Asthma The Challenge of Children, Minorities, and Low-Income Populations

1. AsthmaThe Challenge of Children, Minorities, and Low-Income Populations Thomas Owens, MD

2. Asthma: A Chronic Lung Disease • Characterized by recurrent cough and wheeze that is increasing in prevalence among children • From 1980 to 1996 • the number of Americans afflicted with asthma more than doubled to 15 million • with children under 5 experiencing the highest rate of increase This constitutes an epidemic

3. Review of Asthma A.D.A.M., 2007

4. Objectives • Describe the highest risk asthma populations • Outline the significant features of the asthma management guidelines • Describe adherence issues and methods to overcome difficulties • Describe new advances in the diagnosis and pharmacological treatments of asthma

5. Objectives • Describe the highest risk asthma populations • Outline the significant features of the asthma management guidelines • Describe adherence issues and methods to overcome difficulties • Describe new advances in the diagnosis and pharmacological treatments of asthma

6. Prevalence in High-Risk Populations Nearly 5 million children (<5% population 18 & younger) African-Americans & Hispanic Americans (Highest rates of asthma) Urban areas with poor living conditions (near transportation and industrial activity) Low SES (<$20,000/yr) (poor access to healthcare and education) (Carmago,2007) (Morris, 2007)

7. Children with Asthma • Usually begins in early childhood (Carmago, 2007) • 80-90% have symptoms by age 6 • > ½ develop by age 3 • < 10 yrs. male-to-female ratio is 2:1 • Between the ages of 18 and 54 years the ratio is reversed (University of Aberdeen, 2007)

8. Ethnicity Prevalence • Caucasian children lowest at risk (Sharma,2007) • African-Americans 44% higher • 5-8% have asthma at sometime • 20-25% of inner-city children • Hispanics 15% higher • 20-25% of inner-city children • U.S. average prevalence: • 7.6%, with ethnic minority prevalence of 3-14%

9. African-American Child Hospitalizations • African-American children are hospitalized 3 times more than Caucasians (Bolte, 2007) • 1998 statistics: African-Americans more than 4 times likely to die • Mortality rates doubled 1980 to 1996 • More deaths occur in inner city areas

10. Mortality Rates in Pediatric Asthma • More than doubled between 1980 and 1996 • disproportionate number of deaths occur in inner city areas • There are 5,000 deaths annually from asthma • some have been linked to management failure (especially in younger persons) • highest mortality rates occur in adolescents • persons who have had prior asthmatic exacerbation requiring intubations are at significantly increased risk for subsequent fatal exacerbations (Morris, 2007)

11. Significant Factors in Pediatric Asthma Deaths • Inappropriate delay in seeking medical attention • Limited access to care • Under-use of anti-inflammatory agents • Overuse of beta agonists (Morris, 2007)

12. Barriers to Healthcare: Inner City Residents • Inner city inhabitants may: • low income • medically underserved • less likely to have routine doctor visits • poor access to the availability of medications (Morris, 2007) The source of primary and follow-up care for this population is often in the hospital emergency department.

13. Barriers to Healthcare: Ethnic Minorities • Lower quality health care • even when insurance, age, income and severity of conditions are the same • Tend to use inhaled corticosteroid suppressants less than Caucasians • Results from cost, inadequate literacy or competing priorities • These patients also received less follow-up after hospital emergency department visits (Morris, 2007)

14. Barriers to Asthma Management • Asthma is a disease that requires maximum cooperation of the patient and family • Parents must oversee a complicated regimen of inhalers, pills, and breathing exercises (Morris, 2007) • this type of supervision and assistance may not be available in poverty situations

15. Cultural Asthma Research • Cultural competence policies and other predictors of asthma care quality for Medicaid-insured children (Lieu, 2004) • evaluated medical clinics serving primarily inner city patients • best management of asthma was rendered where: • physicians and caregivers improved their communication skills • were trained in cultural differences • utilized bilingual or low-literacy instructions, posters, teaching • medication feedback was encouraged • asthma case managers were utilized • ethnic minority caregivers were employed

16. Latino Populations • Puerto Ricans having highest mortality rates • followed by Cuban Americans and Mexican Americans (Homa et al. 2000; Sly, 2006)

17. The Effect of Urbanization • Asthma emergency visits account for approximately 2% of all emergency visits • In urban centers acute asthma may comprise up to 10% of all emergency visits • Worldwide, 130 million people have asthma • The prevalence is 8-10 times higher in developed, industrialized countries (like Canada, England, Australia, Germany and New Zealand; prevalence rate = 2-10%) than in the developing countries. (Morris, 2007) • In developed countries, the prevalence is higher in low income groups in urban areas and inner cities than in other groups • Prevalence increases as a developing country becomes more Westernized and urbanized

