Baltimore, Maryland - Taking a daily aspirin was linked to reduced COPD exacerbations, less shortness of breath, and better quality of life, an analysis of the ongoing SPIROMICS study found. At 3 years follow-up, aspirin users were less likely to have acute COPD exacerbations (adjusted incidence rate ratio [IRR] 0.78, 95% CI 0.65-0.94) compared with non-users, with a similar effect seen for moderate acute COPD exacerbations (IRR 0.86, 95% CI 0.63-1.18), according to Ashraf Fawzy, MD, of Johns Hopkins University in Baltimore, and colleagues. The association was strongest among study participants reporting symptoms of chronic bronchitis at enrollment, as reported in the journal CHEST. Aspirin use has been associated with reduced mortality in previous studies, but the newly published investigation is among the first to examine the impact of daily aspirin therapy on respiratory morbidity in COPD. Preliminary data from this study were presented earlier this year at the American Thoracic Society annual conference. "The reduced incidence of total and moderate acute COPD exacerbations among aspirin users was independent of concurrent respiratory or cardiovascular medication use and robust when analyzing the entire follow-up period, limiting the analysis to the first year of follow-up, and across all sensitivity analyses," the authors wrote. Aspirin use was also associated with lower total scores on the St. George Respiratory Questionnaire (β -2.2, 95% CI -4.1 to -0.4); reduced odds of moderate-to-severe dyspnea, score ≥2 on the modified Medical Research Council Questionnaire (adjusted OR 0.69, 95% CI 0.51-0.93); and lower COPD Assessment Test scores (β -1.1, 95% CI -1.9 to -0.2). No difference was observed between groups in 6-minute walk distance (β 0.7 meters, 95% CI -14.3 to 15.6). The analysis included COPD patients in SPIROMICS who self-reported daily aspirin use at study entry, 45% of the 1,698 study participants. Acute exacerbations of COPD were prospectively determined through quarterly structured telephone questionnaires for up to 3 years and categorized as moderate (symptoms treated with antibiotics or oral corticosteroids) or severe (requiring an emergency department visit or hospitalization). Aspirin users were matched 1:1 with non-users based on propensity score, which resulted in 503 participant-pairs. The association of aspirin use with total, moderate, and severe acute COPD exacerbation was investigated using zero-inflated negative binomial models. Linear or logistic regression were used to investigate the association with baseline respiratory symptoms, quality of life, and exercise tolerance. The researchers noted that aspirin has several systemic and local pulmonary mechanisms of action that could explain the findings, including "inactivation of platelets and reduced inflammation," among them. "A urinary metabolite of thromboxane A2, which is secreted by activated platelets, has been shown to be elevated among patients with COPD and represents the pathway irreversibly blocked by aspirin. Persistent systemic elevation of inflammatory markers interleukin-6 and CRP may represent a systemic inflammatory phenotype of COPD which are attenuated by aspirin in other patient populations," the researchers wrote. They further noted that in a 2017 study, treatment with aspirin was found to reduce pro-inflammatory cytokines in bronchoalveolar lavage samples of 33 healthy volunteers. Study limitations cited by the researchers included the study participants' self-reporting of daily aspirin use, without dosing information. Information on duration of aspirin use and adherence to therapy before and during the study was also unavailable. COPD exacerbations were not confirmed with medical records, which may have led to misclassification of events. And despite propensity score matching and other efforts to avoid confounding, the researchers acknowledged that they may not have controlled for all factors that could have impacted their outcomes. They concluded that a randomized study is needed to determine whether daily aspirin use is protective against COPD exacerbations. "Prospective randomized clinical trials of aspirin use are warranted to explore its potential effect in reducing COPD morbidity," they wrote.

