Objective: To evaluate physical performance on the six-minute walk test (6MWT) in patients with non-cystic fibrosis bronchiectasis and to investigate its relationship with quality of life (QoL). To identify predictors of exercise performance, we also investigated whether six-minute walk distance (6MWD) is associated with clinical and spirometric findings. Methods: This was a cross-sectional study involving patients with non-cystic fibrosis bronchiectasis (age,  18 years), with at least one respiratory symptom for  2 years and an FEV1  70% of predicted. Patients underwent clinical evaluation, pulmonary function tests, the 6MWT, and QoL assessment with the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36). Results: We included 70 patients (48 females). Mean age was 54.5 ± 17.7 years, and mean FEV1 was 44.9 ± 14.5% of predicted. The patients were divided into two groups: 6MWD-low (6MWD below the predicted lower limit; n = 23); and 6MWD-norm (normal 6MWD; n = 47). The following variables were significantly lower in the 6MWD-low group than in the 6MWD-norm group: age; age at diagnosis of bronchiectasis; proportion of former smokers; body mass index (BMI); FEV1% of predicted; and MEP% of predicted. There were no significant differences in the SF-36 scores between the groups. In the logistic regression model, lower age and lower BMI were significantly associated with lower 6MWD. Conclusions: In this sample, there was a high proportion of patients who had a lower than expected 6MWD. Although 6MWD was not related to QoL, it was associated with age and BMI.

Keywords: Bronchiectasis; Quality of life; Respiratory function tests; Exercise tolerance.

Objective: To determine the cut-off point for the six-minute walk distance (6MWD) that indicates lower survival time in patients with idiopathic pulmonary fibrosis (IPF) in Brazil. Methods: This was retrospective study carried out in two referral centers for IPF. The 6MWT was performed twice, considering the highest value of the 6MWD. Various cut-off points were estimated, in absolute values and in percentage of predicted values, using ROC curves, the Kaplan-Meier method, and data from other studies. Results: The sample comprised 70 patients with IPF. The mean age was 71.9 ± 6.4 years, and 50 patients (71.4%) were male. The mean FVC was 76.6 ± 18.2% of predicted value. The mean SpO2 at rest before and after 6MWT were 93.8 ± 2.5% and 85.3 ± 6.5%, respectively. The median survival time was 44 months (95% CI: 37-51 months). The mean 6MWD was 381 ± 115 m (79.2 ± 24.0% of predicted). After the analyses, the best cut-off points for estimating survival were 6MWD < 330 m and < 70% of predicted. The median survival time of patients with a 6MWD < 330 m was 24 months (95% CI: 3-45 months), whereas that of those with a 6MWD ≥ 330 m was 59 months (95% CI: 41-77 months; p = 0.009). Similarly, the median survival times of those with a 6MWD < 70% and ≥ 70% of predicted, respectively, were 24 months (95% CI: 13-35 months) and 59 months (95% CI: 38-80 months; p = 0.013). Cox multivariate regression models including age, sex, smoking status, SpO2 at the end of the 6MWT, and FVC% showed that 6MWD remained significantly associated with survival (p = 0.003). Conclusions: Values of 6MWD < 330 m and < 70% of predicted value were associated with lower survival time in IPF patients in Brazil.

Keywords: Lung diseases, interstitial; Pulmonary fibrosis; Exercise tolerance.

Objective: To assess the quality of life (QoL) of patients with cystic fibrosis (CF) followed at a university referral center for CF. Methods: A cross-sectional study involving application of the Cystic Fibrosis Questionnaire (CFQ) and Shwachman score in CF patients between April of 2008 and June of 2009. Results: The sample consisted of 75 patients. The mean age was 12.5 ± 5.1 years (range, 6.1-26.4 years). The patients were divided into three groups by age in years: group I (< 12), II (12-14), and III (≥ 14). The highest and lowest CFQ scores were for the nutrition domain in group III (89.3 ± 16.2) and the social domain in group II (59.5 ± 22.3), respectively. Groups I and III differed significantly regarding the treatment domain (p = 0.001). Regarding Shwachman scores, there were significant differences between patients scoring ≤ 70 and those scoring > 70 in the social (group I; p = 0.045), respiratory (group II; p = 0.053), and digestive (p = 0.042) domains. In group III, severity did not correlate with QoL. In groups I and II, patients with an FEV1 < 80% of predicted did not differ from other patients for any CFQ domain. However, in group III, values for the following domains were significantly lower in patients with an FEV1 < 80%: physical (p = 0.012); body image (p = 0.031); respiratory (p = 0.023), emotional (p = 0.041); and social role (p = 0.024). Conclusions: It is important to assess QoL in CF patients, because it can improve treatment compliance.

