Reference values for the 6-Min Walking Test in obese subjects

Usefulness of an Easy, Structured, and Home-Based Exercise Program to Improve Physical Performance and Quality of Life in a Patient's Cohort with Obesity

INTRODUCTION

The benefits of exercise in patients with obesity are clear; physical performance and quality of life improve after exercise programs in patients with obesity. Our aim was to evaluate the usefulness of an easy, structured, and home-based exercise program to improve physical performance and quality-of-life in patients with obesity.

METHODS

A cohort of patients with obesity (BMI ≥30 kg/m2) was recruited during 2017-2020. Patients who met the inclusion criteria were invited and those who accepted signed informed consent. Patients were evaluated by the same team of physicians who performed the 6-min walking test and collected the clinical and biochemical variables, also applied quality-of-life questionnaire at baseline and 3 months after starting the exercise program that was divided in two levels: level 1: active mobilization of four limbs (15 min) + cardiovascular exercise (15 min walking), 5 days/week; level 2: eight strengthening exercises for upper and lower limbs with an elastic band + cardiovascular exercise (15 min walking), 5 days/week. This study used means (SD), frequencies (percent), Student's t test, and Pearson correlation test.

RESULTS

We included 151 patients, mostly women (81.5%), age 46.3 ± 9.8 years old, BMI 40.3 ± 8.56 kg/m2, 34.4% performed some type of exercise, and the most frequents comorbidities were dyslipidemia and diabetes. After 3 months, 86 patients (57%) remained in the study and attended the final evaluation. Evident changes in physical performance were reported (distance traveled, speed walking and VO2max); however, improvement in quality of life was remarkable.

CONCLUSION

An easy, structured, and home-based exercise program improves physical performance and quality of life in patients with obesity, without losing its benefits for the health.

A pilot study of the effects of supervised exercise training on body composition, cardiometabolic risk factors, muscle strength and functional capacity in individuals with bariatric surgery

The main objective of this pilot study was to evaluate the effects of functional exercise training (FET) and home exercise training (HET) on body composition, cardiometabolic risk factors, muscle strength, and functional capacity in individuals with bariatric surgery. The sample of the study included 30 individuals who underwent bariatric surgery. The FET group had functional exercise training consisting of stretching, aerobic, strengthening, and balance exercises assigned by a physiotherapist (n = 15), and the HET group had the same exercises under supervision (n = 15). The training sessions were planned as × 3 per week for a period of 8 weeks. Body composition, cardiometabolic risk factors, cardiometabolic risk status, muscle strength, and functional capacity of all individuals were evaluated before and after training. According to the measurements, body weight (BW), body mass index (BMI), body fat mass (BFM), C-reactive protein, glycated hemoglobin, insulin resistance, cardiovascular risk total score, and ten-year cardiovascular percentage risk decreased significantly (p < 0.05), while HDL-C, leg, back, and hand grip strength (right-left), and walking distance increased significantly (p < 0.05) in the FET group. In the HET group, there were significant increases in body fat percentage (BFM %), BFM, and body muscle mass percentage (BMM %) (p < 0.05), while body muscle mass (BMM), right hand grip strength, leg and back muscle strength, and walking distance scores significantly decreased (p < 0.05). It was concluded that personalized and supervised FET has a positive effect on body composition, cardiometabolic risk factors, muscle strength, and functional capacity, and it can be recommended as a safe exercise model for bariatric surgery patients.

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.

Impact of a Preoperative Exercise Program on General Fitness in Patients Awaiting Bariatric Surgery: A Pilot Randomized Trial

Background

Evidence supports the association between exercise and outcomes following bariatric surgery. However, there is a lack of knowledge regarding the short-term benefits of preoperative exercise.

Objectives

The objective of this pilot study was to evaluate the feasibility and functional benefits of a 12-week preoperative exercise program in patients awaiting bariatric surgery. The primary aim was the six-minute walk test (6MWT). The secondary aim of this study included anthropometric measures, strength, and quality of life.

Methods

A total of 54 patients were enrolled in this pilot randomized controlled study. Of them, 29 patients received standard multidisciplinary preoperative care, while 25 patients participated in a 12-week supervised exercise program in addition to standard preoperative care consisting of strength and aerobic exercises three times per week in a fitness facility. The primary outcome was improvement in 6MWT. Secondary outcomes included other functional outcomes, quality of life, and anthropometric measures.

Results

Average attendance for the intervention group was 27.2 (75.6%) of 36 sessions. There was a mean improvement of 27 ± 10 meters in the intervention group compared with a reduction of 5 ± 10 meters in the control group (p = 0.003). Patients in the intervention group had significant improvement in all self-reported quality-of-life domains, particularly in the variables related to symptoms, hygiene, and emotions.

Conclusions

A 12-week preoperative exercise intervention was feasible and showed association with a statistically significant improvement in 6MWT and quality-of-life measures in patients awaiting bariatric surgery. The results of this study will inform sample size calculations and recruitment planning for a future study that will assess the longer-term benefits of a pre-surgical fitness intervention.

