Predictors of obstructive lung disease among seafood processing workers along the West Coast of the Western Cape Province

Transcription

1 Predictors of obstructive lung disease among seafood processing workers along the West Coast of the Western Cape Province Adams S 1, Jeebhay MF 1, Lopata AL 2, Bateman ED 3, Smuts M 4, Baatjies R 1, Robins TG 5 1 Occupational and Environmental Health Research Unit, School of Public Health, UCT 2 Division of Immunology, IIDMM, NHLS, Groote Schuur Hospital, UCT 3 UCT Lung Institute, UCT 4 Medical Research Council, South Africa 5 Department of Environmental Health Sciences, University of Michigan, U.S.A Funded by: MRC, NIOSH R01 Grant No. F002304

2 Literature review Demographic Household Survey: SA prevalence of asthma diagnosis was 2.7% (men) and 3.1% (women) with PAF for occupational exposure 13.6%. Ehrlich et al,thorax 2004 Risk factors for NSBH in SA adults are female sex and occupational al exposure to a job causing wheeze Van Schalkwyk et al, ERS,2005 Role of dietary polyunsaturated fatty acids in obstructive lung disease uncertain but some protection for NSBH and exercise-induced induced bronchospasm Mickleborough TD, Journal of Asthma 2005 Patterns of sensitization impact on clinical expression of asthma Bousquet J et al, Allergy 2006 Burden of obstructive lung disease is considerable and COPD projected to become the 3rd leading cause of death by Viegi et al, Respiration 2001 Occupational exposure accounts for a large proportion of symptoms and functional impairment consistent with COPD (15%). ATS review, 2001

3 Objectives To determine the prevalence of asthma and COPD in a To determine the prevalence of asthma and COPD population of seafood processing workers on the West Coast of the Western Cape Province. To describe the host and environmental determinants associated with obstructive lung disease (asthma and COPD) To conduct a detailed analysis of IgE reactivity profiles (SPT) and their relationship with asthma outcomes To examine the relationship between serum fatty acid profiles and the relationship with asthma outcomes

4 Common fish processing activities in factories Fish Fish canning Fishmeal production

5 Methodology Study design and population Cross-sectional sectional study of two factory population groups (N=643) Comprised 76% adults resident in this fishing village Instruments Questionnaire- modified ECHRS Skin prick test to common aeroallergens Spirometry Methacholine challenge test (tidal breathing method) according to t ATS guidelines Serum omega-3 3 and omega-6

6 Results

7 Occupational factors

8 Outcome definitions for asthma 1. Atopy: A positive SPT with a wheal read 15 minutes after testing that had a diameter (mean of two perpendicular measures) of 3 mm more than the negative control to any allergen 2. Asthma symptoms: yes to any of: Have you had an attack of asthma in the last 12 months?, Have you been woken by an attack of shortness of breath in the last 12 months?, Have you been woken up with a feeling of tightness in your chest any time in the last 12 months? 3. Current asthma: Self-reported wheeze in the past 12 months and the presence of NSBH

9 Outcome definitions for asthma 4. Doctor-diagnosed asthma: yes to both questions: Have you ever had asthma? and Was this confirmed by a doctor? 5. Non-specific bronchial hyperresponsiveness: A positive methacholine challenge test with a PC20 8 mg/ml causing a drop in FEV1 of 20% or more or an increase in FEV1 of 12 % after 10 minutes of bronchodilator administration on baseline spirometry, was considered indicative of the presence of NSBH.

10 Demographic, medical and occupational factors and asthma outcomes

11 Sensitization to common aeroallergens (N=626) 2 % 3 % 4 % 5 % 9 % 1 4 % 1 5 % 2 5 % H D M C o c k r o a c h R y e g r a s s B e r m u d a g r a s s D o g M o u ld m ix C a t A s p e r g illu s

12 Patterns of allergic sensitization and asthma

13 Polyunsaturated fatty acids and asthma

14 Definitions for COPD-related outcomes 1. Chronic bronchitis symptoms: Reporting a chronic productive cough for 3 months in 2 or more consecutive years 2. Airway obstruction: FEV1 / FVC < 70% 3. Fixed airway obstruction: FEV1 / FVC < 70% and absence of NSBH 4. COPD: FEV1 / FVC < 70% and post- bronchodilator FEV1 < 80% predicted

15 Demographic factors and COPD

16 Medical and occupational factors and COPD outcomes

17 Conclusion Prevalence of asthma 5% - 26% and of COPD 3-5% Pre-existing respiratory disease is important as a risk factor for asthma and COPD in working adults Work is an important risk factor for obstructive lung disease particularly peak exposures and work-related ocular-nasal and chest symptoms Sensitization to indoor allergens is an important risk factor for asthma The potentially protective role of dietary fats (n-3) in asthma needs further investigation

18 Thank You