For more information: https://tinyurl.com/y83g3dwm  

Washington, DC - The U.S. Surgeon General on Tuesday declared electronic cigarette use among America's youth "an epidemic" and called for new restrictions on the products. The action comes a day after release of a Monitoring the Future report, which confirmed that teen vaping nearly doubled in 2018, with one in five high school seniors reporting current use of e-cigarettes. More than 3.6 million teens in the U.S. reported that they regularly used the vaping products. Recommendations in an advisory by Surgeon General Jerome Adams, MD, include banning vaping from establishments now covered by indoor smoke-free air policies, further restricting youth access to e-cigarettes in retail establishments, implementing new price policies, and banning marketing to youth. "The recent surge in e-cigarette use among youth, which has been fueled by new types of e-cigarettes that have recently entered the market, is cause for great concern," he said. "We must take action now to protect the health of our nation's young people." In a press conference, Adams cited a Surgeon General's report issued 2 years ago on e-cigarette use among youth and young adults. He was joined by U.S. Health and Human Services Secretary Alex Azar and FDA Commissioner Scott Gottlieb, MD. "We know that nicotine exposure during adolescence can uniquely harm the developing adolescent brain, impacting learning, memory, and attention," Adams said. "We know that exposure during this critical period can lead to further addiction. And we know that the notion that e-cigarette aerosol is harmless water vapor -- something even my 14-year-old son thought was true -- is a myth." "Studies show youth, like my son, have no clue what's in these products most of the time," Adams continued. "And shockingly to me as a parent, a third of youth who have ever used e-cigarettes have used marijuana in them. Yet, 2 years after [the Surgeon General's report] sounded the alarm bells, youth e-cigarette use has skyrocketed. So much so, that I am officially declaring e-cigarette use among youth an epidemic in the United States." Azar noted that the Monitoring the Future survey (sponsored by the National Institute on Drug Abuse) confirmed that the rise in youth e-cigarette use during 2017 and 2018 was the largest-ever single-year increase in use of a single substance ever recorded in the 43 years of the survey. "We have never seen the use of any substance by America's young people rise this rapidly. This is an unprecedented challenge," Azar said. "We are at risk of a huge share of a whole generation developing an addiction to nicotine, and that is not a future that anyone wants for our country." Azar reaffirmed HHS's commitment to exploring the potential of e-cigarettes as smoking-cessation products to help traditional cigarette smokers kick the habit. "We want to ensure that e-cigarettes can be used as an off-ramp for adults who want to quit combustible cigarettes," he said. "Traditional combustible cigarettes remain the leading cause of preventable death in the United States, and providing an effective off-ramp from them is a public health priority. But at the same time, we can’t allow e-cigarettes to become an on-ramp to nicotine addiction for younger Americans." Earlier this month, it was announced that the FDA will restrict the sale of certain flavored e-cigarettes in a move to address the epidemic increase in use among teens. At that time, Gottlieb warned that the agency may go much further if the flavor ban did not lead to reductions in youth tobacco use.

For more information: https://www.medpagetoday.com/primarycare/smoking/77000

Barcelona, Spain -There is a need to increase and maintain physical activity in patients with chronic obstructive pulmonary disease (COPD). Researchers here assessed 12-month efficacy and effectiveness of the Urban Training intervention on physical activity in COPD patients. This randomised controlled trial (NCT01897298) allocated 407 COPD patients from primary and hospital settings 1:1 to usual care (n=205) or Urban Training (n=202). Urban Training consisted of a baseline motivational interview, advice to walk on urban trails designed for COPD patients in outdoor public spaces and other optional components for feedback, motivation, information and support (pedometer, calendar, physical activity brochure, website, phone text messages, walking groups and a phone number). The primary outcome was 12-month change in steps·day−1measured by accelerometer. Efficacy analysis (with per-protocol analysis set, n=233 classified as adherent to the assigned intervention) showed adjusted (95% CI) 12-month difference +957 (184–1731) steps·day−1between Urban Training and usual care. Effectiveness analysis (with intention-to-treat analysis set, n=280 patients completing the study at 12 months including unwilling and self-reported non-adherent patients) showed no differences between groups. Leg muscle pain during walks was more frequently reported in Urban Training than usual care, without differences in any of the other adverse events. Urban Training, combining behavioral strategies with unsupervised outdoor walking, was efficacious in increasing physical activity after 12 months in COPD patients, with few safety concerns. However, it was ineffective in the full population including unwilling and self-reported non-adherent patients.

For more information: http://erj.ersjournals.com/content/52/4/1800063?ctkey=shareline

