Assessing the prevalence and severity of asthma, rhinitis, and eczema among schoolchildren (6-7 and 13-14 years old) in Khuzestan, Iran: a cross-sectional survey.

BACKGROUND: Asthma and allergic complications are the most common chronic disorders in children and adolescents. This study aimed to determine the prevalence and severity of asthma, allergic rhinitis, eczema among schoolchildren, and some related risk factors. METHODS: The cross-sectional study was performed in 2019 and involved 4000 students aged 6-7 years and 4000 students aged 13-14 years (both girls and boys) from urban schools in Khuzestan Province, southwestern Iran. We used the multi-stage sampling method. Data were collected using the Persian version of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. RESULTS: The prevalence of current wheeze, wheeze ever and asthma ever in the age group of 6-7 years was 3.8, 4.5, and 1.8%, respectively; in the age group of 13-14 years, it was 4.4, 5.9, and 3.4, respectively. In terms of gender, males (4.9, 6.0, and 2.7 percent, respectively) had substantially higher rates of current wheeze, wheeze ever, and asthma ever compared to the girls (2.8, 3.6, and 2.0 percent, respectively) (p < 0.001). The prevalence of rhinitis, Hay fever, and eczema among young people was 5.3%, 3.5%, and 1.0%, respectively. Current wheeze was more common in children with allergic rhinitis in the last 12 months (30.3% vs. 2.7%, p < 0.001), Hay fever (32.8% vs. 0.3%, p < 0.001) and eczema (27.8% vs 3.8%, p < 0.001), compared to children who did not. CONCLUSIONS: The prevalence and severity of asthma symptoms were significantly associated with allergic rhinitis, eczema, and gender.

National Research Institute of Tuberculosis and Lung Disease (NRITLD) Protocol for the Treatment of Patients with COVID-19.

More than a year after the onset of the coronavirus disease pandemic in 2019, the disease remains a major global health issue. During this time, health organizations worldwide have tried to provide integrated treatment guidelines to control coronavirus disease 2019 (COVID-19) at different levels. However, due to the novel nature of the disease and the emergence of new variants, medical teams' updating medical information and drug prescribing guidelines should be given special attention. This version is an updated instruction of the National Research Institute of Tuberculosis and Lung Disease (NRITLD) in collaboration with a group of specialists from Masih Daneshvari Hospital in Tehran, Iran, which is provided to update the information of caring clinicians for the treatment and care of COVID-19 hospitalized patients.

Physiological equivalent temperature (PET) and non-accidental, cardiovascular and respiratory disease mortality in Ahvaz, Iran.

Climate change may be associated with human morbidity and mortality through direct and indirect effects. Ahvaz is one of the hottest cities in the world. The aim of this study was to investigate the relation between physiological Equivalent Temperature (PET) and non-accidental, cardiovascular and respiratory disease mortality in Ahvaz, Iran. Distributed Lag Non-linear Models (DLNM) combined with quasi-Poisson regression were used to investigate the effect of PET on death. The effect of time trend, air pollutants (NO2, SO2 and PM10), and weekdays were adjusted.The results showed that in cold stress [1st percentile of PET (2.7 °C) relative to 25th percentile (11.9 °C)] the risk of total respiratory mortality, respiratory mortality in men, and mortality in people under 65 year olds, significantly decreased in the cumulative lags of 0-2, 0-6 and 0-13; but the risk of respiratory mortality increased in the elderly and in the final lags. In contrast, heat stress [99th percentile of PET (44.9 °C) relative to 75th percentile (43.4 °C)] significantly increased the risk of total cardiovascular mortality (CVD), cardiovascular mortality in men, ischemic heart disease and cerebrovascular disease mortality in lags 0 and 0-2. It seems that high PET values increase the risk of cardiovascular mortality, while low PET values increase respiratory mortality only among the elderly in Ahvaz.

Risk factors for current wheeze among school children (6-7 and 13-14 years old) in Khuzestan, Iran.

