Inhaled glucocorticoids in COPD: immortal time bias.
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Administration, Inhalation↗
Biomedical subjects
Don D Sin
Publications and source records attributed to Don D Sin.
Why are patients with chronic obstructive pulmonary disease at increased risk of cardiovascular diseases? The potential role of systemic inflammation in chronic obstructive pulmonary disease.
BACKGROUND: Chronic obstructive pulmonary disease (COPD) increases the risk of cardiovascular disease 2- to 3-fold. The factors responsible for this association remain largely unknown. METHODS AND RESULTS: We analyzed data from participants, > or =50 years of age, of the Third National Health and Nutrition Examination Survey (n=6629) to determine whether C-reactive protein (CRP) and other systemic inflammatory markers are present in participants with chronic airflow obstruction and are associated with cardiac injury. Participants with severe airflow obstruction had circulating leukocyte, platelet, and fibrinogen levels that were 460/ microL (95% confidence interval [CI], 30 to 890/ microL), 39 510/ microL (95% CI, 21 730 to 57 290/ microL), and 41.63 mg/dL (95% CI, 19.87 to 63.39 mg/dL) higher, respectively, than in those without airflow obstruction. They were also 2.18 times (95% CI, 1.46 to 3.27) more likely to have an elevated circulating CRP level. Moderate airflow obstruction was associated with smaller but still significant increases in these levels. Moderate and severe airflow obstruction was associated with increased occurrence of ischemic changes on electrocardiograms of participants. In the presence of both highly elevated CRP and moderate or severe airflow obstruction, the Cardiac Infarction Injury Score was 2.68 and 5.88 U higher, respectively, than in those without airflow obstruction and with low CRP, which suggests an additive effect of CRP and COPD on the risk of cardiac injury. CONCLUSION: Low-grade systemic inflammation was present in participants with moderate to severe airflow obstruction and was associated with increased risk of cardiac injury. This may in part explain the high rates of cardiovascular complications in COPD.
Aged↗
The risk of osteoporosis in Caucasian men and women with obstructive airways disease.
PURPOSE: Because patients with obstructive airways disease may be susceptible to osteoporosis, we sought to determine the association between airflow obstruction and osteoporosis. SUBJECTS AND METHODS: We analyzed data from Caucasian participants (n = 9502) in the Third National Health and Nutrition Examination Survey, conducted in the United States between 1988 and 1994. We used data from dual-energy x-ray absorptiometry measurements of the total femur to determine whether a study participant had osteoporosis (defined as total bone mineral density values < or =2.5 SD below the corresponding mean values from young, healthy participants). We calculated the odds ratio (OR) for osteoporosis in four lung function categories: none, mild, moderate, and severe airflow obstruction. RESULTS: Overall, airflow obstruction was associated with increased odds of osteoporosis compared with without airflow obstruction (OR = 1.9; 95% confidence interval [CI]: 1.4 to 2.5). Participants with severe airflow obstruction were at especially increased risk (OR = 2.4; 95% CI: 1.3 to 4.4). Moderate but not mild airflow obstruction was also associated with osteoporosis. CONCLUSION: Airflow obstruction was an important risk factor for osteoporosis in the study population. These data highlight the importance of measuring bone mineral density in those with moderate-to-severe airflow obstruction for the detection and prevention of osteoporosis-related morbidity.
Adult↗
Relationship of systolic BP to obstructive sleep apnea in patients with heart failure.
STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is an independent risk factor for hypertension in the general population. Hypertension is, in turn, an important risk factor for the development and progression of congestive heart failure (CHF). Our objective was to determine whether OSA would be associated with elevated daytime BP in medically treated patients with CHF. DESIGN: Cross-sectional study. SETTING: Tertiary care, university-affiliated sleep disorders and heart failure clinics. PATIENTS: Three hundred one consecutive patients with CHF. MEASUREMENTS AND RESULTS: We measured daytime BP and performed overnight sleep studies to assess for the presence of OSA. Among these patients, OSA was present in 121 patients (40%) and their systolic BP was significantly higher than in patients without OSA. Patients with OSA were 2.89 times (95% confidence interval, 1.25 to 6.73) more likely to have systolic hypertension (ie, BP > or = 140 mm Hg) than those without OSA after controlling for other risk factors, including obesity. The degree of systolic BP elevation was directly related to the frequency of obstructive apneas and hypopneas. CONCLUSIONS: In medically treated patients with CHF, daytime systolic BP and the prevalence of systolic hypertension are significantly increased in patients with OSA, compared to those without OSA, independent of other potentially confounding factors. OSA may therefore have contributed to the presence of systolic hypertension in some of these patients.
