Association between Serum Cotinine Levels and Bone Mineral Density: An Analysis of the National Health and Nutrition Examination Survey (NHANES)

PURPOSE: To investigate the relationship between serum cotinine and lumbar bone mineral density (BMD) among 7905 participants aged 30 years and over. METHOD: A total of 3945 men and 3960 women from the National Health and Nutrition Examination Survey 2011–2018 were included in this cross-sectional analysis. Independent variable was serum cotinine, which is a biomarker of cigarette exposure. The outcome variable was lumbar BMD. We investigated the associations of serum cotinine levels and lumbar BMD using multivariable linear regression models. RESULTS: Serum cotinine concentration was negatively associated with lumbar BMD after adjustment of relevant covariables (β = −0.039, 95% CI: −0.078 to −0.014, P = 0.005). However, in the subgroup analysis stratified by gender, this negative association remained only in women (β = −0.072, 95% CI: −0.132 to −0.012, P = 0.019). CONCLUSION: Our study suggested that elevated serum cotinine level correlated with decreased lumbar BMD, especially in women. This finding indicated that reducing cigarette exposure and maintaining serum cotinine at a low level may be beneficial to bone health for adults.