Effect of oral contraceptives on respiratory function

The present study was carried out to assess the lung functions in oral contraceptive administered women. Lung function tests were carried out with Spirometer (Vitallograph Compact II). A significant increase in vital capacity (VC) was observed in these women as compared to normal control. There was also a significant decrease in forced expiratory volume in 1 sec./vital capacity (FEV1/VC%) and forced expiratory volume in 1 sec./forced vital capacity (FEV1/FVC%) among oral contraceptive administered women as compared to controls. Further, a significant increase in peak expiratory flow rate (PEF), reduction in forced expiratory flow rate (FEF75-85%) and FEF75% were observed among oral contraceptive administered women as compared to controls. The increase in VC and PEF might be due to the synthetic form of progesterone (progestins) present in oral contraceptive pills which causes hyperventilatory changes. Synthetic progesterone during luteal phase of menstrual cycle might increase the static and dynamic volumes of lung i.e. VC and PEF. But FEF75% showed a decrease which might be due to the lower neuromuscular coordination during breathing.     

Cardiorespiratory responses to submaximal incremental exercise are not affected by one night's sleep deprivation during the follicular and luteal phases of the menstrual cycle

The purpose of the study was to investigate the effects of one night's sleep deprivation on the cardiorespiratory responses to exercise during the follicular and luteal phases of the menstrual cycle. We have studied nine, healthy females aged 24-35 years with regular menstrual cycles. Each subject performed spirometric tests at rest and then an incremental exercise testing during 11-13 days of follicular phase and 22-24 days of luteal phase following one normal night's sleep or one night's sleep loss. Compared with resting values exercise produced significant increases in cardiorespiratory variables including oxygen uptake (VO2), carbon dioxide production (VCO2), tidal volume (VT), respiratory rate (RR), minute ventilation (VE), systolic blood pressure, heart rate (HR) and respiratory quotient (R). However, it did not alter significantly diastolic blood pressure, end-tidal PO2 (PETO2), end-tidal PCO2 (PETCO2) and arterial oxygen saturation (SaO2). Spirometric variables which include forced vital capacity (FVC), forced expiratory volume in one s (FEV1), FEV1/FVC%, forced expiratory volume in three s (FEV3), forced expired flow from 25-75% of FVC (FEF 25-75%), forced expired flow at 25% of FVC (FEF 25%), forced expired flow at 50% of FVC (FEF 50%), forced expired flow at 75% of FVC (FEF 75%), forced expired flow from 75-85% of FVC (FEF 75-85%), peak expiratory flow (PEF), expiratory reserve volume (ERV), inspiratory capacity (IC) and maximal voluntary ventilation (MVV) and cardiorespiratory variables were not different between the cycle phases after one normal night's sleep or one night's sleep deprivation. Neither menstrual cycle phase nor sleep deprivation affected spirometric and cardiorespiratory parameters. We suggest that one night's sleep deprivation does not produce alterations in spirometric parameters and cardiorespiratory responses to submaximal incremental exercise during the follicular and luteal phases.     

Respiratory effects of non-tobacco cigarettes.

Data from the Tucson epidemiological study of airways obstructive disease on smoking of non-tobacco cigarettes such as marijuana were analysed to determine the effect of such smoking on respiratory symptoms and pulmonary function. Among adults aged under 40, 14% had smoked non-tobacco cigarettes at some time and 9% were current users. The prevalence of respiratory symptoms was increased in smokers of non-tobacco cigarettes. After tobacco smoking had been controlled for men who smoked non-tobacco cigarettes showed significant decreases in expiratory flow rates at low lung volumes and in the ratio of the forced expiratory volume in one second to the vital capacity. This effect on pulmonary function in male non-tobacco cigarette smokers was greater than the effect of tobacco cigarette smoking. These data suggest that non-tobacco cigarette smoking may be an important risk factor in young adults with respiratory symptoms or evidence of airways obstruction.     

Bronchial lability in allergic rhinitis.