Keywords: Cystic fibrosis; Quality of life; Questionnaires.

Objective: To evaluate oral health-related quality of life (OHRQoL) among individuals with severe asthma, comparing it with that observed among individuals with mild-to-moderate asthma and individuals without asthma. Methods: We conducted a cross-sectional study of 125 individuals: 40 with severe asthma; 35 with mild-to-moderate asthma; and 50 without asthma. We calculated the decayed, missing, and filled teeth (DMFT) index, as well as the Periodontal Screening and Recording index, and determined the stimulated salivary flow rate. We applied three structured questionnaires: the 14-item Oral Health Impact Profile (OHIP-14); the Medical Outcomes Study 36-Item Short-Form Health Survey, version 2 (SF-36v2); and the Work Ability Index (WAI). Results: Periodontitis and reduced salivary flow were both more common in the severe asthma group than in the mild-to-moderate asthma and no-asthma groups. In addition, the WAI scores were lower in the severe asthma group than in the mild-to-moderate asthma and no-asthma groups, as were the scores for all SF-36v2 domains. The individuals with severe asthma also scored lower for the OHIP-14 domains than did those without asthma. Although the mean DMFT index did not differ significantly among the groups, the mean number of missing teeth was highest in the severe asthma group. Strong correlations between the SF-36v2 Component Summaries and poorer OHRQoL were only observed in the severe asthma group. Conclusions: Severe asthma appears to be associated with poorer oral health, poorer OHRQoL, a lower WAI, and lower scores for SF-36v2 domains.

Keywords: Oral health; Periodontal diseases; Asthma.

Background: Hyperhidrosis or excessive sudoresis is a chronic disease associated with important subjective distress. Objective: To propose a specific questionnaire to evaluate the quality of life of patients with hyperhidrosis. Methods: From October 1995 to March 2002, 378 patients (234 females), with a mean age of 26.8 years, were evaluated before and after video-assisted thoracic sympathectomy. Results: Therapeutic success was obtained in 90% of the procedures. The recurrence rate was 10% for palmar and 11% for axillary hyperhidrosis; 27% of the patients who had recurrence were re-operated successfully. No serious complications were reported. Of the total number of patients, 91% answered to the quality of life questionnaire, and 86% of them reported improvement after the procedure. Conclusions: Thoracic sympathectomy is a therapeutic method capable of changing the quality of life of patients with hyperhidrosis. The questionnaire applied has shown these changes.

Keywords: Thoracic sympathectomy. Quality of life.

Objective: Barriers to physical activity can affect the functional capacity and quality of life of patients with pulmonary hypertension (PH). This study aimed to identify the main barriers to physical activity in patients with PH and to examine whether those barriers are related to functional capacity, echocardiographic variables, or quality of life. Methods: This was a cross-sectional observational study involving 70 patients. Participants scored seven potential barriers to their activities, with a score = 5 indicating a significant barrier. Participants completed the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) and Manchester Respiratory Activity of Daily Living questionnaire, as well as the six-minute walk test. Correlation analysis, univariate analysis and multiple logistic regression were performed. Results: As a perceived barrier to physical activity, 'lack of will' or 'lack of energy' was cited by 67% of the patients. The 'lack of will' barrier was found to correlate with all SF-36 domains except bodily pain. We also identified a correlation between the SF-36 vitality domain and the barriers 'lack of energy', 'lack of will' and 'lack of structure'. The logistic regression analysis indicated that the vitality domain correlated significantly with the barriers 'social influence', 'lack of energy', 'lack of will', and 'lack of structure'. For each unit decrease in the vitality score, there was a 10% increase in the probability of citing the barrier 'lack of will'. No significant correlations were identified between any of the perceived barriers and echocardiographic parameters. Conclusions: The perceived barrier most commonly reported was 'lack of will/energy', which correlated with almost all SF-36 domains, especially vitality. The 'lack of will' barrier also correlated with functional capacity.

Keywords: Pulmonary arterial hypertension; Exercise; Motivation; Quality of life; Surveys and questionnaires; Walk test.

