Impairment of (inspiratory and expiratory) respiratory muscles is a common clinical finding, not only in patients with neuromuscular disease but also in patients with primary disease of the lung parenchyma or airways. Although such impairment is common, its recognition is usually delayed because its signs and symptoms are nonspecific and late. This delayed recognition, or even the lack thereof, occurs because the diagnostic tests used in the assessment of respiratory muscle strength are not widely known and available. There are various methods of assessing respiratory muscle strength during the inspiratory and expiratory phases. These methods are divided into two categories: volitional tests (which require patient understanding and cooperation); and non-volitional tests. Volitional tests, such as those that measure maximal inspiratory and expiratory pressures, are the most commonly used because they are readily available. Non-volitional tests depend on magnetic stimulation of the phrenic nerve accompanied by the measurement of inspiratory mouth pressure, inspiratory esophageal pressure, or inspiratory transdiaphragmatic pressure. Another method that has come to be widely used is ultrasound imaging of the diaphragm. We believe that pulmonologists involved in the care of patients with respiratory diseases should be familiar with the tests used in order to assess respiratory muscle function.Therefore, the aim of the present article is to describe the advantages, disadvantages, procedures, and clinical applicability of the main tests used in the assessment of respiratory muscle strength.

Keywords: Respiratory muscles; Muscle weakness; Diaphragm; Respiratory function tests; Diagnostic tests, routine.

Objective: To compare children/adolescents with mild or moderate asthma and healthy subjects in terms of respiratory muscle strength, correlating it with spirometric variables in the former group. Methods: This was a cross-sectional study involving individuals 6-16 years of age and clinically diagnosed with mild/moderate asthma, together with a group of healthy, age- and gender-matched subjects. We determined spirometric values, as well as MIP and MEP, and we selected three reproducible measurements (variation < 10%). Results: We evaluated 75 patients with asthma and 90 controls. The mean age was 10.0 ± 2.6 years. There were no statistically significant differences between the controls and the asthma group regarding MIP (−89.7 ± 26.7 cmH2O vs. −92.2 ± 26.3 cmH2O; p = 0.541) or MEP (79.2 ± 22.9 cmH2O vs. 86.4 ± 24.0 cmH2O; p = 0.256). The groups were subdivided by age (children and adolescents: 6-12 and 13-16 years of age, respectively). Within the asthma group, there was a significant difference between the child and adolescent subgroups in terms of MEP (74.1 ± 24.1 cmH2O vs. 92.1 ± 21.9 cmH2O; p < 0.001) but not MIP (p = 0.285). Within the control group, there were significant differences between the child and adolescent subgroups in terms of MIP (−79.1 ± 17.7 cmH2O vs. −100.9 ± 28.1 cmH2O; p < 0.001) and MEP (73.9 ± 18.7 cmH2O vs. 90.9 ± 28.1cmH2O; p < 0.001). In the asthma group, spirometric variables did not correlate with MIP or MEP. Conclusions: In our sample, asthma was found to have no significant effect on respiratory muscle strength.

Objective: The aim of the present study was to evaluate the effects that inspiratory muscle training (IMT) and respiratory exercises have on muscle strength, peak expiratory flow (PEF) and severity variables in children with asthma. Methods: This was a randomized analytical study involving 50 children with asthma allocated to one of two groups: an IMT group, comprising 25 children submitted to IMT via an asthma education and treatment program; and a control group, comprising 25 children who were submitted only to monthly medical visits and education on asthma. The IMT was performed using a pressure threshold load of 40% of maximal inspiratory pressure (MIP). The results were evaluated using analysis of variance, the chi-square test and Fisher's exact test, values of p > 0.05 being considered significant. Results: In the comparative analysis, pre- and post-intervention values of MIP, maximal expiratory pressure (MEP) and PEF increased significantly in the IMT group: MIP from −48.32 ± 5.706 to −109.92 ± 18.041 (p < 0.0001); MEP from 50.64 ± 6.55 to 82.04 ± 17.006 (p < 0.0001); and PEF from 173.6 ± 50.817 to 312 ± 54.848 (p < 0.0001). In the control group, however, there were no significant differences between the two time points in terms of MIP or MEP, although PEF increased from 188 ± 43.97 to 208.80 ± 44.283 (p < 0.0001). There was a significant improvement in the severity variables in the IMT group (p < 0.0001). Conclusions: Programs involving IMT and respiratory exercises can increase mechanical efficiency of the respiratory muscles, as well as improving PEF and severity variables.