Predicting recovery and disability after surgery in patients with severe obesity: The role of the six-minute walk test

The most appropriate method to predict postoperative outcomes in patients with severe obesity undergoing elective non-bariatric surgery is not known. We conducted a single-centre prospective cohort study in patients with a body mass index of at least 35 kg/m² undergoing non-bariatric, non-cardiac surgery. Patients completed the six-minute walk test prior to surgery. Disability was measured before and six months after surgery using the World Health Organization disability assessment schedule. Primary outcome measures included quality of recovery at one month and significantly increased disability at six months after surgery. A total of 293 patients participated. The median body mass index was 41 kg/m². Patients generally recovered well. Following surgery, 9% of patients experienced a poor quality of recovery and 7% developed a significant increase in disability. The proportion of patients free from clinically significant disability increased from 66% prior to surgery to 90% at six months after surgery. The distance walked in six minutes was weakly predictive of poor recovery at one month and significantly increased disability at six months; weight and body mass index were not. The area under the receiver operating characteristic curve was 0.65 (95% confidence intervals 0.51 to 0.78) for poor recovery and 0.64 (95% confidence intervals 0.51 to 0.77) for increased disability. A preoperative six-minute walk test distance of 308 m was the best cut-off value for predicting increased postoperative disability (sensitivity 0.68, specificity 0.63). The six-minute walk test was most discriminatory at shorter distances. This population of patients with severe obesity appeared to recover well and had few adverse outcomes. The degree of functional capacity was more important than the degree of obesity in predicting postoperative outcomes.

Functional neurological symptom disorder: Preliminary findings of factors associated with walking ability post integrative pediatric rehabilitation

PURPOSE

The current study's aims were to (1) examine long-distance walking ability (6-minute walking test [6MWT]) and walking hemodynamic responses (i.e., heart rate) among youth with functional neurological symptom disorder (FNSD) before and after an integrative pediatric rehabilitation (IPR) program; and (2) explore factors predicting improvement in walking ability.

METHODS

Thirty-one youth with FNSD participating in an IPR program were recruited. The IPR program was activated biweekly in an ambulatory format. Study measures included the 6MWT, hemodynamic characteristics, rate of perceived exertion (RPE), pain-intensity perception, and Child's Somatization Inventory-24 (CSI-24). All measures were conducted upon admission to the IPR and discharge.

RESULTS

Findings indicated a significant increase in 6MWT distance, as well as decreases in heart rate, RPE, and pain-intensity perception from admission to discharge. At admission, CSI-24 and pain intensity predicted 6MWT distance (adjusted R2 = 0.68). Pain intensity predicted discharge 6MWT distance (adjusted R2 = 0.18). Initial 6MWT predicted changes in 6MWT distance from admission to discharge (adjusted R2 = 0.33).

CONCLUSION

Using an integrative rehabilitation approach increases walking distance and decreases pain-related symptoms in youth with FNSD, emphasizing the need for collaboration between physical therapists and pediatric psychologists. Moreover, changes in walking ability may increase participation and thus should be the focus of IPR.

Physical activity in management of persons with obesity

Physical activity and exercise have many benefits in persons with obesity, helping with weight loss, body fat loss, abdominal visceral fat loss and possibly with weight maintenance after weight loss. The effect of exercise training (endurance or endurance plus resistance or high-intensity interval training) alone on weight loss as outcome appears relatively modest, amounting to only a few kg. However, endurance training during weight loss has been shown to increase V̇O₂max and resistance training during weight loss leads to lower loss in lean body mass and increased muscle strength. In addition, higher physical activity levels improve cardiovascular risk, whatever weight variations. Specifically, physical activity or exercise is part of lifestyle measures for prevention of type 2 diabetes and substantially helps with metabolic control in patients with type 2 diabetes. The importance of physical activity counselling and exercise prescription in the management strategy will depend on specific treatment objectives as defined for a given patient, including weight loss, prevention of weigh regain, prevention of cardio-metabolic comorbidities, lean body mass preservation but also improvement in quality of life or development of social links. The 5 A's strategy consisting in: Ask, Assess, Advise, Agree, Assist (or Arrange) appears well adapted in this setting. Professionals need to be aware of the many barriers patients with obesity may meet on their way to increase habitual physical activity as specific solutions should be proposed. A major challenge is how to improve adherence to new physical activity habits over time.

Effects of technology-based physical activity interventions for women after bariatric surgery: study protocol for a three-arm randomised controlled trial

INTRODUCTION

A recent meta-analysis provided proof of efficacy for mobile technology to increase physical activity or weight loss in the short term. Videoconferencing may also be effective, especially as it reduces the barriers related to face-to-face physical activity interventions. Both technologies seem particularly interesting for bariatric surgery management, but their long-term effects on physical activity maintenance are unknown. Moreover, the mechanisms underlying their effectiveness, such as technology acceptability and motivational processes, have not been examined.The objectives of this study are to determine the effects of two technology-based (mobile technology and videoconferencing) physical activity programmes after bariatric surgery compared with standard care and to assess the contribution of acceptability and motivational mechanisms in explaining these effects on physical activity, physiological measures and health indicators.