Objective: To evaluate the effects that pulmonary resection has on pulmonary function and quality of life (QoL) in patients with primary or metastatic lung cancer. Methods: This was a prospective cohort study involving all patients submitted to pulmonary resection for cancer between September of 2006 and March of 2007 at the A. C. Camargo Hospital in São Paulo, Brazil. Patients underwent spirometry in the preoperative period and at six months after the surgical procedure. After a postoperative period of six months, the patients completed an overall QoL questionnaire (the Medical Outcomes Study 36-item Short-form Health Survey) and another one, specific for respiratory symptoms (the Saint George's Respiratory Questionnaire). The scores obtained in our study were compared with those previously obtained for a general population and for a population of patients with COPD. Results: We included 33 patients (14 males and 19 females), ranging in age from 39 to 79 years. All of the patients, smokers and nonsmokers alike, presented significant worsening of pulmonary function. The mean scores on the overall QoL questionnaire were approximately 5% lower than those obtained for the general population. The scores of various domains of the symptom-specific QoL questionnaire were 50-60% lower than those obtained for the general population and approximately 20% higher than those obtained for the population with COPD. Conclusions: Pulmonary resection has a direct negative impact on pulmonary function and QoL, especially on the QoL related to aspects directly linked to pulmonary function. We highlight the importance of preoperative assessment of pulmonary function in patients undergoing pulmonary resection, in order to predict their postoperative evolution.

Keywords: Thoracic surgery; Lung neoplasms/surgery; Spirometry; Quality of life; Questionnaires.

Objective: To identify, characterize, and quantify associations of various factors with quality of life (QoL) in patients with asthma, according to the pharmacotherapy employed. Methods: This was a cross-sectional study involving 49 patients (≥ 18 years of age) with severe uncontrolled or refractory asthma treated at a specialized outpatient clinic of the Brazilian Unified Health Care System, regularly using high doses of inhaled corticosteroids (ICs) or other medications, and presenting comorbidities. At a single time point, QoL was assessed with the Asthma Quality of Life Questionnaire (AQLQ). The overall AQLQ score and those of its domains were correlated with demographic variables (gender and age); Asthma Control Questionnaire score; pharmacotherapy (initial IC dose, inhaler devices, and polytherapy); and comorbidities. Results: Better AQLQ scores were associated with asthma control-overall (OR = 0.38; 95% CI: 0.004-0.341; p < 0.001), "symptoms" domain (OR = 0.086; 95% CI: 0.016-0.476; p = 0.001), and "emotional function" domain (OR = 0.086; 95% CI: 0.016-0.476; p = 0.001)-and with IC dose ≤ 800 µg-"activity limitation" domain (OR = 0.249; 95% CI: 0.070-0.885; p = 0.029). Worse AQLQ scores were associated with polytherapy-"activity limitation" domain (OR = 3.651; 95% CI: 1.061-12.561; p = 0.036)-and number of comorbidities ≤ 5-"environmental stimuli" domain (OR = 5.042; 95% CI: 1.316-19.317; p = 0.015). Conclusions: Our results, the importance of this issue, and the lack of studies taking pharmacotherapy into consideration warrant longitudinal studies to establish a causal relationship between the identified factors and QoL in asthma patients.

Keywords: Asthma; Asthma/drug therapy; Quality of life; Medication therapy management.

Objective: To evaluate whether a six-minute walk distance (6MWD) of < 80% of the predicted value can predict the occurrence of acute exacerbations of COPD in patients in Brazil over a 2-year period. Methods: This was a retrospective cross-sectional study involving 50 COPD patients in Brazil. At enrollment, anthropometric data were collected and patients were assessed for pulmonary function (by spirometry) and functional exercise capacity (by the 6MWD). The patients were subsequently divided into two groups: 6MWD ≤ 80% of predicted and 6MWD > 80% of predicted. The occurrence of acute exacerbations of COPD over 2 years was identified by analyzing medical records and contacting patients by telephone. Results: In the sample as a whole, there was moderate-to-severe airflow obstruction (mean FEV1 = 41 ± 12% of predicted) and the mean 6MWD was 469 ± 60 m (86 ± 10% of predicted). Over the 2-year follow-up period, 25 patients (50%) experienced acute exacerbations of COPD. The Kaplan-Meier method showed that the patients in whom the 6MWD was ≤ 80% of predicted were more likely to have exacerbations than were those in whom the 6MWD was > 80% of predicted (p = 0.01), whereas the Cox regression model showed that the former were 2.6 times as likely to have an exacerbation over a 2-year period as were the latter (p = 0.02). Conclusions: In Brazil, the 6MWD can predict acute exacerbations of COPD over a 2-year period. The risk of experiencing an acute exacerbation of COPD within 2 years is more than twice as high in patients in whom the 6MWD is ≤ 80% of predicted.

