Airway and systemic inflammation and decline in lung function in patients with COPD

Study objective: Patients with COPD experience lower airway and systemic inflammation, and an accelerated decline in FEV. There is no evidence on whether this inflammation changes over time, or if it is associated with a faster decline FEV. Patient and design: a cohort of 148 COPD patients (100 men) was monitored daily for a median 2.9 years (interquartile range [IQR], 2.1 to 4.8). At recruitment median age was 68.5 years (IQR, 62.5 to 73.6) and FEV as percentage of predicted (FEV percent Pred) was 38.5 percent (IQR, 27.7 to 50.3). Results: During the study, the patients experienced 1,389 exacerbations, a median of 2.52/yr (IQR 1.48 to 3.96) and FEV declined by 40.2 mL/yr or as FEV percent Pred by 1.5 percent/yr. Concerning inflammatory markers, sputum interlukin (IL)-6 rose by 9 pg/mL, sputum neutrophil count rose by 1.64 x 10,000,000 cells per gram sputum per year, and plasma fibrinogen rose by 0.10 g/L/yr (all p, 0.05). Patients with frequent exacerbations (less than or equal to 2.52/yr) had a faster rise over time in plasma fibrinogen and sputum IL-6 of 0.063 g/L/yr (p= 0.046, n= 130) and 29.5 pg/mL/yr (p< 0.001, n=98), respectively, compared to patients with infrequent exacerbations (<2.52/yr). Using the earliest stable (nonexacerbation) measured marker, patients whose IL-6 exceeded the group median had a faster FEV percentPred decline of 0.97 percent/yr (p=0.001 and .40 percent/yr (p=0.014). respectively. Conclusions: In COPD, airway and systemic inflammatory markers increase over time; high levels of these markers are associated with a faster decline in lung function (AU)

Critique of a study on ganja in Jamaica

In this study of "Ganja in Jamaica" by Rubin and Comitas, no significant differences between heavy ganja smokers and controls could be demonstrated in physical and psycological symptoms or social adjustment. This lack of difference may be attributed to methodological limitations in the sampling technique and examinations performed. The number of subjects studied was small (30 in both control and test group). The selection of controls was inadequate: only 12 controls had never smoked ganja, and 8 were current occasional users. Methodological limitations flawed the physical examinations of the lung and cardiovascular system, cytogenetic studies, psycological assessment and psychiatric evaluation. Acceptance by the authors of a positive motivational infleunce of cannabis smoking and other socially beneficial properties of such smoking by others in Jamaica and other countries. (AU)

Socio-economic status and lung function in Jamaican children

A study was carried out in Afro-Jamaican children of both sexes, 6 to 15 years of age, to examine the role of socio-economic status on various pneometric tests such as forced vital capacity (FVC), mid-expiratory flow rate (MEFR 0.2-1.2), mean transit time (MTT), peak expiratory flow rate (PEFR), forced expiratory volume (FEV 1.0) and FEV 1.0 percent. Based on the annual income of the parents, the children were subdivided into 3 groups (I,II,III). Statistical analysis of the data revealed significant differences in all pulmonary function tests in children >10 years of age in both sexes and in all the groups, except PEFR in girls and MEFR 0.2-1.2 in boys <10 years of age in group II. The girls belonging to the same groups had higher values for all lung functions except significantly lower values of MTT. The study suggests differences in both central and peripheral airway function, with poorer function in the lower income group children who may be more susceptible to subclinical infections, probably due to malnutrition. The lower lung function in boys was attributed inter alia to lower mean values of height and weight than in girls (AU)

Pulmonary function in cement industry workers

Pulmonary function studies, including one second forced expiratory volume (FEV 1.0 percent) and mean transit time, were carried out in 217 persons employed in the cement manufacturing industry. The results showed that abnormal pulmonary functions were positively correlated with the length of employment and dust concentration. The highest incidence of low FEV 1.0 percent, peak expiratory flow rate and mid-expiratory flow rate were found in the high dust areas where the dust concentration exceeded the threshold limit value (TLV) by 2620 per cent. Most of the abnormalities were of the restrictive type. It is suggested that the quartz content of the raw and finished product may be a causative factor in the disease entity (AU)

