Low-intensity resistance training with blood flow restriction improves vascular endothelial function and peripheral blood circulation in healthy elderly people.

PURPOSE: The present study aimed to investigate the effects of low-intensity resistance training with blood flow restriction (BFR resistance training) on vascular endothelial function and peripheral blood circulation. METHODS: Forty healthy elderly volunteers aged 71 ± 4 years were divided into two training groups. Twenty subjects performed BFR resistance training (BFR group), and the remaining 20 performed ordinary resistance training without BFR. Resistance training was performed at 20 % of each estimated one-repetition maximum for 4 weeks. We measured lactate (Lac), norepinephrine (NE), vascular endothelial growth factor (VEGF) and growth hormone (GH) before and after the initial resistance training. The reactive hyperemia index (RHI), von Willebrand factor (vWF) and transcutaneous oxygen pressure in the foot (Foot-tcPO2) were assessed before and after the 4-week resistance training period. RESULTS: Lac, NE, VEGF and GH increased significantly from 8.2 ± 3.6 mg/dL, 619.5 ± 243.7 pg/mL, 43.3 ± 15.9 pg/mL and 0.9 ± 0.7 ng/mL to 49.2 ± 16.1 mg/dL, 960.2 ± 373.7 pg/mL, 61.6 ± 19.5 pg/mL and 3.1 ± 1.3 ng/mL, respectively, in the BFR group (each P < 0.01). RHI and Foot-tcPO2 increased significantly from 1.8 ± 0.2 and 62.4 ± 5.3 mmHg to 2.1 ± 0.3 and 68.9 ± 5.8 mmHg, respectively, in the BFR group (each P < 0.01). VWF decreased significantly from 175.7 ± 20.3 to 156.3 ± 38.1 % in the BFR group (P < 0.05). CONCLUSIONS: BFR resistance training improved vascular endothelial function and peripheral blood circulation in healthy elderly people.

Six-minute walk distance is an independent predictor of hospital readmission in patients with chronic heart failure.

Patients with chronic heart failure (CHF) are frequently readmitted to the hospital due to disease progression. Although a shorter 6-minute walk distance (6MWD) is correlated with poor prognosis, 6MWD is not considered a clinical indicator for predicting hospital readmission.We investigated whether 6MWD measured at the time of hospital discharge predicted readmission due to heart failure in CHF patients.Patients admitted to the hospital for the first time due to heart failure were enrolled. After 6MWD was measured at discharge, patients were followed-up for 3 years. Clinical characteristics, 6MWD and readmission due to heart failure were evaluated in 252 patients (68.5 ± 11.8 years old, 162 males). Significant factors that affected readmission were extracted and cut-off values were determined using multivariate logistic regression analysis and receiver operating characteristic curves.Of 252 CHF patients, 103 were readmitted within 3 years. 6MWD at the time of discharge was significantly shorter in readmitted patients than non-readmitted patients (P < 0.001) and was a significant predictor of readmission (P < 0.001). The odds ratio for readmission was 1.22 (P < 0.001) with each 10-meter decrease in 6MWD. The 6MWD cut-off value was determined to be 390 meters, with a sensitivity of 0.75 and a specificity of 0.77.6MWD measured at the time of discharge is an independent predictor of hospital readmission in CHF patients, with a cut-off value of 390 meters.

Stretching exercises enhance vascular endothelial function and improve peripheral circulation in patients with acute myocardial infarction.

The purpose of this study was to clarify the acute effects of a single session of stretching exercises on vascular endothelial function and peripheral circulation in patients with acute myocardial infarction. This study evaluated 32 patients (mean age, 66 ± 9 years) who received phase I cardiac rehabilitation after acute myocardial infarction. Five types of stretching exercises were performed on the floor: wrist dorsiflexion, close-legged trunk flexion, open-legged trunk flexion, open-legged lateral trunk bending, and cross-legged trunk flexion. Each exercise entailed a 30-second stretching followed by a 30-second relaxation, and was repeated twice. Low- and high-frequency components (LF and HF) of heart rate variability (LF, 0.04-0.15 Hz; HF, 0.15-0.40 Hz) were analyzed, and HF and LF/HF were used as indices of parasympathetic and sympathetic nervous activities, respectively. Reactive hyperemia peripheral arterial tonometry (RH-PAT) index was measured and used as a parameter for vascular endothelial function. Transcutaneous oxygen pressure (tcPO2) on the right foot and chest was also measured, and the Foot-tcPO2/Chest-tcPO2 ratio was used as a parameter for peripheral circulation. The HF, RH-PAT index, and Foot-tcPO2/Chest-tcPO2 ratio were significantly higher after the exercises than before (P < 0.05, P < 0.01, and P < 0.05, respectively). There was no significant difference in the LF/HF ratio measured before and after stretching exercises. These findings demonstrate that stretching exercises improve vascular endothelial function and peripheral circulation in patients with acute myocardial infarction.

Stretching Exercises Improve Vascular Endothelial Dysfunction Through Attenuation of Oxidative Stress in Chronic Heart Failure Patients With an Implantable Cardioverter Defibrillator.

