Six-minute walking distance in healthy Chinese people older than 60 years

Moxibustion for declined cardiorespiratory fitness of apparently healthy older adults: A study protocol for a randomized controlled trial

BACKGROUND

Aging and age-related declines lead to varying degrees of decreased cardiorespiratory fitness (CRF) in apparently healthy older adults. Exercise training, the primary approach for enhancing CRF, encounters several constraints when used with elderly individuals. Existing evidence implies that moxibustion might enhance the CRF of older adults. However, clinical research in this area still needs to be improved.

METHODS

This study will employ a randomized, assessor-blinded, controlled trial design involving 126 eligible participants. These participants will be stratified and randomly assigned to one moxibustion group, one sham moxibustion group, and one blank control group. Acupoints of bilateral Zusanli (ST36), Shenque (CV8), and Guanyuan (CV4) are selected for both real and sham moxibustion groups. The treatment will last 60 min per session, 5 sessions a week for 12 weeks. The blank control group will not receive any intervention for CRF improvement. Primary outcomes will be the mean change in peak oxygen uptake (VO2peak), anaerobic threshold (AT), and serum central carbon metabolites (CCB) from the baseline to observation points. Secondary outcome measures involve the six-minute walk distance (6MWD), the Short Form 36 Health Survey (SF-36), and the Qi and Blood Status Questionnaire (QBSQ). Outcome assessments will be conducted at weeks 4, 8, 12, and 24 as part of the follow-up. Adverse events will be assessed at each visit.

DISCUSSION

This trial can potentially ascertain moxibustion's effectiveness and safety in enhancing CRF among apparently healthy older adults.

TRAIL REGISTRATION

ChiCTR, ChiCTR2300070303. Registered on April 08, 2023.

Performance of physical, cardiovascular, and psychological functions in middle-aged women with and without breast cancer

PURPOSE

To compare the physical performance, including upper-limb motor and cardiovascular functions, and psychological functions, including anxiety and depression, sleep, and fatigue, between women with and without breast cancer.

METHODS

Thirty-two women with breast cancer and 32 healthy counterparts were recruited for the study. Upper-limb muscle strength, shoulder range of motion, and upper-limb function were assessed using a handheld dynamometer, a goniometer, and the short form of the Disabilities of Arm-Shoulder-Hand Questionnaire, respectively. Exercise endurance and cardiovascular functions were assessed using the 6-min walk test and blood pressure and heart rate variability, respectively. The Hospital Anxiety and Depression Scale, the Pittsburgh Sleep Quality Index, and the Fatigue Assessment Scale were used to assess the symptoms of anxiety and depression, sleep quality, and fatigue, respectively.

RESULTS

Breast cancer participants' body-weight-adjusted upper-limb strength of both the affected and unaffected sides (0.11-0.14) was only 61.1-77.8% of those of the healthy participants (0.18). Their shoulder mobility of the affected side (flexion: 161.64°; abduction: 157.01°) were 94.2% (flexion) and 92.5% (abduction) of those of the healthy participants (flexion: 171.56°; abduction: 169.68°), respectively. Breast cancer participants had higher quickDASH mean score (19.53), HADS-A mean score (6.78), HADS-D mean score (4.72), global PSQI mean score (7.22) and FAS mean score (25.97) as well as shorter mean distance covered by 6 MWT (496.66 m) than those of the healthy participants.

CONCLUSIONS

Rehabilitative interventions, such as mind-body interventions and exercise training, target physical fitness and promote the psychological health of women with breast cancer are necessary.

Heart Rate Response Predicts 6-Minutes Walking Distance in Pulmonary Arterial Hypertension

Because the 6-minute walking test (6MWT) is a self-paced submaximal test, the 6-minute walking distance (6MWD) is substantially influenced by individual effort level and physical condition, which is difficult to quantify. We aimed to explore the optimal indicator reflecting the perceived effort level during 6MWT. We prospectively enrolled 76 patients with pulmonary arterial hypertension and 152 healthy participants; they performed 2 6MWTs at 2 different speeds: (1) at leisurely speed, as performed in daily life without extra effort (leisure 6MWT) and (2) an increased walking speed, walking as the guideline indicated (standard 6MWT). The factors associated with 6MWD during standard 6MWT were investigated using a multiple linear regression analysis. The heart rate (HR) and Borg score increased and oxygen saturation (SpO2) decreased after walking in 2 6MWTs in both groups (all p <0.001). The ratio of difference in HR before and after each test (ΔHR) to HR before walking (HRat rest) and the difference in SpO2 (ΔSpO2) and Borg (ΔBorg) before and after each test were all significantly higher in both groups after standard 6MWT than after leisure 6MWT (all p <0.001). Multiple linear regression analysis revealed that ΔHR/HRat rest was an independent predictor of 6MWD during standard 6MWT in both groups (both p <0.001, adjusted R2 = 0.737 and 0.49, respectively). 6MWD and ΔHR/HRat rest were significantly lower in patients than in healthy participants (both p <0.001) and in patients with cardiac functional class III than in patients with class I/II (both p <0.001). In conclusion, ΔHR/HRat rest is a good reflector of combined physical and effort factors. HR response should be incorporated into 6MWD to better assess a participant's exercise capacity.