Open study to establish the efficacy and tolerance of detotifen in the prophylactic treatment of bronchial asthma - abstract

Seventeen hospital outpatients with extrinsic bronchial asthma were treated with 1 mg ketotifen for sixteen weeks. The evaluation of overall efficacy was based on five clinical examinations on each patient, including lung function studies, frequency of symptoms and decrease in concomitant drug utilization. The tolerance of the drug and periodic assessment of adverse reactions were also evaluated. Both peak flow and FEV1 showed a progressive increase over four months of treatment with ketotifen. Peak flow increased from an initial value of 225ñ89 1/min. (mean ñ SD) to 303 ñ 122 1/min. Only the values at the fourth month were statistically significant (p<0.01). FEV1 increased progressively from 1.25 ñ 0.45 litres. Again only the values at the fourth month were significant (p<0.025). There was no increase in FVC or FEV1/FVC, even at the fourth month. A number of subjects appeared to have great difficulty grasping the techniques required to perform pulmonary function tests. There were four subjects whose performance was consistently unsatisfactory (wider inter test variation) and well below the others even when clinically asymptomatic; these subjects' values were consistently less than 200 1/min. (peak flow) and 1 l/sec FEV1). The results of re-analysis excluding these subjects were as follow: Both peak flow and FEV1 showed higher values and the differences at the fourth month were greater, reaching a level of p<0.005 for peak flow and p<0.01 for FEV1. Ketotifen was beneficial in reducing the frequency of attacks in 14 out of 17 patients. It was very effective in two patients (not a single attack after starting the trial); nine patients did not have any attacks after 12 weeks. No concomitant medication was used by two patients, while seven have considerably reduced the doses of concomitant medication. One patient showed no response. Tolerance was good in all patients, the only side effect being mild daytime sedation in twelve patients. Cessation of therapy was not warranted in any patient because of this side effect. These results suggest that improvement with ketotifen is most marked after three months of therapy (AU)

Maternal respiratory function during pregnancy

Maternal respiratory function in the second (26) and third (76) trimesters of pregnancy was measured in 102 women and showed that: (i) Thirty-eight per cent and 36 percent of the women in second and third trimesters respectively had FEV1.0 percent<75 percent. MTT 0.7 sec. (ii) Nineteen per cent and 29 percent of the women in the second and third trimesters respectively had MTT>0.7 sec. (iii) Pregnancy superimposed on previous respiratory disorders such as bronchial asthma potentiated the compromisation of both central and peripheral airway function in the third trimester in that 41 percent had FEV<75 percent and 34 percent MTT>0.7 sec. It is concluded that normal pregnancy does not significantly affect central and peripheral airway function. However, pregnancy in the presence of upper or lower respiratory tract disease may influence respiratory function negatively. (AU)

Cardio-pulmonary responses and gas exchange during exercise in adults with homozygous sickle-cell disease (sickle-cell anaemia)

Cardio-pulmonary responses and gas exchange during progressive exercise, the ventilatory response to hypercapnia and anthropometric indices were measured in twenty-two Jamiacan adults with homozygous sickle-cell disease. Their anthropometric indices and exercise performances were compared with those observed in healthy but sedentary adults in the Caribbean. The patients had long lower limbs for their height; their body fat, proportion of lean body mass as muscle and vital capacity reduced. Haemoglobin concentration ranged from 4 to 10g/100ml. Heart rate and ventilation were normal at rest. During exercise in the male patients haemoglobin concentrations below about 8g/100ml were associated with an increased demand for anaerobic metabolism. This resulted in excessive lac ticacidaemia and increased ventilation at standard oxygen uptake (hyperpnoea). The ventilation-tidal volume relationship was normal. When allowance was made for differences in body muscle, anaemia did not appear to affect the heart-rate response to exercise. Hyperventilation with respect to carbon dioxide output, increased alveolar-arterial oxygen-tension gradients and abnormal deadspace ventilation during exercise indicated a pulmonary perfusion disturbance with mixed venous shunting. The most likely basis for this disorder was considered to be the sickling phenomenon. Arterial hypoxaemia produced by the pulmonary shunt probably accounted for some of the exercise hyperpnoea, partly by increasing the chemoreceptor drive and partly by encouraging lacticacidaemia. Reduced arterial carbon dioxide tensions and bicarbonate concentrations had lowered the threshold and increased the sensitivity of the ventilatory response to carbon dioxide as measured by rebreathing. Increased chemosensitivity was not thought to have contributed towards the exercise hyperpnoea since arterial carbon dioxide tensions were below the threshold value for ventilatory drive. Exertional dyspnoea in sickle-cell disease was attributed to the combination of hyperpnoea and reduced maximum breathing capacity (MBC) owing to small lung volumes. The fraction of (MBC) used at standard work was therfore abnormally large, and the increased ventilatory effort produced a sensation of breathlessness in some patients (Summary)