Objectives: In recent years, there has been a clear trend of increasing allergic diseases especially in children, and developing countries are no exception. Thepresentstudy sought to determine the risk factors associated with wheezing among school children aged 6-7 and 13-14 years living in Khuzestan Province, Iran. Study design: Cross-sectional. Methods: Data for this cross-sectional study is the history of wheeze in the last 12 months. The participants included 6-7- and 13-14-year-old girls and boys studying in urban schools in Khuzestan Province in 2019. We collected the data using the multi stage sampling technique as suggested in the International Study of Asthma and Allergies in Childhood (ISAAC). The research reviewed the literature and consulted experts to collect the risk factors for demographic and clinical information, environmental exposure and lifestyle. Results: Eight thousand questionnaires were handed out to both age groups, of which 7344 were completed. Two hundred ninety-nine (4.1 %) of the participants had current wheeze. Three-point four percent (124 individuals) in the 6-7 year age group and 4.8 % in the 13-14-year-old age group had current wheezing. The results of the logistic regression model suggest that the most significant risk factors associated with the chance of developing current wheeze in the both age groups are: being male (OR: 1.46, 95 % CI: 1.12-1.88), being from employed mother families (OR: 1.50, 95 %, CI:1.05-2.08), property ownership (OR:1.36, 95 %, CI:1.04-1.79) bugs in the property (OR: 1.29, 95 %, CI:0.99-1.70) mold in the property (OR: 1.75, 95 %, CI:1.12-2.76), pet(s) in the student's bedroom (OR: 1.75, 95 %, CI: 0.97-3.14), a family history of asthma and allergic diseases (OR: 2.20, 95 %, CI: 1.69-2.87), tobacco smoke exposures in the property (OR: 1.43, 95 %, CI:1.04-1.96), having allergic rhinitis (OR: 7.86, 95 % CI: 5.89-10.50) and eczema (OR: 3.85, 95 % CI: 2.10-7.08). Conclusions: Families are suggested to adopt strategies to reduce exposure to outdoor air pollutants and contain indoor allergens. More studies are necessary to further explore the effects of modifying and changing these risk factors.

Three Consecutive Episodes of Thunderstorm Asthma in Ahvaz, Iran: the Possible Role of Conocarpus Pollen.

Background: The aim of this study is to evaluate the clinical pattern of thunderstorm asthma (TA) and the possible environmental hypotheses involved in the escalation of these epidemics. Materials and Methods: This retrospective descriptive study examined patients with respiratory problems referred to the clinics and emergency departments in Ahvaz, Iran during 2013-2016 periods following the first episodes of rainfall in autumn. The seasonal profile of airborne pollens and fungal spores in Ahvaz were characterized and clinical and spirometry findings of 443 patients were evaluated. Results: Of 56,000 people referred to the emergency department due to respiratory problems associated with the first rainfall in Khuzestan province, 91.4% displayed asthma-like symptoms and 71.3% had a history of allergic rhinitis. According to the results of spirometry test 38%, 52.9%, and 9.1% of patients had normal, obstructive, and restrictive patterns, respectively. Our results highlight the importance of allergic rhinitis as risk factors of TA epidemics. In terms of pollen, seasonal pollen integral was much higher in autumn than in winter. Conclusion: Our results highlight the importance of seasonal allergy and rhinitis as risk factors for thunderstorm asthma epidemics.

Comparison of high-flow oxygenation with noninvasive ventilation in COPD exacerbation: A crossover clinical trial.

