Effects of ascorbic acid on pulmonary functions in mild asthma

Twenty subjects with mild asthma took a short course of moderately high doses of Vitamin C (500 mg four times daily for 3 days and 1 g prior to spirometric evaluation). There were no differences in pulmonary functions just prior to and after therapy. There were no adverse reactions noted. If, as reported, Vitamin C has a beneficial effect in asthma, it does not appear to be due to a bronchodilatory effect.     

Patterns of recovery of pulmonary functions in severe acute bronchial asthma

The recovery of pulmonary function were studied in fifty patients of acute bronchial asthma receiving a standard therapeutic regime. Sixty-two per cent of patients had achieved 50% of their total improvement in peak expiratory flow rate (PEFR) within 24 hours (fast responders) as against slow responders. Duration of asthma, characteristics of present exacerbation, mean pulse rate and presence of pulsus paradoxus on admission did not differ in fast and slow responders. The rise in PEFR within 4 hours of starting treatment was highly significantly correlated with a higher PEFR at 24 hours and a faster recovery. The mean arterial PaCO2 was higher (P less than 0.02) in slow responding group and they were slightly older (P less than 0.01), had lower mean FVC (P less than 0.01), mean FEV1 (P less than 0.02) and PEFR (P less than 0.001). The mean PaO2 of less than 80 mm Hg at 48 hours was more common in those with delayed recovery of PEFR.     

Effects of asthma on pulmonary function in children. A longitudinal population-based study.

Data from a longitudinal study of childhood factors influencing the development of chronic obstructive lung disease were used to assess the effects of asthma on lung function development in male and female children. A population-based cohort of 602 white children, initially aged 5 to 9 yr, was observed prospectively for 13 yr. Spirometry was performed and a standardized respiratory and illness questionnaire was administered by trained interviewers on a yearly basis. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and forced expiratory flow between 25 and 75% of vital capacity (FEF25-75) were used as measures of lung function. The total number of children reporting asthma over the course of the study was 67. Male asthmatic subjects (n = 42) had larger average percentage of predicted FVC than nonasthmatic males (n = 277). Female asthmatic subjects (n = 23) had a lower average percentage of predicted FEV1 than nonasthmatic females (n = 260). In a multivariate analysis of the individual lung function measures, adjusting for previous level of pulmonary function, age, height, change in height, and personal and maternal smoking, males reporting active asthma had a significantly larger FVC than males with no history of asthma. In contrast, females with active asthma had a significantly smaller FEV1 than females with no history of asthma. Both males and females with active asthma had decreased FEF25-75. From our analysis, we would predict that a female who develops asthma at age 7 would experience a 5% reduction in FEV1 by age 10 and a 7% deficit by age 15.(ABSTRACT TRUNCATED AT 250 WORDS)     

哮喘与肺结核的关系探讨

目的　探讨哮喘与肺结核关系。方法 在河南省结核病流行病学调查的同时进行河南省哮喘流行病学调查。结果 肺结核病人的哮喘患病率为2.3%,非肺结核组的哮喘患病率为1.0%;肺结核病人中的哮喘患病率是非肺结核组的2倍。哮喘病人中的肺结核患病率为1.2%,非哮喘组的肺结核患病率为0.5%;哮喘病人的肺结核患病率为非哮喘的2倍多。结论 肺结核易并发哮喘,哮喘亦易并发肺结核,二者互为促发因素。     

Remission of asthma: a prospective longitudinal study from northern Europe (RHINE study).

The aim of the present study was to investigate the remission rate of adult asthma in a general population sample in relation to age, sex, asthma symptoms, allergic rhinitis and smoking. A follow-up of the random population samples from the European Community Respiratory Health Survey in Northern Europe was conducted from 1999-2001 on 1,153 individuals (aged 26-53 yrs) with reported asthma. Remission was defined as no asthmatic symptoms in two consecutive years and no current use of asthma medication. Remission rates per 1,000 person-yrs were calculated and Cox regression models, adjusting for confounders, were used to estimate hazard ratios (HR) with 95% confidence intervals (CI). An average remission rate of 20.2 per 1,000 person-yrs was found. There was no significant difference according to sex; the remission rates were 21.7 and 17.8 per 1,000 person-yrs in females and males, respectively. An increased remission rate was observed among subjects who quit smoking during the observation period. Subjects not reporting any asthma symptom at baseline had an increased remission rate. In the Cox regression model, ex-smoking (HR 1.65, 95% CI 1.01-2.71) was associated with increased remission rate, and reporting any asthma symptom at baseline was associated with decreased remission rate (HR 0.7, 95% CI 0.40-0.90). In conclusion, the present prospective longitudinal study showed that quitting smoking and the presence of mild disease appeared to favour remission.     