The lipoid pneumonia of blackfat tobacco smokers in Guyana

In Guyana, a large number of patients have been diagnosed as having a diffuse pulmonary fibrosis of unknown aetiology, characterized by typical radiological appearances, dyspnoea, cough, weight loss, and eventually pulmonary heart disease. Investigation of 56 patients showed that all had smoked a tobaco known as 'blackfat' or 'black tobacco'. In a community survey 20.4 per cent of the population aged 55 years and over smoked this tobbaco. 19.6 per cent of the blackfat smokers but no non-blackfat smokers showed definite radiological evidence of pulmonary fibrosis. Smokers with, but not those without fibrosis, had severe airway obstruction. Immunological studies made it unlikely that an extrinsic allergic aveolitis had caused the radiological changes. Three post-mortem open-lung specimens were obtained and in each case the histology showed a diffuse interstitial fibrosis and vasculitis associated with large deposits of lipid surrounded by black amorphous material. Blackfat is a tobacco leaf to which mineral oil and vaseline is added for flavouring and as humectants. The presence of oil in the tobacco, and the post-mortem findings of oil in the lungs, indicate that the diffuse pulmonary fibrosis can be more accurately described as a lipoid pneumonia caused by the inhalation of mineral oils when blackfat is smoked. The potential health hazards of many tobacco additives, particularly oils, employed by the tobacco industry should be recognized. A similar type of disease as that found in Guyana may be present in other parts of the world where blackfat, or related tobacco, are smoked.(Summary)

Ethnic variation in forced expiratory volume and forced vital capacity of African and Indian adults in Guyana

In Guyana, forced expiratory volume in one second and forced vital capacity were measured in 96 African men, 109 African women, 129 Indian men, and 99 Indian women between 35 and 54 years old. No subject had evidence of any disorder that might have impaired ventilatory capacity. Indians of both sexes had significantly smaller values by approximately 4 percent to 7 percent than Africans, and both groups had smaller values than those quoted for white persons. These differences remained significant after standardization for age and body size. The forced expiratory volume and forced vital capacity values of the subjects are described as multiple regression equations on height and age.(Summary)

Diffuse pulmonary fibrosis and blackfat-tobacco smoking in Guyana

The clinical features and epidemiology of diffuse pulmonary fibrosis in Guyana have been investigated. The condition is limited to East Indians and is characterised by progressive dyspnoea leading to pulmonary heart-disease and congestive heart-failure. 19 hospital patients studied, and 7 others radiographically confirmed, had all smoked "blackfat" tobacco, a variety which is not widely used.(Summary)

Desquamative interstitial pneumonia

The clinical radiological and pathological features of desquamative interstitial pneumonia in a 55-year old Jamaican male negro are described. Although the patient presented with progressive effort dyspnoea there were minimal abnormal chest signs but marked derangement of the respiratory function tests. The most severe radiological changes were demonstrated in the middle zones of the lung fields, and a follow-up chest film 2 months later showed slight involvement of the lower zones as well. The microscopic appearance was typical of the condition except that the vascular changes overshadowed the other abnormalities present. Although there was an excellent subjective response to steroid therapy, lung function tests repeated 2 months after the onset of the disease showed no significant change. (Summary)