OBJECTIVES: To compare the therapeutic effects of high-flow-oxygen-Therapy (HFT) and noninvasive-ventilation (NIV) for stabilizing chronic obstructive pulmonary disease during exacerbation. METHODS: In this randomized clinical trial at Masih-Daneshvari hospital, between July 2019 and Oct 2019, 30 exacerbated-COPD-patient with PaCO2 64.58 ± 11.61 mm Hg, Respiratory Rate 24.43 ± 2.75, and PH 7.31 ± 0.02 were divided into two groups, N = 15. By a simple randomized allocation, patients receive either NIV or HFT for 1 hour, and following a washout period of 30 minutes, they switched to the other treatment option. Arterial Blood Gas Parameters, as well as Respiratory Rate (RR), Dyspnea Score, Heart Rate (HR), and Oxygen Saturation (SO2 ), were compared before and after the intervention and between groups. RESULTS: Baseline patient characteristics were similar in the two groups. Pre and post-analysis revealed that in both groups, all improved significantly. After the first period, there was no difference in all parameters between groups except for SO2 which was significantly higher in HFT (%92.1 ± 1) than that of NIV (%89 ± 1), P = .001. Likewise, following the washout period, patients in HFT and NIV had a dyspnea score of 1.93 ± 0.7 and 2.73 ± 0.9, respectively, P = .01. No carryover-effect and was observed but the period effect was significant for some outcomes. A significant improvement in SO2 and HR was observed by HFT according to treatment effect by combining two periods' results. During the study, no side effects were reported. CONCLUSION: In this short-term study HFT appears feasible for patients with COPD exacerbation to reduce dyspnea score and improve respiratory distress.

Developing "Code of Ethics for Medical Professionals, Medical Council of Islamic Republic of Iran".

BACKGROUND: The medical profession has always been an inspiration for human societies throughout its diverse history. This position and historical authority in the field of ethics has had a different and higher status, in such a way that many of the norms of general ethics and professional ethics, especially principles, such as trust, confidentiality and respect for human dignity, have been developed by medical professionals. Developing guidelines of general and professional ethics is one of the inherent duties of the Medical Council of the Islamic Republic of Iran (IRIMC) as a professional organization. In this regard, the Supreme Council of IRIMC has approved the "Code of Ethics for Medical Professionals" and, in accordance with its legal authority, has annexed it to the disciplinary regulations of IRIMC. METHODS: A draft document, the result of extensive literature review, was discussed in 27 expert panel meetings and after receiving and endorsing the stakeholders' point of view, was approved by the IRIMC Supreme Council. RESULTS: The first edition of "Code of Ethics for Medical Professionals, Medical Council of Islamic Republic of Iran" was developed on July 6, 2017 by the Supreme Council of IRIMC. The guideline was set to take effect one year after its enactment. The first edition was revised and completed and final edition was adopted on August 9, 2018 by IRIMC in 13 chapters and 140 articles (original full text is available in the Supplementary file 1). CONCLUSION: According to the approved decision by the Supreme Council of IRIMC on May 10, 2018, the final edition takes effect as of October 7, 2018.

Blood Purification Techniques, Inflammatory Mediators and Mortality in COVID-19 Patients.

BACKGROUND: Inflammatory mediators are an important component in the pathophysiology of the coronavirus disease 2019 (COVID-19). This study aimed to assess the effects of reducing inflammatory mediators using hemoperfusion (HP) and continuous renal replacement therapy (CRRT) on the mortality of patients with COVID-19. MATERIALS AND METHODS: Twelve patients with confirmed diagnosis of COVID-19 were included. All patients had acute respiratory distress syndrome (ARDS). Patients were divided into three groups, namely, HP, CRRT and HP+CRRT. The primary outcome was mortality and the secondary outcomes were oxygenation and reduction in inflammatory mediators at the end of the study. RESULTS: Patients were not different at baseline in demographics, inflammatory cytokine levels, and the level of acute phase reactants. Half of the patients (3 out of 6) in the HP+CRRT group survived along with the survival of one patient (1 out of 2) in the HP group. All four patients in the CRRT group died. Serum creatinine (SCr), Interleukin-1 (IL1), Interleukin-6 (IL6), Interleukin-8 (IL8), partial pressure of oxygen (PaO2), O2 saturation (O2 sat), and hemodynamic parameters improved over time in HP+CRRT and CRRT groups, but no significant difference was observed in the HP group (All Ps > 0.05). CONCLUSION: Combined HP and CRRT demonstrated the best result in terms of mortality, reduction of inflammatory mediators and oxygenation. Further investigations are needed to explore the role of HP+CRRT in COVID-19 patients.