18. Environmental Factors • Exposure to maternal environmental tobacco smoke • which during pregnancy or the first year appears to predispose children to reactive airway disease • Efforts to mitigate cockroach and mold reduced symptoms successfully and significantly for urban children (Morgan et al., 2004)

19. Status Asthmaticus • Appears to be on the rise • Several retrospective studies reflect an increase in hospital admissions • particularly in those younger than 4 years • Fewer hospital and emergency visits are needed in children using inhaled corticosteroid therapy

20. Urbanization Pollution • Main contributor to the development of this disease • Gasoline (car) & diesel fuel (truck) combustion engines produce similar and yet different types of respiratory toxins (Pandya, 2001)

21. Gasoline Exhaust • Produces known pollutants and several components of air pollution have been linked to asthma • U.S. Clean Air Act requires the EPA to monitor: • nitrogen dioxide, sulfur dioxide, lead, carbon monoxide and ozone particulate matter (both PM(10 microns (um)) and PM(2.5) • diesel exhaust and diesel exhaust particles (DEPs) also appear to play a role in respiratory and allergic diseases (Pandya, 2001)

22. Diesel Exhaust • Smog-forming and toxic air pollutant vapors and gases that you get when you burn gasoline • also composed of small particles of carbon, known as fine particulate matter and also referred to as Diesel Exhaust Particles (DEPs) (Johnson, 2007; Graham, 2007)

23. Diesel Particulates • EPA classifies and measures these particulate matter according to their size • (PM2.5 = 2.5 microns (micromenter, um), PM 10 = 10 microns) • Unfortunately, the average diameter of diesel particulates is 0.2 microns, and nearly 94% of diesel particulates have diameters less than 2.5 micrometers (um) (Johnson, 2007; Graham, 2007)

24. Tiny Toxins EPA, 2007

25. DEPs • Hundreds of chemicals adsorbed to their surfaces • Cooked but unburned hydrocarbons could combine in thousands of combinations or permutations • are large, complex, carbon-ringed, planar, lipid soluble • similar to those we find in nature or design to penetrate the cell walls and enter the nucleus to interact with DNA (Pandya, 2001)

26. DEPs • Bind to airborne allergens and other debris • may alter these complex organic allergen molecules further (Pandya, 2001) One could not design a more effective delivery method or toxic product to enter the deepest of our lungs

27. Diesel Emissions • Include over 40 substances that are listed by the EPA as hazardous air pollutants • Federal agencies have classified diesel exhaust as a probable human carcinogen • Benzene, an important component of the fuel and exhaust • is designated to be a known human carcinogen (Pandya, 2001)

28. Polyaromatic Hydrocarbons • Contain larger, more complex • (anthracene, fluoranthene, pyrene, phenanthrene) • In addition, DEPs contain • aldehydes (formaldehyde, acetaldehyde, acrolein), benzene, 1,3-butadiene, polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs and hundreds of others Diesel exhaust ranks among the air pollutants that EPA believes pose the greatest public health risks(Pandya, 2001)

29. Diesel Exhaust Components • Genotoxic and mutagenic • can produce symptoms of allergy • including inflammation and irritation of airways • Exposure to diesel exhaust can cause lung damage and respiratory problems • diesel exhaust can also exacerbate asthma and existing allergies • long-terms exposure is thought to increase the risk of lung cancer (Pandya, 2001)

30. Children & Air Pollution There is no known safe level of exposure to diesel exhaust for children, especially those with respiratory illness • May be more susceptible to air pollution • they breathe 50 % more air per lb. of body weight than adults • May be especially susceptible to DEPs due to the small size of the particle • Smaller particles are able to penetrate children’s narrower airways reaching deeply within the lung, where they are more likely to be retained (Pandya, 2001)

31. DEPs • DEPs act as generic respiratory irritant at high concentrations • At lower levels: • DEPs act as pro-inflammatory agents • promote release of specific cytokines, chemokines, immunoglobulins, and oxidants in the upper and lower airway • DEPs cause formation of reactive oxygen species that trigger pro-inflammatory cytokine release (Takizawa, 2007)

32. Immunologic Evidence • May help explain the epidemiologic studies indicating that children living along major trucking thoroughfares are at increased risk for: • asthmatic and allergic symptoms • more likely to have objective evidence of respiratory dysfunction (Pandya, 2001)