Washington, DC - Following a severe 2017-2018 influenza season in which an estimated 900,000 people were hospitalized and 80,000 died, United States officials reemphasized the need for everyone aged 6 months or older to get vaccinated. “Those 80,000 who died, guess what, they got that influenza from someone,” U.S. Surgeon General Jerome M. Adams, MD, MPH, said Thursday during the annual influenza news conference hosted by the National Foundation for Infectious Diseases (NFID). “It’s critically important that we impress upon folks. A projected 168 million doses of influenza vaccine that will be available this season. Adams said influenza caused 180 deaths in children last season “and the majority of them were not vaccinated.” The CDC believes 180 deaths is an underestimation because not all influenza-related deaths are reported. The study showed that the highest coverage was associated with workplace vaccination requirements and was consistently higher among health care personnel working in hospital settings. Influenza vaccination coverage among health care personnel working in long-term care settings remains consistently lower than all other settings — a concerning finding considering many of them work as assistants and aides to the elderly, who experience lower vaccine efficacy and are at increased risk for severe disease, the authors said. Additionally, older adults and those with certain chronic health conditions, such as heart and lung disease, diabetes and obesity, are at risk for serious influenza complications, according to NFID. Last season took the greatest toll on adults aged 65 years and older. According to the CDC, 70% of hospitalizations and 90% of deaths occurred in that age group. “Influenza is difficult to predict and can cause serious complications even for the healthy,” Adams said. “Vaccination is the best thing you can do to protect yourself, your family, and my family. Together, let’s fight flu.”

For more information: https://tinyurl.com/y83fes2l  

Boston, MA - Smoking causes not only cancer but also cardiovascular diseases such as stroke, coronary heart disease, hypertension, thromboembolism, and peripheral artery disease, lung disease such as chronic obstructive pulmonary disease (COPD), and many other diseases, including (but not limited to) type 2 diabetes, rheumatoid arthritis, cataracts, and macular degeneration.1 These diseases develop with age and contribute in different measure to the current epidemic of chronic noncommunicable diseases that are associated with smoking and aging. Even though the effects of smoking are broad and devastating, much smoking-related research traditionally focuses on the lung because the lung is considered to be the primary target organ of smoking.3 Even though COPD is one of the major consequences of smoking, COPD usually does not exist by itself, because it is almost invariably associated with concomitant chronic respiratory and non-respiratory diseases that contribute to the clinical manifestations and severity of the smoking-induced systemic disease. COPD, as defined by the Global Initiative for Chronic Obstructive Lung Disease, is diagnosed as persistent airflow limitation in smokers. This definition has limitations for clinical practice, because it does not mention symptoms and applies only to smokers in whom airflow limitation has developed. In fact, the only COPD we know well is the one that is defined as airflow limitation in smokers, because most of the data available on the pathophysiology and management of COPD have been derived from smokers with airflow limitation that was defined according to spirometric assessment. Woodruff and colleagues report appeared in a recent issue the New England Journal of Medicine. Their report looked at a group of smokers with normal findings on spirometry who have chronic respiratory symptoms, exacerbations (identified as the use of antibiotic agents, systemic glucocorticoids, or both or an event of health care utilization such as an office visit, hospital admission, or emergency department visit for a respiratory flare-up), lower than normal exercise tolerance, and imaging evidence of bronchiolitis. Thus, they conclude that spirometry is not adequate to define the breadth of smoking-induced lung disease. These results confirm and extend the findings of another recent large study that showed that more than 50% of symptomatic smokers with normal findings on spirometry have considerable respiratory-related impairment and evidence of emphysema on imaging. Most of these symptomatic smokers with normal findings on spirometry are often treated (without any evidence) with inhaled bronchodilators and glucocorticoids — that is, they are treated like patients with COPD, but they do not have COPD according to our current definition. These two studies introduce an important paradigm shift in our approach to smoking-induced disease. Both studies show that patients who have chronic respiratory symptoms without airflow limitation have the same respiratory consequences as those who have mild-to-moderate airflow obstruction and get the official diagnostic label of COPD. This finding tells us that symptoms are at least as sensitive as airflow limitation in establishing a diagnosis of smoking-induced disease. The observation that bronchiolitis and emphysema that are detected by means of computed tomographic scanning may be present in some smokers without airflow limitation lends a firm biologic basis to these inferences and reminds us, once again, that COPD may be a disease of the “lung’s quiet zone,” as defined by Mead almost 50 years ago — a place where there can be pathobiologic changes that are not detected by changes in the forced expiratory volume in 1 second (FEV1). These two studies have identified a complex clinical syndrome that is treated as COPD in practice even when airflow limitation is not present — a syndrome that very much resembles heart failure without impairment of ejection fraction.