Effects of PM2.5 and NO2 on the 8-isoprostane and lung function indices of FVC and FEV1 in students of Ahvaz city, Iran.

The aim of this study was to determine the correlation between PM2.5 and NO2 pollutants and oxidative stress marker (8-isoprostane) and lung function tests (FVC and FEV1) in healthy children who were living and studying in three different areas of Ahvaz city including A1: Naderi site with high traffic, A2: Alavi Alley site with average traffic, and A3: Ein 2 site with low traffic (a rural area on the suburb of Ahvaz). 30 students in the 12-13 year-old range were selected from each studied zone (1, 2 and 3 sites) during three months of year. Of each student, one sample was taken every two weeks to measure 8-isoprostane of exhaled breath condensate (EBC). Air pollution data were collected from three air quality monitoring stations. Also, the relationship between air pollution and 8-isoprostane as well as lung function tests were determined using generalized estimating equations (GEE). The mean concentration of PM2.5 and NO2 in A1, A2 and A3 areas were 116, 92 and 45 (µg/m3) also 77, 53 and 14 (ppb) respectively. Among all studied students, there was a significant correlation between the increase of mean concentration of PM2.5 and NO2 in 1-4 before sampling day, increased 8-isoprostane concentration and decreased FEV1, while there was no significant correlation between them and decreased FVC. In A1 site, an increase in IQR (13 µg/m3) PM2.5 and IQR (6.5 ppb) NO2 on 1-4 days before sampling was associated with 0.38 unit (95% CI: 0.11, 0.65) and 1.1 unit (95% CI: 0.85, 1.35) increase in 8-isoprostane concentration, also decreased 121 ml and 190 ml FEV1, respectively. Results showed that the short-term exposure to traffic-related air pollution can decrease the values of lung function indices and increase the oxidative stress. It may adversely affect children's lungs.

Prevalence of asthma and other allergic conditions in adults in Khuzestan, southwest Iran, 2018.

BACKGROUND: Health information on the dimensions of asthma and allergic conditions in Khuzestan Province, as a major industrial and polluted area in Iran as and the Middle East, is inadequate. This study was performed to measure the prevalence of asthma and other allergic conditions in adults in Khuzestan Province. METHODS: This population-based cross-sectional study was carried out in 17 villages and 27 cities of Khuzestan Province during the years 2017-2018 on 20 to 65 year old respondents. Two-stage cluster sampling was used. The ECRHS (European Community Respiratory Health Survey) questionnaire was completed for individuals with additional questions regarding other allergic conditions. RESULTS: In the study, 5720 questionnaires were distributed of which 5708 were returned. The prevalence of current asthma was 8.5% and that of asthma-like symptoms was 19.0%. The most common symptoms of asthma were nocturnal cough (13.6%), chest tightness (12.3%) and wheezing (13.1%). The prevalence of allergic rhinitis (AR), eczema and airway hyperresponsiveness were 27.2, 10.7, and 38.7%, respectively. The prevalence of current asthma was strongly correlated with age, current location (city, village), and the smoking status of respondents (p < 0.05). CONCLUSION: The prevalence of current asthma and asthma-like symptoms in Khuzestan Province is almost twice as high as in Iran. Given the high prevalence of symptoms of airway hyperresponsiveness in the entire province, it is necessary to take environmental measures to mitigate the emergence of new cases of asthma among the residents. In addition, surveillance studies are necessary to monitor the trends in the prevalence of asthma in this province.

Short-term effects of air pollution on respiratory mortality in Ahvaz, Iran.