METHODS AND ANALYSIS

One hundred and twenty young women who have undergone bariatric surgery in the last 3-6 months will be included. The volunteers will be randomly assigned to one of three arms: CONTROL (standard care), ACTI-MOBIL (mobile technology) or ACTI-VISIO (videoconferencing). The primary outcome is the distance travelled during a 6 min walk test relativised according to Capadaglio's theoretical distance. Secondary outcomes are behavioural measures of physical activity, physiological measures, health indicators, technology acceptability and motivational concepts. Data will be collected at baseline (T0), 3 months (T3) and 6 months (T6). The technology groups will receive a physical activity programme for 12 weeks (between T0 and T3). A mixed model approach will be used to analyse the change in outcomes over time for each group.

ETHICS AND DISSEMINATION

This study protocol was reviewed and approved by the French East 1 Protection of Persons Ethics Committee (number: 2020.A00172-37) and the French National Commission for Information Technology and Civil Liberties (number: UCA-R20-034). The results will be disseminated through conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT04478331.

Increased Cardiopulmonary Fitness Is Associated with a Greater Reduction in Depression among People Who Underwent Bariatric Surgery

The aim of this study was to determine the effect of changes in cardiopulmonary fitness on the mental health of patients with severe obesity who underwent gastric bypass surgery (prior to and 1, 3, and 6 months after surgery). Study participants were recruited from among patients of a regional hospital in Czechia who underwent gastric bypass surgery between April 2018 and October 2019. They were eligible if they (a) were between 18 and 65 years old, (b) provided written informed consent, and (c) were able to walk independently. Twenty-six patients (age 45.4 ± 9.0 years, body mass index 45.1 ± 7.4 kg·m⁻², body fat 43.8 ± 4.8%) were included in the analysis. The key finding revealed that the greater the increase in cardiopulmonary fitness (i.e., longer distance walked in the six-minute walk test, 6MWT), the better the improvement in depression score among patients who underwent bariatric surgery. In particular, increments of 10 m in the 6MWT lead to the improvement of 0.5 points on the depression subscale of the Hospital Anxiety and Depression Scale (HADS) questionnaire. As the main implication, these results suggest that patients should participate in exercise training programs to increase their fitness status for optimal physical and mental outcomes of bariatric surgery.

Reference Value for the Distance Walked in the Six-Minute Walk Test in Obese Brazilian Men in the Preoperative Period of Bariatric Surgery

BACKGROUND

Obesity has several effects on the mechanics of the rib cage that may impair the exercise performance of obese individuals and therefore impact the assessment of surgical risk. This study aimed to establish a reference value for the 6-minute walk distance (6 MWD) in obese Brazilian men in the preoperative period of bariatric surgery that considers the effect of lung function.

METHODS

This was a cross-sectional study in which 104 obese men underwent the six-minute walk test (6 MWT) before bariatric surgery. They also underwent the spirometry test and respiratory muscle strength measurement before the 6 MWT.

RESULTS

The 6 MWD was correlated with age (r = -0.388, p=0.0005), weight (r = -0.365, p=0.0007), height (r = 0.285, p=0.022), body mass index (BMI) (r = -0.543, p < 0.0001), forced vital capacity (FVC) (r = 0.472, p < 0.0001), peak expiratory flow (r = 0.253, p=0.031), and maximal inspiratory pressure (r = 0.313, p=0.017). In the stepwise forward regression analysis, BMI, FVC, and age were the only variables that independently predicted the 6 MWD and explained 40% of its variability. The reference equation proposed for obese Brazilian men is 6 MWD (m) = 570.5 - (3.984 × BMI_kg/m2) + (1.093 × FVC_%predicted) - (0.836 × age_yrs).

CONCLUSION

In this sample of obese Brazilian men, lung function contributed to poor performance in the 6 MWT. In these individuals, BMI, FVC, and age were the variables that composed the reference equation for the 6 MWD. Thus, in several clinical settings, such as in the evaluation before bariatric surgery, pulmonary function data are important to determine the reference value for the 6 MWD.

Contribution of lung function in predicting distance covered in the 6-min walk test in obese Brazilian women

Obesity affects the respiratory system through various mechanisms, including systemic inflammation and direct mechanical hindrance due to fat deposition in the chest and abdomen. In addition, changes in the neural control of respiration and increases in thoracic blood volume can promote abnormalities in lung function. Thus, determining relationships between the distance covered in the 6-min walk test (6MWT) and demographic and lung function variables may help us better understand the mechanisms involved in reduced functional exercise capacity in obesity. To explore the determinants of the 6-min walking distance (6MWD) and evaluate the influence of lung function on the distance covered, 263 obese Brazilian women performed the 6MWT and underwent spirometry and respiratory muscle strength measurement. The mean age was 41.8±11.1 years. The mean body mass index (BMI) was 45±8 kg/m². The 6MWD showed correlations with height (r=0.319), age (r=-0.281), weight (r=-0.370), BMI (r=-0.561), forced vital capacity (FVC, r=0.443), expiratory peak flow (r=0.278), maximal inspiratory pressure (MIP, r=0.326), and maximal expiratory pressure (r=0.259), all with P<0.0001. In the stepwise forward regression analysis, BMI, FVC, age, and MIP were the independent predictive variables for 6MWD, explaining 41% of its variability. The reference equation including lung function was as follows: 6MWD (m) = 513.6 - (4.439 × BMI_kg/m2) + (1.136 × FVC_%predicted) - (1.048 × age_yrs) + (0.544 × MIP_%predicted). Thus, the inclusion of lung function in a reference equation for 6MWD contributes to a better prediction of the distance covered in this population.