Keywords: Breathing exercises; Asthma/therapy; Asthma/rehabilitation.

Objective: To describe and to compare MIP and MEP in primigravidae and nulligravidae in the 20-29 year age bracket and paired by age. Methods: We included 120 primigravidae with low obstetric risk (5th-40th week of gestation) and 40 nulligravidae. All of the participants were of normal weight and none exercised regularly. All were recruited from the metropolitan area of Recife, Brazil. Measurements of MIP and MEP were obtained from RV and TLC, respectively, with a digital manometer. We used Student's t-test to compare the two groups, and we used multiple linear regression in order to determine whether group or chronological age correlated with MIP or MEP. Results: In the primigravida and nulligravida groups, the mean MIP values were 88.50 ± 16.52 cmH2O and 94.22 ± 22.63 cmH2O, respectively, (p = 0.08), whereas the mean MEP values were 99.76 ±18.19 cmH2O and 98.67 ± 20.78 cmH2O (p = 0.75). Gestational age did not correlate with MIP (r = −0.06; p = 0.49) or MEP (r = −0.11; p = 0.22). The relationship between chronological age and MIP/MEP did not differ between primigravidae and nulligravidae (angular coefficient = 0.028 and 0.453, respectively). Conclusions: Within this sample of women in the 20-29 year age bracket, the respiratory pressures of primigravidae remained stable during pregnancy and did not differ significantly from those of nulligravidae.

Keywords: Pregnancy; Respiratory function tests; Muscle strength.

Background: Gastroplasty has been increasingly used in the treatment of morbidly obese patients, who typically present pronounced alterations in lung volume and capacity. Objective: To evaluate post-gastroplasty lung volume, lung capacity, respiratory muscle strength and respiratory pattern, as well as any postoperative pulmonary complications. Method: 21 patients (3 of them men), with an average age of 39 ± 9.7 years and an average body mass index of 50.4 kg/m2, all candidates for gastroplasty, were evaluated during the preoperative period and again on the first, third and fifth postoperative days. Tidal volume, vital capacity, minute volume, maximal expiratory pressure and maximal inspiratory pressure, as well as chest and waist circumferences, were measured. Postoperative pulmonary complications and mortality were assessed. Results: On the first and third postoperative days, respectively, there were drops of 47% and 30.5% in vital capacity, 18% and 12.5% in minute volume, 28% and 21% in tidal volume, 47% and 32% in the diaphragmatic index, 51% and 26% in maximal inspiratory pressure, and 39.5% and 26% in maximal expiratory pressure (p < 0.05). On the fifth postoperative day, all variables analyzed were higher than on the first postoperative day, indicating a linear increase, with only tidal volume, minute volume diaphragmatic index returning to preoperative values. The incidence of postoperative pulmonary complications was 4.7%, and there were no deaths. Conclusion: Patients submitted to gastroplasty present reduced pulmonary function, following a pattern quite similar to that previously observed following other types of upper abdominal surgery.

Keywords: Key words: Gastroplasty. Obesity. Respiratory function tests. Postoperative care.