The aim of this study was to assess the relationship between exercise bronchial lability and the changes in pulmonary function over a one year period in allergic rhinitis. Eighty four nonsmoking male medical students of whom twenty two were allergic rhinitics were studied. Pulmonary function status was significantly lower and exercise bronchial lability significantly higher in the allergics. Over a one year period the mean decline in the forced expiratory volume in one second (FEV1) was three times greater and in the forced expiratory flow rate in the middle half of the vital capacity (FEF 25-75%) 50% greater among the allergics. The change in FEV1 was positively related to the bronchial lability, indicating that greater bronchial lability was associated with less decline in pulmonary function in these subjects.     

Pulmonary functions in air conditioner users

Air conditioning may affect human health since it has profound effect on our environment, than just lowering temperature. The present study was planned to assess the effect of air conditioners (AC) on pulmonary functions in young healthy non-smoker males. The study group comprised of ten subjects who were using AC's in their cars for at least 1 hr daily since last 6 months. While ten subjects who did not use AC at all served as controls. The pulmonary functions were assessed using PK Morgan 232 spirometer in a closed room. The peak expiratory flow rate (PEFR) and Forced expiratory flow between 25-75% of vital capacity (FEF25-75) were significantly reduced in subjects using car AC's. Inspiratory flow rates also showed a trend towards decline in AC users but could not reach the level of significance. The lung volumes and capacities were not significantly different in the two groups except for forced expiratory volume in 0.5 sec (FEV 0.5 sec), which also decreased in AC users. The airway resistance and lung compliance did not show significant change. In the presence of normal FEV1, reduced FEF25-75% which is the flow rate over the middle half of vital capacity, is an evidence of mild airflow limitation. The result is suggestive of predisposition of AC users towards respiratory disorders in form of mild airflow restriction.     

肺高分辨率CT马赛克样灌注与小气道功能指数的相关分析

目的探讨肺小气道病变时高分辨率CT（HRCT）所示马赛克样灌注与小气道功能指标的相关性。方法选择HRCT上显示马赛克样灌注病例80例,由3位放射诊断医师对马赛克样灌注与小气道功能指标的相关性进行分析。结果马赛克样灌注与FEF 25%呈负相关（r=-0.48,P〈0.05）,与FEV1、FEF50%无相关性（r值分别为-0.27和-0.19,P〉0.05）。而空气潴留的程度与FEF25%、FEV1呈负相关（r值分别为-0.62和-0.41,P〈0.05）,与FEF 50%无相关性（r=-0.29,P〉0.05）。结论马赛克样灌注作为小气道病变的主要征象,其与FEF 25%具有良好的相关性,而空气潴留作为小气道阻塞的直接后果,其程度与FEV1、FEF 25%具显著相关性,即使肺功能检查结果正常时,也可以辅助诊断临床可疑的小气道阻塞。     

Lung function development in Indian men and women during late adolescence and early adulthood--a longitudinal study

Lung function development was studied in a cohort of Indian men (n = 31) and women (n = 36), over a period of four years during late adolescence and early adulthood. Forced expiratory spirograms and peak expiratory flow rates were recorded at intervals of approximately two years. All volumes and flow rates were higher in men, but volume adjusted flow rates were higher in women. Forced vital capacity (FVC) forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF) were significantly higher in men even after standardizing for age, height and weight. Height and PEF increased significantly in men and women over the four years. Volumes showed a greater increase whereas flow rates and volume adjusted flow rates showed a greater decrease in men. The decline in the forced expiratory flow in the middle half of the FVC (FEF 25-75%) was significantly less in women. These results suggest that although lung size is greater in men, small airway dynamics may be better in young women.     

Combined effects of cigarette smoking and sulfur dioxide on lung function in Koreans

Both smoking and air pollution impair lung function, but little information is available regarding the combined effects on the pulmonary system. The potential effects of smoking and sulfur dioxide (SO2) were examined on lung function. Data were collected from family health examinations of 867 subjects, aged 20-86 yr, in a Korean community. The subjects responded to a questionnaire interview and completed lung function tests. Data on SO2 exposure were obtained from the Environmental Management Corporation. Studies showed that exposure to SO2 induced a short, marked decrease in forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) in smokers compared with nonsmokers. The effect lasted up to 30 h after exposure. Consequently, preventive efforts are necessary to reduce the risks that air pollution and smoking pose to the respiratory system.     