Reference values for the 12 minute walk test in McArdle patients

The maximum distance achieved on a modified 12 min walk test (12MWT) is a well-established measure in McArdle disease glycogen storage disease type V (GSDV). Age, height, body mass and gender are known predictors of walking distance in other patient groups. Reference values to correct for these predictors are necessary for comparisons between individuals. To date, there has not been a systematic investigation of these predictors in the 12MWT in GSDV. This study explores the contribution of these predictors on distance achieved in GSDV. Data, included maximum distance walked, age, gender, height and body mass, was collected from 103 GSDV patients who underwent 12MWT between 2011 and 2017. Analysis showed a significant correlation between distance achieved and height, age, body mass and gender. Multiple linear regression analysis revealed a model accounting for 29.7% of variance (R = 0.545, R² 0.297, adjusted R^{2 0}.269). Gender was not significant after height, age and body mass were entered into the regression analysis. This is the first study to report the contribution of non-disease related factors on distance achieved on the 12MWT in the GSDV population. The reference values generated will allow for improved monitoring and assessment of GSDV patients in clinical and research settings.

Weight-based reference equations for the 6-min walk test can be misleading in obese patients

A 79-year-old female presented to a hospital-based laboratory for pulmonary function testing and a 6-min walk test (6MWT). The patient's chief complaint was dyspnoea on exertion. The patient was a life-long nonsmoker with a history of interstitial lung disease and morbid obesity (body mass index (BMI) 44.9 kg·m⁻²). The patient's baseline spirometry data were within normal limits but the diffusing capacity was moderately reduced (50% of predicted; z-score −4.05) [1, 2].

Weight-based reference equations for the 6-min walk test can produce normal results despite poor performance. Using ideal body weight- or non-weight-based reference equations for the 6-min walk test may produce more clinically meaningful results.https://bit.ly/2wE9Sdn

Quality of Life and Physical Performance in Patients with Obesity: A Network Analysis

BACKGROUND

The aim of this study was to investigate the interconnections between specific quality-of-life domains in patients with obesity and high or low physical performance using a network approach.

METHODS

716 consecutive female and male patients (aged 18-65 years) with obesity seeking weight-loss treatment were included. The 36-item Short Form Health Survey (SF-36) and the six-minute walking test (6MWT) were used to assess quality of life and physical performance, respectively. The sample was split into two groups according to the distance walked in the 6MWT. Network structures of the SF-36 domains in the two groups were assessed and compared, and the relative importance of individual items in the network structures was determined using centrality analyses.

RESULTS

35.3% (n = 253) of participants covered more distance than expected, and 64.7% (n = 463) did not. Although low-performing patients showed lower quality of life domain scores, the network structures were similar in the two groups, with the SF-36 Vitality representing the central domain in both networks. Mental Health was a node with strong connections in patients who walked less distance.

CONCLUSIONS

These findings indicate that psychosocial variables represent the most influential and interconnected features as regards quality of life in both groups.

OBEDIS Core Variables Project: European Expert Guidelines on a Minimal Core Set of Variables to Include in Randomized, Controlled Clinical Trials of Obesity Interventions

Heterogeneity of interindividual and intraindividual responses to interventions is often observed in randomized, controlled trials for obesity. To address the global epidemic of obesity and move toward more personalized treatment regimens, the global research community must come together to identify factors that may drive these heterogeneous responses to interventions. This project, called OBEDIS (OBEsity Diverse Interventions Sharing - focusing on dietary and other interventions), provides a set of European guidelines for a minimal set of variables to include in future clinical trials on obesity, regardless of the specific endpoints. Broad adoption of these guidelines will enable researchers to harmonize and merge data from multiple intervention studies, allowing stratification of patients according to precise phenotyping criteria which are measured using standardized methods. In this way, studies across Europe may be pooled for better prediction of individuals' responses to an intervention for obesity - ultimately leading to better patient care and improved obesity outcomes.

Effect of 4 Weeks of Foot Orthosis Intervention on Ambulatory Capacities and Posture in Normal-Weight and Obese Patients

BACKGROUND

Several works have shown the benefits of foot orthosis intervention on postural stability in healthy individuals and patients with foot malalignment. However, the effects of foot orthoses on the daily ambulatory activities explored by the Six-Minute Walk Test (6MWT) were never examined. We hypothesized that foot orthoses could increase the gait distance and attenuate the post-6MWT posture alterations already reported in healthy individuals.

