercise rehabilitation, except for diabetic women (P > .05). Only 37% of women with diabetes had an increase in COT compared with 100% of men with diabetes (P < .01), and their risk ratio for nonresponse was 9.2 (P < .0001).

CONCLUSIONS

Women with PAD and claudication, particularly those with diabetes, represent a vulnerable subgroup of patients who respond poorly to a program of exercise rehabilitation. Diabetic women with PAD and claudication may need a greater dose of exercise or another intervention separate from or in combination with exercise to elicit improvements in claudication measures that are similar to nondiabetic women and to diabetic and nondiabetic men.

Influence of peripheral artery disease and statin therapy on apolipoprotein profiles

Apolipoprotein B is a stronger predictor of myocardial infarction than LDL cholesterol, and it is inversely related to physical activity and modifiable with exercise training. As such, apolipoprotein measures may be of particular relevance for subjects with PAD and claudication. We compared plasma apolipoprotein profiles in 29 subjects with peripheral artery disease (PAD) and intermittent claudication and in 39 control subjects. Furthermore, we compared the plasma apolipoprotein profiles of subjects with PAD either treated (n = 17) or untreated (n = 12) with statin medications. For the apolipoprotein subparticle analyses, subjects with PAD had higher age-adjusted Lp-B:C (P < 0.05) and lower values of Lp-A-I:A-II (P < 0.05) than controls. The PAD group taking statins had lower age-adjusted values for apoB (P < 0.05), Lp-A-II:B:C:D:E (P < 0.05), Lp-B:E + Lp-B:C:E (P < 0.05), Lp-B:C (P < 0.05), and Lp-A-I (P < 0.05) than the untreated PAD group. Subjects with PAD have impaired apolipoprotein profiles than controls, characterized by Lp-B:C and Lp-A-I:A-II. Furthermore, subjects with PAD on statin medications have a more favorable risk profile, particularly noted in multiple apolipoprotein subparticles. The efficacy of statin therapy to improve cardiovascular risk appears more evident in the apolipoprotein sub-particle profile than in the more traditional lipid profile of subjects with PAD and claudication. This trial is registered with ClinicalTrials.gov NCT00618670.

Impaired vascular endothelial growth factor A and inflammation in patients with peripheral artery disease

We compared apoptosis, cellular oxidative stress, and inflammation of cultured endothelial cells treated with sera from 130 patients with peripheral artery disease (PAD) and a control group of 36 patients with high burden of comorbid conditions and cardiovascular risk factors. Second, we compared circulating inflammatory, antioxidant capacity, and vascular biomarkers between the groups. The groups were not significantly different (P > .05) on apoptosis, hydrogen peroxide, hydroxyl radical antioxidant capacity, and nuclear factor κ-light-chain enhancer of activated B cells. Circulating tumor necrosis factor α (TNF-α; P = .016) and interleukin 8 (IL-8; P = .006) were higher in the PAD group, whereas vascular endothelial growth factor A (VEGF-A; P = .023) was lower. The PAD does not impair the endothelium beyond that which already occurs from comorbid conditions and cardiovascular risk factors in patients with claudication. However, patients with PAD have lower circulating VEGF-A than the control group and higher circulating inflammatory parameters of TNF-α and IL-8.

The effect of dietary and physical activity pattern on metabolic profile in individuals with schizophrenia: a cross-sectional study

OBJECTIVE

With the rate of obesity on the rise worldwide, individuals with schizophrenia represent a particularly vulnerable population. The aim of this study was to assess the metabolic profile of individuals with schizophrenia in relation to dietary and physical activity habits compared with healthy controls.

METHODS

Dietary and physical activity habits of 130 individuals with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis of schizophrenia or schizoaffective disorder were compared with 250 body mass index-, age-, and sex-matched and racially matched controls from the 2005-2008 National Health and Nutrition Examination Surveys using a 24-hour diet recall and a self-report physical activity questionnaire.