Outcome of asthma: longitudinal changes in lung function.

Current knowledge about factors determining outcome of asthma is limited, but observations over the last few decades suggest that active asthma has a negative impact on the longitudinal changes in lung function. This review aims to give an overview of the present knowledge concerning longitudinal changes in lung function, including clinical markers for distinctly poor outcome with regard to lung function, in children and adults suffering from asthma. The majority of patients with asthma have a good prognosis. However, some patients with asthma, especially those with more severe disease, are at risk of impaired growth of lung function during childhood, a lower maximally attained level of lung function and excessive decline in lung function in adulthood, which may lead to life-threatening lung function impairment. Clinical markers of poorly controlled airway inflammation appear to have a negative impact on the longitudinal changes in lung function, and disease progression to nonreversible airflow obstruction may be observed in a minority of patients with asthma. Early intervention with anti-inflammatory therapy may improve the short-term outcome of asthma, but long-term controlled studies are clearly needed in order to verify whether or not treatment, especially with inhaled corticosteroids, according to the current international guidelines alters the natural history of asthma, i.e. disease progression with regard to changes in lung function and possible development of nonreversible airflow obstruction.     

The use of household cleaning sprays and adult asthma: an international longitudinal study

RATIONALE: Cleaning work and professional use of certain cleaning products have been associated with asthma, but respiratory effects of nonprofessional home cleaning have rarely been studied. OBJECTIVES: To investigate the risk of new-onset asthma in relation to the use of common household cleaners. METHODS: Within the follow-up of the European Community Respiratory Health Survey in 10 countries, we identified 3,503 persons doing the cleaning in their homes and who were free of asthma at baseline. Frequency of use of 15 types of cleaning products was obtained in a face-to-face interview at follow-up. We studied the incidence of asthma defined as physician diagnosis and as symptoms or medication usage at follow-up. Associations between asthma and the use of cleaning products were evaluated using multivariable Cox proportional hazards or log-binomial regression analysis. MEASUREMENTS AND MAIN RESULTS: The use of cleaning sprays at least weekly (42% of participants) was associated with the incidence of asthma symptoms or medication (relative risk [RR], 1.49; 95% confidence interval [CI], 1.12-1.99) and wheeze (RR, 1.39; 95% CI, 1.06-1.80). The incidence of physician-diagnosed asthma was higher among those using sprays at least 4 days per week (RR, 2.11; 95% CI, 1.15-3.89). These associations were consistent for subgroups and not modified by atopy. Dose-response relationships (P < 0.05) were apparent for the frequency of use and the number of different sprays. Risks were predominantly found for the commonly used glass-cleaning, furniture, and air-refreshing sprays. Cleaning products not applied in spray form were not associated with asthma. CONCLUSIONS: Frequent use of common household cleaning sprays may be an important risk factor for adult asthma.     

The influence of lower respiratory illness on childhood asthma: defining risk and susceptibility.

This article reviews the role of lower respiratory illness as a risk factor for the development of asthma in childhood. Lower respiratory illness may influence the natural course of lung-function growth and decline directly or indirectly promoting the development of asthma symptoms in susceptible individuals. The authors discuss the current definitions of lower respiratory illness and asthma and the characteristics of the individuals most prone to their effects. Last, they review how socioeconomic status and race affect the lower respiratory illness-asthma relationship.     

Diagnosis of chronic obstructive pulmonary disease and differentiation from asthma

Asthma and chronic obstructive pulmonary disease are both common diseases, which together afflict approximately 25 million Americans. Although expiratory airflow obstruction is the common physiologic abnormality, asthma and chronic obstructive pulmonary disease are characterized by unique pathologic findings, clues from clinical histories, and laboratory test results. Despite some overlap in these characteristics, it is usually possible to differentiate these two conditions. This distinction is important for the healthcare provider to communicate a realistic prognosis to the patient and the patient's family, and to institute appropriate therapy.