沙美特罗/丙酸氟替卡松对哮喘儿童肺功能的改善及临床意义

目的:观察沙美特罗/丙酸氟替卡松对哮喘儿童肺功能改善情况。方法:采用德国Jaeger公司的MasterscreenIOS测定仪,对61例支气管哮喘患儿在沙美特罗/丙酸氟替卡松治疗前后进行通气肺功能(F-V)和脉冲振荡(IOS)检测。观察用力肺活量(FVC)、第一秒用力呼气容积(FEV1)、最大呼气流速(PEF)、呼出25%肺活量时最大呼气流量(FEF25)、呼出50%肺活量时最大呼气流量(FEF50)、呼出75%肺活量时最大呼气流量(FEF75);呼吸阻抗(Zrs)、气道总阻力(R5)、中心气道阻力(R20)、响应频率(Fres)。结果:沙美特罗/丙酸氟替卡松治疗后FVC、FEV1、PEF均明显升高(P<0.001),而Zrs、R5、R20、Fres均明显降低(P<0.05),两者检查结果均有显著统计学意义。结论:吸入沙美特罗/丙酸氟替卡松能改善哮喘儿童的肺通气功能,降低气道阻力,是治疗儿童哮喘的理想药物之一。     

Lung function tests in electroplaters of East Delhi

The presence of high concentration of metals (Cr, Cd, Co, Ni, Pb, etc.) in the work place environments of various types of industries including electroplating units are well known to influence respiratory system. Pulmonary function tests including forced expiratory capacity (FVC), volumes, mechanics and slow vital capacity (SVC) were studied in 80 males, divided into group I and Group II of 40 each were drawn from electroplating and non-electroplating units, respectively from East Delhi factories. The lung function tests were measured using computerized Spiro-232 of P.K. Morgan, Values of majority of lung function parameters such as FEV1/FVC%, FEF50 FEF75, PIFR, FIF50, MVV and SVC were decreased in electroplaters, perhaps due to the exposure to metals and their lower anthropmetric results as compared with non electoplaters. Where as results of TLC, FRC, RV & RV/ TLC% were higher in electroplaters and this may be attributed to higher values of RV in them as compared with non electroplaters.     

Pulmonary function in patients with diabetes mellitus.

The present study was carried out to assess the lung functions in oral medicated and insulin administered patients with normal controls. 20 subjects were selected as the study group for oral medication (Group I), 20 subjects were selected as the study group for insulin treatment (Group II) and 40 subjects were selected as normal controls. Age group of Group I and Group II were 51.25 +/- 6.28 and 50.8 +/- 6.56 respectively and controls were age and height matched. Seventeen patients of Group I were undergoing treatment for the last 10-20 years and 20 patients in Group II were undergoing treatment for the last 30 years. Only male subjects were selected for the study. Lung function test were carried out with Spirometer (Vitallograph Compact II). A significant reduction in forced expiratory volume/forced vital capacity (FEV1/FVC%) was observed in oral pills used subjects and insulin administered subjects as compared to controls. Significant decrease in forced expiratory flow rate (FEF25-75%) in group I subjects was also observed as compared to controls. Forced mid flow time (FMFT) showed a significant increase in group II in comparison to controls. These changes clearly show the expiratory flow rates are reduced both in orally medicated and insulin administered patients. Increase in FMFT in group I may be due to the reduced respiratory ability to carry out the FVC test along with the side effects of oral medication for diabetes mellitus.     

