3 New Things About Respiratory Disease

Respiratory Disease Research in the News

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death in the United States, behind cancer and heart disease, according to the American Lung Association.

Mortality and hospitalizations resulting from asthma have decreased since 1999, but asthma prevalence now appears to be increasing. Children aged 5 to 17 years have had the highest prevalence rates.

Cigarette smoking, identified as the leading cause of preventable morbidity and premature mortality in the United States, is responsible for about 1 in 5 deaths in this country.

Highlights of recent research findings in these key areas of respiratory disease are shown on the pages that follow.

Chronic Respiratory Diseases: Meeting the Challenges

Practicing physicians can reduce the impact of chronic respiratory diseases by better understanding their manifestations, the exposures that cause them, and the steps to take to treat and prevent them.

Existing knowledge about chronic respiratory diseases and newer findings for clinicians are reviewed in a series of articles in the March 2015 Current Opinion in Pulmonary Medicine. Highlights here:

• A trigger of automatic health alert for spirometry in smokers 40 years or older with respiratory symptoms could help prevent a delayed diagnosis of COPD.

• A combination of body mass index, airflow obstruction, dyspnea, and exercise capacity index with COPD comorbidity test index provides the best indicator for all-cause mortality.

• An inhaled corticosteroid and an inhaled long-acting bronchodilator are not superior to 2 long-acting bronchodilators with different pharmacology and different mechanism of action in prolonging time between acute exacerbations of COPD.

• Inhaled corticosteroids can be safely withdrawn after long-term use in COPD.

More COPD Highlights: Connecting Lung Disease and Exposure

More than 15% of COPD cases are attributed to exposures in the workplace. To make the connection between lung disease and exposure, clinicians can start obtaining an occupational and environmental history. They need to ask patients:

• What they do

• How they do it

• Whether they are concerned about exposures on or off the job

• Whether coworkers are sick

Asthma Prevalence Differs Between Boys and Girls

• Sex-related differences influence the risk of wheezing illnesses and the prevalence of asthma throughout childhood.

• University of Wisconsin School of Medicine researchers analyzed longitudinal relationships between sex, lung physiology, and asthma in the Childhood Origins of ASThma birth cohort study.

• Lower airflow values were present by spirometry for prepubertal boys than for age-matched girls.

• Girls had higher ventilation defects on helium ion MRI than did boys.

Asthma Sex Differences Continued

• Subclinical air trapping in prepubertal girls may lead to residual volumes that are not detected on standard spirometric readings, the Childhood Origins of ASThma birth cohort study authors suggested.

• No differences were noted between the two sexes with airway hyperresponsiveness or inflammation.

• The investigators plan to prospectively follow the patients into puberty to determine whether the differences persist or change with the expression and remission of asthma, based on sex and age.

The researchers published their results online February 9, 2015, in the Journal of Allergy and Clinical Immunology.

Smoking Deaths Go Beyond Established Causes

• Most of the excess mortality among smokers-2 to 3 times that of never-smokers-can be explained by 21 common diseases that have been formally established as caused by cigarette smoking.

• However, smoking appears to cause additional diseases and therefore leads to significantly more deaths attributable to smoking than current estimates.

• Researchers pooled data from 5 contemporary cohort studies from 2000 to 2011, including more than 954,000 men and women aged 55 years and older.

• About 17% of the excess mortality among current smokers was related to diseases not commonly associated with smoking.

Specific Diseases That Caused Smoking Deaths

• Diseases that caused smoking deaths included various respiratory diseases, renal failure, intestinal ischemia, hypertensive heart disease, infections, breast cancer, and prostate cancer.

• Among former smokers, the relative risk for each of these outcomes declined as the number of years since quitting increased.

• These associations should be investigated further and when appropriate taken into account when the mortality burden of smoking is investigated, the researchers concluded.

The researchers published their results February 12, 2015, in The New England Journal of Medicine.

Take-Home Messages:

• Understanding the impact of chronic respiratory diseases and the exposures that cause them can help clinicians take steps to prevent and treat them.

• Sex differences influence the risk of wheezing illnesses and the prevalence of asthma among children.

• Respiratory diseases not commonly associated with smoking are also associated with excess mortality resulting from smoking.