METHODS

In ten normal-weight (NW) and ten obese patients with foot malalignment and/or abnormal foot arch, we examined the benefits of 4 weeks of custom-molded orthosis intervention (D30) on 6MWT gait distance, fatigue sensation scores, ankle plantarflexion force, and post-6MWT sway of the center of pressure (COP) measured by a pedobarographic platform. Data were compared with those measured in two control-matched groups of ten NW and ten obese individuals, explored at study inclusion and at D30.

RESULTS

At study inclusion, the post-6MWT changes in COP surface and the medial and lateral COP deviations were significantly higher in obese participants who needed to wear the foot orthoses compared with obese control subjects. The foot orthosis intervention significantly improved the ambulatory performances of NW and obese individuals during the 6MWT, attenuated the bodily fatigue sensation after the 6MWT, and reduced the post-6MWT COP deviations, with the benefits of insoles being significantly accentuated in obese participants.

CONCLUSIONS

Four weeks of foot orthosis intervention significantly increases gait distance and is an effective means to reduce postural sway after walking.

The clinical, functional and disability characteristics of patients with severe obesity presenting for non-bariatric surgery

The clinical and functional characteristics of patients with severe obesity who present for non-bariatric surgery have rarely been described. For this study, 293 such patients (mean body mass index 42 kg/m2) were investigated using their medical records, a 6-minute walk test, N-terminal pro B-type natriuretic peptide measurement, and the World Health Organization Disability Assessment Schedule 2.0 measure of disability. Cardiorespiratory disease and diabetes were common, with blood tests revealing a high probability of additional unexpected and undiagnosed renal and cardiac disease in a significant proportion of patients. One-third of patients had natriuretic peptide values that identify early left ventricular dysfunction in the community, with 16% above a value described as useful in predicting adverse outcomes for elective surgical patients. Only 10% of patients walked a distance within 10% of that predicted in six minutes, and 22% did not complete the test. Over one-third of patients (34%) had a clinically significant level of disability, with those unable to walk for six minutes describing higher levels of disability. Functional capacity as measured by the 6-minute walk test was significantly lower than would be expected from age, gender, and weight alone, and was related to age and degree of disability but not body mass index. We describe a severely obese population presenting for non-bariatric surgery who had significant levels of comorbid disease, functional impairment, and disability that were not apparent on routine preoperative assessment.

Validation of the two-minute step test in obese with comorbibities and morbidly obese patients

Cardiopulmonary fitness assessment is a valuable resource to obtain quantitative indicators of an individual's physical performance. The cardiopulmonary exercise test (CPX), considered the gold standard test for this evaluation, is costly and difficult to be accessed by the general population. In order to make this evaluation more accessible, and to better reflect the performance of daily life activities, alternative tests were proposed. Morbidly obese patients present limitations that impair physical performance assessment and could benefit from a test of shorter duration, provided it is validated. This observational study aimed to validate the two-minute step test (2MST) as a tool to evaluate functional capacity (FC) in obese with comorbidities and morbidly obese patients, compared the 2MST with CPX as a measure of physical performance, and developed a predictive equation to estimate peak oxygen uptake (VO₂) in the 2MST. The CPX and the 2MST were performed and metabolic and ventilatory parameters were recorded in 31 obese individuals (BMI>35 kg/m²). Pearson correlation and multiple linear regression analyses were performed to evaluate the peak VO₂ best predictors. Bland-Altman analysis was performed to assess the agreement between the two methods. Peak VO₂ measured by CPX and 2MST showed a strong correlation (r=0.70, P<0.001) and there was a moderate correlation between peak VO₂ of the 2MST and the number of up-and-down step cycles (UDS) (r=0.55; P=0.01). The reference equation obtained was: VO₂ (mL·kg^-1·min^-1) = 13.341 + 0.138 × total UDS – (0.183 × BMI), with an estimated standard error of 1.3 mL·kg^-1·min^-1. The 2MST is a viable, practical, and easily accessible test for FC. UDS and BMI can predict peak VO₂ satisfactorily.

Assessment of a Multidisciplinary Intervention in Patients With BMI ≥35 kg/m2 and Recently Diagnosed Type 2 Diabetes

CONTEXT

Patients with a body mass index (BMI) ≥35 kg/m2 have lower benefits with intensive treatments and metabolic control goals are more difficult to reach.

OBJECTIVE

Evaluate the effect of a comprehensive care program in patients with a BMI ≥35 kg/m2.

DESIGN

Prospective cohort study.

SETTING

Comprehensive Care Center in a National Institute of Health.

PATIENTS

Patients with type 2 diabetes, ≤5 years of diagnosis, without disabling complications, nonsmokers, and a BMI <45 kg/m2.

INTERVENTIONS

Exercise and nutritional interventions are modified for patients with a higher BMI to achieve metabolic control.

MAIN OUTCOME MEASURES

Main outcome is achievement of treatment goals defined as HbA1c <7%, low-density lipoprotein cholesterol (LDL-c) <100 mg/dL, and blood pressure <130/80 mm Hg. Secondary measures were the percentage of patients achieving three metabolic goals.