For more information: https://tinyurl.com/yc4d9hzz

Melbourne, Australia - MedPage Today reported that daily aspirin not only failed to help generally healthy older individuals reduce their risk of disability-free survival and cardiovascular disease in the placebo-controlled ASPREE trial, it also appeared to raise overall mortality and particularly death from cancer. The primary endpoint of combined death, dementia, persistent physical disability came up in equal rates among healthy seniors randomized to 100 mg daily enteric-coated aspirin or placebo for 5 years (21.5 versus 21.2 events per 1,000 person-years, HR 1.01, 95% CI 0.92-1.11), according to ASPREE investigators led by John J. McNeil, MD, of Monash University in Australia. Major hemorrhages were found to be more common in the aspirin group (8.6 versus 6.2 per 1,000 person-years, HR 1.38, 95% CI 1.18-1.62). This counted the uptick in upper GI bleeding (HR 1.87, 95% CI 1.32-2.66) and intracranial bleeds (HR 1.50, 95% CI 1.11-2.02). Aspirin users also showed a higher risk of all-cause mortality (12.7 versus 11.1 per 1,000 person-years, HR 1.14, 95% CI 1.01-2.19), which was driven by cancer deaths (6.7 versus 5.1 per 1,000 person-years, HR 1.31, 95% CI 1.10-1.56). "The trial was terminated at a median of 4.7 years of follow-up after a determination was made that there would be no benefit with continued aspirin use with regard to the primary end point," the authors noted in a report published online in the New England Journal of Medicine (one of three covering various aspects of the trial). No individual component of the primary endpoint made a case for the benefit of aspirin, which failed to reduce the risk of cardiovascular disease as well (10.7 versus 11.3 events per 1,000 person-years, HR 0.95, 95% CI 0.83-1.08). "Interpretation of these results should take into account the lower-than-expected rate of cardiovascular disease among the trial participants ... most likely reflecting the relatively good health of the participant population at recruitment and the declining rate of cardiovascular disease in the two countries over time and across all age groups," the investigators suggested. Steven Nissen, MD, of Cleveland Clinic, said that the main results of ASPREE are not surprising. "Many people, including me, do not believe that aspirin offers meaningful benefits in primary prevention and carries substantial bleeding risks ... Unless the cardiovascular risk is very high (>20% over ten years), prophylactic aspirin results in more harm than good." The trial follows in the heels of other major studies offering mixed-to-negative data on aspirin for primary prevention, most recently ASCEND and ARRIVE in diabetes and moderate-risk patients, respectively (both were recently presented at the European Society of Cardiology meeting). ASPREE was a 19,114-person study of low-dose aspirin conducted in Australia and the U.S. McNeil and colleagues noted that adherence to the assigned treatment was 62.1% and 64.1% among aspirin and placebo recipients, respectively, during the final year of trial participation. Participants had to be 70 years or older (or 65 and older among blacks and Hispanics in the U.S.). The trial cohort was a median age 74 years at the time of enrollment in 2010-2014; 56.4% were women and 91.3% were white. The lack of racial diversity limits the generalizability of the trial, the authors said.

For more information: https://www.medpagetoday.com/cardiology/prevention/75123

San Antonio, TX - This review highlights the differences in diagnosis and treatment between COPD, asthma, and ACO and discusses the data supporting guideline recommendations for use of bronchodilators in COPD treatment in contrast to asthma or ACO. Despite the availability of well-established recommendations for diagnosis and management, COPD is often misdiagnosed and inappropriately treated in many patients, with approximately 50% of adults with COPD in the United States misdiagnosed or undiagnosed. Despite a common pathophysiology, COPD is a distinct disease from adult-onset asthma and clinicians need to be confident in their diagnosis to ensure the correct treatment. To further complicate the matter, approximately 15% to 20% of patients with COPD may present with features of asthma, described as asthma-COPD overlap (ACO). Long-acting β2-agonist (LABA) bronchodilators and inhaled corticosteroids (ICS) both have a place in standard maintenance treatment of COPD and asthma; however, recommendations for use differ widely between diagnoses. In patients with COPD, LABAs are effective initial monotherapy treatments, whereas ICS use is only recommended in combination with LABA treatment in patients with more advanced disease. Contrastingly, ICS monotherapy is recommended as initial treatment in patients with asthma, whereas LABA monotherapy was associated with an increase in asthma-related death, resulting in a “black box” warning being required on LABA-containing drug labels. It is recommended that LABAs always be administered in combination with ICS when treating persistent asthma of any severity. There is limited pharmacologic evidence for the optimal treatment of ACO because these patients have historically been excluded from clinical trials. However, it is recommended that patients with ACO not be treated with a LABA without an ICS. A diagnosis of COPD should be considered in patients who have symptoms such as dyspnea, chronic cough or sputum production, and/or a history of exposure to risk factors such as tobacco smoke or occupational exposures. Importantly, postbronchodilator spirometry is required to confirm the presence of persistent airflow limitation. In some patients with mild airflow obstruction, spirometry values may be normalized with smoking cessation or use of bronchodilators. In fact, up to 27.2% of subjects in a Canadian study and 15.6% of smokers in a Spanish study had a reversal of their COPD diagnosis. Therefore, patients initially diagnosed with COPD, even those admitted with an exacerbation, should be reassessed at follow-up to avoid overdiagnosis and overtreatment.

