CONTEXT: Asthma is a chronic airway disorder which is associated to the inflammatory cells. Inflammatory and immune cells generate more reactive oxygen species in patients suffering from asthma which leads to tissue injury. AIMS: To investigate the role of oxidant-antioxidant imbalance in disease progression of asthmatic patients. SETTINGS AND DESIGN: In this study, 130 asthmatic patients and 70 healthy controls were documented. METHODS: For this malondialdehyde level, total protein carbonyls, sulfhydryls, activity of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), total blood glutathione, and total antioxidant capacity (FRAP) were measured. STATISTICAL ANALYSIS USED: Analysis of the data was done using unpaired student t test and one-way ANOVA analysis. P < 0.05 was considered significant. RESULTS: The present work showed that the systemic levels of MDA (4.19 +/- 0.10 nmol/ml, P < 0.001) and protein carbonyls (1.13 +/- 0.02 nmol/mg, P < 0.001) were found to be remarkably higher in asthmatic patients while protein sulfhydryls (0.55 +/- 0.01 mmol/l, P < 0.05) decreased as compared to controls (2.84 +/- 0.12 nmol/ml, 0.79 +/- 0.02 nmol/mg and 0.60 +/- 0.02 mmol/l, respectively). We also observed decrease in activities of SOD (2047 +/- 50.34 U/g Hb, P < 0.05), catalase (4374 +/- 67.98 U/g Hb, P < 0.01), and GPx (40.97 +/- 1.05 U/g Hb, P < 0.01) in erythrocytes compared to control (2217 +/- 60.11 U/g Hb, 4746 +/- 89.94 U/g Hb, and 48.37 +/- 2.47 U/g Hb, respectively). FRAP level (750.90 +/- 21.22 mu mol/l, P < 0.05) in plasma was decreased, whereas total blood glutathione increased (0.94 +/- 0.02 mmol/l, P < 0.05) as seen in control (840.40 +/- 28.39 mu mol/l and 0.84 +/- 0.04 mmol/l). CONCLUSIONS: This work supports and describes the hypothesis that an imbalance between oxidant-antioxidant is associated to the oxidative stress which plays a significant role in severity of the disease.
This an updated guidelines for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of SINA is to have updated guidelines, which are simple to understand and easy to use by non-asthma specialists, including primary care and general practice physicians. This new version includes updates of acute and chronic asthma management, with more emphasis on the use of Asthma Control Test in the management of asthma, and a new section on "difficult-to-treat asthma." Further, the section on asthma in children was re-written to cover different aspects in this age group. The SINA panel is a group of Saudi experts with well-respected academic backgrounds and experience in the field of asthma. The guidelines are formatted based on the available evidence, local literature, and the current situation in Saudi Arabia. There was an emphasis on patient-doctor partnership in the management that also includes a self-management plan. The approach adopted by the SINA group is mainly based on disease control as it is the ultimate goal of treatment.
OBJECTIVE: Newly arising enlarged or hypermetabolic mediastinal/hilar lymph nodes (LNs) in patients with previously diagnosed extrathoracic malignancies raise suspicion of metastasis. Relatively high proportion of these LNs is due to a benign condition. We aimed to determine frequency of malignant LNs and role of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for clarification of the origin of suspicious LNs in these patients. METHODS: Consecutive patients with a known extrathoracic malignancy and suspected hilar/mediastinal LN were included in this prospective study. Computed tomography (CT) of thorax and positron emission tomography-CT of all patients were taken. LNs with short axis >1 cm at CT of thorax and SUV >= 2.5 were accepted suspicious for malignancy. All patients underwent EBUS-TBNA for pathological verification of LNs. Patients with benign diagnosis either underwent invasive procedures or were followed up. The results were evaluated for frequency of malignant hilar/mediastinal LNs and sensitivity, specificity, and diagnostic values of EBUS-TBNA. RESULTS: A total of 48 cases with a mean age of 57.4 +/- 11.6 were included. All cases had the diagnosis of an extrathoracic malignancy. 78 LNs were aspirated with EBUS-TBNA in 48 cases (1.62 LNs/patient). The mean short axis of aspirated LNs was 1.51 +/- 0.63. Results of EBUS-TBNA revealed malignancy in 15 cases (31.2%), tuberculosis in six cases (12.5%), sarcoidosis in four cases (8.3%), and reactive adenitis in 23 cases (48%). The sensitivity, specificity, and negative predictive value of EBUS-TBNA for malignancy were 83.3%, 100%, and 90.9%, respectively. When both benign and malignant diseases were considered, sensitivity, specificity, negative predictive value, and diagnostic accuracy of EBUS-TBNA were 89.2%, 100%, 86.9%, and 93.7%, respectively. CONCLUSIONS: The ratio of benign LNs in patients with extrathoracic malignancies is relatively high. EBUS-TBNA is a safe, minimally invasive, and effective method for clarification of intrathoracic LNs.