The effect of tiotropium on the pulmonary diffusing capacity

To our knowledge, there is no data on the effect of tiotropium on pulmonary gas exchange in healthy subjects. The aim of this study was to assess the effects of tiotropium on pulmonary diffusing capacity. Twenty-one healthy volunteers were enrolled for a prospective, randomized, double-blind, placebo-controlled study. Spirometric measurements, including pulmonary-diffusing capacity, were obtained before and after inhalation of drug or placebo. There was a significant decrease in forced vital capacity (FVC) and, consequently, an increase in the forced expiratory volume in one second (FEV1) to FVC ratio after placebo inhalation (p < 0.05), but no changes were found for percent-predicted FVC, FEV1, percent-predicted FEV1, percent-predicted forced expiratory flow (FEF25%-75%), percent-predicted peak expiratory flow (PEF), diffusing capacity of the lung for carbon monoxide (DLCO), single-breath alveolar volume (VA) and DLCO/VA ratio when compared with the baseline. Tiotropium inhalation caused a significant increase in FVC, percent-predicted FEV1, FEV1/FVC and percent-predicted FEF25%-75%, although the decrease in DLCO was insignificant (12.4 +/- 0.9 to 11.4 +/- 0.9). In conclusion, tiotropium does not change the pulmonary-diffusing capacity in healthy volunteers.     

Effect of short term 'Pranayam' practice on breathing rate and ventilatory functions of lung.

Thirty three normal male and forty two normal female subjects, of average age of 18.5 years, underwent six weeks course in 'Pranayam' and their ventilatory lung functions were studied before and after this practice. They had improved ventilatory functions in the form of lowered respiratory rate (RR), and increases in the forced vital capacity (FVC), forced expiratory volume at the end of 1st second (FEV1%), maximum voluntary ventilation (MVV), peak expiratory flow rate (PEFR-lit/sec), and prolongation of breath holding time.     

小气道功能指标在儿童哮喘病情严重程度评估及临床诊断中的应用

目的 探讨小气道功能指标在儿童哮喘病情严重程度评估及临床诊断中的应用价值。方法 选取2013年5月至2016年4月于郑州市第二人民医院56例哮喘急性发作期病儿作为哮喘组,并根据哮喘急性发作严重程度分为轻度(21例)、中度(20例)和重度(15例)三个亚组,同时选取同期、年龄相仿及性别相匹配的30例因其他原因引起喘息咳嗽的慢性炎症病儿和32例入院检查健康儿童分别作为非哮喘组和对照组,收集各组儿童一般资料,采用肺功能测定系统检测各组儿童用力肺活量(FVC)、最大呼气流量(PEF)、第1秒用力呼气容积(FEV1)和FEV1/FVC比值、呼出25%肺活量时呼气流速(FEF25%)、呼出50%肺活量时呼气流速(FEF50%)、呼出75%肺活量时呼气流速(FEF75%)、最大中期呼气流速(MMEF)等指标。结果 与对照组比较,非哮喘组和哮喘组病儿FVC、FEV1、PEF、FEF25%、FEF50%、FEF75%和MMEF等指标均显著降低(P<0.05),且哮喘组病儿上述指标显著低于非哮喘组[(1.42±0.36)L比(1.85±0.47)L、(1.25±0.32)L比(1.42±0.41)L、(2.68±0.64)L比(3.25±0.77)L/s、(2.54±0.65)L/s比(3.74±0.68)L/s、(1.58±0.36)L/s比(2.24±0.71)L/s、(0.61±0.37)L/s比(1.02±0.41)L/s、(1.42±0.49)L/s比(1.89±0.68)L/s)](均P<0.05),而三组病儿FEV1/FVC指标差异无统计学意义(P>0.05)。哮喘急性发作期不同程度病儿用力呼出25%肺活量的呼气流量占预计值百分比(FEF25pred%)、用力呼出50%肺活量的呼气流量占预计值百分比(FEF50pred%)、用力呼出75%肺活量的呼气流量占预计值百分比(FEF75pred%)、最大呼气中期流量占预计值的百分比(MMEFpred%)等指标比较差异有统计学意义(P<0.05),且随着病情程度增加,病儿FEF25pred%、FEF50pred%、FEF75pred%、MMEFpred%等指标呈现明显降低趋势(P<0.05),FEF25%和FEF75%指标在不同严重程度哮喘病儿中异常率比较,差异有统计学意义(P<0.05),FEF50%和MMEF指标比较差异无统计学意义(P>0.05),其中FEF25%主要表现为轻度异常,而FEF75%主要表现为重度异常。结论 小气道功能指标在儿童哮喘病情严重程度评估及临床诊断具有重要意义,随着病情加剧,小气道功能指标明显降低,且异常率显著增加。     

