Development of a multivariate model of the six-minute walked distance to predict functional exercise capacity in hypertension.

BACKGROUND: Hypertension is associated with deterioration of musculoskeletal function and functional capacity. Existing prediction models for assessment of the 6-min walk test (6MWT) do not capture the disease-related functional capacity. This study developed a multivariate prediction model of the measured 6-min walked distance (6MWDM) in hypertension and proposed target-values based on optimal therapeutic aims. METHODS: Seventy-six patients (38 men, 56.1 ±â€¯14.3 years, systolic pressure 156.7 ±â€¯17.5 mmHg, diastolic pressure 92.9 ±â€¯6.9 mmHg) underwent anamnesis, physical examination, and laboratory analysis. Functional capacity was assessed using the 6MWT, being the 6MWDM considered as the dependent variable. Independent variables included sex (S, coded 'male' = 1, 'female' = 0), age (A), body height (H), body mass, mean blood pressure (MBP), and physical activity (IPAQ, coded 1-5). Target-values were derived from theoretical scenarios of optimal blood pressure and physical activity, separately and combined. RESULTS: Patients walked 324.5 ±â€¯10.1 m in the average of two trials 30-min apart. Pearson's correlation coefficient showed moderate-to-weak significant associations between 6MWDM and all independent variables. The final multivariate model was 6MWDP = 611.347-4.446 × MBP + 267.630 × H - 1.511 × A + IPAQcode + Scode (adjusted R2 = 0.680, SE of bias = 6.3 m), suggesting that clinical, anthropometric, and hemodynamic information determines functional capacity. Predicted values yielded a group-average of 325 ±â€¯87 m. Target-values under the optimal scenario resulted in 420 ±â€¯60 m. CONCLUSIONS: Sex (men), higher body height, higher physical activity, lower mean blood pressure, and lower age are independently correlated with higher 6MWDM in patients with hypertension. Target-values can be estimated for therapeutic aims related to hemodynamics and lifestyle.

Functional electrical stimulation improves endothelial function and reduces peripheral immune responses in patients with chronic heart failure.

BACKGROUND: Previous studies have shown beneficial effects of functional electrical stimulation (FES) on muscle performance and exercise capacity of patients with chronic heart failure. This study evaluates the impact of FES on endothelial function and peripheral markers of immune activation in patients with moderate to severe heart failure. METHODS: Twenty-four patients with a left ventricular ejection fraction of less than 40% and New York Heart Association class II-III symptoms, undergoing optimized drug therapy, were randomly assigned (2 : 1) to a 6-week training programme of FES (n=16) or served as controls (n=8). Endothelial function was assessed by Doppler flow-mediated dilatation (FMD) of the brachial artery before and after the training programme. Peripheral pro-inflammatory/anti-inflammatory markers such as tumour necrosis factor (TNF)-alpha, interleukin (IL)-6, soluble intercellular adhesion molecule (sICAM)-1, soluble vascular cell adhesion molecule (sVCAM)-1 and IL-10 were also measured before and after training. RESULTS: A significant improvement on the 6-min walk test (7.5+/-3.3%), Minnesota Living Score (18.2+/-8.6%) and FMD (38.5+/-15.1%) was observed only in the FES-treated group. FES also causes a significant reduction of TNF-alpha (-11.5+/-8.9%), sICAM-1 (-13.1+/-9.8%), and sVCAM-1 (-10.6+/-6.6%), as well as a respective increase in the ratio IL-10/TNF-alpha (37.1+/-29.4%). In the FES group, the percentage improvement in the Minnesota Living Score was significantly correlated with respective changes in circulating TNF-alpha (r=0.624, P<0.01), sVCAM-1 (r=0.665, P<0.001) and the ratio IL-10/TNF-alpha (r=-0.641, P<0.01). CONCLUSION: FES is an exercise training programme that improves endothelial function in patients with chronic heart failure, and also has anti-inflammatory effects.