Adequate sleep has been considered important for the adolescent's health and well being. On the other hand, self-imposed sleep curtailment is now recognized as a potentially important and novel risk factor for obesity. The present study aimed to assess the prevalence of short sleep duration and its association with obesity among Saudi adolescents. This is a school-based cross-sectional study with self-reported sleep questionnaires. It was conducted during the years 2009/2010 in three cities in Saudi Arabia; Al-Khobar, Jeddah, and Riyadh. Participants were 2868 secondary-school males (1379) and females (1389) aged 15 to 19 years, randomly selected using a multistage stratified sampling technique. Measurements included weight, height, waist circumference, BMI, and sleeping duration. Logistic regression analysis while adjusted for age, gender, and location was used to examine the associations between sleep duration and obesity measures. The mean (SD) of sleep duration was 7.2 (1.6) hours/day with no significant differences between males and females. About 31% of the participants obtain less than 7 hours of sleep per day, while approximately 50% of the sample gets less than 8 hours of daily sleep. Two-way ANCOVA results while controlling for the effect of age revealed a significant gender by school-type interaction (P<0.001). In addition, adequate sleep duration increased the odds of having normal weight (adjusted odds ratios = 1.28, 95% CI = 1.08-1.50, P = 0.003). The present study observed a high prevalence of short sleep duration among Saudi adolescents 15- to 19-year olds and that short sleep duration was significantly associated with increased risk of overweight and obesity. Future interventions should investigate whether adopting a healthy lifestyle by adolescents with short sleep duration would improve their sleeping habits or not.
Most lung abscesses (80-90) are now successfully treated with antibiotics; however, this conservative approach may occasionally fail. When medical treatment fails, pulmonary resection is usually advised. Alternatively, percutaneous transthoracic tube drainage or endoscopic drainage can be considered, though both remain controversial. In this communication, the medical literature focusing on percutaneous tube drainage efficacy, indications, techniques, complications, and mortality, as well as available data regarding endoscopic drainage are reviewed.
PURPOSE: To describe the consequences of the cranial displacement of the diaphgram occurring during pneumoperitoneum (Pnp) and/or Trendelenburg (Tnd) position on respiratory mechanics. Possible addictive effects and the changes of the viscoelastic respiratory system resistance were studied, which were not extensively described before. METHODS: The end-inflation occlusion method was applied on eight rats. It allows us to determine mechanical parameters such as respiratory system static elastance, the ohmic resistance due to frictional forces in the airways, and the additional viscoelastic impedance due to tissues deformation. Measurements during mechanical ventilation were taken in controls (supine position), after 20-25 degrees head-down tilting (Tnd), after abdominal air insufflation up to 12 mmHg abdominal pressure in the supine position (Pnp), and combining Tnd + Pnp. Tnd and Pnp modalities were similar to those commonly applied during surgical procedures in humans. RESULTS: We confirmed the previously described detrimental effects on respiratory mechanics due to the diaphgram displacement during both Pnp and Tnd. The increment in the total resistive pressure dissipation was found to depend primarily on the effects on the viscoelastic characteristics of the respiratory system. Data suggesting greater effects of Pnp compared to those of Tnd were obtained. CONCLUSION: The cranial displacement of the diaphgram occurring as a consequence of Pnp and/or Tnd, for example during laparoscopic surgical procedures, causes an increment of respiratory system elastance and viscoelastic resistance. The analysis of addictive effects show that these are more likely to occur when Pnp + Tnd are compared to isolated Tnd rather than to isolated Pnp.
