The relation of body mass index to asthma,chronic bronchitis,and emphysema

BACKGROUND: Recent studies have suggested a relationship between asthma and obesity. Despite these reports, the effect of being underweight or overweight as a risk factor for airway obstructive diseases (AODs) is not clear. OBJECTIVES: To determine whether a relation of body mass index (BMI) to asthma, chronic bronchitis (CB), or emphysema exists (analysis 1), and, if so, whether the association between obesity and asthma is modified by gender (analysis 2). DESIGN: Nested case-control study from the longitudinal cohort of the Tucson Epidemiologic Study of Airways Obstructive Diseases. PATIENTS: Analysis 1: physician-confirmed incident cases of asthma (n = 102), CB (n = 299), or emphysema (n = 72) who denied any prior AODs. Analysis 2: all 169 incident cases of asthma, regardless of any previous AODs, stratified by gender and by other potential effect modifiers. In both analyses, we selected only subjects at least 20 years old who had weight and height measured during the study. MEASUREMENTS: BMI and other risk factors were assessed prior to the onset of the AOD (cases) or prior to the last completed survey (control subjects). RESULTS: A diagnosis of emphysema was significantly associated with a BMI < 18.5 (odds ratio [OR], 2.97; 95% confidence interval [CI], 1.33 to 6.68, when compared to healthy control subjects). A BMI >/= 28 increased the risk of receiving a diagnosis of asthma (OR, 2.10; 95% CI, 1.31 to 3.36) and CB (OR, 1.80; 95% CI, 1.32 to 2.46). About 30% of the patients with asthma and 25% of the patients with CB (vs 16% of the control subjects, p < 0.001) were preobese or obese, regardless whether BMI was assessed before the diagnosis or before the onset of respiratory symptoms. The relation of elevated BMI to asthma was significant only among women. CONCLUSIONS: Patients with emphysema are more likely to be underweight, and patients with CB are more likely to be obese. However, the temporal relationship between abnormal BMI and the onset of COPD is uncertain. Preobese and obese women are at increased risk of acquiring asthma. This relation, particularly if it is causal, has potentially relevant public health implications.     

Comparisons of asthma, emphysema, and chronic bronchitis diagnoses in a general population sample

This report is an analysis of cases of obstructive lung disease diagnosed during the first 8 yr of a community study. Of 351 subjects who received a new diagnosis of asthma, emphysema, or chronic bronchitis from community physicians, 152 (44.5%) had a prior or concomitant diagnosis of another obstructive disease. Asthma developed most often in young subjects, emphysema in older subjects, and chronic bronchitis occurred in all age groups. Among older subjects, disease groups were surprisingly similar, with wheeze, dyspnea, and attacks of shortness of breath with wheeze all occurring frequently in diagnosed subjects, including those with emphysema. The majority of subjects who developed emphysema were males. In contrast, 72.8% of the asthma and chronic bronchitis subjects were females. These results suggest that physician bias may result in labeling male patients as emphysematous and female patients as asthmatic or bronchitic.     

Recent advances in diagnosis and management of chronic bronchitis and emphysema

Chronic obstructive pulmonary disease is a progressive inflammatory disease of the airways and lung parenchyma. Expiratory airflow limitation is the hallmark of chronic obstructive pulmonary disease. It is a significant cause of morbidity and mortality in the United States and worldwide and results in a large consumption of health care resources. Unfortunately, despite efforts to curb this disease, its prevalence is increasing. The diagnosis is usually made when the patient complains of dyspnea on exertion; by this time, irreversible structural damage to the lung has already occurred. Given the nonspecific symptoms of the disease and the inability to effectively treat and reverse the damage, it is essential to diagnose the disease in its early stages and take the necessary preventive measures, thus avoiding disability or death. This review summarizes the latest developments in the diagnosis and management of chronic obstructive pulmonary disease. The first half of the review discusses functional, radiographic, biochemical, and cellular/histopathologic issues in the diagnosis of chronic obstructive pulmonary disease. The second half focuses on the current pharmacologic and nonpharmacologic advances in chronic obstructive pulmonary disease, including the role of respiratory support and surgical treatment. Based on the research on the cellular mechanisms of chronic obstructive pulmonary disease, the review also makes a reference to novel and experimental therapies for chronic obstructive pulmonary disease.     

Reported prevalence and co-morbidity of asthma, chronic bronchitis and emphysema: a pan-European estimation.

