Serum cadmium and lead, current wheeze, and lung function in a nationwide study of adults in the United States

ABSTRACT Background Cadmium and lead are hazardous pollutants. Objective We examined the relation between serum levels of cadmium and lead and current wheeze, current asthma, and lung function in U.S. adults. Methods Cross-sectional study of 13,888 adults aged 20 to 79 years old in 2007-2012 National Health and Nutrition Examination Survey (NHANES). Multivariable logistic or linear regression was used for the analyses of current wheeze, current asthma, and lung function measures (FEV1% predicted, FEV1/FVC% predicted, and fractional exhaled nitric oxide [FeNO]), which were conducted first in all participants, and then separately in never/former smokers and current smokers. Results High levels of serum cadmium were significantly associated with current wheeze in all participants and in current smokers (odds ratio for fourth vs. first quartile = 2.84, 95% confidence interval = 2.07 to 3.90, P for linear trend 0.01), as well as with current asthma in current smokers. Serum lead was not significantly associated with current wheeze or current asthma, regardless of smoking status. Serum cadmium was significantly associated with lower FEV1% predicted, FEV1/FVC% predicted, and fractional exhaled nitric oxide in all participants and in never/former smokers, and serum lead was significantly associated with lower FEV1/FVC% predicted in all participants, with similar findings in never/former smokers and in current smokers. Conclusions Our findings suggest that exposure to cadmium is associated with an increased risk of wheeze and asthma in U.S. adults who currently smoke. Moreover, our results suggest that exposure to cadmium or lead has negative effects on lung function in non-smoking U.S. adults.