It has been well established that, in addition to the pulmonary involvement, COPD has systemic consequences that can lead to peripheral muscle dysfunction, with greater muscle fatigue, lower exercise tolerance and lower survival in these patients. In view of the negative repercussions of early muscle fatigue in COPD, the objective of this review was to discuss the principal findings in the literature on the metabolic and bioenergy determinants of muscle fatigue, its functional repercussions, as well as the methods for its identification and quantification. The anatomical and functional substrate of higher muscle fatigue in COPD appears to include lower levels of high-energy phosphates, lower mitochondrial density, early lactacidemia, higher serum ammonia and reduced muscle perfusion. These alterations can be revealed by contraction failure, decreased firing rates of motor units and increased recruitment of motor units in a given activity, which can be functionally detected by a reduction in muscle strength, power and endurance. This review article also shows that various types of muscle contraction regimens and protocols have been used in order to detect muscle fatigue in this population. With this understanding, rehabilitation strategies can be developed in order to improve the resistance to muscle fatigue in this population.

Keywords: Pulmonary disease, chronic obstructive; Neuromuscular manifestations; Muscle fatigue; Exercise tolerance; Energy metabolism; Evaluation.

Objective: To determine whether inspiratory muscle training can increase strength and endurance of these muscles in quadriplegic patients. Methods: Eight quadriplegic patients (7 males and 1 female) with injury to the lower cervical spine (segments C4-C7) were submitted to inspiratory muscle training with a threshold inspiratory muscle trainer adjusted to 30% of MIP. The training sessions were carried out with the patients in a sitting position, 5 days a week for 8 weeks. Endurance time, MIP, MEP and FVC were determined at baseline, week 4 and week 8. Results: In comparison with the mean baseline value, there was an increase in MIP, measured in the sitting position, at weeks 4 and 8 (−83.0 ± 18.9 cmH2O vs. −104.0 ± 19.4 cmH2O and −111.3 ± 22.7 cmH2O). There was an increase in MEP, also in the sitting position, at week 4 (from 36.8 ± 8.1 to 42.6 ± 8.8 cmH2O). There was an improvement in FVC at week 4 (from 2.1 ± 0.8 to 2.5 ± 0.6 L, representing an increase of 24 ± 22%). Although there was an increase in endurance (sitting) at week 8, the difference was not significant in comparison with the baseline value (29.8 ± 21.0 vs. 35.9 ± 15.5 min, an increase of 173 ± 233%). Conclusions: Quadriplegic patients can benefit from training at low loads (30% of MIP), which can improve inspiratory muscle strength, FVC and expiratory muscle performance.

Keywords: Respiratory mechanics; Quadriplegia; Breathing exercises.

Objective: To compare the behavior of the oxygen uptake efficiency slope (OUES) with that of oxygen uptake at peak exertion (VO2peak). Methods: This was a prospective cross-sectional study involving 21 patients (15 men) with mild-to-moderate COPD undergoing spirometry, handgrip strength (HGS) testing, cardiopulmonary exercise testing, and determination of lactate at peak exertion (LACpeak). Results: Mean weight was 66.7 ± 13.6 kg, and mean age was 60.7 ± 7.8 years. With the exception of FEV1 and FEV1/FVC ratio (75.8 ± 18.6% of predicted and 56.6 ± 8.8%, respectively), all spirometric variables were normal, as was HGS. The patients exhibited significant metabolic and hemodynamic stress, as evidenced by the means (% of predicted) for VO2peak (93.1 ± 15.4), maximum HR (92.5 ± 10.4), and OUES (99.4 ± 24.4), as well as for the gas exchange rate (1.2 ± 0.1). The correlation between VO2peak and OUES was significant (r = 0.747; p < 0.0001). The correlation between HGS and VO2peak (r = 0.734; pX< 0.0001) was more significant than was that between HGS and OUES (r = 0.453; p < 0.05). Similar results were found regarding the correlations of VO2peak and OUES with MIP. Although LACpeak correlated significantly with VO2peak (r = −0.731; p < 0.0001), only LACpeak/maximum power correlated significantly with OUES (r = −0.605; p = 0.004). Conclusions: Our findings suggest that, in mild-to-moderate COPD, VO2 determinants other than overall muscle strength have a greater impact on OUES than on VO2peak.