RESULTS

Individuals with schizophrenia had significantly higher levels of glycosylated hemoglobin and insulin compared with matched controls. In addition, these individuals had an increased waist circumference and diastolic blood pressure than did the comparison group. Daily energy intake was not different between groups; however, individuals with schizophrenia consumed significantly greater amounts of sugar and fat. Individuals with schizophrenia reported engaging in moderate physical activity less frequently compared with the National Health and Nutrition Examination Surveys group, but there was no difference in reported vigorous physical activity.

CONCLUSIONS

These findings suggest that the dietary and physical activity habits of individuals with schizophrenia contribute to an adverse metabolic profile. Increased opportunities for physical activity and access to healthy foods for individuals with schizophrenia may ease the burden of disease.

Calf muscle hemoglobin oxygen saturation in patients with peripheral artery disease who have different types of exertional leg pain

BACKGROUND

This study compared calf muscle hemoglobin oxygen saturation (Sto(2)) and exercise performance during standardized treadmill exercise in patients with peripheral artery disease (PAD) who describe different types of exertional leg pain and compared secondary outcomes consisting of daily ambulatory activity and exercise performance during a 6-minute walk test (6MWT).

METHODS

Leg pain symptoms were evaluated in 114 patients with PAD using the San Diego Claudication Questionnaire, by which atypical exertional leg pain was defined in 31, claudication in 37, and leg pain on exertion and rest in 46. Patients were evaluated on a standardized, graded treadmill test during which calf muscle Sto(2) was continuously monitored. The 6MWT distance, Walking Impairment Questionnaire (WIQ), and ambulatory activity were monitored during 1 week.

RESULTS

All patients experienced symptoms during the treadmill test consistent with claudication. The groups were not significantly different on the primary outcomes of time to reach the minimum calf muscle Sto(2) (P = .350) or peak walking time (P = .238) during treadmill exercise. Patients with atypical leg pain had the highest daily ambulatory activity for total strides per day (P = .032), average daily cadence (P = .010), maximum cadences for durations between 5 minutes (P = .035) and 60 minutes (P = .029), speed score on the WIQ (P = .006), and lowest rating of perceived exertion at the end of the 6MWT (P = .017).

CONCLUSIONS

PAD patients with atypical leg pain have vascular-mediated limitations in exercise performance during standardized treadmill testing similar to patients with claudication and patients with leg pain on exertion and rest but have higher levels of daily ambulatory activity in the community setting and higher perceived ambulatory function.

Long-term quality of life and mobility after prosthetic above-the-knee bypass surgery

BACKGROUND

Multiple studies have addressed above-the-knee femoral artery bypass grafting; however, information on late quality of life (QoL) and mobility is scarce. We studied long-term QoL and mobility after above-the-knee bypass surgery.

METHODS

Consecutive patients presenting with claudication, ischemic rest pain, or gangrene who received above-the-knee prosthetic bypass grafting between December 1997 and January 2003 were included in this observational study. Data used were recorded in a prospectively collected database of patients receiving Dacron and polytetrafluoroethylene (PTFE) supragenicular bypasses for lower limb ischemia. Primary outcomes were QoL and mobility, and secondary outcomes were patency and patient survival. QoL was measured with the EuroQol questionnaire (EQ-5D/EQ-VAS). Mobility was assessed with the Walking Impairment Questionnaire (WIQ) and analyzed in univariate and multivariate models. Patency and survival were computed with Cox regression.

RESULTS

One hundred forty patients were treated during the study period. Sixty-nine patients (50%) died during follow-up, leaving 71 survivors who were asked (63 [89%] complied) to complete the EQ-5D/EQ-VAS and WIQ questionnaires. None of the primary outcome parameters (WIQ, EQ-5D, EQ-VAS) were affected by primary bypass occlusion (p = 0.34, p = 0.44, and p = 0.27, respectively) or long-term patency (p = 0.07, p = 0.54, and p = 0.36, respectively). Male sex was significantly associated with a better outcome on all primary outcome parameters. Patients with Dacron versus PTFE grafts had WIQ scores of 0.49 and 0.26, respectively (p = 0.01). EQ-5D scores of patients with Dacron and PTFE were 0.576 and 0.409 (p = 0.08) and EQ-VAS scores were 61 and 54, respectively (p = 0.24). Graft type was not independently associated with occlusion, but runoff was. The 5-year and 10-year patient survival rates were 58% and 51%, respectively.