BACKGROUND: Isolated pulmonary amyloidosis is a very rare disease. METHODS: We retrospectively reviewed the records of patients with pathologically proven isolated pulmonary amyloidosis treated at our hospital from 1990 to 2011. RESULTS: There were 9 males and 4 females with a mean age of 54.7 years (range, 45-72 years) and the mean course of disease was 46.5 months (range, 5 months-15 years). The most common symptoms were cough (10/13), expectoration (8/13), hemoptysis (4/13), chest tightness (12/13), dyspnea (10/13), chest pain (3/13), fever (5/13), and body weight loss (2/13). Radiological findings included tracheal stenosis (2/13), bronchial stenosis with atelectasis (5/13), pulmonary nodules (3/13), lung consolidation (1/13), and lymph node enlargement with pleural effusion (2/13). Treatments included endotracheal stenting, endoscopic resection of tracheal and bronchial lesions, lung resection, and drug therapy with glucocorticoids, antineoplastic agents, or antibiotics. Four patients died of the disease within 1 year of diagnosis, 2 died of pneumonia at 3-4 years after original treatment, and the remaining patients are alive with follow-up ranging from 3 to 15 years. CONCLUSIONS: Isolated pulmonary amyloidosis is a rare disease with a relatively high mortality and its various manifestations make diagnosis challenging. Surgical resection of lesions and chemotherapy tend to be effective treatments.
Objective: This study was designed to compare the pattern of obstructive sleep apnea (OSA) among obese and nonobese subjects regarding clinical and polysomnographic data obtained for a polysomnographic study. Methods: A cross-sectional retrospective descriptive study was conducted by analyzing polysomnographic data in 112 consecutive patients underwent a sleep study at our sleep laboratory from January 2009 to July 2010. Out of them, 81 were diagnosed to have OSA (apnea-hypopnoea Index >= 5). These patients were classified in two groups with body mass index (BMI) = 27.5 kg/m (2) as obese. Clinical as well as polysomnographic data were evaluated and compared between the two groups. Patients were also evaluated for other risk factors such as smoking, alcoholism, and use of sedatives. Data were subjected to statistical analysis ((2) -test, P value < 0.05 considered to be significant). The Fisher Exact test was applied wherever the expected frequency for a variable was <= 5. Results: Of 81 patients with OSA, 36 (44.4) were nonobese with a mean BMI of 26.62 2.29 kg/m (2) and 45 (55.6) were obese with a mean BMI of 35.14 3.74 kg/m (2) . Mean AHI per hour was significantly more in the obese than in the nonobese group (50.09 29.49 vs. 24.36 12.17, P < 0.001). The use of one or more sedatives was more in nonobese as compared to obese (58.3 vs. 24.4, P=0.002). The obese group had significantly higher desaturation and arousal index (P < 0.001). The minimal oxygen saturation was lower in the obese than the nonobese group (68.5 13.00 vs. 80.3 7.40, P < 0.001) and was well below 90 in both groups. Overall, the OSA in nonobese patients was mild-to-moderate as compared to that of the obese and no significant differences were observed between them as regard to age, gender, mean neck circumference, excessive daytime sleepiness, adenoid or tonsillar enlargement, smoking, and remaining polysomnographic parameters. Conclusion: Obstructive sleep apnea can occur in nonobese persons though with less severity as compared to obese leading to a concept that OSA is not restricted to obese persons only and there is a high demand of its awareness regarding evaluation, diagnosis, and management in such individuals.
Context: Asthma is a complex inflammatory condition often associated with bronchial hyper reactivity and atopy. Genetic and environmental factors are implicated in the etiopathogenesis of asthma. Regulated upon Activation Normal T- cell Expressed and Secreted (RANTES) is a CC chemokine responsible for the recruitment of inflammatory cells, suggesting a possible role for this chemokine in asthma. Both -403A and -28G alleles of the RANTES promoter region were found to be associated with asthma/atopy in some but not all studies. Aim: The purpose of this study was to investigate the genetic influence of -403A and -28G alleles of the RANTES promoter region on the development of asthma in Lebanon. Settings and Design: This case control study was conducted at Makassed Hospital, Beirut on 40 asthmatic patients and 38 healthy controls. Methods: RANTES gene polymorphisms -403G/A and -28C/G alleles were genotyped using PCR-RFLP. Results: No significant differences in allele or genotype frequencies for the RANTES gene polymorphisms between asthmatic patients and controls were found. The difference of the -403 GA genotype frequency between patients and controls was not statisti-cally significant; (OR=0.8, 95 CI=0.2-2.3, P=0.8). Similarly, the difference of the A-allele frequencies between patients and con-trols was not significant (OR=0.824, CI=0.3-2.2, P=0.7). Conclusions: Our data show that RANTES gene promoter polymorphisms are not associated with asthma susceptibility in the Lebanese population.