Aged↗
Can universal access to health care eliminate health inequities between children of poor and nonpoor families?: A case study of childhood asthma in Alberta.
STUDY OBJECTIVE: Children from poor families are much more likely to have emergency visits for asthma than those from nonpoor families, which may be related to financial access barriers to good preventive care for the poor. We sought to determine whether in a health-care system that provides free access to outpatient and hospital services, the disparities in the rates of emergency visits for asthma would be less apparent across the income gradient. DESIGN: Longitudinal, population-based study. SETTING: Alberta, Canada. PARTICIPANTS: All children born in Alberta, Canada between 1985 and 1988 (n = 90,845) were classified into three mutually exclusive groups based on the reported annual income of their parents from the previous year: very poor, poor, and nonpoor groups. MEASUREMENTS AND RESULTS: We compared the relative risk (RR) of emergency visits for childhood asthma among children of very poor, poor, and nonpoor families using a Cox proportional hazard model during a 10-year follow-up. We found that the very poor children were 23% more likely to have had an emergency visit for asthma than those from nonpoor families (RR, 1.23; 95% confidence interval [CI], 1.14 to 1.33), adjusted for a variety of factors. The poor group, however, had a similar risk of asthma emergency visits as the nonpoor group (RR, 0.97; 95% CI, 0.91 to 1.04). The average number of office visits for asthma was similar between the very poor and nonpoor groups. CONCLUSIONS: In a setting of universal access to health care, children of poor and nonpoor families had similar rates of asthma emergency visits; the very poor children, however, continued to experience an excess risk. These findings suggest that a universal health-care system can reduce, but not fully eliminate, the disparities in emergency utilization of asthma across income categories.
Adult↗
Sleep-disordered breathing: a heart-changing experience?
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Coronary Artery Disease↗
Cheyne-Stokes respiration: a consequence of a broken heart?
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Cheyne-Stokes Respiration↗
Inhaled corticosteroids in the long-term management of patients with chronic obstructive pulmonary disease.
Chronic obstructive pulmonary disease (COPD) is a major problem in the elderly population, with approximately 10% of the population affected. Since COPD is an inflammatory disorder of the pulmonary system, corticosteroids might be expected to improve clinical outcomes of the disease. Data from large, well designed randomised clinical trials in which approximately one third of patients were > or =65 years of age indicate that inhaled corticosteroids do not modify the natural history of COPD, as measured by the rate of decline in forced expiratory volume in 1 second (FEV1). However, these same studies also suggest that corticosteroids reduce the frequency of clinical exacerbations by nearly a third (compared with placebo). This beneficial effect is particularly pronounced among those with an FEV1 less than 50% of the predicted value. Withdrawal of inhaled corticosteroids, on the other hand, leads to increased symptoms and elevates the risk of exacerbations by 50% above baseline levels. Patients' health-related quality of life is also improved by the use of inhaled corticosteroids. It is clear that inhaled corticosteroids elevate the risk of thrush, dysphonia and skin bruising by 2-fold compared with placebo. In addition, the sum of evidence suggests a modest deleterious effect for inhaled corticosteroids on bone mineral density, especially for formulations that have an increased rate of systemic absorption. However, the clinical evidence of this observation is uncertain. The effect of inhaled corticosteroids on fracture risk is controversial with some observational studies suggesting a possible association. Whether inhaled corticosteroids increase the risk of ophthalmic complications (cataracts and glaucoma) is also uncertain. In conclusion, the current evidence indicates that inhaled corticosteroid therapy produces short- and long-term clinical benefits in COPD patients with moderate-to-severe disease and should be used as adjunctive therapy for elderly patients with COPD who experience frequent exacerbations or have moderately reduced lung function.