CONCLUSIONS

In this study, long-term QoL and mobility did not seem to be associated with bypass patency, as assessed in a single late follow-up. Revision of bypasses did not contribute to long-term QoL and walking ability. Therefore, the necessity of graft surveillance and subsequent revision and/or thrombectomy in case of synthetic bypass failure in absence of critical limb ischemia seems to be questionable.

Oxygen uptake before and after the onset of claudication during a 6-minute walk test

OBJECTIVE

This study compared oxygen uptake before and after the onset of claudication in individuals with peripheral artery disease (PAD) during a 6-minute walk test, and identified predictors of the change in oxygen uptake after the onset of claudication pain.

METHODS

The study included 50 individuals with PAD. During a 6-minute walk test, 33 experienced claudication (pain group), and 17 were pain-free (pain-free group). Oxygen uptake and ambulatory cadence were the primary outcomes evaluated during the 6-minute walk test.

RESULTS

The pain group experienced onset of claudication pain at a mean (standard deviation) of 179 (45) meters and continued to walk to achieve a 6-minute walk distance of 393 (74) meters, which was similar to the 401 (76) meters walked in the pain-free group (P = .74). Oxygen uptake increased (P < .0001) after the onset of pain in the pain group, and this change was greater (P = .025) than the increase in oxygen uptake from the second to fifth minutes of walking in the pain-free group. Ambulatory cadence decreased after the onset of pain in the pain group (P = .0003). The change in oxygen uptake was associated with metabolic syndrome (P = .0023), 6-minute walk distance (P = .0037), age (P = .0041), and oxygen uptake during the second minute of the test (P = .012).

CONCLUSION

Claudication increases oxygen uptake of self-paced, over-the-ground ambulation, despite a decrease in cadence. The pain-mediated increase in oxygen uptake was blunted in individuals with metabolic syndrome, suggesting that the ability to increase oxygen uptake during ambulation is impaired. The clinical significance is that claudication increases the metabolic cost of ambulation, thereby increasing the relative intensity of exercise and reducing the tolerance to sustain ambulation.

Lack of physical activity during leisure time contributes to an impaired health related quality of life in patients with schizophrenia

OBJECTIVE

The aim of the present study was to identify if lack of physical activity participation and an impaired functional exercise capacity compared with healthy controls contributed to an impaired health related quality of life (HRQL). We also evaluated whether the presence of metabolic syndrome (MetS) could explain the variability in HRQL in patients.

METHOD

Patients with DSM-IV schizophrenia (n=60) and age- and gender-matched healthy controls (n=40) completed the SF-36 quality of life scale and the Baecke Physical Activity Questionnaire and performed a 6 minute walk test (6MWT). Patients also received a fasting metabolic laboratory screening. Linear multiple regression analysis was used to assess the associations between demographical and clinical variables and HRQL outcomes.

RESULTS

Physical and mental HRQL and the Baecke and 6MWT-scores were significantly lower in patients with schizophrenia compared with matched healthy controls. When in schizophrenia patients all individual HRQL-predictors were included in a regression model, only BMI and lack of PA during leisure time remained significant predictors for physical HRQL while for mental HRQL no significant predictor remained. The impaired functional exercise capacity and the presence of MetS did not additionally explain the variance in HRQL.

CONCLUSIONS

Physical HRQL in patients with schizophrenia is not only related to increased BMI but also to lack of leisure time physical activity. A reduced physical HRQL in patients with MetS appears to be related to their greater BMI, rather than to MetS per se. Present findings provide further support for routinely incorporating physical activity within rehabilitation programs and clinical assessments.