Safety pharmacology of the respiratory system: Techniques and study design

The known effects of drugs from a variety of pharmacologic/therapeutic classes on the respiratory system and worldwide regulatory requirements support the need for conducting respiratory evaluations in safety pharmacology. The objective of these studies is to evaluate the potential for drugs to cause secondary pharmacologic or toxicologic effects that influence respiratory function. Changes in respiratory function can result either from alterations in the pumping apparatus that controls the pattern of pulmonary ventilation or from changes in the mechanical properties of the lung that determine the transpulmonary pressures (work) required for lung inflation and deflation. Defects in the pumping apparatus are classified as hypo- or hyperventilation syndromes and are evaluated by examining ventilatory parameters in a conscious animal model. The ventilatory parameters include respiratory rate, tidal volume, minute volume, peak (or mean) inspiratory flow, peak (or mean) expiratory flow, and fractional inspiratory time. Defects in mechanical properties of the lung are classified as obstructive or restrictive disorders and can be evaluated in animal models by performing flow-volume and pressure-volume maneuvers, respectively. The parameters used to detect airway obstruction include peak expiratory flow, forced expiratory flow at 25 and 75% of forced vital capacity, and a timed forced expiratory volume, while the parameters used to detect lung restriction include total lung capacity, inspiratory capacity, functional residual capacity, and compliance. Measurement of dynamic lung resistance and compliance, obtained continuously during tidal breathing, is an alternative method for evaluating obstructive and restrictive disorders, respectively, and is used when the response to drug treatment is expected to be immediate (within minutes post-dose). The species used in the safety pharmacology studies conducted in our laboratory are the same as those used in toxicology studies since pharmacokinetic and toxicologic/pathologic data are available in these species. These data can be used to help select test measurement intervals and doses and to aid in the interpretation of functional change. The techniques and procedures for measuring respiratory function parameters are well established in guinea pigs, rats, and dogs.     

Association between cytochrome P450 3A5 polymorphism and the lung function in Saskatchewan grain workers

OBJECTIVE: The activity of the enzymes that metabolize tobacco smoke may affect the susceptibility to chronic obstructive pulmonary disease (COPD). Cytochrome P450 (CYP) 3A5 is expressed selectively over CYP3A4 in human lung, but the association between the CYP3A5 polymorphisms and the airway injury is unknown. METHODS: Two hundred and six male Saskatchewan grain workers participated in this longitudinal study, and their lung function values of forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC), respiratory symptoms, smoking status, and the occupational history were analyzed. RESULTS: A significant interactive effect was observed between the CYP3A5 genotype and current smoking status on FEV1, and the annual decline rates of FEV1 and FVC in current smokers were greater among CYP3A5*1/*3 carriers than CYP3A5*3/*3 carriers (-48.7+/-16.4 vs. -31.5+/-4.7 ml/years, P=0.02; -27.4+/-18.9 vs. -5.8+/-6.5 ml/years, P=0.04). The incidences of chronic cough and COPD were also higher in current smokers with CYP3A5*1/*3 than in nonsmokers and current smokers with CYP3A5*3/*3. The adjusted odds ratios for chronic cough and COPD current smokers with CYP3A5*1/*3 versus nonsmokers with the CYP3A5*3/*3 genotype were 11.4 (P=0.009) and 4.3 (P=0.13), respectively. CONCLUSION: The results suggest that CYP3A5*1 may be a novel genetic risk factor for airway injury in smokers, and that CYP3A5 may play a role in airway injury owing to the bioactivation of chemicals in tobacco smoke.     

Comparison of fenoterol, isoproterenol, and isoetharine with phenylephrine aerosol in asthma

The bronchodilator effect of fenoterol hydrobromide (0.5, 1.25, and 2.5 mg) was compared with either isoproterenol (2.8 mg) or isoetharine (5 mg) with phenylephrine (1.25 mg) in a double-blind placebo-controlled study. When delivered by an intermittent positive-pressure breathing device to 24 nonsmoking young adult asthmatic subjects, fenoterol produced significant improvement in forced expiratory volume at 1 second (FEV1), in maximum midexpiratory flow (FEF25-75%), and in forced expiratory flow at 25 per cent of vital capacity (FEF25%) for 6 to 8 hours, whereas isoproterenol and isoetharine with phenylephrine produced improvement for 1 and 2 hours, respectively. The lowest dosage of fenoterol was as effective as the highest but had fewer adverse effects.     