RESULTS

A total of 587 patients with annual evaluation were included. Mean age was 55.3 ± 9.5 years, 56.6% women, time since diagnosis of 1 year (0 to 5). BMI <35 kg/m2 group included 521 patients and BMI ≥35 kg/m2 group included 66 patients. In the BMI ≥35 kg/m2 group, we observed a greater decrease in weight and fat mass at 3 months compared with <35 kg/m2 group, but the HbA1c, LDL-c, or blood pressure goals were similar at 3 months and 1 year between groups.

CONCLUSIONS

Comprehensive interventions are equally effective in patients with recently diagnosed type 2 diabetes with BMI ≥35 kg/m2 compared with patients with a lower BMI.

Six minute walk distance and reference values in healthy Italian children: A cross-sectional study

The 6-minute walking test (6MWT) is a simple assessment tool to evaluate exercise capacity. The result of the test is the distance that a subject can walk at a constant and normal pace within 6 minutes (6MWD) and reflects the aerobic/fitness performance related to walking function. Use of 6MWT has been relevant to assess exercise tolerance either in healthy children or in patients with, heart, lung and metabolic diseases. Our aim was to find 6MWT reference values in healthy Italian children. The 6MWT was performed in 5614 children aged 6–11 years recruited from primary Italian schools. Age related reference percentiles of the covered distance were gender-modeled. A linear and quadratic regression model was used to predict 6MWT performance. Males walked longer distances than females, respectively 598.8±83.9 m vs 592.1±77.6 m (p = 0.0016). According to the regression analysis, 6MWD was positively related to age, gender and height, while it was negatively related to body weight [(6MWD = -160.16 + 93.35× age (years) -4.05× age²(years) +7.34× gender (m) +2.12× weight (kg) −2.50× height (cm)]. Reference values were established for the 6MWT in healthy children. The age related 6MWD percentiles provided a useful tool in the assessment of capacity in 6–11 year children, in fact they may be helpful to evaluate the effect of a given treatment or rehabilitation program and represent a feasible measure as to prevention within the primary school context. It was found a substantial difference from other countries for 6mwd values. In our study, factors such as age, weight and height were relevant for the prediction of 6MWD, similarly to other studies. Therefore, these variables should be taken into account in context of exercise performance.

Physical performance measures in screening for reduced lean body mass in adult females with obesity

BACKGROUND & AIMS

Little is known about the reduction of lean body mass (LBM) in obesity, or how to identify it in standard clinical settings. We therefore aimed to assess the prevalence of low LBM in adult females with obesity, and to identify the reliability of simple tools for its screening in this population.

METHODS AND RESULTS

Dual-energy X-ray absorptiometry (DXA) body composition assessment was used to categorise 147 female participants with obesity as with or without low LBM, according to the new definition that takes into account both appendicular lean mass (ALM) and body mass index (BMI)-ALM/BMI <0.512. Participants were also administered the six-minute walking test, handgrip-strength test and 4-metre gait-speed test. Of the sample of 147 participants, 93 (63.3%) met the criteria for reduced LBM. Stepwise multivariate logistic regression analysis showed that the six-minute walking test was the only independent test associated with low LBM (OR = 0.992, 95%CI 0.987-0.998). Receiver operating characteristic (ROC) curve analysis found that the discriminating cut-off points of the tests considered were 470 m, 3.30 s (gait speed = 1.2 m/sec) and 23.5 kg respectively; the 4-metre gait-speed test seems to provide the best balance of sensitivity and specificity, and the greatest discriminatory power at 90% sensitivity.

CONCLUSIONS

Treatment-seeking adult females with obesity display a great prevalence of reduced LBM. The six-minute walking test was the only independent test associated with low LBM, but the 4-metre gait-speed test seems to be the most accurate functional test for screening for this condition in that population.

Weight Management in Patients with Type 2 Diabetes: a Multidisciplinary Real-world Approach

PURPOSE OF REVIEW

Obesity and type 2 diabetes (T2D) are closely linked metabolic diseases. Most individuals with T2D are overweight or obese, which raises their cardiovascular risk. The etiology of both diseases is multifaceted, thus requiring a multidisciplinary approach to control them. This review describes the most effective multidisciplinary approach to weight management in patients with T2D in real-world clinical practice.

RECENT FINDINGS

Weight management programs in real-world clinical settings lead to long-term weight loss for up to 5 years. Multidisciplinary approach to manage obesity and T2D through weight reduction is feasible in real-world clinical practice and is recommended as part of the treatment plan for patients with T2D who are overweight or obese. Recent data demonstrates that multidisciplinary approach to weight management in patients with T2D results in long-term weight loss and is associated with improved cardiovascular risk factors.

Prediction equation to estimate heart rate at individual ventilatory threshold in female and male obese adults

Objective

Prescribing individualized moderate exercise intensity is a useful method to reach positive effects on health status in obese adults. This study aimed to establish a practical reference equation to estimate the heart rate (HR) at individual ventilatory threshold (IVT) (HR_IVT).