Dietary intake of participants with peripheral artery disease and claudication

We compared the dietary intake of participants with peripheral artery disease (PAD) and claudication with diet recommendations of the National Cholesterol Education Program (NCEP) and dietary reference intake values recommended by the Institute of Medicine (IOM) of the National Academy of Sciences. Forty-six participants consumed a mean macronutrient composition of 17% protein, 51% carbohydrate, and 30% fat. Compared to the NCEP and IOM recommendations, few participants met the recommended daily intake for sodium (0%), vitamin E (0%), folate (13%), saturated fat (20%), fiber (26%), and cholesterol (39%). Participants with PAD and claudication have poor nutrition, with diets particularly high in saturated fat, sodium, and cholesterol, and low in fiber, vitamin E, and folate intakes. Participants should be encouraged to reduce consumption of dietary fat, saturated fat, cholesterol, and sodium and to increase fiber and vitamin intakes to meet recommendations of the NCEP and IOM.

Gender differences in the prevalence and management of metabolic syndrome and its components in patients with peripheral artery disease

We compared the prevalence and management of metabolic syndrome (MetS) and its components in men and women with peripheral artery disease (PAD). A total of 70 men and 70 women with PAD were evaluated for presence of MetS. There was no significant gender difference in presence of MetS (P = .399) and the number of MetS components (P = .411). Among PAD patients with each MetS component, there was no significant gender difference in the use (P = .617) and number (P = .716) of blood pressure medications, the use (P = .593) and number (P = .591) of lipid-lowering medications, and the number (P = .155) of diabetic medications. Significantly more women were treated with diabetic medications compared with men (85 vs 57%, P = .026). The prevalence and management of MetS and its components was similar between men and women with PAD, except that more women were treated for diabetes. Patients with PAD having MetS did not receive optimal medical management.

Exercise performance, physical activity, and health-related quality of life in participants with stable angina

We compared exercise performance, daily physical activity, and health-related quality of life in 115 participants with stable angina and 441 controls without coronary artery disease or stable angina. Participants with stable angina had shorter 6-min walk distance (P = .003), and lower total leisure-time physical activity (P = .003) than the controls. Group differences in these measures remained (P < .05) after adjusting for age, race, current smoking, diabetes, hypertension, and obesity. Participants with stable angina also had lower health-related quality of life for physical function (P < .001), general health (P = .002), and vitality (P < .001), but group differences did not remain (P > .05) after adjustment for comorbid conditions. Participants with stable angina have impaired exercise performance and reduced daily physical activity. Thus, they are prime candidates for exercise interventions designed to improve daily physical activity and exercise performance.

Association of the metabolic syndrome with physical activity performance in patients with schizophrenia

AIM

The primary aim of this study was to determine whether the presence of the metabolic syndrome (MetS) limits physical activity (PA) in patients with schizophrenia. A secondary aim was to investigate cross-sectional associations of leisure-time PA, sports participation and PA performance with MetS parameters.

METHODS

Patients with schizophrenia who had MetS (n=37) were compared with those without MetS (n=69). Patients were assessed for PA performance using a 6-minute walk test (6MWT) and PA participation using the Baecke PA questionnaire, as well as for antipsychotic medication dose (expressed in chlorpromazine equivalents), negative symptoms and smoking behaviour.

RESULTS

The two patient groups were similar in age, gender, mean antipsychotic medication dose, negative symptomatology and smoking behaviour. Distance achieved on the 6MWT was 13.7% shorter (P<0.001) in patients with versus patients without MetS (527.6±108.9 m vs 610.0±93.7 m, respectively). Patients with MetS were also significantly less involved in sports activities (P=0.001) and less physically active during leisure time (P=0.002). Also, the distance of the 6MWT was moderately correlated with body mass index (r=-0.44, P<0.001), waist circumference (r=-0.43, P<0.001), sports participation (r=0.60, P<0.001) and leisure-time PA (r=0.42, P<0.001).

CONCLUSION

MetS is associated with poorer PA performance in patients with schizophrenia. The additional burden of MetS places patients with schizophrenia at even greater risk for physical and functional limitations in daily life.