For more information: https://journal.chestnet.org/article/S0012-3692(18)30390-8/fulltext

New York, NY - Researchers here hypothesized that regular use of aspirin, a platelet inhibitor, would be associated with a slower progression of emphysema-like lung characteristics on CT imaging and a slower decline in lung function. It was noted in their study that platelet activation reduces pulmonary microvascular blood flow and contributes to inflammation; these factors have been implicated in the pathogenesis of COPD and emphysema. The Multi-Ethnic Study of Atherosclerosis (MESA) enrolled participants 45 to 84 years of age without clinical cardiovascular disease from 2000 to 2002. The MESA Lung Study assessed the percentage of emphysema-like lung below –950 Hounsfield units (“percent emphysema”) on cardiac (2000-2007) and full-lung CT scans (2010-2012). Regular aspirin use was defined as 3 or more days per week. Mixed-effect models adjusted for demographics, anthropometric features, smoking, hypertension, angiotensin-converting enzyme inhibitor or angiotensin II-receptor blocker use, C-reactive protein levels, sphingomyelin levels, and scanner factors. At baseline, the 4,257 participants' mean (± SD) age was 61 ± 10 years, 54% were ever smokers, and 22% used aspirin regularly. On average, percent emphysema increased 0.60 percentage points over 10 years (95% CI, 0.35-0.94). Progression of percent emphysema was slower among regular aspirin users compared with patients who did not use aspirin (fully adjusted model: –0.34% /10 years, 95% CI, –0.60 to –0.08; P = .01). Results were similar in ever smokers and with doses of 81 and 300 to 325 mg and were of greater magnitude among those with airflow limitation. No association was found between aspirin use and change in lung function. The researchers concluded that regular aspirin use was associated with a more than 50% reduction in the rate of emphysema progression over 10 years. They added that further study of aspirin and platelets in emphysema may be warranted. Lead author of the study is Carrie P. Aaron, MD., Assistant Professor of Medicine at Columbia University Medical Center, New York Presbyterian Hospital

For more information: https://journal.chestnet.org/article/S0012-3692(17)33210-5/fulltext

Toronto, ON – In 2003, tobacco smoking accounted for 9.5 per cent of all health spending in Ontario. By 2041, if the decrease in tobacco smoking rates continues, the researchers say this proportion will drop by more than one-third, to 5.9 per cent of total health spending. Between 2003 and 2041, there will be an estimated $51-billion reduction in tobacco smoking-attributable health care expenditures in Ontario. Despite this reduction, tobacco smoking-attributable health care expenditures will amount to $164 billion between 2003 and 2041. “Tobacco smoking profoundly affects not only health but also almost all aspects of health care. Smoking harms nearly every organ and system in the body. Diseases directly related to smoking are a major source of hospital admission, but even seemingly unrelated admissions are also affected. A person who smokes and has hip surgery will have a greater risk of complications, slower recovery and more likely to require the surgery be redone than a non-smoker,” added Dr. Manuel. The researchers add that investing in strategies to encourage the decrease of unhealthy behaviours such as smoking, ideally preventing the behaviours from starting in the first place, will go far to improve the health of Ontario’s population, while improving the sustainability of our health care system. "Health Care Cost of Smoking in Ontario, 2003 to 2041” is being published July 12, 2018. Author block: Douglas G. Manuel, Andrew S. Wilton, Adrian Rohit Dass, Audrey Laporte, Sima Gandhi and Carol Bennett. The Institute for Clinical Evaluative Sciences (ICES) is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of health care issues.