Administration, Inhalation↗
The effects of beta-blockers on morbidity and mortality in a population-based cohort of 11,942 elderly patients with heart failure.
PURPOSE: Randomized trials have shown that beta-blockers prevent morbidity and mortality in heart failure. However, whether beta-blockers are effective in older patients or those with conditions that would have led to their exclusion from these trials remains unclear. SUBJECTS AND METHODS: The associations between beta-blocker use and outcomes were examined in a population-based cohort of 11,942 older (age >/=65 years) patients with incident heart failure between 1994 and 1999. Cox proportional hazards models were used to adjust for propensity scores, age, sex, comorbid conditions, and other medications. RESULTS: The mean (+/- SD) age of the patients was 79 +/- 8 years, 5819 (49%) were men, and 2569 (22%) had Charlson comorbidity scores of at least 2. During follow-up (median, 21 months), 3539 patients were hospitalized for heart failure and 6757 died. Overall, 1162 patients received beta-blockers. After adjustment, beta-blocker use was associated with substantial reductions in all-cause mortality (hazard ratio [HR] = 0.72; 95% confidence interval [CI]: 0.65 to 0.80), mortality due to heart failure (HR = 0.65; 95% CI: 0.47 to 0.90), and hospitalizations for heart failure (HR = 0.82; 95% CI: 0.74 to 0.92). These endpoints were less frequent in patients treated with beta-blockers than in untreated patients in all examined subgroups. All doses of beta-blockers were associated with benefit, but there was a trend towards greater benefit in patients prescribed higher doses. CONCLUSIONS: The benefits of beta-blockers seen in randomized trials extend to older patients and to those with conditions that would have led to their exclusion from the trials. There is a need for a randomized trial comparing different doses of beta-blockers in heart failure.
Adrenergic beta-Antagonists↗
Low-dose inhaled corticosteroid therapy and risk of emergency department visits for asthma.
BACKGROUND: Patients who visit the emergency department (ED) because of asthma frequently have a relapse. While the use of inhaled corticosteroids has been demonstrated to improve asthma symptoms and lung function, it is not clear whether their use after discharge from the ED reduces asthma relapse rates. OBJECTIVE: To determine whether inhaled corticosteroid therapy reduces ED asthma relapse rates. METHODS: We analyzed ED visit and medication data on patients 5 to 60 years of age who were enrolled in a government-sponsored drug plan and who visited an ED because of asthma between April 1, 1997, and March 31, 1999, in Alberta, Canada (N = 1293). Using a Cox proportional hazards model, we determined the relative risk (RR) of relapse ED visits among users and nonusers of inhaled corticosteroids after discharge from the ED. We also compared the RR of relapse ED visits across different dose categories. RESULTS: Users of inhaled corticosteroids after ED discharge had 45% fewer relapse ED visits than did nonusers (adjusted RR, 0.55; 95% confidence interval [CI], 0.44-0.69). Low-, medium-, and high-dose therapies were associated with similar reductions in the risk of relapse ED visits: low-dose therapy (RR, 0.52; 95% CI, 0.39-0.68), medium-dose therapy (RR, 0.51; 95% CI, 0.34-0.76), and high-dose therapy (RR, 0.67; 95% CI, 0.47-0.94). CONCLUSIONS: Inhaled corticosteroid therapy after ED discharge is associated with a significant reduction in the risk of subsequent ED visits. Low-dose therapy appears to be as effective as high-dose therapy. However, further studies are needed to determine the optimal dosing regimen for inhaled corticosteroid therapy for asthma.
Administration, Inhalation↗
Obesity is a risk factor for dyspnea but not for airflow obstruction.