Gender differences among middle-aged Koreans for health-related quality of life related to metabolic syndrome

PURPOSE

The influence of metabolic syndrome (MS) on quality of life has not been studied much among Asians, especially Koreans. This study compared the association between MS and health-related quality of life (HRQL) by gender for middle-aged Koreans.

METHODS

We used data containing 2,264 adults between the ages of 40 and 59 years who participated in the 2005 Korean National Health and Nutrition Examination Surveys. The criteria for MS were defined by the National Cholesterol Education Program Adult Treatment Panel III. HRQL was measured by the EQ-5D preference score. Good health status was defined as having higher scores than the mean EQ5D preference score. We used logistic regression methods to adjust for socioeconomic covariates and survey sample design.

RESULTS

The mean EQ-5D preference score was significantly lower in women with MS compared to women without MS (0.81 vs. 0.88), but this was not the case for men (0.92 vs. 0.92). These consistent results were observed after adjusting for socioeconomic covariates. In multiple logistic analyses, women with MS had a lower likelihood of having good health status compared to women without MS (OR = 0.60, 95% CI 0.38-0.96). For men, there was no difference.

CONCLUSIONS

Our study identified a nationally representative health preference score for MS in Korean middle-aged men and women while highlighting a gender difference that merits more research (i.e., MS appeared to have a significant negative impact for women's HRQL, but not for men). At the very least, future studies should consider gender differences when addressing quality of life among patients with MS.

Gender differences in daily ambulatory activity patterns in patients with intermittent claudication

OBJECTIVES

To compare the pattern of daily ambulatory activity in men and women with intermittent claudication, and to determine whether calf muscle hemoglobin oxygen saturation (StO2) is associated with daily ambulatory activity.

METHODS

Forty men and 41 women with peripheral arterial disease limited by intermittent claudication were assessed on their community-based ambulatory activity patterns for 1 week with an ankle-mounted step activity monitor and on calf muscle StO2 during a treadmill test.

RESULTS

Women had lower adjusted daily maximal cadence (mean±SE) for 5 continuous minutes of ambulation (26.2±1.2 strides/min vs 31.0±1.2 strides/min; P=.009), for 1 minute of ambulation (43.1±0.9 strides/min vs 47.2±0.9 strides/min; P=.004), and for intermittent ambulation determined by the peak activity index (26.3±1.2 strides/min vs 31.0±1.2 strides/min; P=.009). Women also had lower adjusted time to minimum calf muscle StO2 during exercise (P=.048), which was positively associated with maximal cadence for 5 continuous minutes (r=0.51; P<.01), maximal cadence for 1 minute (r=0.42; P<.05), and peak activity index (r=0.44; P<.05). These associations were not significant in men.

CONCLUSION

Women with intermittent claudication ambulate slower in the community setting than men, particularly for short continuous durations of up to 5 minutes and during intermittent ambulation at peak cadences. Furthermore, the daily ambulatory cadences of women are correlated with their calf muscle StO2 during exercise, as women who walk slower in the community setting reach their minimum calf muscle StO2 sooner than those who walk at faster paces. Women with intermittent claudication should be encouraged to not only walk more on a daily basis, but to do so at a pace that is faster than their preferred speed.

Resting energy expenditure in patients with intermittent claudication and critical limb ischemia

OBJECTIVE

The primary aim of this study was to compare the resting energy expenditure of patients with intermittent claudication and critical limb ischemia. A secondary aim was to identify predictors of resting energy expenditure.

METHODS

One hundred patients limited by intermittent claudication and 40 patients with critical limb ischemia participated in this study. Patients were assessed on resting energy expenditure, body composition, ankle brachial index (ABI), and calf blood flow.