Methods

One hundred sixty-one obese subjects were clinically evaluated and characterized by anthropometric and body composition. Participants performed the six-minute walking test (6-MWT) and the cardiopulmonary exercise test to assess IVT. Multiple regression analysis for HR_IVT, including 6-MWT, anthropometric, and body composition parameters, as independent variables, was performed for both gender separately. A cross-validation study was also performed to determine the accuracy of the prediction equation.

Results

Whereas HR_IVT was not significantly different between males (121.5±18.3 bpm) and females (117.6±17.1 bpm), it differently correlated with physical and performance parameters. Therefore, two sex-specific equations were developed including 6-MWT_HR and HR_rest (R² = 0.69 and 0.65 and root mean square errors of 8.8 and 10.1 bpm for females and males, respectively).

Conclusion

In conclusion, in female and male obese adults, the 6-MWT might be used to predict HR at IVT. These outcomes are useful to prescribe optimal physical activity intensity when gold standard methods (e.g. gas exchange analysis) are unavailable.

Step Activity and 6-Minute Walk Test Outcomes When Wearing Low-Activity or High-Activity Prosthetic Feet

OBJECTIVE

To determine changes in average daily step count (ADSC) and 6-minute walk test (6MWT) due to use of low-activity feet (LA) and high-activity energy-storage-and-return (ESAR) feet, and examine the sensitivity of these measures to properly classify different prosthetic feet.

DESIGN

Individuals with transtibial amputations (n = 28) participated in a 6-week, randomized crossover study. During separate 3-week periods, participants wore either a LA foot (eg, solid-ankle-cushioned-heel) or an ESAR foot. Differences in 6MWT and ADSC at the end of the 3-week period were recorded.

RESULTS

Subjects performed similarly in the 6MWT with the LA and ESAR foot (P = 0.871) and ADSC (P = 0.076). The correct classification of ESAR is only 51.9% and 61.5% with 6MWT and ADSC, respectively. For the LA foot, correct classification is less than 50% for both tests.

CONCLUSIONS

Neither ADSC or 6MWT are responsive to changes in prosthetic feet. The pitfalls and shortcomings of these instruments with regard to their ability to detect differences in prosthetic feet are outlined. Based on these results, it is not recommended that the 6MWT and ADSC are used as a means to assess outcomes for different prosthetic feet.

Effect of the 6-minute walk test on plantar loading and capability to produce ankle plantar flexion forces

The six-minute walk test (6MWT) is used to evaluate the ambulatory capacity of patients suffering from respiratory disorders, obesity or neuromuscular diseases. Our primary aim was to evaluate the effects of the 6MWT on the postural sway and the ankle plantar flexion forces in healthy subjects. We measured the ankle plantar flexion forces and the plantar contact area before and after a 6MWT in normal weight and overweight subjects with no history of respiratory, cardiac, and neuromuscular disorders. A post-6MWT sensation of bodily fatigue was evaluated by Multidimensional Fatigue Inventory (MFI) and Pichot fatigue scales. A computerized pedobarographic platform was used to collect the mean plantar contact area, the changes of the center of pressure (CoP) surface and its medial and lateral deviations. In a limited number of subjects, the reproducibility of all the measurements was explored. In both groups, the 6MWT elicited a sensation of bodily fatigue. It also significantly reduced the ankle plantar flexion forces, and increased both the mean plantar contact area and the CoP surface, the changes being not apparent after 10min. The post-6MWT lateral CoP deviations were accentuated in normal weight subjects, while an increase in medial CoP deviations occurred in overweight ones. The 6MWT-induced changes in the plantar flexion force and pedobarographic variables were reproducible. Because this study clearly showed some post-6MWT alterations of the subjects' posture sway of our subjects, we questioned the possible mechanisms occurring that could explain the altered muscle force and the transient destabilization of posture after the 6MWT.

Six-minute walk distance in patients with chronic obstructive pulmonary disease: Which reference equations should we use?

The use of different 6-min walk distance (6MWD) reference equations probably results in different predicted 6MWD reference values. We wished to investigate the impact of several 6MWD reference equations for adults in patients with chronic obstructive pulmonary disease (COPD) and factors accountable for different 6MWD% predicted values. Twenty-two 6MWD reference equations were applied to a data set of 2757 patients with COPD. The predicted 6MWD reference value of Troosters and colleagues was used as the point of reference. Four out of 21 remaining equations resulted in comparable 6MWD% predicted, 16 equations resulted in significantly higher 6MWD% predicted and 1 equation resulted in a significantly lower 6MWD% predicted. Similar differences in 6MWD% predicted were observed after stratification by sex. Body mass index and global initiative for chronic obstructive lung disease (GOLD) stage classification demonstrated varying results within and between the groups; 9 out of 21 equations resulted in comparable 6MWD% predicted in underweight patients but only 1 equation demonstrated comparable result in obese. Eight equations in GOLD I, whilst 5 out of 21 equations in GOLD IV resulted in comparable 6MWD% predicted. Existing 6MWD reference equations will give varying results. The choice of 6MWD reference equation should consider the consistency of 6-min walk test operating procedures and at least be specific for the country/region of origin.

