Serum Cotinine and Chronic Pain: NHANES 2003-2004.

PURPOSE Tobacco smoke exposure continues to be the leading preventable risk factor for many diseases and has the potential to be a risk factor for chronic pain. The purpose of this study is to determine the relationship of chronic pain with smoking, secondhand smoke exposure and non-smoking using serum cotinine (and self-report of living with someone who smokes in the home) to identify the tobacco exposure groups. METHODS The National Health and Nutrition Examination Survey (NHANES) 2003-2004 was used for this study. Participants were queried about pain duration and had serum cotinine levels determined during the course of the NHANES examination/survey. Participants, ages 20 years and above, with complete data on chronic pain, cotinine level, sex, race/ethnicity, and responses concerning living with someone who smoked in the home were included in the study (n=4429). RESULTS The adjusted odds ratio of tobacco smoke exposure on chronic pain was 1.67 (95% CI: 1.08, 2.59; p=0.0220) for participants with a serum cotinine level >10 ng/mg (smokers) as compared with individuals who had a non-detectable serum cotinine level. For individuals with a serum cotinine level >0.011 ng/mg to 10 ng/mg who identified as living with someone who smoked in the home, the adjusted odds ratio was 0.88 (95% CI: 0.47, 1.65; p=0.6785) as compared with individuals who had a non-detectable serum cotinine level. CONCLUSION Chronic pain is a complex situation with many factors affecting it. Similarly, smoking is a complex addiction. The interplay of chronic pain and cotinine levels in this study were significant.