Keywords: Pulmonary disease, chronic obstructive; Risk groups; Exercise.

Objective: To determine whether the Body mass index, airway Obstruction, Dyspnea, and Exercise capacity (BODE) index correlates with health-related quality of life in patients with COPD. Methods: We evaluated 42 patients with COPD, quantifying the following: lung function parameters; anthropometric variables; exercise capacity, with the six-minute walk test; dyspnea, with the modified Medical Research Council (MRC) scale; the BODE index; and quality of life, with the modified Saint George's Respiratory Questionnaire (mSGRQ). Patients were divided into two groups by disease severity: FEV1 ≥ 50% and FEV1 < 50%. Results: The mean BODE index was 2.58 ± 1.17 and 4.15 ± 1.81, respectively, for the FEV1 ≥ 50% and FEV1 < 50% groups. There was a significant difference between the groups in terms of FEV1 and the FEV1/FVC ratio. There were moderate to significant correlations between the BODE index scores and all of the mSGRQ domains in the group of patients with FEV1 <50%. Conclusions: The BODE index score correlated with the scores of all of the mSGRQ domains in COPD patients with FEV1 < 50%. Therefore, COPD patients with FEV1 < 50% die sooner and have a poorer quality of life.

Keywords: Pulmonary disease, chronic obstructive; Quality of life; Severity of illness index; Prognosis.

Objective: To evaluate the effect of chemotherapy on the physical condition of patients with advanced lung cancer. Methods: We evaluated 50 patients with non-small cell lung cancer (in stages IIIB and IV) and Eastern Cooperative Oncology Group (ECOG) performance status scale scores between zero and two. All patients underwent chemotherapy using paclitaxel and platinum derivatives and were evaluated at three time points (prechemotherapy, postchemotherapy and six months after starting the treatment), at which the ECOG scale, the body mass index (BMI) and the six-minute walk distance (6MWD) were assessed. Results: Of the 50 patients included in the study, 14 died, 5 were excluded due to the worsening of their performance status, and 31 completed the six-month follow-up. There was no statistically significant difference between the time points of assessment for BMI (prechemotherapy vs. postchemotherapy, p = 1.00; and prechemotherapy vs. six months later, p = 0.218) or for 6MWD. Performance status improved, and this was especially due to the increase in the number of asymptomatic patients after the six-month follow-up (p = 0.031). Conclusions: Chemotherapy had a beneficial effect on the performance status of the patients. No significant changes in BMI or 6MWD were found during the study period, which might suggest the maintenance of the physical condition of the patients.

Keywords: Drug therapy; Lung neoplasms; Exercise tolerance.

Objective: To compare two quality of life questionnaires-the Saint George's Respiratory Questionnaire (SGRQ) and the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36)-in patients with COPD, focusing on the discriminative properties of the questionnaires and correlating their domains with the following variables: Modified Medical Research Council Dyspnea Scale score; Beck Depression Inventory score; visual analog scale general health perception; Mini-Mental State Examination score; and a COPD clinical score developed specifically for the study. Methods: We interviewed 30 COPD patients between May and September of 2006. For the SF-36 and SGRQ, scores (total and domain) were compared and correlated. Results: With the exception of the pain domain, all of the SF-36 domains correlated significantly with the SGRQ total score (r = −0.5 to −0.69; p < 0.01). Of the SGQR domains, only the symptoms domain correlated significantly with all of the variables studied (p < 0.05). Conclusions: The majority of the expected correlations between the SGRQ and the SF-36 were observed, as were those expected between the two questionnaires and the other variables studied. The SGRQ, notably the symptoms domain, presented better discriminative properties than did the generic SF-36 questionnaire. The SF-36 is not an appropriate instrument for determining the affective state of COPD patients.

Keywords: Pulmonary disease, chronic obstructive; Quality of life; Data collection.