BACKGROUND AND OBJECTIVE: Some studies show a decline of FEV1 only one month after withdrawal of inhaled corticosteroids (ICS), while others show no decline. We speculate that the presence of an asthma phenotype in the Chronic Obstructive Pulmonary Disease (COPD) population, and that its exclusion may result in no spirometric deterioration. METHODS: We performed a prospective clinical observation study on 32 patients who fulfilled the Global Initiative for Chronic Obstructive lung disease definition of COPD (Grade II-IV). They were divided into two phenotypic groups. 1. Irreversible asthma (A and B) (n = 13): A. Asthma: Bronchial biopsy shows diffuse thickening of basement membrane (>= 6.6 mu m). B. Airflow limitation (AFL) likely to be asthma: KCO > 80% predicted if the patient refused biopsy. 2. COPD (A and B) (n = 19): A. COPD: hypercapneic respiratory failure with raised bicarbonate, panlobular emphysema with multiple bullas, or bronchial biopsy showing squamous metaplasia and epithelial/subepithelial inflammation without thickening of the basement membrane. B. AFL likely to be COPD: KCO < 80% predicted. RESULTS: The asthma phenotype was significantly younger, had a strong association with hypertrophy of nasal turbinates, and registered a significant improvement of FEV1 (350 ml) vs a decline of - 26.5 ml in the COPD phenotype following therapy with budesonide/formoterol for one year. Withdrawal of budesonide for 4 weeks in the COPD phenotype resulted in FEV1 + 1.33% (SD +/- 5.71) and FVC + 1.24% (SD +/- 5.32); a change of <12% in all patients. CONCLUSIONS: We recorded no spirometric deterioration after exclusion of the asthma phenotype from a COPD group.
CONTEXT: Prevalence of tuberculous pleural effusion is very high in the Asian subcontinent but very few studies have come up from this part of the world about the course of recovery of pulmonary functions after institution of anti-tubercular therapy (ATT) and thoracentesis. AIMS: To study initial lung function impairment, changes over time after institution of ATT and thoracentesis and residual abnormalities left at the end of six months of treatment. SETTINGS AND DESIGN: Randomized open level interventional study over two years in 52 patients at a tertiary level teaching hospital. METHODS: The study population was divided into two equal groups, A (therapeutic thoracentesis) and B (diagnostic thoracentesis). Spirometry, chest radiograph and ultrasonography of thorax were done initially and at each follow-up visit up to six months. Statistical analysis was done (P value < 0.05 considered significant). RESULTS: Both groups were comparable initially. After six months none in group A and five patients in group B had minimal pleural effusion. During follow up, mean percentage predicted of FEV1 and FVC increased more in A than in B and the differences were statistically significant (P < 0.05). Pleural thickening, initially absent in both groups, was found to be more in B as compared to A at subsequent follow-up visits and this was statistically significant (P < 0.05). CONCLUSIONS: Thoracentesis should be considered in addition to anti-TB treatment, especially in large effusions, in order to relieve dyspnea, avoid possibility of residual pleural thickening and risk of developing restrictive functional impairment.
Background and Aim: Noninvasive ventilation (NIV) decreases mechanical ventilation indication in the early period of acute hypercapnic respiratory failure (AHcRF) and factors for success have been studied well. But, less is known about the factors influencing the NIV response in the subacute period. This study was aimed to determine the factors influencing the reduction of PaCO 2 levels within first 24 hours of therapy. Methods: NIV response was defined as reduction of PaCO 2 level below 50 mmHg within first 24 hours. Patients with AHcRF, treated with NIV, were divided into 2 groups according to this criterion; group 1 as the nonresponsive, group 2 as the responsive. The differences in NIV methods and characteristics of the two groups were evaluated and compared in this retrospective study. Results: A total of 100 patients were included in the study; 66 of them in group 1 and 34 in group 2. No significant differences were identified between the length of NIV application and intensive care unit (ICU) stay, intubation and mortality rates, across the groups. Ninety-one percent of the patients in group 2 had received all night long NIV therapy; this was just 74 in group 1 (P=0.036). Results of multivariate analysis showed that while nocturnal application was significantly associated with better response, prior home ventilation and requirement of higher pressure support (PS) levels significantly and independently associated with poorer response to NIV therapy. Conclusion: In patients with AHcRF, all night long use of NIV may accelerate healing by improving PaCO 2 reduction within the first 24 hours. A rapid response in PaCO 2 levels should not be expected in patients requiring higher PS levels and using prior home ventilation.