RESULTS

Patients with critical limb ischemia had a lower resting energy expenditure than patients with intermittent claudication (1429 +/- 190 kcal/day vs 1563 +/- 229 kcal/day; P = .004), and higher body fat percentage (34.8 +/- 7.8% vs 31.5 +/- 7.8%; P = .037), higher fat mass (30.0 +/- 9.3 kg vs 26.2 +/- 8.9 kg;P = .016), and lower ABI (0.31 +/- 0.11 vs 0.79 +/- 0.23; P < .001). Resting energy expenditure was predicted by fat free mass (P < .0001), age (P < .0001), ABI (P < .0001), ethnicity (P < .0001), calf blood flow (P = .005), and diabetes (P = .008). Resting energy expenditure remained lower in the patients with critical limb ischemia after adjusting for clinical characteristics plus fat free mass (1473 +/- 27.8 kcal/day [mean +/- SEM] vs 1527 +/- 19.3 kcal/day; P = .031), but it was no longer different between groups after further adjustment for ABI and calf blood flow (1494 +/- 25.2 kcal/day vs 1505 +/- 17.7 kcal/day; P = .269).

CONCLUSION

Resting energy expenditure is decreased with a progression in peripheral arterial disease (PAD) symptoms from intermittent claudication to critical limb ischemia. Furthermore, patients with critical limb ischemia who are most susceptible for decline in resting energy expenditure are older, African American patients with diabetes. The lower resting energy expenditure of patients with critical limb ischemia, combined with their sedentary lifestyle, suggests that they are at high risk for long-term positive energy balance and weight gain.

Caregiving, metabolic syndrome indicators, and 1-year decline in walking speed: results of Caregiver-SOF

Background.

Chronic stress may lead to health decline through metabolic syndrome. Thus, persons in stressful caregiving situations who also have more indicators of metabolic syndrome may experience more decline than other caregivers or noncaregivers.

Methods.

The sample included 921 women (338 caregivers and 583 noncaregivers) from the Caregiver-Study of Osteoporotic Fractures study. Participants had home-based baseline and 1-year follow-up interviews between 1999 and 2003. At baseline, caregivers were categorized as long term (³4 years) versus short term (<4 years), and caring for someone with Alzheimer's disease/dementia or not. A metabolic risk composite score was the sum of four indicators: body mass index ³30, and diagnosis or using medications for hypertension, diabetes, or high cholesterol. Walking speed (m/second) was measured at both interviews.

Results.

Walking speed declined for the total sample (adjusted mean = −0.005 m/second, ±0.16) over an average of 1.04 years (±0.16). Overall, caregiving was not associated with decline. Increasing metabolic risk score was associated with greater decline for the total sample and long-term and dementia caregivers, but not other caregivers or noncaregivers. Metabolic risk score modified the adjusted associations between years of caregiving and dementia caregiving with walking speed decline (p values for interaction terms were 0.039 and 0.057, respectively). The biggest declines were in long-term caregivers and dementia caregivers who also had 3–4 metabolic indicators (−0.10 m/second and −0.155 m/second, respectively).

Conclusions.

Walking speed declined the most among older women who had both stressful caregiving situations and more metabolic syndrome indicators, suggesting these caregiver subgroups may have increased risk of health decline.

Update on peripheral arterial disease and claudication rehabilitation

The prevalence of peripheral arterial disease is high and will continue to grow with our aging population. It is often under diagnosed and under treated due to a general lack of awareness on the part of the patient and the practitioner. The evidence-base is growing for the optimal medical management of the patient with peripheral arterial disease; in parallel, endovascular revascularization options continue to improve. Exercise training for claudication rehabilitation plays a critical role. Comprehensive care of the peripheral arterial disease patient focuses on the ultimate goals of improving quality of life and reducing cardiovascular morbidity and mortality.

Resting energy expenditure in subjects with and without intermittent claudication