For more information: https://tinyurl.com/ydzanbgo

Toronto, ON - Advocates say this information should be widely disseminated in the medical community, and alternative treatments for COPD patients should be considered. People with chronic pulmonary obstructive disease (COPD) suffer from symptoms that include breathlessness, coughing, and chest tightness. The disease is also associated with mood disorders such as depression and anxiety. By one estimate, as many as 70 percent of COPD patients deal with anxiety and other mood disorders. Now, a new study suggests certain antidepressants may increase the risk of death in people with COPD by 20 percent. Users of serotonergic antidepressants also had higher rates of hospitalization and emergency room visits. Dr. Nicholas Vozoris, lead author of the study and an assistant professor in the Department of Medicine at the University of Toronto, as well as a respirologist at St. Michael’s Hospital, says the findings are not surprising. “These drugs can cause sleepiness, vomiting, and can negatively impact immune system cells. This increases the likelihood of infections, breathing issues, and other respiratory adverse events, especially in patients with COPD,” Vozoris said in an article on the St. Michael’s website. Russell Winwood, an athlete and COPD advocate, argues that the research should be widely disseminated to all physicians, especially those treating respiratory patients. “Unfortunately, information like this can take years to get out into clinics. By this time, many patients can already have experienced adverse side effects,” he said. For John Linnell, another COPD advocate, the new study poses more questions than answers. “I’m very curious if this problem is common knowledge among pulmonologists,” he said. “If it’s common knowledge to every doctor that it’s bad for respiratory patients, then the study is worthless. Well, I shouldn’t say worthless, but it doesn’t mean as much. But if this is something that’s new, that pulmonologists are not aware of, and it’s the primary care physician doing the prescribing and the pulmonologist is unaware of it, and all of a sudden, you’ve got more re-admissions, then yeah, then you’re really onto something.” Linnell agrees that this question is a major issue. “Who is prescribing the antidepressant? Is it the pulmonologist? Or is it the primary care physician?” he asked. Linnell added he knows from personal experience the problematic nature of several doctors managing one patient. “None of them knew what the other was doing at all unless I took the burden upon myself to let them know,” he said. “The underlying message is that the patient needs to make sure that one doctor needs to know what the other doctor is doing.” For COPD advocates, it’s clear there’s an association with COPD and mood disorders. Linnell, among others, suggests anxiety and depression are due to the nature of the disease. “A lot of times because, well, you become anxious because you can’t breathe,” he explained. He added that depression occurs because COPD patients spend so much time at home. “They don’t get out, which makes their COPD worse,” he said. Winwood expressed similar sentiments, stating that COPD is an isolating disease with a lot of stigma still attached to it. “COPD is misunderstood by many people,” he said.