BACKGROUND: Previous research suggests that obesity is an important risk factor for asthma. However, since obesity can cause dyspnea through mechanisms other than airflow obstruction, diagnostic misclassification of asthma could partially account for this association. OBJECTIVE: To determine whether there is a relationship between obesity and airflow obstruction. METHODS: A total of 16 171 participants (17 years or older) from the Third National Health and Nutrition Examination Survey (NHANES III) were divided into 5 quintiles based on their body mass index (BMI) to determine the association between BMI quintile and risk of self-reported asthma, bronchodilator use, exercise performance, and airflow obstruction. Significant airflow obstruction was defined as a ratio less than 80% the predicted value of forced expiratory volume in 1 second to forced vital capacity adjusted for age, sex, and race. RESULTS: The highest BMI quintile (ie, the most obese participants) had the greatest risk of self-reported asthma (odds ratio [OR], 1.50; 95% confidence interval [CI], 1.24-1.81), bronchodilator use (OR, 1.94; 95% CI, 1.38-2.72), and dyspnea with exertion (OR, 2.66; 95% CI, 2.35-3.00). Paradoxically, the highest BMI quintile had the lowest risk for significant airflow obstruction (P =.001). CONCLUSIONS: This study demonstrates that while obesity is a risk factor for self-reported asthma, obese participants are at a lower risk for (objective) airflow obstruction. Many more obese than nonobese participants were using bronchodilators despite a lack of objective evidence for airflow obstruction. These data suggest that mechanisms other than airflow obstruction are responsible for dyspnea genesis in obesity and that asthma might be overdiagnosed in the obese population.
Adolescent↗
The impact of chronic obstructive pulmonary disease on work loss in the United States.
Chronic obstructive pulmonary disease (COPD) is a rapidly growing public health problem in the United States and elsewhere. Although direct costs of COPD are well documented, the impact of COPD and its severity on labor force participation is not well known. Using population-based data from the Third National Health and Nutrition Examination Survey (NHANES III), we determined the adjusted relationship between COPD (and its severity) and labor force participation in the U.S. We used data from 12,436 participants involved in NHANES III; 1,073 of these participants (8.6% of the total) reported COPD. These participants were 3.9% (95% confidence interval, 1.3% to 6.4%) less likely to be in the labor force than those without COPD. Increasing severity of COPD was associated with decreased probability of being in the labor force (p for linear trend = 0.001). Mild, moderate, and severe COPD was associated with a 3.4%, 3.9%, and 14.4% reduction in the labor force participation rate relative to those without COPD. These data suggest that COPD has a considerable adverse impact on work force participation. Based on these data, we estimate that, in 1994, COPD was responsible for work loss of approximately $9.9 billion in the U.S.
Absenteeism↗
The impact of follow-up physician visits on emergency readmissions for patients with asthma and chronic obstructive pulmonary disease: a population-based study.
PURPOSE: To examine the relation between follow-up office visits after emergency discharge and the risk of emergency readmissions in patients with asthma or chronic obstructive pulmonary disease (COPD). SUBJECTS AND METHODS: We used population-based data to identify all patients in Alberta, Canada, who had at least one emergency visit for asthma or COPD between April 1, 1996, and March 31, 1997 (N = 25 256). A Cox proportional hazards model was used to estimate the adjusted relative risk (RR) of a repeat visit to an emergency department within 90 days of an initial emergency visit in patients who did or did not have an office follow-up within the first 30 days. RESULTS: There were 7829 patients (31%) who had an office visit during the 30 days after their initial emergency encounter. Follow-up visits were associated with a significant reduction in the 90-day risk of an emergency readmission (RR = 0.79; 95% confidence interval [CI]: 0.73 to 0.86). Sensitivity analyses showed that a follow-up visit was inversely associated with a repeat emergency visit after adjusting for age, sex, area of residence, and income. CONCLUSION: Although these data should be interpreted with caution because of missing information on factors such as quality of care, they suggest that follow-up office visits are effective in reducing early relapses in patients who have been recently treated in emergency departments for asthma or COPD.
Acute Disease↗
The effects of inhaled corticosteroids in chronic obstructive pulmonary disease: a systematic review of randomized placebo-controlled trials.