Keywords: Respiratory function tests; Pulmonary disease, chronic obstructive; Muscle strength; Oxygen consumption.

Objective: To evaluate the magnitude of diurnal changes in the parameters of pulmonary function and respiratory muscle strength/endurance in a sample of patients with COPD. Methods: A group of 7 patients underwent spirometry, together with determination of MIP and MEP, at two distinct times (between 8:00 and 8:30 a.m. and between 4:30 and 5:00 p.m.) on a single day. Between assessments, the patients remained at rest in the laboratory. Results: In accordance with the Global Initiative for Chronic Obstructive Pulmonary Disease staging system, COPD was classified as moderate, severe, and very severe in 1, 3, and 3 of the patients, respectively. From the first to the second assessment, there were significant decreases in FVC, FEV1, and MEP (of 13%, 15%, and 10%, respectively), as well as (less than significant) decreases in PEF, MIP, and maximal voluntary ventilation (of 9%, 3%, and 11%, respectively). Conclusions: In this sample of COPD patients, there were diurnal variations in the parameters of pulmonary function and respiratory muscle strength. The values of FEV1, FVC, and MEP were significantly lower in the afternoon than in the morning.

Keywords: Pulmonary disease, chronic obstructive; Respiratory function tests; Respiratory muscles.

Objective: To evaluate pulmonary function and respiratory muscle strength in chronic renal failure patients, correlating these variables with hemodialysis-related weight fluctuation; to study the correlation between the duration of hemodialysis and potential respiratory alterations. Methods: Seventeen patients (median age, 47 years; interquartile range, 41-52 years), submitted to three weekly hemodialysis sessions for a median of 27 months (interquartile range, 14-55) were evaluated. Twelve of the patients were male. The patients underwent spirometry. Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were measured prior to and after the first hemodialysis session of the week. Body weight was quantified prior to and after each of the three weekly sessions. Results: Before the first hemodialysis session of the week, 8 patients presented mild restrictive defect, which normalized after the session in 2 of those patients. After dialysis, there was a significant increase in forced vital capacity (p = 0.02) and a significant decrease in body weight (p = 0.0001). Weight fluctuation over 3 days without hemodialysis tended to correlate with the variation in forced vital capacity in the first weekly session (r = 0.47; p = 0.055). Duration of hemodialysis correlated with predialysis MIP (r = −0.3; p = 0.03) and MEP (r = −0.63; p = 0.006). Conclusions: More pronounced weight gain in the interdialytic period is associated with worsening of lung function, which is almost fully reversible by hemodialysis. In addition, longer duration of hemodialysis is associated with decreased respiratory muscle strength.

Keywords: Spirometry; Respiratory muscles/physiopathology; Kidney failure, chronic; Renal dialysis.

Objective: To evaluate respiratory muscle strength and six-minute walk test (6MWT) variables in patients with uncontrolled severe asthma (UCSA). Methods: This was a cross-sectional study involving UCSA patients followed at a university hospital. The patients underwent 6MWT, spirometry, and measurements of respiratory muscle strength, as well as completing the Asthma Control Test (ACT). The Mann-Whitney test was used in order to analyze 6MWT variables, whereas the Kruskal-Wallis test was used to determine whether there was an association between the use of oral corticosteroids and respiratory muscle strength. Results: We included 25 patients. Mean FEV1 was 58.8  21.8% of predicted, and mean ACT score was 14.0  3.9 points. No significant difference was found between the median six-minute walk distance recorded for the UCSA patients and that predicted for healthy Brazilians (512 m and 534 m, respectively; p = 0.14). During the 6MWT, there was no significant drop in SpO2. Mean MIP and MEP were normal (72.9  15.2% and 67.6  22.2%, respectively). Comparing the patients treated with at least four courses of oral corticosteroids per year and those treated with three or fewer, we found no significant differences in MIP (p = 0.15) or MEP (p = 0.45). Conclusions: Our findings suggest that UCSA patients are similar to normal subjects in terms of 6MWT variables and respiratory muscle strength. The use of oral corticosteroids has no apparent impact on respiratory muscle strength.