Background: Urban air pollutants may affect respiratory mortality. This study was conducted to investigate this effect in Ahvaz, one of the most polluted cities in the world. Methods: The impact of 7 major air pollutants including O3, PM10, NO2, CO, and SO2 were evaluated on respiratory mortality in different gender and age groups using a quasi-Poisson, second degree polynomial constrained, distributed lag model, with single and cumulative lag structures adjusted by trend, seasonality, temperature, relative humidity, weekdays, and holiday. Data were analyzed using the dlnm package in R x64 3.2.5 software. Significance level was set at less than 0.05. Results: In adjusted models, for each IQR increase of O3 in the total population, the risk ratio (RR) for respiratory deaths in 0 to 14- day lags was, respectively, 1.009 (95% CI:1.001-1.016) and 1.009 (95% CI:1.002-1.017), and it was 1.021 (95% CI: 1.002-1.040) in cumulative 0 to 14- day lags. For PM10, in the total population and in adjusted models after 0 to 14- day lags and in cumulative lags of 0 to 14 for an IQR increase in the mean concentration of PM10, the RR for respiratory deaths increased significantly and was, respectively, 1.027 (95% CI:1.002-1.051), 1.029 (95% CI:1.006-1.052), and 1.065 (95% CI:1.005-1.128). NO2 showed a significant association with respiratory deaths only in the 18 to 60 year- old age group and in 9- day lags (RR= 1.318, 95% CI:1.002-1.733). Finally, the results showed that for an IQR increase in the mean concentration of CO and SO2, the adjusted RR for respiratory deaths in 9- day lags in the total population was, respectively, RR= 1.058 (95% CI:1.008-1.111) and 1.126 (95% CI:1.034-1.220). Conclusion: Air pollution in Ahvaz is probably causing increased respiratory mortality.

Association of esophageal dilatation in chest CT scan with gastroesophageal reflux disease: A case control study.

The presence of increased air bubble in the lumina of esophagus on a chest CT scan may be associated with esophageal disorders. The purpose of this study was to determine the association between the appearance of air bubbles on chest CT scan and gastroesophageal Reflux Disease (GERD). In this case-control study, thirty-two patients with endoscopically proved GERD and 32 subjects without GERD underwent chest computed tomography (CT) scanning. Esophageal dilatation (ED) was defined as the presence of air bubbles greater than 10 mm in the supra ventricle (SV) and ventricle (CV), and air bubbles >15 mm in the ventricle to the lower esophageal sphincter (V-LES). The results were compared between the two groups. The GERD patients included 16 (50%) males with a mean age of 58.5±11.2 years and the control group included 17 (54.8%) males and 14 (45.1%) females with a mean age of 66.7±10.5 years. There was a significant relationship between the presence of GERD and esophageal dilation (ED) in the V-LES sections on the CT scan (P=0.002). The mean size of the air bubbles in the V-LES section was 11.73 mm in the case group in comparison to 4.32 mm in the control group (P<0.001).  The size and location of the air bubbles in the esophagus can vary and be important. The possibility of GERD increases in the presence of esophageal dilation on CT scan.

Association between cancer risk and polycyclic aromatic hydrocarbons' exposure in the ambient air of Ahvaz, southwest of Iran.