Although inhaled corticosteroids are commonly used to treat patients with chronic obstructive pulmonary disease (COPD), their effect on clinical outcomes such as exacerbation and mortality is unknown. This systematic review was conducted to determine whether inhaled corticosteroids improve clinical outcomes for patients with stable COPD. All placebo-controlled randomized trials of inhaled corticosteroids given for at least 6 months for stable COPD were identified by searching MEDLINE (1966-2000), EMBASE (1980-2001), CINAHL (1982-2000), SIGLE (1980-2000), the Cochrane Controlled Trial Registry, and the bibliographies of published studies. We independently extracted data from each of the studies using a specified protocol, and determined the summary risk ratios (RRs) and 95% confidence intervals (CIs) for exacerbations and deaths. Nine randomized trials (3976 patients with COPD), including four with a systemic steroid run-in phase, were identified. Use of inhaled corticosteroid therapy reduced the rate of exacerbations (RR = 0.70; 95% CI: 0.58 to 0.84), with similar benefits in those who were and were not pretreated with systemic steroids. Inhaled corticosteroid therapy was also associated with increased rates of oropharyngeal candidiasis (RR = 2.1; 95% CI: 1.5 to 3.1), skin bruising (RR = 2.1; 95% CI: 1.6 to 2.8), and lower mean cortisol levels. No effects were seen on all-cause mortality (RR = 0.84; 95% CI: 0.60 to 1.18) in the five trials that measured this outcome. This systematic review demonstrates a beneficial effect of inhaled corticosteroids in reducing rates of COPD exacerbation. Further research is required to define the long-term effects of these medications and the benefit/risk ratio for patients with COPD.
Administration, Inhalation↗
Long-term compliance rates to continuous positive airway pressure in obstructive sleep apnea: a population-based study.
STUDY OBJECTIVES: To determine long-term compliance rates to continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnea enrolled in a comprehensive CPAP program in the community. DESIGN: Prospective cohort longitudinal study. SETTING: University sleep disorders center. PATIENTS: Two hundred ninety-six patients with an apnea-hypopnea index (AHI) > or = 20/h on polysomnography. INTERVENTIONS: A CPAP device equipped with a monitoring chip was supplied. Within the first week, daily telephone contacts were made. Patients were seen at 2 weeks, 4 weeks, 3 months, and 6 months. RESULTS: Of the 296 subjects enrolled, 81.1% were males. Mean +/- SD AHI was 64.4 +/- 34.2/h of sleep; age, 51 +/- 11.7 years; and body mass index, 35.2 +/- 7.9 kg/m(2). The mean duration of CPAP use was 5.7 h/d at 2 weeks, 5.7 h/d at 4 weeks, 5.9 h/d at 3 months, and 5.8 h/d at 6 months. The percentage of patients using CPAP > or = 3.5 h/d was 89.0% at 2 weeks, 86.6% at 4 weeks, 88.6% at 3 months, and 88.5% at 6 months. There was a decrease in the Epworth Sleepiness Scale (ESS) score of 44% by 2 weeks of therapy. The patients continue to improve over the follow-up period, with the lowest mean ESS score observed at 6 months. With multiple regression analysis, three variables were found to be significantly correlated with increased CPAP use: female gender, increasing age, and reduction in ESS score. CONCLUSION: A population-based CPAP program consisting of consistent follow-up, "troubleshooting," and regular feedback to both patients and physicians can achieve CPAP compliance rates of > 85% over 6 months.
Cohort Studies↗
Asthma and COPD among aboriginals in Alberta, Canada.