Subjects with peripheral arterial disease and intermittent claudication have ischemia of the lower extremities, but little is known how this influences resting energy expenditure. The objective of the study was to compare the resting energy expenditure of subjects with and without intermittent claudication. One hundred six subjects limited by intermittent claudication and 77 controls who did not have peripheral arterial disease and intermittent claudication participated in this study. Subjects were assessed on resting energy expenditure, body composition, ankle/brachial index (ABI), and calf blood flow. Subjects with intermittent claudication had a lower resting energy expenditure (1585 +/- 251 vs 1716 +/- 277 kcal/d, P = .019), higher body fat percentage (33.4% +/- 10.7% vs 29.6% +/- 7.7%, P = .016), higher fat mass (29.6 +/- 10.6 vs 24.2 +/- 8.9 kg, P = .011), and lower ABI (0.66 +/- 0.20 vs 1.19 +/- 0.12, P < .001). Resting energy expenditure was predicted by fat-free mass (P < .001), ABI (P = .027), and calf blood flow (P = .040). Resting energy expenditure remained lower in the subjects with intermittent claudication after adjusting for clinical characteristics plus fat-free mass (1611 +/- 171 vs 1685 +/- 209 kcal/d, P = .035), but was no longer different between groups after further adjustment for ABI and calf blood flow (1622 +/- 165 vs 1633 +/- 185 kcal/d, P = .500). Subjects with intermittent claudication have lower resting energy expenditure than controls, which is partially explained by ABI and calf blood flow.

Association between daily ambulatory activity patterns and exercise performance in patients with intermittent claudication

PURPOSE

To determine the association between daily ambulatory activity patterns and exercise performance in patients with intermittent claudication.

METHODS

One hundred thirty-three patients limited by intermittent claudication participated in this study. Patients were assessed on their ambulatory activity patterns for 1 week with a small, lightweight step activity monitor attached to the ankle using elastic velcro straps above the lateral malleolus of the right leg. The step activity monitor recorded the number of strides taken on a minute-to-minute basis and the time spent ambulating. Patients also were characterized on ankle-brachial index (ABI), ischemic window (IW) after a treadmill test, as well as initial claudication distance (ICD), and absolute claudication distance (ACD) during treadmill exercise.

RESULTS

The patient characteristics (mean +/- SD) were as follows: ABI = 0.71 +/- 0.23, IW = 0.54 +/- 0.72 mm Hg.min.meter(-1), ICD = 236 +/- 198 meters, and ACD = 424 +/- 285 meters. The patients took 3366 +/- 1694 strides/day, and were active for 272 +/- 103 min/day. The cadence for the 30 highest, consecutive minutes of each day (15.1 +/- 7.2 strides/min) was correlated with ICD (r = 0.316, P < .001) and ACD (r = 0.471, P < 0.001), and the cadence for the 60 highest, consecutive minutes of each day (11.1 +/- 5.4 strides/min) was correlated with ICD (r = 0.290, P < .01) and ACD (r = 0.453, P < .001). Similarly, the cadences for the highest 1, 5, and 20 consecutive minutes, and the cadence for the 30 highest, nonconsecutive minutes all were correlated with ICD and ACD (P < .05). None of the ambulatory cadences were correlated with ABI (P > .05) or with ischemic window (P > .05).

CONCLUSION

Daily ambulatory cadences are associated with severity of intermittent claudication, as measured by ACD and ICD, but not with peripheral hemodynamic measures.

The effect of metabolic syndrome components on exercise performance in patients with intermittent claudication

PURPOSE

To determine the effect of metabolic syndrome components on intermittent claudication, physical function, health-related quality of life, and peripheral circulation in patients with peripheral arterial disease (PAD), and to identify the metabolic syndrome components most predictive of each outcome measure.

METHODS

Patients limited by intermittent claudication with three (n = 48), four (n = 45), or five (n = 40) components of metabolic syndrome were studied. Patients were assessed on PAD-specific measures consisting of ankle-brachial index (ABI), initial claudication distance, absolute claudication distance, physical function measures, health-related quality of life, and calf blood flow and transcutaneous oxygen tension responses after 3 minutes of vascular occlusion.

RESULTS

Initial claudication distance (mean +/- SD) progressively declined (P = .019) in those with three (203 +/- 167 m), four (124 +/- 77 m), and five (78 +/- 57 m) metabolic syndrome components, and absolute claudication distance progressively declined (P = .036) in these groups as well (414 +/- 224 m vs 323 +/- 153 m vs 249 +/- 152 m, respectively). Furthermore, compared with patients with only three components of metabolic syndrome, those with all five components had impaired values (P < .05) for peak oxygen uptake, ischemic window, 6-minute walk distance, self-perceived walking ability and health, daily physical activity, health-related quality of life on six of eight domains, calf hyperemia, and calf ischemia after vascular occlusion. Abdominal obesity was the predictor (P < .05) of exercise performance during the treadmill and 6-minute walk tests, as well as physical activity. Elevated fasting glucose was the predictor (P < .05) of peripheral vascular measures, self-perceived walking ability and health, and health-related quality of life.

