248037 Role of heavy metals in chronic obstructive pulmonary disease (COPD): Results from National Health and Nutrition Examination Survey (NHANES) 1999-2008

Tuesday, November 1, 2011: 3:35 PM

Haala Rokadia, MD , Internal Medicine Department, Cleveland Clinic, Cleveland, OH
Shikhar Agarwal, MD, MPH, CPH , Internal Medicine Department, Cleveland Clinic, Cleveland, OH
Cigarette smoke is the primary mechanisms of exposure to heavy metals. We aim to assess the role of lead and cadmium as partial mediators in the association between smoking and COPD.

Methods Cross-sectional data from NHANES 1999-2008 were used. The outcome of COPD was determined using standardized questionnaires regarding a history of emphysema and active and past chronic bronchitis. Active smoking was defined by self-report or measured serum cotinine > 10 ng/mL. Serum lead and cadmium levels were measured by mass spectrometry. Survey statistics were employed to analyze the complex semi-random survey design. Data were pooled using standard methods and 10 year combined weights were calculated.

Results After adjusted analysis, odds ratios (OR) (95%CI) for COPD in former and active smokers relative to never smokers was 1.79 (1.49-2.15) and 2.44 (2.07-2.88) respectively. These ORs were unchanged when adjusted for lead levels, however significantly reduced when adjusted for cadmium to 1.66 (1.39-1.99 and 1.72 (1.34-2.19), respectively. On adjusted analysis, higher levels of serum cadmium were associated with higher risk of COPD (p for trend <0.001). This trend was primarily driven by emphysema group; ORs (95%CI) for COPD by cadmium quintiles 2 to 5 compared to lowest quintile were 0.88 (0.35-2.24), 1.69 (0.77-3.69), 3.27 (1.59-6.70), 5.26 (2.28-12.11).

Conclusions The relationship of smoking and COPD may be partially mediated through cadmium. COPD is increasing with higher levels of serum cadmium and emphysema is primarily driving that trend. The risk of COPD was significantly higher despite cadmium levels lower than the current safety standard.

Learning Areas:
Chronic disease management and prevention
Public health or related public policy

Learning Objectives:
To assess the association between serum cadmium and lead levels with COPD To assess the role of cadmium and lead exposure as partial mediator in the association between smoking and COPD

Keywords: Tobacco, Chronic Diseases

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: i was involved in the formation of hypothesis, data collection, analysis of data, and preparation of abstract
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

See more of: Chronic Disease Epidemiology
See more of: Epidemiology