Objective: To investigate parameters of lung function and respiratory muscle strength in different stages of Parkinson's disease (PD), as well as to determine their correlation with motor function and quality of life. Methods: This was a cross-sectional study conducted at a referral center for PD in the city of Recife, Brazil. Respiratory muscle strength and lung function, as well as their relationship with motor function and quality of life, were evaluated in patients with PD, stratified by the level of severity, and were compared with the data obtained for a control group. After confirming the normality of data distribution, we performed one-way ANOVA with a post hoc t-test. Results: The sample comprised 66 individuals, in two groups: PD (n = 49) and control (n = 17). All of the parameters investigated showed inverse correlations with PD severity, and there were significant differences among the levels of severity, as well as between the PD and control groups, in terms of the MIP, MEP, FVC, FEV1, and FEF25-75%. The lung function parameters also showed moderate to weak inverse correlations with bradykinesia and rigidity. On a quality of life questionnaire, the total score and mobility domain score both presented a moderate inverse correlation with FVC, FEV1, PEF, and MEP. Conclusions: Respiratory muscle strength and some lung function parameters are impaired from the early stages of PD onward, bradykinesia and rigidity being the cardinal signs that correlate most strongly with impairment of those parameters. Such alterations negatively affect the quality of life of patients with PD.

Keywords: Parkinson disease; Respiratory mechanics; Maximum respiratory pressures; Quality of life.

Objective: To establish reference values and prediction equations for the strength index (S-Index), in order to meet the growing demand for clinical application and diagnostic understanding of maximal dynamic inspiratory pressure. Methods: This was a prospective study of 120 healthy subjects between 18 and 80 years of age. The S-Index, measured from RV to TLC after at least eight reproducible maximal maneuvers with a < 10% difference, was obtained. The MIP was also measured, and differences between S-Index and MIP values were analyzed. A multiple linear regression model estimating the S-Index value was based on clinically significant independent variables. For model cross-validation and diagnostic accuracy, we used a separate sample of COVID-19 survivors to compare the observed and predicted S-Index values. Results: The S-Index strongly correlated with the FEV1 and FVC. However, sex, age, weight, and height retained their significance in all final models, collectively explaining 62% of the variation in the observed values. The performance of the prediction equation was satisfactory in suggesting differences between COVID-19 survivors with an MIP < 80 cmH2O and those with an MIP = 80 cmH2O. For both sexes, the S-Index exhibited the potential for ruling out, rather than confirming, inspiratory muscle weakness. If below the lower limit of normal, further evaluation is important, especially in men. Conclusions: To our knowledge, this is the first set of reference equations for the S-Index based on a healthy adult population across various age groups in Brazil. Its potential as an adjunct index in evaluating inspiratory muscle strength was also explored for the first time.

Keywords: Maximal respiratory pressures; Muscle strength; Respiratory muscles.

To evaluate handgrip strength (HGS) as a diagnostic tool for frailty risk in elderly patients with asthma, as well as to investigate the prevalence of frailty in this population. Methods: This was a cross-sectional study including 96 patients = 60 years of age diagnosed with moderate to severe asthma and treated at a tertiary referral center in Brazil. We measured HGS using a calibrated hydraulic hand dynamometer. We used a frailty scale and the AUC to assess the diagnostic accuracy of the HGS test. Results: The median age of participants was 67 years. Most (78%) were women and non-White (91%) of low socioeconomic status. HGS identified those at risk for frailty, with an AUC of 71.6% (61.5-80.4%; p < 0.002), as well as a sensitivity of 73.58% and a specificity of 67.53%, on the basis of a cutoff of = 19 kgf. Conclusions: HGS appears to be a simple, reliable tool for clinicians to determine frailty risk in older asthma patients in a point-of-care setting.