Nowadays, a large number of health endpoints such as disease rates, treatment costs, and death, by air pollutants, have been a serious health problem for humans. One of the most hazardous air pollutants, which is highly dangerous for human health, is polycyclic aromatic hydrocarbons (PAHs). The existence of the emission of industries' pollutants and seasonal variations are the primary agents affecting PAHs' concentration. The purposes of this study were to calculate the cancer risk and measure PAHs' exposure in the ambient air of Ahvaz, southwest of Iran, during 2017. Three distinct areas ((S1) industrial, (S2) high traffic, and (S3) residential) of Ahvaz metropolitan were selected. Omni sampler equipped with polytetrafluoroethylene (PTFE) filters were used for active sampling of PAHs. To detect the level of PAHs, gas chromatography with mass spectrometry (GC/MS) was used. Incremental lifetime cancer risk (ILCR) and lifetime average daily dose (LADD) were used to estimate the health risk caused by PAHs. The results showed that the residential and industrial areas had the lowest and highest level of PAHs. Moreover, the average levels of PAHs in industrial, high traffic, and residential areas were 8.44 ± 3.37, 7.11 ± 2.64, and 5.52 ± 1.63 ng m-3, respectively. Furthermore, ILCR in autumn and winter was higher than EPA standard, 0.06307 and 0.04718, respectively. In addition, ILCR in different areas was significantly higher than standard. Research findings imply that the levels of exposure to PAHs can increase ILCR and risk of health endpoint. The cancer risk attributed to PAHs should be further investigated from the perspective of the public health in metropolitans.

Lag time structure of cardiovascular deaths attributed to ambient air pollutants in Ahvaz, Iran, 2008-2015.

OBJECTIVES: There are few studies about the association between breathing polluted air and increased risk of cardiovascular diseases and cardiac death in the Middle East. This study aimed to investigate the relation between air pollutants and cardiovascular mortality (based on ICD-10) in Ahvaz. MATERIAL AND METHODS: In this ecological study, the data about cardiovascular disease mortality and air pollutants from March 2008 until March 2015 was inquired from the Ahvaz City Authority and the Khuzestan Province Environmental Protection Agency. The quasi-Poisson, second degree polynomial constrained, distributed lag model; using single and cumulative lag structures, adjusted by trend, seasonality, temperature, relative humidity, weekdays and holidays was used for the data analysis purposes. RESULTS: Findings indicated a direct significant relation between an interquartile range (IQR) increase in ozone and cardiovascular deaths among men after 3 days' lag. There was also a significant relation between an IQR increase in particulate matter below 10 µm and cardiovascular deaths for all people, over 60 years old and under 18 years old after 3 and 13 days' lags. There was a significant relation between an IQR increase in nitrogen dioxide and carbon monoxide, and cardiovascular deaths in the case of under 18-year-olds (in the lag 11) and over 60-year-olds (in the lag 9), respectively. We finally found a significant association between an IQR increase in sulfur dioxide and cardiovascular deaths in the case of men, under 18-year-olds and from 18- to 60-year-olds in the lag 9, 0, and 11, respectively (p-values < 0.05). CONCLUSIONS: It appears that air pollution is significantly associated with cardiovascular deaths in Ahvaz City. Int J Occup Med Environ Health 2018;31(4):459-473.

Health risk assessment on human exposed to heavy metals in the ambient air PM10 in Ahvaz, southwest Iran.

Heavy metals (HM) are one of the main components of urban air pollution. Today, megacities and industrial regions in southwest of Iran are frequently suffering from severe haze episodes, which essentially caused by PM10-bound heavy metals. The purpose of this study was to evaluate the health risk assessment on human exposed to heavy metals (Cr, Ni, Pb, and Zn) in the ambient air PM10 in Ahvaz, southwest Iran. In this study, we estimated healthy people from the following scenarios: (S3) residential site; (S2) high-traffic site; (S1) industrial site in Ahvaz metropolitan during autumn and winter. In the current study, high-volume air samplers equipped with quartz fiber filters were used to sampling and measurements of heavy metal concentration. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was utilized for detection of heavy metal concentration (ng m-3). Also, an estimate of the amount of health risk assessment (hazard index) of Cr, Ni, Pb, and Zn of heavy metal exposure to participants was used. Result of this study showed that the residential and industrial areas had the lowest and the highest level of heavy metal. Based on the result of this study, average levels of heavy metal in industrial, high-traffic, and residential areas in autumn and winter were 31.48, 30.89, and 23.21 µg m-3 and 42.60, 37.70, and 40.07 µg m-3, respectively. Based on the result of this study, the highest and the lowest concentration of heavy metal had in the industrial and residential areas. Zn and Pb were the most abundant elements among the studied PM10-bound heavy metals, followed by Cr and Ni. The carcinogenic risks of Cr, Pb, and the integral HQ of metals in PM10 for children and adults via inhalation and dermal exposures exceeded 1 × 10-4 in three areas. Also, based on the result of this study, the values of hazard index (HI) of HM exposure in different areas were significantly higher than standard. The health risks attributed to HM should be further investigated from the perspective of the public health in metropolitans. The result of this study showed increasing exposure concentrations to heavy metal in the studied scenarios have a significant potential for generating different health endpoints, while environmental health management in ambient air can cause disorders in citizenship and causing more spiritual and material costs.