Congenital H-type tracheoesophageal fistula (TEF) in adults is a rare presentation and can test the diagnostic acumen of a surgeon, endoscopist, and the radiologist. These undetected fistulas may present as chronic lung disease of unknown origin because repeated aspirations can lead to recurrent lung infections and bronchiectasis. Congenital TEFs should be considered in the diagnosis of infants and young adults with recurrent respiratory distress and/or infections. Here, we present the successful management of this rare case in an adult patient.
Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal cancer-related pulmonary complication with rapidly progressing dyspnea, and occasionally induces sudden death. Here, we describe a postmortem-diagnosed PTTM case caused by gastric cancer, with the complaint of progressing dyspnea for 5 days.He did not have any abdominal symptoms or cancer history. PTTM should be considered in patients with rapidly worsening respiratory conditions, even if there is no cancer history.
BACKGROUND: Noninvasive diagnosis of pleural tuberculosis (TB) remains a challenge due to the paucibacillary nature of the disease. As Mycobacterium tuberculosis (MTB)-specific T cells are recruited into pleural space in TB effusion; their indirect detection may provide useful clinical information. OBJECTIVES: Evaluation of pleural fluid interferon (INF)-gamma levels vs Quantiferon-TB Gold In tube assay (QFT-IT) in blood and its adapted variants, using pleural fluid or isolated pleural fluid cells in the diagnosis of pleural TB. METHODS: Thirty-eight patients with pleural effusion of unknown etiology presented at Assiut University Hospital, Egypt, were recruited. Blood and pleural fluid were collected at presentation for INF-gamma assays. Ex vivo pleural fluid INF-gamma levels, QFT-IT in blood and its adapted variants were compared with final diagnosis as confirmed by other tools including blind and/or thoracoscopic pleural biopsy. RESULTS: The final clinical diagnosis was TB in 20 (53%), malignancy in 10 (26%), and effusion due to other causes in eight patients (21%). Ex vivo pleural fluid INF-gamma levels accurately identified TB in all patients and were superior to the QFT-IT assays using blood or pleural fluid (70 and 78% sensitivity, with 60 and 83% specificity, respectively). QFT-IT assay applied to isolated pleural fluid cells had 100% sensitivity and 72% specificity. The optimal cut-off obtained with ROC analysis was 0.73 for TB Gold assay in blood assay, 0.82 IU/ml for the cultured pleural fluid assay, and 0.94 for isolated pleural cells assay. CONCLUSION: The ex vivo pleural fluid INF-gamma level is an accurate marker for the diagnosis of pleural TB. QFT-IT assay in peripheral blood or its adapted versions of the assay using pleural fluid and/or washed pleural fluid cells had no diagnostic advantage over pleural fluid INF-gamma in the diagnosis of pleural TB.
Introduction: Chronic obstructive pulmonary disease (COPD) is a leading cause of respiratory-related morbidity and mortality. Inhaled steroids are frequently used in patients with moderate to severe disease and may lead to adrenal suppression. Objectives: The aim of this study was to compare the effect of inhaled budesonide/formoterol with inhaled fluticasone/salmeterol in severe COPD. Methods: It was a prospective open-label crossover study of 22 patients. Adrenal suppression was measured by overnight urinary cortisol/creatinine ratio. The measurements were taken while patients were on either combination for at least 4 weeks. Results: A total of 12 patients completed the study. The mean age was 64 years (8 males, 4 females). The mean FEV1 was 1 L (range, 0.5-1.8). There was no significant difference in adrenal suppression measured by overnight urinary cortisol/creatinine ratio (budesonide 5.2 4.3, fluticasone 4.7 3.1; 95 CI -2.2 to 1.2; P = 0.52) and urinary cortisol concentration (budesonide 51 53, fluticasone 43 31 [nmol/l]; 95 CI -35 to 20; P = 0.56). Conclusion: Inhaled budesonide and fluticasone have no significantly different effect on adrenal function in moderate to severe COPD. The adverse event profile of high-dose inhaled steroids should not influence the choice of medication.