Keywords: Hand strength; Frailty; Asthma; Aged.

Objective: To evaluate the effect that respiratory muscle stretching using the global postural reeducation (GPR) method has on respiratory muscle strength, thoracic expansion and abdominal mobility in sedentary young males. Methods: This was a randomized study involving 20 sedentary volunteers, aged 22.7 ± 2.5 years, divided into two groups of 10: a control group, composed of subjects not performing any exercises, and a group of subjects submitted to the GPR method. The protocol consisted of a program to stretch the respiratory muscles with participants in the 'open-arm, open hip joint angle' position, which was regularly performed twice a week for 8 weeks, totaling 16 sessions. The two groups were submitted to measurements of maximal inspiratory pressure, maximal expiratory pressure, thoracic expansion and abdominal mobility, prior to and after the intervention period. Results: The initial and final values for maximal respiratory pressures, thoracic expansion and abdominal mobility for the control group showed no significant differences (p > 0.05). However, for the GPR group, all values increased after the intervention (p < 0.05). Conclusions: Respiratory muscle stretching using the GPR method was efficient in promoting an increase in maximal respiratory pressures, thoracic expansion and abdominal mobility, suggesting that it could be used as a physiotherapy resource to develop respiratory muscle strength, thoracic expansion and abdominal mobility.

Keywords: Posture; Muscle Strength; Respiratory Muscles; Muscle Stretching Exercises.

Objective: To determine the effect that re-education of the thoracic and abdominal muscles has on the respiratory muscle strength of patients with cystic fibrosis evaluated over time at the Cystic Fibrosis Outpatient Clinic of the Universidade Católica de Brasília (Catholic University of Brasília). Methods: The sample consisted of 29 cystic fibrosis patients, characterized based on anthropometric, genetic and bacterial colonization data. The patients were submitted to physical therapy sessions, involving re-education of the respiratory muscles, twice a week for four months. Spirometry, pressure manometry and anthropometry were performed before and after each session. Results: Comparing baselines values to those obtained after physical therapy, increases in maximum inspiratory pressure and maximum expiratory pressure were observed in all patients, those without any obstructive respiratory disease and those with mild obstructive respiratory disease (p < 0.05). A positive correlation between age and maximum expiratory pressure was observed for most of the patients. Maximum inspiratory pressure correlated positively with age only in the group with mild obstructive respiratory disease (p = 0.012; r = 0.817). In female patients and in the group of patients without obstructive respiratory disease, a negative correlation was observed between maximum expiratory pressure and colonization with Pseudomonas aeruginosa (p = 0.036; r = -0.585). Conclusion: Use of the thoracic and abdominal muscle re-education technique increased respiratory muscle strength in the cystic fibrosis patients studied, a finding that underscores the importance of including physical therapy in the treatment of these patients.

Keywords: Cystic fibrosis/rehabilitation; Physical therapy technique; Respiratory muscles; Forced expiratory volume; Inspiratory capacity; Vital capacity