Validity of the two-minute step test for healthy older adults

BACKGROUND

In healthy older adults, the two-minute step test (2MST) does not have its concurrent validity tested against the six-minute walk test (6MWT), which is a valid cardiorespiratory fitness test frequently applied in geriatric samples.

OBJECTIVE

To derive an equation to predict 6MWT from 2MST and to observe the agreement between observed and estimated 6MWT distances.

METHODS

6MWT and 2MST were measured in 51 older adults (72.9±4.6 years) from community multicomponent exercise programs. Multiple linear regression derives the predictive equation of 6MWT walked distance (dependent outcome) from steps obtained in 2MST, age, sex, and body mass index (independent outcomes).

RESULTS

Correlation between 6MWT and 2MST was strong (r=0.696, p<0.001). The regression equation showed good agreement with measured values, when 6MWT was below 600 m.

CONCLUSION

The equation stands as a novel approach to obtaining a valid 6MWT estimation from the 2MST. 2MST is easier and faster, representing an alternative approach when time and space are limited.

Reference equations for the six-minute walking distance in obese Chinese subjects more than 40 years old

BACKGROUND

Studies have shown that the reference equations for the six-minute walking distance (6MWD), which were mainly derived from healthy, normal-weight people, are not suitable for individuals with obesity. The main purpose of this study was to establish reference equations for the 6MWD in obese Chinese subjects.

METHODS

In our study, a total of 214 individuals with obesity performed the six-minute walking tests (6MWTs) according to the American thoracic society (ATS) guidelines, and the longer 6MWD was used for further analysis. The reference equations for the 6MWD were developed using stepwise multiple regression analysis. The newly established equations for the 6MWD were compared to the existing prediction equations.

RESULTS

The mean 6MWD for the cohort was 523 ± 56 m. We found that the reliability of two 6MWTs was good. Age and BMI were identified as independent factors, and explained 31% and 27% of the variance in the 6MWD for the male and female participants, respectively. Thus, the reference equations reported in the previous studies did not accurately predict the 6MWD in our subjects.

CONCLUSION

Our study was the first to describe the 6MWD in obese Chinese subjects and to propose new predictive equations. These established equations can improve the assessment of the health of obese Chinese patients whose exercise capacity is affected by the disease.

LEVEL OF EVIDENCE

III, Cohort study.

Validity of a novel respiratory rate monitor comprising stretchable strain sensors during a 6-min walking test in patients with chronic pulmonary obstructive disease

BACKGROUND

Breathing frequency is rarely measured during a field walking test since the current monitoring system using a face mask is cumbersome for older adults. For effective clinical application, we aimed to validate the new respiratory monitor using wearable strain sensors during a 6-min walk test (6MWT) in young adults and patients with chronic obstructive pulmonary disease (COPD).

METHODS

The study included young adults and patients with stable COPD voluntarily recruited from three hospitals. Breathing frequency during 6MWT were measured by the strain sensor and a nasal capnometer. Total breathing frequencies were measured by the capnometer. The Bland-Altman method was used to estimate the mean limit of agreement for breathing frequency.

RESULTS

A total of 23 young adults (age = 23.1 ± 3.7, mean ± SD) and 50 patients with COPD (age = 75.2 ± 7.2, %FEV1 = 59.1 ± 19.7) were analyzed. During the entire test period, the total breathing frequencies were measured based on an average of 252 ± 46 breaths, and the total breathing frequency was higher in patients with COPD than in young adults (mean difference = -3.349, p < 0.0013). The mean difference in breathing frequency between the strain sensors and capnometer was -0.28 (95%CI: 0.75 to 0.20), and the limit of agreement ranged from -4.1 to 3.6. The CI of the limit of agreement included the limit of equivalence (4 counts/min).

CONCLUSIONS

The novel respiratory monitor with wearable sensors achieved the target accuracy in both young adults and patients with COPD in the 6MWT.