For more information: https://tinyurl.com/ydbegpgk

San Francisco, CA - Frequent marijuana use was associated with an increase in respiratory symptoms, including cough, sputum production and wheezing, in a newly published meta-analysis, but the quality of the evidence was poor, researchers reported. They concluded that there was low-strength evidence linking marijuana smoking with the respiratory symptoms in the more than 20 studies included in the analysis and insufficient evidence to link daily marijuana use to changes in pulmonary function or development of obstructive lung disease. "Given rapidly expanding use, we need large-scale longitudinal studies examining the long-term pulmonary effects of daily marijuana use," wrote Mehrnaz Ghasemiesfe, MD, and colleagues, wrote in Annals of Internal Medicine. Ghasemiesfe explained that several previous prospective studies have linked marijuana use with an increased risk for respiratory issues, but evidence of an effect on pulmonary function and obstructive lung disease has been limited by use of marijuana in primarily younger populations. He said the study highlights the limitations of previous research examining marijuana use and pulmonary outcomes, including the lack of standardized use assessment tools and well-defined study designs with robust assessment and adequate follow-up. "Future studies need to focus on middle-aged to older populations who have been heavier marijuana users to identify the potential effects on lung function and developing obstructive lung disease," he said. Ghasemiesfe noted that smoke from burning marijuana contains many of the same toxic gases, particulates and polycyclic aromatic hydrocarbons as cigarette smoke. Ghasemiesfe and colleagues conducted data searches of studies conducted between 1973 and 2018, identifying 22 studies that met their inclusion criteria, including 10 prospective cohort studies and 12 cross-sectional studies. Methods of quantifying marijuana use varied (i.e., as monthly, weekly, or daily). The researchers used the "joint-year" -- the equivalent of one marijuana cigarette a day for 1 year -- as their measure of lifetime exposure. Across all outcomes and studies, 1,255 participants had more than 10 joint-years of exposure and 756 marijuana-only smokers had more than 20 joint-years. Four prospective observational studies and seven cross-sectional studies examined the association between marijuana use and cough, sputum production, wheezing, or dyspnea. One prospective study with moderate risk of bias (ROB) followed a random sample of the population of Tucson, Arizona (n = 1,802), in four sequential surveys from 1981 through 1988, finding current marijuana smoking to be associated with the following: Chronic cough, chronic sputum production, and wheezing. The researchers noted that while the study had strengths (robust exposure assessment and moderate length of follow-up), it presented limited data and could not be included in the pooled analysis. Another prospective study with moderate ROB included participants from Los Angeles, California (n=299), who had smoked a mean of 3.0 (SE 0.4) joints per day for 9.8 years. Baseline exposure assessment was adequate, but half the participants were lost to follow-up. Two prospective studies (low ROB) used the Dunedin Multidisciplinary Health and Development cohort of 1,037 children born in New Zealand between 1972 and 1973. Marijuana exposure data were collected several times during 15 years of follow-up. Compared to non-smokers, marijuana users had increased risks for cough (RR 2.04, 95% CI 1.02 to 4.06) and sputum production (RR 3.84, 95% CI 1.62 to 9.07). The studies found that quitting smoking marijuana led to a significant reduction in respiratory symptoms. No relationship was found between marijuana use and impairment of spirometric indices, but the researchers warned that this finding should be interpreted with caution, noting that exposures may have been insufficient to alter pulmonary function test results. "Because obstructive lung disease develops in only about a third of long-term tobacco smokers, is usually not identified until after age 35 or 40 years, and increases in prevalence with age, large cohorts with middle-aged to older populations of heavier marijuana users may be necessary to identify effects on lung function and obstructive lung disease," the researchers wrote. "On the other hand, given the psychoactive effects of tetrahydrocannabinol and its effect on overall function, few users may have heavy enough exposure to cause significant changes in pulmonary function testing. In other words, marijuana's effect on lung function may not be among its most important health outcomes in the long term."

For more information: https://tinyurl.com/y7f8d28u

Vancouver, BC - The concept that small conducting airways less than 2 mm in diameter become the major site of airflow obstruction in chronic obstructive pulmonary disease (COPD) is well established in the scientific literature, and the last generation of small conducting airways, terminal bronchioles, are known to be destroyed in patients with very severe COPD. Researchers here aimed to determine whether destruction of the terminal and transitional bronchioles (the first generation of respiratory airways) occurs before, or in parallel with, emphysematous tissue destruction. In this cross-sectional analysis, they applied a novel multiresolution CT imaging protocol to tissue samples obtained using a systematic uniform sampling method to obtain representative unbiased samples of the whole lung or lobe of smokers with normal lung function (controls) and patients with mild COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage 1), moderate COPD (GOLD 2), or very severe COPD (GOLD 4). Patients with GOLD 1 or GOLD 2 COPD and smokers with normal lung function had undergone lobectomy and pneumonectomy, and patients with GOLD 4 COPD had undergone lung transplantation. Lung tissue samples were used for stereological assessment of the number and morphology of terminal and transitional bronchioles, airspace size (mean linear intercept), and alveolar surface area. Of the 34 patients included in this study, ten were controls (smokers with normal lung function), ten patients had GOLD 1 COPD, eight had GOLD 2 COPD, and six had GOLD 4 COPD with centrilobular emphysema. The 34 lung specimens provided 262 lung samples. Compared with control smokers, the number of terminal bronchioles decreased by 40% in patients with GOLD 1 COPD (p=0·014) and 43% in patients with GOLD 2 COPD (p=0·036), the number of transitional bronchioles decreased by 56% in patients with GOLD 1 COPD (p=0·0001) and 59% in patients with GOLD 2 COPD (p=0·0001), and alveolar surface area decreased by 33% in patients with GOLD 1 COPD (p=0·019) and 45% in patients with GOLD 2 COPD (p=0·0021). These pathological changes were found to correlate with lung function decline. We also showed significant loss of terminal and transitional bronchioles in lung samples from patients with GOLD 1 or GOLD 2 COPD that had a normal alveolar surface area. Remaining small airways were found to have thickened walls and narrowed lumens, which become more obstructed with increasing COPD GOLD stage. These data show that small airways disease is a pathological feature in mild and moderate COPD. Importantly, this study emphasises that early intervention for disease modification might be required by patients with mild or moderate COPD.