The Effects of Walking or Walking-with-Poles Training on Tissue Oxygenation in Patients with Peripheral Arterial Disease

This randomized trial proposed to determine if there were differences in calf muscle StO(2) parameters in patients before and after 12 weeks of a traditional walking or walking-with-poles exercise program. Data were collected on 85 patients who were randomized to a traditional walking program (n = 40) or walking-with-poles program (n = 45) of exercise training. Patients walked for 3 times weekly for 12 weeks. Seventy-one patients completed both the baseline and the 12-week follow-up progressive treadmill tests (n = 36 traditional walking and n = 35 walking-with-poles). Using the near-infrared spectroscopy measures, StO(2) was measured prior to, during, and after exercise. At baseline, calf muscle oxygenation decreased from 56 ± 17% prior to the treadmill test to 16 ± 18% at peak exercise. The time elapsed prior to reaching nadir StO(2) values increased more in the traditional walking group when compared to the walking-with-poles group. Likewise, absolute walking time increased more in the traditional walking group than in the walking-with-poles group. Tissue oxygenation decline during treadmill testing was less for patients assigned to a 12-week traditional walking program when compared to those assigned to a 12-week walking-with-poles program. In conclusion, the 12-week traditional walking program was superior to walking-with-poles in improving tissue deoxygenation in patients with PAD

Measurement invariance of the kidney disease and quality of life instrument (KDQOL-SF) across Veterans and non-Veterans

<p>Abstract</p> <p>Background</p> <p>Studies have demonstrated that perceived health-related quality of life (HRQOL) of patients receiving hemodialysis is significantly impaired. Since HRQOL outcome data are often used to compare groups to determine health care effectiveness it is imperative that measures of HRQOL are valid. However, valid HRQOL comparisons between groups can only be made if instrument invariance is demonstrated. The Kidney Disease Quality of Life-Short Form (KDQOL-SF) is a widely used HRQOL measure for patients with chronic kidney disease (CKD) however, it has not been validated in the Veteran population. Therefore, the purpose of this study was to examine the measurement invariance of the KDQOL-SF across Veterans and non-Veterans with CKD.</p> <p>Methods</p> <p>Data for this study were from two large prospective observational studies of patients receiving hemodialysis: 1) Veteran End-Stage Renal Disease Study (VETERAN) (N = 314) and 2) Dialysis Outcomes and Practice Patterns Study (DOPPS) (N = 3,300). Health-related quality of life was measured with the KDQOL-SF, which consists of the SF-36 and the Kidney Disease Component Summary (KDCS). Single-group confirmatory factor analysis was used to evaluate the goodness-of-fit of the hypothesized measurement model for responses to the subscales of the KDCS and SF-36 instruments when analyzed together; and given acceptable goodness-of-fit in each group, multigroup CFA was used to compare the structure of this factor model in the two samples. Pattern of factor loadings (configural invariance), the magnitude of factor loadings (metric invariance), and the magnitude of item intercepts (scalar invariance) were assessed as well as the degree to which factors have the same variances, covariances, and means across groups (structural invariance).</p> <p>Results</p> <p>CFA demonstrated that the hypothesized two-factor model (KDCS and SF-36) fit the data of both the Veteran and DOPPS samples well, supporting configural invariance. Multigroup CFA results concerning metric and scalar invariance suggested partial strict invariance for the SF-36, but only weak invariance for the KDCS. Structural invariance was not supported.</p> <p>Conclusions</p> <p>Results suggest that Veterans may interpret the KDQOL-SF differently than non-Veterans. Further evaluation of measurement invariance of the KDQOL-SF between Veterans and non-Veterans is needed using large, randomly selected samples before comparisons between these two groups using the KDQOL-SF can be done reliably.</p

Importance of obesity, race and age to the cardiac structural and functional effects of hypertension

AbstractObjectives. The purpose of this study was to determine the effects of obesity and its interaction with age, race and the magnitude of blood pressure elevation in a large cohort of patients with mild to moderate hypertension and a high prevalence of left ventricular hypertrophy.Background. Obesity, race and age each have important effects on the incidence and severity of hypertension and may contribute to the effects of blood pressure elevation on the cardiac manifestations of hypertension.Methods. Left ventricular structure and function were assessed with two-dimensional targeted M-mode echocardiography in 692 men with mild to moderate hypertension (average blood pressure 153/100 mm Hg), and the data were compared in relation to obesity (determined from body mass index), age, race, blood pressure, physical activity, plasma renin activity, urinary sodium excretion, hematocrit, heart rate and serum lipids.Results. Left ventricular hypertrophy was common (630% with increased left ventricular mass, 22% with left ventricular hypertrophy on the electrocardiogram [ECG]). On multivariable regression analysis, body mass index was the strongest predictor of left ventricular mass and magnified the slope relation of blood pressure to left ventricular mass. Despite a greater prevalence of ECG left ventricular hypertrophy in blacks (31%) than in whites (10%), left ventricular mass and echocardiographic prevalence of left ventricular hypertrophy did not differ by race. However, septal, posterior left ventricular and relative wall thickness were greater in black than in white men.Conclusions. Obesity is the strongest clinical predictor of left ventricular mass and left ventricular hypertrophy la men, even in those with mild to moderate hypertension of sufficient severity to be associated with a high prevalence of left ventricular hypertrophy. Moreover, independent effects of systolic blood pressure on left ventricular mass an amplified by obesity. Although race does not affect left ventricular mass or the prevalence of left ventricular hypertrophy, black race is associated with greater relative wall thickness, itself a predictor of unfavorable cardiovascular outcome

A comparison of sequential procedures to monitor recruitment rates in clinical trials.

A comparison of sequential procedures to monitor recruitment rates in clinical trials

Volume (Weight) Loss and Blood Pressure Response Following Thiazide Diuretics

Correlations were made between weight change (as an index of volume loss) and blood pressure (BP) reduction before and after hydrochlorothiazide treatment A total of 343 patients with mild to moderate hypertension (95–114 mm Hg) received hydrochlorothiazkle alone. The diuretk was titrated from 50 to 100 to 200 mg daily as needed until the diastolic BP fell below 90 mm Hg (goal BP) or side effects supervened. Of the 305 patients who completed the 10-week titration period, 65% attained goal BP. The effective dose of hydrochlorothiazide in 52% of these responders was 50 ing/day, and this was associated with weight loss averaging 1.58 kg. An additional 29% achieved goal BP with a similar degree of weight loss, but they required double the dose, or 100 ing/day. The remaining 19% of responders required significantly greater weight reductions averaging 3.14 kg to achieve goal BP, which necessitated hydrochlorothiazide, 200 mg/day. More blacks than whites attained goal BP despite similar degrees of weight loss in the two races. Plasma renin activity was initially higher in whites than in blacks and rose significantly more in blacks and whites requiring the greatest volume losses and the highest dose of hydrochlorothiazide to attain goal BP. Nonresponders had less weight loss than responders. Thus, diuretic dose requirements vary in different patients and are related either to different volume losses in response to a given dose or to different degrees of BP reduction in response to the same volume loss

Correction: Single-Drug Therapy for Hypertension in Men

To the Editor: During further analysis of the data used in our study of single-drug therapy for hypertension in men (April 1, 1993, issue), 1 we discovered two errors in the computer program; these errors affected the results that we reported in Figures 2 and 3 of the article. One error permitted a small group of patients who had not completed one year of maintenance therapy to be excluded from the analysis, even though we had planned an intention-to-treat analysis. The second error was due to an unrecognized deletion of an entire line of code that provided the definition of treatment . .