Purpose: This study was designed to evaluate the levels of hepcidin in the serum of patients with chronic obstructive pulmonary disease (COPD). Methods: In the study, 74 male patients (ages 45-75) in a stable period for COPD were grouped as Group I: Mild COPD (n:25), Group II: Moderate COPD (n:24), and Group III: Severe COPD (n:25). Healthy non-smoker males were included in Group IV (n:35) as a control group. The differences of hepcidin level among all the groups were examined. Also, in the patient groups with COPD, hepcidin level was compared with age, body mass index, cigarette (package/year), blood parameters (iron, total iron binding capacity, ferritin, hemoglobin, hematocrit [hct]), respiratory function tests, and arterial blood gas results. Results: Although there was no difference between the healthy control group and the mild COPD patient group (P=0.781) in terms of hepcidin level, there was a difference between the moderate (P=0.004) and the severe COPD patient groups (P=0.002). The hepcidin level of the control group was found to be higher than the moderate and severe COPD patient groups. In the severe COPD patients, hepcidin level increased with the increase in serum iron (P=0.000), hct (P=0.009), ferritin levels (P=0.012), and arterial oxygen saturation (SaO2, P=0.000). Conclusion: The serum hepcidin level that is decreased in severe COPD brings into mind that it may play a role in the mechanism to prevent hypoxemia. The results suggest that serum hepcidin level may be a useful marker in COPD. Larger prospective studies are needed to confirm our findings between hepcidin and COPD.
To identify the predictors that lead to cigarette smoking among high school students by utilizing the global youth tobacco survey in Riyadh, Kingdom of Saudi Arabia (KSA). A cross-sectional study was conducted among high school students (grades 10-12) in Riyadh, KSA, between April 24, 2010, and June 16, 2010. The response rate of the students was 92.17%. The percentage of high school students who had previously smoked cigarettes, even just 1-2 puffs, was 43.3% overall. This behavior was more common among male students (56.4%) than females (31.3%). The prevalence of students who reported that they are currently smoking at least one cigarette in the past 30 days was 19.5% (31.3% and 8.9% for males and females, respectively). "Ever smoked" status was associated with male gender (OR = 2.88, confidence interval [CI]: 2.28-3.63), parent smoking (OR = 1.70, CI: 1.25-2.30) or other member of the household smoking (OR = 2.11, CI: 1.59-2.81) who smoked, closest friends who smoked (OR = 8.17, CI: 5.56-12.00), and lack of refusal to sell cigarettes (OR = 5.68, CI: 2.09-15.48). Several predictors of cigarette smoking among high school students were identified.
Objective: This study tried to evaluate whether a methacholine test may be influenced by the seasons. Methods: We considered 4826 consecutive subjects with normal spirometry (50.53 males; age: 35.116.2; forced expiratory volume in one second: 99.513.0) who underwent a methacholine test for suspected asthma symptoms between 2000 and 2010. They were subdivided into four groups, like the seasons, according to the test dates. Results: A total of 1981 (41) resulted normal (no PD 20 was obtained with 2400 g of methacholine); the others showed a mean LogPD 20 of 2.520.5 g. The number of subjects with bronchial hyper-responsiveness (BHR) found in autumn (789, 62.3) was higher than in summer (583, 56.7; P=0.03). A higher number of females and overweight/obese subjects showed a BHR in autumn compared with the other seasons. The spring mean LogPD 20 value (2.480.48 g) was lower if compared with the one measured in summer (2.590.49 g; P=0.05). LogPD 20 value was lower in females and non-smokers in spring compared with summer (P < 0.05). Overweight/obese non-smokers showed a lower LogPD 20 in spring and autumn compared with that in summer (P < 0.05). Autumn was a risk factor (OR: 1.378; P=0.001) for BHR (using a PD 20 < 2 400 g as BHR limit), while spring (OR: 1.330; P=0.021) and autumn (OR: 1.331; P=0.020) were risk factors for a more severe BHR (using a PD 20 < 400 g as BHR limit). Conclusion: There was a higher probability of finding BHR in outpatients with suspected asthma in autumn and spring compared with summer. Spring is the season where BHR may be more severe. Females and overweight/obese subjects were those mainly involved in this seasonal variability of BHR.