OBJECTIVE: Comparable population-based data exist at the European level for asthma but not for chronic obstructive pulmonary disease. Data from the World Health Organization's Large Analysis and Review of European Housing and Health Status Study conducted in random samples from eight European cities were used 1) to describe the prevalence of chronic bronchitis and emphysema (CBE) and asthma according to socio-demography, addictions, physical activities and body mass index; and 2) to identify the co-morbidities of these respiratory diseases. DESIGN: A total of 6915 adults filled out a standardised questionnaire on health outcomes, including major respiratory diseases and individual characteristics. RESULTS: Data showed that in the year preceding the survey, 3.3% of individuals had been diagnosed or treated for asthma and 6.2% for CBE. One per cent suffered simultaneously from both. Large variations were observed between cities. Physical activities and never smoking were inversely associated with CBE, independently of socio-cultural differences between the eight cities. Furthermore, both asthma and CBE were significantly related to several non-respiratory diseases, after adjustment for potential confounders. CONCLUSION: Population-based data from eight European cities show that there is a link between chronic respiratory diseases and various non-respiratory co-morbidities that needs further investigation.     

The left ventricle in emphysema and chronic bronchitis.

There's no doubt that chronic obstructive lung disease can have a disastrous impact on the heart's right ventricle--often producing hypertrophy or even failure--but its effects on the left ventricle are less clear. Some researchers speculate that disease of the right ventricle leads to disease of the left, while others consider the lung disease itself to be the more likely mechanism. Ordinarily, the left ventricle holds up well, even in far-advanced emphysema and chronic bronchitis. Recognizing the cases that do occur is important, however, since only minimal left ventricular failure can seriously compromise respiratory function. Treatment is the same as for left ventricular failure of any cause, but special precautions should be observed, particularly in prescribing diuretics. If frank pulmonary edema supervenes, mechanical ventilation and supplemental oxygen are necessary.     

Symptoms and experiences in chronic bronchitis and emphysema

A heterogeneous group of 146 patients with chronic bronchitis and emphysema were asked to rate the frequency with which 89 symptoms and experiences occurred during their breathing difficulties. Normative values and the reported frequency of occurrence for the 11 symptom categories are presented. As expected, symptoms of dyspnea were the most frequently reported during breathing difficulties. In decreasing order, symptoms of dyspnea were followed by symptoms of fatigue, sleep disturbance, congestion, irritability, anxiety, decathexis, helplessness-hopelessness, poor memory, alienation. Separation of the patients into subgroups revealed that women reported more anxiety and helplessness-hopelessness than men. Younger patients reported more irritability and anxiety than older patients. Patients with mixed disease reported more dyspnea than those with chronic bronchitis or emphysema, although patients with emphysema reported more loss of interest in life than patients with chronic bronchitis. Self-ratings of functional incapacitation were clearly related to the symptom reports. Relationships among the symptom categories were discussed, as was the potential usefulness of symptom patterns in exploring coping styles in respiratory disease.     

Central and peripheral airways as determinants of ventilatory function in patients with chronic bronchitis, emphysema, and bronchial asthma

We studied central and peripheral airways as determinants of ventilatory function in patients with chronic bronchitis (CB), bronchial asthma (BA), and emphysema (CPE), which were identified using the selective alveolobronchogram (SAB) (see reference 14). First, the relationship between SAB and morphologic findings in the airway was examined in 16 autopsy lungs. The irregularity indices of both central (C-II) and peripheral airways (P-II), obtained from SAB, showed a significant correlation with pathologic abnormalities in both airways (p less than 0.01). Second, SAB were obtained in 38 CB, 25 BA, and 62 CPE patients in whom pulmonary function tests were performed. In CB, C-II were significantly correlated with P-II (p less than 0.001). In CB, inspiratory lung resistance (RL) was significantly correlated with P-II (p less than 0.001) and with C-II (p less than 0.01), and FEV/VC% was significantly correlated with P-II (p less than 0.0001) but not with C-II. In BA and CPE, little correlation was observed between any SAB parameter and RL or FEV/VC%. We conclude that the present SAB parameters represent morphometric abnormalities of the central and peripheral airways, and that in CB, peripheral airway abnormalities correlated well with chronic airway obstruction.     

Prevalence of nasal symptoms and their relation to self-reported asthma and chronic bronchitis/emphysema.

Little information is available on associations between rhinitis and chronic bronchitis/emphysema (CBE). Self-reported upper airway symptoms, asthma, and CBE were examined in 12,079 adults living in southern Sweden. The response rate was 70% (n=8,469), of whom 33% reported significant nasal symptoms: a blocked nose was reported by 21%; sneezing by 18%; nasal discharge by 17%; and thick yellow nasal discharge by 5.7%. Nasal symptoms and combined nasal and self-reported bronchial disease were generally more common among smokers than nonsmokers. There was little overlap between asthma and CBE, but 46% of those with asthma and 40% of those with CBE had significant nasal symptoms. Best predicting factors (odds ratios >3) for asthma and CBE were nasal symptoms due to exposure to animals and damp/cold air, respectively. One-third of an adult, southern Swedish population, had significant allergic and/or nonallergic nasal symptoms. Nasal symptoms were frequently found to coexist with both asthma and chronic bronchitis/emphysema, suggesting that pan-airway engagement is common in both diseases. Differing associations between types of nasal symptoms and allergic and irritant triggers of nasal symptoms, with regard to asthma and chronic bronchitis/emphysema, emphasize the different natures of these bronchial diseases.