Effects of the menstrual cycle on timing and depth of breathing at rest

Volume and timing components of resting ventilation were measured serially in 40 women aged 18 to 36 yr, during menstrual, follicular and luteal phases of menstrual cycle. Resting minute ventilation (VE) was significantly higher (P < 0.001) in luteal phase than in menstrual and follicular phases; in the two latter phases VE was almost equal. This increment in VE during the luteal phase was due to a significant rise (P < 0.001) in tidal volume (VT). Respiratory frequency (f) was unchanged throughout the cycle. Although there was a mean increases in inspiratory time (T1) during the luteal phase compared to the other two phases, the difference did not reach statistical significance. Duty cycle, T1/Ttot, was also unchanged throughout menstrual cycle. However, mean inspiratory flow, VT/T1, was significantly higher (P < 0.05 and P < 0.01) during luteal phase as compared to that during menstrual or follicular phases respectively. Pulmonary mechanics, as measured by forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and forced mid expiratory flow rate (FEF25%, 75%), were within normal limits and remained unaltered during the menstrual cycle. Therefore, in the absence of alteration of pulmonary mechanics, the luteal increase in ventilation and inspiratory flow suggests a possible role for progesterone in stimulating the respiratory drive, either centrally or through the peripheral chemoreceptors or by both.     

A study of lung function abnormalities in workers of cotton spinning shops

Lung function was studied by forced expiratory spirograms and measurement of peak expiratory flow in fourteen young male subjects of the age 20 to 30 years. Seven of the subjects were cotton spinners in small shops in Paharganj market with the duration of work from 1 to 3 years. The other seven subjects served as controls. All the subjects were of the same socio-economic status and were North Indians. Forced vital capacity; forced expiratory volume in 1 sec; forced expiratory volume in 1 sec expressed as a percentage of forced vital capacity; forced expiratory flow between 80 and 70 per cent, between 55 and 45 per cent, between 30 and 20 per cent and between 15 and 5 per cent of the forced vital capacity were determined from forced expiratory spirograms. Peak expiratory flow and FEB-80-70% were significantly lower in cotton spinners suggesting involvement of larger airways.     

Inhaled dopamine induces bronchodilatation in patients with bronchial asthma.

OBJECTIVE: To determine the probable bronchodilating effect of dopamine administered by inhalation route in patients with crisis of bronchial asthma and the effect of dopamine on bronchial motor tone. DESIGN AND METHOD: We have studied eighteen (18) patients with crisis of bronchial asthma, ten (10) subjects with bronchial hyperreactivity and ten (10) healthy subjects. Patients with other pulmonary or cardiac disease were excluded. All received by inhalation placebo (0.9% saline solution), dopamine at 0.5 microg/kg/min (controlled by heart rate and arterial pressure with a dynamap), and placebo. Respiratory parameters: forced vital capacity (FVC), forced expiratory volume at the first second (FEV1), forced maximal expiratory flow (FEFmax) and forced expiratory flow at the 50% of vital capacity (FEF50) were measured in each protocol period. Student's paired t test, Wilcoxon and Mann Whitney analysis were performed. RESULTS: After dopamine inhalation, there was an increase of FVC by 23% (p<0.001); an increase of FEV1 by 39% (p<0.0001); an increase of FEF50 by 33% (p<0.001) and an increase of FEFmax by 31% (p<0.001). There were no respiratory parameter changes in both, subjects with bronchial hyperreactivity and normal after dopamine inhalation. CONCLUSIONS: Inhaled dopamine induces bronchodilatation in patients with crisis of bronchial asthma. Inhaled dopamine neither alters basal bronchial tone in healthy subjects nor in subjects with bronchial hyperreactivity.