Background: Pulmonary rehabilitation is widely recommended for the treatment of chronic obstructive pulmonary disease. Objective: To evaluate the efficacy of pulmonary rehabilitation in improving exercise capacity, respiratory muscle strength and quality of life of chronic obstructive pulmonary disease patients. Method: This was an open, non-randomized clinical trial involving 27 clinically stable ex-smokers with chronic obstructive pulmonary disease who were enrolled in a pulmonary rehabilitation program. All were evaluated before and after pulmonary rehabilitation. Results: Mean age was 65 ± 5 years, mean body mass index was 25 ± 4 kg/m2, mean forced expiratory volume in one second was 55 ± 25% of predicted, mean ratio between forced expiratory volume in one second and forced vital capacity was 50 ± 12%, and mean arterial oxygen tension was 70 ± 7 mmHg. Comparison of pre- and post-pulmonary rehabilitation values revealed improvement in the distance walked in the 6-minute walk test (513 ± 99 m vs. 570 ± 104 m), maximum upper limb load (2 ± 1 kg vs. 3 ± 1 kg) and maximal inspiratory pressure (-89 ± 23 cmH2O vs. -102 ± 23 cmH2O), as well as in the activity domain, impact domain and total score on the Saint George's Respiratory Questionnaire. Conclusion: Pulmonary rehabilitation, when performed with care and with a focus on physical training, is efficacious in increasing not only the distance walked in the 6-minute walk test but maximum upper limb load, maximal inspiratory pressure and quality of life as well.

Keywords: Key words: Pulmonary rehabilitation. Chronic obstructive pulmonary disease. Quality of life. Respiratory muscles.

Objective: To analyze the effects of Pilates mat exercises in patients with cystic fibrosis (CF). Methods: This was a clinical trial involving 19 CF patients recruited from either the CF Outpatient Clinic of the State University at Campinas Hospital de Clínicas or the Children's Institute of the University of São Paulo School of Medicine Hospital das Clínicas. All of the patients performed Pilates mat exercises for four months (one 60-min session per week). The variables studied (before and after the intervention) were respiratory muscle strength, MIP, MEP, FVC, and FEV1. Results: After the intervention, MIP was significantly higher in the male patients (p = 0.017), as were MIP and MEP in the female patients (p = 0.005 and p = 0.007, respectively). There were no significant differences between the pre- and post-intervention values of FVC or FEV1, neither in the sample as a whole nor among the patients of either gender. Conclusions: Our results show that Pilates mat exercises have beneficial effects on respiratory muscle strength in CF patients. (Brazilian Registry of Clinical Trials - ReBEC; identification number RBR-86vp8x [http://www.ensaiosclinicos.gov.br])

Keywords: Cystic fibrosis; Muscle strength; Exercise movement techniques; Respiratory function tests.

Objective: To determine the relationships that smoking history has with inflammatory markers, metabolic markers, body composition, muscle strength, and cardiopulmonary capacity in current smokers. Methods: This was a cross-sectional study involving 65 smokers (age range: 18-60 years). On three non-consecutive days, each participant was evaluated in terms of smoking history, pre-existing comorbidities, lung function (by spirometry), peripheral muscle strength (by dynamometry), body composition (by bioelectrical impedance analysis), levels of metabolic/inflammatory markers, and maximum cardiopulmonary capacity (by treadmill exercise test). We evaluated the relationships that smoking history has with inflammatory markers, metabolic markers, body composition, muscle strength, and cardiopulmonary capacity, using logarithmic transformation of the data and calculating Pearson's correlation coefficient and for partial correlations adjusted for age, gender, body mass index (BMI), and comorbidities. To identify the influence of smoking history on pre-existing comorbidities, we used a logistic regression model adjusted for age, BMI, and duration of smoking. Results: Smoking history correlated significantly, albeit weakly, with triglyceride level (r = 0.317; p = 0.005), monocyte count (r = 0.308; p = 0.013), and waist circumference (r = 0.299; p = 0.017). However, those correlations did not retain their significance in the adjusted analysis. In the logistic regression model, smoking more than 20 cigarettes/day correlated significantly with the presence of metabolic diseases (OR = 0.31; 95% CI: 1.009-1.701; p = 0.043). Conclusions: In this sample of smokers, smoking history correlated positively with the triglyceride level, the monocyte count, and waist circumference. The prevalence of metabolic disease was highest in those who smoked more than 20 cigarettes/day.

Keywords: Tobacco; Smoking; Triglycerides; Monocytes; Waist circumference; Body composition.