Objective: The objective of this study was to evaluate the applicability of a modified version of the Saint George's Respiratory Questionnaire. The version evaluated elicits "agree" and "do not agree", rather than "yes" and "no", responses. The intention is to facilitate the comprehension of double-negative questions and to promote better recollection of symptoms by patients by shortening their symptom histories from 12 months to 3 months. Methods: A total of 30 clinically stable patients with chronic obstructive pulmonary disease were evaluated. The Saint George's Respiratory Questionnaire and the modified version of the same were administered 15 days apart. Results: All of the patients presented health-related alterations in their quality of life. Comparing mean scores between the two questionnaires, the greatest difference was seen in the Symptoms domain. No significant differences were found in any of the remaining domains or in the total scores. In a subsequent analysis, significant correlations between the two questionnaires were found in all domains: Symptoms (r = 0.71; p < 0.001); Activity (r = 0.75; p < 0.001); Impact (r = 0.73; p < 0.001) and Total (r = 0.86; p < 0.001). Conclusion: The modified version of the Saint George's Respiratory Questionnaire is as effective as the original in gauging quality of life. However, various symptoms recollection time frames should be investigated in order to determine which would be the best time frame to employ in the analysis.

Keywords: Pulmonary disease, chronic obstructive; Quality of life; Reproducibility of results; Cross-cultural comparison; Questionnaires

Objective: To identify the predictive factors of oxygen desaturation during the six-minute walk test (6MWT) in patients with cystic fibrosis (CF). Methods: Prospective cross-sectional study involving clinically stable patients with CF aged ≥ 10 years. The patients were submitted to nutritional evaluations, oral glucose tolerance tests, pulmonary function tests, chest X-rays and 6MWTs. Results: The study included 88 patients (43 females and 45 males; mean age, 19.9 ± 7.2 years; mean FEV1, 65.4 ± 28.4%). We observed oxygen desaturation in 13 patients (OD+ group) and no oxygen desaturation in 75 (OD− group). In comparison with OD− group patients, OD+ group patients presented higher mean age (p = 0.004), worse clinical score (p < 0.001), worse radiological score (p < 0.001), higher incidence of glucose intolerance (p = 0.004), lower incidence of methicillin-sensitive Staphylococcus aureus infection (p < 0.001), higher incidence of methicillin-resistant S. aureus infection (p = 0.016), higher incidence of Pseudomonas aeruginosa infection (p = 0.008), lower mean resting SpO2 (p < 0.001) and lower mean FEV1 (p < 0.001). In the logistic regression analysis, oxygen desaturation during the 6MWT correlated with resting SpO2 (OR = 0.305, p < 0.001) and FEV1 (OR = 0.882, p = 0.025). The parameters maximizing the predictive value for oxygen desaturation were resting SpO2 < 96% and FEV1 < 40%. In this sample, 15% of the patients with CF aged ≥ 10 years presented oxygen desaturation during the 6MWT. Conclusions: Resting SpO2 < 96% and FEV1 < 40% can predict oxygen desaturation during the 6MWT.

Keywords: Cystic fibrosis; Respiratory function tests; Exercise tolerance.

Objective: To evaluate the association between degree of asthma control and health-related quality of life in patients with moderate or severe asthma. Methods: This was a descriptive observational study involving 59 outpatients with moderate or severe asthma under treatment at the Asthma Outpatient Clinic of the Federal University of Ceará Walter Cantídio University Hospital, in the city of Fortaleza, Brazil. The patients were evaluated regarding sociodemographic and clinical characteristics, as well as spirometric parameters. The asthma control status was assessed using the asthma control test (ACT), and quality of life was assessed using the Saint George's Respiratory Questionnaire (SGRQ). Results: The mean age of the patients was 55.0 ± 12.4 years, and 76.3% were female. The ACT score showed statistically significant negative correlations with all SGRQ scores: total (r = −0.72); symptoms (r = −0.78); activity (r = −0.67); and impact (r = −0.68). Multiple regression analysis showed that the most robust predictive variables for SGRQ total score were ACT score (coefficient = −3.18; 95% CI: −4.14 to −2.23) and duration of disease (coefficient = −0.29; 95% CI: −0.54 to −0.03). The ACT score also explained the linear variation of the SGRQ domains: symptoms (coefficient = −3.41; 95% CI: −4.45 to −2.37); activity (coefficient = −3.07; 95% CI: −4.57 to −1.57); and impact (coefficient = −2.68; 95% CI: −3.71 to −1.65). Conclusions: The degree of asthma control appears to have a significant impact on health-related quality of life.

Keywords: Asthma/prevention and control; Quality of life; Questionnaires.