Acute effects of air pollution on spontaneous abortion, premature delivery, and stillbirth in Ahvaz, Iran: a time-series study.

Living in areas with high air pollution may have adverse effects on human health. There are few studies about the association between breathing polluted air and adverse pregnancy outcomes in the Middle East. The aim of this study was to determine the relationship between air pollution and spontaneous abortion, premature birth, and stillbirth in Ahvaz. A time-series study was conducted. Data about spontaneous abortion, premature deliveries, and stillbirth was collected from Ahvaz Imam Khomeini Hospital. Air pollution data including NO, CO, NO2, PM10, SO2, O3, and climate data were, respectively, collected from the Environmental Protection Agency and the Khuzestan Province Meteorology Office from March 2008 until March 2015. The relationship between air pollutants with the number of abortions, premature births, and stillbirths was found using a quasi-Poisson distributed lag model, adjusted by trend, seasonality, temperature, relative humidity, weekdays, and holidays. The average daily dust in Ahvaz on 7.2% days of the year was higher than 500 µg/m3 (very dangerous). Findings from this study indicate a significant association between each 10-unit increase in SO2 and spontaneous abortion in lag 0 and 9 days. There was a significant relation between each 10-unit increase in NO2 and CO, and premature birth in lag 0. Also, we found a significant association between each 10-unit increase in CO and premature delivery in lag 1; PM10 and premature delivery in lags 10, 11, and 12; and NO and premature delivery in lags 3, 4, 10, 11, 12, and 13 (p value < 0.05). Contact with polluted air during pregnancy may increase adverse pregnancy outcomes and stillbirth. Pregnant women should avoid polluted air.

Forced Expiratory Flow at 25-75% as a Marker for Airway Hyper Responsiveness in Adult Patients with Asthma-like Symptoms.

BACKGROUND: The aim of the present study was threefold: to assess the association between baseline FEF25-75 and Airway Hyper-responsiveness (AHR), to specify whether a decrease in FEF25-75 may reflect severe hyper-responsiveness, and finally to confirm a FEF 25-75 cut-off value. MATERIALS AND METHODS: In a cross sectional study in Imam Khomeini Hospital, Ahvaz, patients suffering from respiratory symptoms due the 2013 autumn rainfall with normal FEV1 and FEV1/FVC were evaluated by methacholine challenge test. Those with PD20<1000, 10002000 µg were classified as severe, moderate and mild AHR, respectively. Data were analyzed using Chi-square, Independent t-test, One-way ANOVA and Receiver Operating Characteristic (ROC) curve. RESULTS: Among the 234 patients, mean baseline FEF25-75 was 84.2±22.7% for 54 patients having a negative bronchial provocation test result and 70.9±19.2% for 179 patients with a positive bronchial provocation test result (P < 0.0001). No change was observed in the median PD20 among patients with a higher baseline FEF25-75. ROC analysis showed that FEF25-75 could potentially be a predictor of AHR, but it could not confirm the cut-off value of FEF25-75 for these patients. CONCLUSION: When asthma begins, AHR could be predicted by impaired FEF25-75 with normal FEV1 and FEV1/FVC. However, we could not determine a cut-off value, and no association was found between a greater impairment of FEF25-75 and a more severe AHR.