CONCLUSION

PAD patients with more metabolic syndrome components have worsened intermittent claudication, physical function, health-related quality of life, and peripheral circulation. Abdominal obesity and elevated fasting glucose are the metabolic syndrome components that are most predictive of these outcome measures. Aggressively treating these metabolic syndrome components may be particularly important in managing symptoms and long-term prognosis of PAD patients.

Is the metabolic syndrome, with or without diabetes, associated with progressive disability in older Mexican Americans?

BACKGROUND

The metabolic syndrome (MetS) is highly prevalent in the growing U.S. Latino population. We hypothesize that MetS, with or without diabetes, is associated with progressive disability in older Mexican Americans.

METHODS

Data from Mexican Americans 60-98 years old participating in the Sacramento Area Latino Study on Aging (SALSA) were analyzed from baseline through 3 years (3 years of follow-up). Disability was assessed by self-reported limitations in activities of daily living (ADLs), instrumental ADLs (IADLs), and mobility/strength tasks. MetS (46% of sample) was defined by National Cholesterol Education Program (NCEP) Adult Treatment Panel III criteria. Diabetes (DM, 33%) was defined by fasting blood sugar>125 mg/dL, physician diagnosis, and/or medication use. Four metabolic groups were defined: MetS with diabetes (MetS+DM+, n=402); MetS without diabetes (MetS+DM-, n=330); diabetes without MetS (MetS-DM+, n=125); and neither (MetS-DM-, n=749). Generalized estimating equation (GEE) regression models were used to evaluate the effect of metabolic group on physical limitations and disability changes over time.

RESULTS

Diabetes, with or without MetS, was associated with a higher percent rate of increase over 3 years in ADL and IADL disability than was no diabetes, even after controlling for demographics, body mass index (BMI), and incident disease. The mean ADL score had a 35% higher rate of increase (higher = more impairment) for the MetS+DM+ group and 68% higher for the MetS-DM+ group. Results for IADL were similar. The baseline MetS, without or with diabetes, was associated with a significantly higher rate of increase in mobility/strength limitations (8% and 36.5%, respectively).

CONCLUSIONS

In older Mexican Americans, MetS is associated with progressive limitations in mobility and strength. Preventing progressive mobility/strength limitations may require assessing and treating these impairments in people with MetS regardless of the presence of diabetes. However, preventing the progression of MetS without to MetS with diabetes may be important to limit the progression of ADL and IADL disability found in people with MetS and diabetes.

Impact of Claudication and Its Treatment on Quality of Life

Improvement in quality of life is the ultimate goal of healthcare for the treatment of intermittent claudication. Until recently, the measures of success after therapy were those derived from the vascular laboratory, including ankle-brachial indices and ankle and toe pressures. There are now several validated and reliable survey tools that can assess patient-reported quality of life in a generic or disease-specific manner. Major survey instruments are reviewed. The information gathered through these quality-of-life assessment tools is important to all those involved in the care of patients with peripheral arterial disease. Although claudication is neither life- nor limb-threatening, it has a significant negative impact on quality of life, as measured by these instruments. Patients so afflicted report more bodily pain, worse physical function, and worse perceived health, in addition to limited walking ability. These measures of quality of life do not correlate with standard parameters of ankle-brachial index or ankle pressures. Treatment of the claudicant with exercise therapy and percutaneous or open revascularization also impacts quality of life. Each of these modalities is capable of improving quality of life, but some are associated with decline over time. The major benefits and risks to quality of life of these specific forms of treatment for the claudicant are reviewed. This data demonstrates that patients suffering from symptoms of intermittent claudication are best served by therapies that address their major self-reported impediments to quality of life.