BACKGROUND: Aboriginals in Canada bear a disproportionately higher burden of some chronic illnesses than nonaboriginals. Although there is a greater prevalence of smoking, poor housing, and overcrowding in aboriginal than nonaboriginal communities, the rates of office and emergency visits for asthma and COPD among aboriginals are not well known. STUDY OBJECTIVE: To determine whether aboriginals require higher rates of asthma and COPD emergency and office visits than nonaboriginals. SETTING: Population-based cohort of people residing in Alberta, Canada (population 2.8 million) between April 1, 1996, and March 31, 1997. DESIGN: Retrospective cohort study. RESULTS: We observed that aboriginals were 2.1 times (95% confidence interval [CI], 2.0 to 2.2) and 1.6 times (95% CI, 1.6 to 1.6) more likely to have an emergency and office visit for asthma or COPD, respectively, when compared to age-matched and sex-matched nonaboriginals. However, they were 55% (95% CI, 52 to 58%) less likely to see a specialist and 66% (95% CI, 63 to 70%) less likely to undergo spirometry than nonaboriginals. CONCLUSIONS: These findings indicate that aboriginals bear a disproportionately higher burden of asthma and COPD than nonaboriginals. However, lower use of spirometry and specialist services suggests that there might be access barriers to quality health care for aboriginals in Canada.
Adolescent↗
Can continuous positive airway pressure therapy improve the general health status of patients with obstructive sleep apnea?: a clinical effectiveness study.
STUDY OBJECTIVES: To determine the short-term and long-term impacts of continuous positive airway pressure (CPAP) therapy on health-related quality of life (HRQL) in patients with obstructive sleep apnea (OSA). DESIGN: Prospective longitudinal cohort study. SETTING: University sleep disorders center. PATIENTS: Three hundred sixty-five patients with an apnea-hypopnea index (AHI) > or = 20 per hour of sleep and 358 patients with an AHI of < 20. INTERVENTIONS: All patients with AHIs > or = 20 received CPAP therapy; those with AHIs < 20 did not. The HRQL of all study participants was measured using the 36-item medical outcomes study short form (SF-36) questionnaire at baseline and then at 3 and 12 months of follow-up. RESULTS: Although the SF-36 scores were similar at baseline, after 3 months of therapy, the CPAP group had higher adjusted emotional summary scores than did those who did not receive CPAP therapy (score increase, 1.72; 95% confidence interval [CI], 0.08 to 3.37). These improvements were maintained for 12 months. The gains in the SF-36 scores were most striking in the vitality domain (score increase, 10.52; 95% CI, 7.04 to 14.00 U increment). The severe OSA group (ie, AHIs > or = 40) experienced the largest benefit. Their adjusted vitality scores were 12.3 U higher (95% CI, 8.0 to 16.6) than those persons without OSA (ie, AHIs < 5). CONCLUSIONS: CPAP therapy was associated with marked short-term and long-term improvements in the vitality of patients with moderate-to-severe OSA in the community. These findings suggest that CPAP therapy is effective in improving the long-term HRQL of patients with OSA.
Female↗
Spirometric findings among school-aged First Nations children on a reserve: a pilot study.
BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD) are increasing concerns for First Nations peoples in Canada. Although hospital utilization for asthma and COPD among First Nations peoples has been increasing, the prevalence of asthma or wheezing is comparable to national averages. OBJECTIVES: A pilot study was conducted to determine the prevalence of impaired lung function in school-aged First Nations children. PATIENTS AND METHODS: A First Nations community in northern Alberta was selected to participate. Consent forms and a school health survey were completed by parents or guardians. Children with consent completed spirometry at school, and results were compared with predicted values. RESULTS: A total of 36 children participated (response rate 70.6%). Of these, 19.4% of parents reported that their child had received a physician diagnosis of asthma at some point in their life; only 28.6% had a parental report of still having asthma. Parents smoked in 73.1% of the children's homes. The mean (+/- SD) percentage of forced expiratory volume in 1 s (FEV1) over forced vital capacity (FVC) was 82.6%+/-6.9% (94.4%+/-0.08% of predicted). Evidence of airflow obstruction was found in 25% of the children. Parental report of the child ever having asthma was associated with impaired lung function (OR 3.20; P=0.033). Children in a home with reported mold exposure were less likely to have impaired lung function (OR 0.68; P=0.030). CONCLUSIONS: Many children in this study already have established airflow obstruction and may be at increased risk for asthma or COPD. Exposure to mold appeared to be protective. Further research is needed to evaluate the lung health concerns of this population.
Alberta↗