33. New & Emerging Factors Wargo, 2002

34. School Bus Study Statistics • U.S. nearly 600,000 school buses transport 24 million students to school daily • Each year buses travel 4.3 billion miles • nearly 10 billion school bus rides • students will spend 180 hours on buses each year • children spend 3 billion hours on school buses each year • More than 99% of U.S. school buses are powered by diesel fuel • Fine particulate concentrations measured on buses in this study were often 5-10 times higher than average levels (Morris, 2007)

35. School Bus DEPs • Levels of DEP often higher under certain circumstances: (Morris, 2007) • were idling with windows opened • ran through their routes with windows closed • moved through intense traffic • queued to load or unload students while idling • Some studies show there would have been less exposure if you ride in the vehicle directly behind the bus than to ride in it

36. NRDC & Coalition for Clean Air Study (2001) • Shows that children who ride a diesel school bus may be exposed to up to four times more toxic diesel exhaust than someone traveling in a car directly behind it • Excess exhaust levels on school buses were 23 to 46 times higher than levels considered to be a significant cancer risk • according to the U.S Environmental Protection Agency and federal guidelines (Morris, 2007)

37. Additional Causes of Asthma • Exposure to: • passive smoking • changes in exposure to environmental allergens • cockroaches, house dust mites, and the mold Alternaria Tenuis • other aeroallergens like pet dander, gas and wood-burning stoves and tobacco smoke • viral respiratory infections • caused by respiratory syncytial virus • possibly rhinovirus are a significant risk factor for the development of childhood wheezing in the first decade of life (Morris, 2007)

38. Chronic Noise Levels • During sleep caused stress and resulted in higher cortisol levels in the first half of the night • Noise may have an adjuvant effect on the pathogenesis of allergies

39. Genetics • Found more often in patients with a personal or family history of atopy • Family history of asthma (Risk) • 7% if neither parent has asthma • 20% if one parent has asthma • 64% if both parents have asthma (Chin, 2001)

40. Allergic March • Infants exhibiting • atopic dermatitis • food intolerance • Followed in time by allergic rhinoconjunctivitis • Ending with development of asthma

41. Hygiene Hypothesis • Proposes that newborns are armed with an immune system ready to respond to natural environmental and infectious stimuli • If not exposed to these • the balance of T lymphocytes will be tilted towards a more ‘angry’ reactive population TH2 • as opposed to a ‘relaxed’ TH1 population with all their cytokine messenger signal proteins

42. Measles Infection • BCG vaccine administration • Hepatitis A seropositivity • Other stimuli that increase production of interferon-gamma • IL-12 may inhibit the TH2 allergic response

43. Increased Atopy & Asthma • Increased atopy and asthma associated with: • Vaccinations, fewer childhood infections, liberal use of antibiotics, more processed food in diets, smaller families, and less exposure to day care environments • Prevalent in western Germany, while bronchitis from power plants is more common in eastern Germany • Chinese from Hong Kong had higher atopy/allergy levels than those living on the mainland • Traffic police officers had higher atopy/allergy levels than those with desk jobs (Polosa, 2002)

44. Further Asthma Study Results • Twins raised separately • farm-reared sibs had lower asthma levels than town-raised sibs • Asthma-free areas are present in certain sub-Saharan areas • Somalia, where hookworm disease is endemic • The parasitic system (eosinophiles) is fully engaged

45. Questions • Could it be that the reactive immune system engages what it has available, (eg. cockroach, mold, cat antigens)? • And the adjuvant effect of air pollution and DEPs turns on the immune reaction to a high level?

46. Let’s Review! Children may be more susceptible to diesel exhaust particles (DEPs) because: • Small size of the DEP particles • Pro-inflammatory agents in the DEPs • High breathing rate

47. Objectives • Describe the highest risk asthma populations • Outline the significant features of the asthma management guidelines • Describe adherence issues and methods to overcome difficulties • Describe new advances in the diagnosis and pharmacological treatments of asthma

48. National Asthma Education & Prevention Program (NAEPP) • National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes Health has assembled: • Best practice guidelines for diagnosis and treatment of asthma • 2007 revision available: • http://www.nhlbi.nih.gov/guidelines/asthma/epr3/resource.pdf

49. Asthma Diagnosis • Confirmed with recurrent wheezing, coughing, dyspnea • Objective PEFR reversibility with medication • Asthma staging helps define management, continued monitoring of symptoms • PEFR helps adjust medication

50. Goals of Treatment • Reduce wheeze and cough • Reduce the risk and number of acute exacerbations • Minimize adverse effects • medications • sleep disturbances • absences from school