Tobacco smoke exposure and spine fracture risk in US adults: A cross-sectional analysis of the National Health and Nutrition Examination Survey 1999-2010, 2013-2014, 2017-2020.

INTRODUCTION

While tobacco smoke is an established risk factor for multiple pathological conditions, its specific relationship with spine fracture remains inadequately characterized in the scientific literature. This study was designed to assess the potential link between tobacco smoke exposure and spine fracture prevalence among US adults, and to investigate the presence of a dose-response gradient.

METHODS

We performed an analytical cross-sectional study utilizing data from the National Health and Nutrition Examination Survey (NHANES) 1999-2010, 2013-2014, 2017-2020. Serum cotinine concentrations were employed as an objective biomarker for tobacco smoke exposure. Multivariable logistic regression models were constructed to quantify the association between smoke exposure and a diagnosis of spine fracture. We performed a rigorous evaluation of the association's consistency through subgroup stratification. Further, we characterized the dose-response relationship using restricted cubic splines (RCS) with threshold effect analysis to detect possible non-linear patterns.

RESULTS

Our final analytical cohort included 31124 eligible participants. After comprehensive covariate adjustment, multivariable analysis revealed a significant positive correlation between tobacco smoke exposure and spine fracture risk. When treated as a continuous variable, a significant positive linear dose-response relationship was observed: the natural log-transformed cotinine concentration maintained a significant positive association with spine fracture risk across all progressively adjusted models (OR=1.04; 95% CI: 1.02-1.06). As a categorical variable, participants with serum cotinine concentrations indicative of active smoking (≥3 ng/mL) demonstrated a 41% elevated spine fracture risk compared to those with unexposed participants (<0.05 ng/mL, reference group). The consistency of the observed association was further affirmed through stratified analyses and interaction testing across all demographic and clinical subgroups, lending robust support to our primary finding.

CONCLUSIONS

Our analysis provides evidence that tobacco smoke exposure is independently associated with an increased risk of spine fracture. These findings underscore the public health imperative to implement tobacco control measures.