Objective: To evaluate quality of life in elderly patients with obstructive sleep apnea (OSA) who have a pacemaker. Methods: This was a cross-sectional study involving elderly patients (≥ 60 years of age) with a pacemaker. The dependent variable was quality of life, as evaluated with the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36). Sociodemographic and clinical parameters, including anxiety and depression (Hospital Anxiety and Depression Scale score), as well as the presence of OSA (defined as an apnea-hypopnea index ≥ 15 events/h), were analyzed as independent variables. Patients with cognitive/neurological deficits or decompensated heart failure were excluded. Results: We evaluated 72 patients, 17 (23.6%) of whom presented OSA. Of those 17 patients, 9 (52.9%) were male. The mean age was 72.3 ± 9.3 years. A diagnosis of OSA was not associated with gender (p = 0.132), age (p = 0.294), or body mass index (p = 0.790). There were no differences between the patients with OSA and those without, in terms of the SF-36 domain scores. Fourteen patients (19.4%) presented moderate or severe anxiety. Of those 14 patients, only 3 (21.4%) had OSA (p = 0.89 vs. no OSA). Twelve patients (16.6%) had moderate or severe depression. Of those 12 patients, only 2 (16.6%) had OSA (p = 0.73 vs. no OSA). Conclusions: In elderly patients with a pacemaker, OSA was not found to be associated with quality of life or with symptoms of anxiety or depression.

Keywords: Quality of life; Aged; Sleep apnea, obstructive.

Objective: To profile the characteristics of adult patients with bronchiectasis, drawing comparisons between cystic fibrosis (CF) patients and those with bronchiectasis from other causes in order to determine whether it is rational to extrapolate the bronchiectasis treatment given to CF patients to those with bronchiectasis from other causes. Methods: A retrospective analysis of the medical charts of 87 patients diagnosed with bronchiectasis and under follow-up treatment at our outpatient clinic. Patients who had tuberculosis (current or previous) were excluded. We evaluated the clinical, functional, and treatment data of the patients. Results: Of the 87 patients with bronchiectasis, 38 (43.7%) had been diagnosed with CF, through determination of sweat sodium and chloride concentrations or through genetic analysis, whereas the disease was due to another etiology in 49 (56.3%), of whom 34 (39.0%) had been diagnosed with idiopathic bronchiectasis. The mean age at diagnosis was lower in the patients with CF than in those without (14.2 vs. 24.2 years; p < 0.05). The prevalence of symptoms (cough, expectoration, hemoptysis, and wheezing) was similar between the groups. Colonization by Pseudomonas aeruginosa or Staphylococcus aureus was more common in the CF patients (82.4 vs. 29.7% and 64.7 vs. 5.4%, respectively). Conclusions: The causes and clinical manifestations of bronchiectasis are heterogeneous, and it is important to identify the differences. It is crucial that these differences be recognized so that new strategies for the management of patients with bronchiectasis can be developed.

Keywords: Cystic fibrosis; Bronchiectasis/diagnosis; Bronchiectasis/therapy; Respiratory function tests.

Objective: To determine reference values for incremental shuttle walk distance (ISWD) and peak physiological responses during the incremental shuttle walk test (ISWT), as well as to develop a series of predictive equations for those variables in healthy adults. Methods: We evaluated 103 healthy participants ≥ 40 years of age (54 women and 49 men). We fitted each participant with a gas analysis system for use during the ISWT. Oxygen consumption (VO2), carbon dioxide production, minute ventilation, heart rate (HR), ISWD, and maximal walking velocity (MWV) were obtained as primary outcomes. We also assessed hand grip strength (HGS) and lean body mass (LBM). Results: The regression analysis models, including physiological variables, ISWD, and MWV (adjusted for age, body mass, height, and sex), produced R2 values ranging from 0.40 to 0.65 (for HR and peak VO2, respectively). Using the models including LBM or HGS, we obtained no significant increase in the R2 values for predicting peak VO2, although the use of those models did result in slight increases in the R2 values for ISWD and MWV (of 8% and 12%, respectively). The variables ISWD, MWV, and ISWD Î body mass, respectively, explained 76.7%, 73.3%, and 81.2% of peak VO2 variability. Conclusions:áOur results provide reference values for ISWD and physiological responses to the ISWT, which can be properly estimated by determining simple demographic and anthropometric characteristics in healthy adults ≥ 40 years of age. The ISWT could be used in assessing physical fitness in the general adult population and in designing individualized walking programs.

Keywords: Reference values; Pulmonary gas exchange; Walking; Exercise test.