PURPOSE: Endurance training improves oxidative stress and vascular endothelial dysfunction in patients with chronic heart failure (CHF). However, patients with CHF and an implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy-defibrillator (CRT-D) often avoid endurance training for fear of ICD shock. Recent studies have reported that stretching exercises enhance antioxidant activity and improve vascular responses. Therefore, we aimed to assess the effects of 4 weeks of stretching exercises on oxidative stress and vascular endothelial function in patients with CHF with an ICD or CRT-D. METHODS: Fifty sedentary patients with CHF (78% males; mean age = 70 ± 9 years; left ventricular ejection fraction = 26% ± 8%) with an ICD or CRT-D were randomly divided into a group that performed 4 weeks of stretching exercises (stretching group) and a group that continued a sedentary lifestyle (control group). We compared the reactive hyperemia peripheral arterial tonometry (RH-PAT) index and blood parameters, such as von Willebrand factor (vWF), malondialdehyde-modified low-density lipoprotein cholesterol (MDA-LDL), reactive oxygen species (ROS), high-sensitivity C-reactive protein, pentraxin 3, and fibrinogen between the 2 groups before and after the 4-week study period. RESULTS: In the stretching group, a significant increase in the RH-PAT index and significant decreases in vWF, MDA-LDL, ROS, and fibrinogen concentrations were observed after the study compared with before (all P < .05). No significant changes were observed in the control group. CONCLUSION: Four weeks of stretching exercises improved vascular endothelial dysfunction through attenuation of oxidative stress in sedentary patients with CHF with an ICD or CRT-D.

Quadriceps isometric strength as a predictor of exercise capacity in coronary artery disease patients.

BACKGROUND: Quadriceps strength is related to exercise capacity in normal subjects and different patient populations, but the relationship between maximal quadriceps isometric strength (QIS) and different exercise capacity levels in coronary artery disease (CAD) patients has not been systematically evaluated yet. METHOD: We studied 621 patients (60.6 ± 9.9 years, 538 males) with recent coronary artery bypass grafting or myocardial infarction, who underwent treadmill exercise testing, maximal QIS measurement (hand-held dynamometry), and coronary arteriography. Maximal QIS was expressed as absolute value (kg), %bodyweight, and %predicted maximum. Logistic regression was used to assess the relationship of maximal QIS, age, sex, number of diseased coronary vessels, peak systolic blood pressure, peak heart rate, brain natriuretic peptide, and left ventricular ejection fraction with 5, 7, and 10 estimated metabolic equivalents (eMETs) exercise capacity levels. RESULTS: Maximal QIS %bodyweight was the strongest predictor of exercise capacity in each eMETs category. Receiver-operating characteristics curves identified maximal QIS of 46, 51, and 59 % bodyweight as the best predictive cut offs for 5, 7 and 10 eMETs, respectively, with positive predictive values of 0.72, 0.66, and 0.67, respectively. CONCLUSIONS: Maximal QIS is related with eMETs levels reached at exercise testing in CAD patients, and identified maximal QIS cut-off values for eMETs prediction may be used to set strength training goals according to patients' needs with regard to habitual physical activity level. Hand-held dynamometry may meet the need of easiness of use and low cost required for strength evaluation in large-scale clinical trials.

Usefulness of pet ownership as a modulator of cardiac autonomic imbalance in patients with diabetes mellitus, hypertension, and/or hyperlipidemia.

Among patients with coronary artery disease, pet owners exhibit a greater 1-year survival rate than nonowners. Lifestyle-related diseases are well-known risk factors for coronary artery disease and induce imbalances in autonomic nervous activity. The purpose of the present study was to determine whether pet ownership modulates cardiac autonomic nervous activity imbalance in patients with lifestyle-related diseases such as diabetes mellitus, hypertension, and hyperlipidemia. A total of 191 patients (mean age 69 ± 8 years) were interviewed about their pet ownership status and were classified into pet owner and nonowner groups. After recording a 24-hour Holter electrocardiogram for heart rate variability analysis, frequency-domain and nonlinear-domain analyses were performed to determine the high-frequency (HF) and low-frequency (LF) components, LF/HF ratio, and entropy. The heart rate variability parameters were assessed for 24 hours, during the day (8.00 A.M. to 5.00 P.M.), and during the night (0:00 A.M. to 6.00 A.M.), and compared between the 2 groups. To evaluate the potential predictive factors for cardiac autonomic imbalance, univariate and multivariate analyses of HF and LF/HF were conducted for potential confounding variables. The pet owner group exhibited significantly greater HF(24h), HF(day), HF(night), entropy(24h), entropy(day), and entropy(night) and significantly lower LF/HF(24h) and LF/HF(night) compared to the nonowner group. On multivariate analysis, pet ownership was independently and positively associated with HF(24h,) HF(day), and HF(night) and inversely associated with LF/HF(24h) and LF/HF(night). In conclusion, these results suggest that pet ownership is an independent modulator of cardiac autonomic imbalance in patients with lifestyle-related diseases.