The influence of body mass index on survival in breast cancer patients

INTRODUCTION

More than half of breast cancer survivors (BCSs) are obese at diagnosis and experience approximately 50% to 96% of weight gain during treatment that could physically affect their survival. The aim of the study was to evaluate the influence of body mass index (BMI) on physical, anthropometric, and physiological parameters in BCSs.

PATIENTS AND METHODS

A cross-sectional study was conducted with 147 BCSs. Health-related fitness, anthropometric measures, cardiovascular state, and cancer-related fatigue (CRF) were assessed for our analysis and 3 groups were formed.

RESULTS

Tests of force handgrip (affected side: F = 3.44; P < .05; nonaffected side: F = 3.067; P < .05), functional capacity (F = 3.239; P = .043), and endurance of trunk flexors (×2 = 8.264; P = .016) were significantly lower in obese BCSs compared with the normal-weight group, whereas systolic (F = 5.839; P = .004) and diastolic blood pressure (F = 8.794; P < .001), waist circumference (F = 85.81; P < .001), and arm circumference at 10 cm (affected side: F = 23.530; P < .001; nonaffected side: F = 17.095; P < .001) and 5 cm (affected side: F = 21.751; P < .001; nonaffected side: F = 22.490; P < .001) were significantly greater in BCSs with higher BMI compared with other groups. No significant differences were observed between groups regarding lower limb endurance, resting heart rate or CRF.

CONCLUSION

This study demonstrated the influence of obesity on health-related fitness, anthropometric measures, and cardiovascular state.

Impact of fibromyalgia on functioning in obese patients undergoing comprehensive rehabilitation

A possible link between fibromyalgia (FM) and obesity has been recently suggested but very scanty data on the prevalence of FM in obese populations are available. The aims of the present cross-sectional study were: 1) to estimate the prevalence of FM in a population of obese patients undergoing rehabilitation and 2) to investigate the effect of FM on obese patients' functional capacities. One hundred and thirty Italian obese (Body Mass Index, BMI ≥30) patients admitted to hospital for 1-month rehabilitation treatment took part in the study. All participants were interviewed by a rheumatologist according to the 2010 American College of Rheumatology (ACR) diagnostic criteria for FM. At admission and discharge from hospital (on average, after 28 days), the following measures were compared between the group of patients with FM and the other patients: body weight, body mass index, functional independence (FIM), obesity-related disability (TSD-OC), self-reported functioning and the Timed-Up-Go (TUG) test. Thirty seven patients out of 130 fulfilled the diagnostic criteria for FM. The prevalence rate was 27.7% (95% CI: 20 to 35.4). Between-group comparisons showed that FM patients had higher disability level at the first assessment, had lower scores on the FIM at the final assessment, scored lower on self-reported functioning both at the first and the final assessments and had a lower body weight. The prevalence of FM in our study is much higher than the rates reported in the general normal-weight population (on average, 3.5%) and the 5.15% rate previously reported in a bariatric population. Functional data showed that the FM obese group yielded lower performance capacity and higher disability level as compared to the non-FM obese group. However, due to the relatively small sample size and the selected population, such results need to be confirmed in larger obese subpopulations.

Disability affects the 6-minute walking distance in obese subjects (BMI>40 kg/m(2))

INTRODUCTION

In obese subjects, the relative reduction of the skeletal muscle strength, the reduced cardio-pulmonary capacity and tolerance to effort, the higher metabolic costs and, therefore, the increased inefficiency of gait together with the increased prevalence of co-morbid conditions might interfere with walking. Performance tests, such as the six-minute walking test (6MWT), can unveil the limitations in cardio-respiratory and motor functions underlying the obesity-related disability. Therefore the aims of the present study were: to explore the determinants of the 6-minute walking distance (6MWD) and to investigate the predictors of interruption of the walk test in obese subjects.

METHODS

Obese patients [body mass index (BMI)>40 kg/m(2)] were recruited from January 2009 to December 2011. Anthropometry, body composition, specific questionnaire for Obesity-related Disabilities (TSD-OC test), fitness status and 6MWT data were evaluated. The correlation between the 6MWD and the potential independent variables (anthropometric parameters, body composition, muscle strength, flexibility and disability) were analysed. The variables which were singularly correlated with the response variable were included in a multivariated regression model. Finally, the correlation between nutritional and functional parameters and test interruption was investigated.

RESULTS

354 subjects (87 males, mean age 48.5 ± 14 years, 267 females, mean age 49.8 ± 15 years) were enrolled in the study. Age, weight, height, BMI, fat mass and fat free mass indexes, handgrip strength and disability were significantly correlated with the 6MWD and considered in the multivariate analysis. The determination coefficient of the regression analysis ranged from 0.21 to 0.47 for the different models. Body weight, BMI, waist circumference, TSD-OC test score and flexibility were found to be predictors of the 6MWT interruption.

DISCUSSION

The present study demonstrated the impact of disability in obese subjects, together with age, anthropometric data, body composition and strength, on the 6-minute walking distance.