Prior Tobacco Use Is Associated With Tibial Microarchitecture In U.S. Army Recruits: A Preliminary Analysis

Abstract

Tobacco use is common and is associated with less favorable bone properties in older adults at risk for osteoporosis. Baseline bone properties are related to stress fracture risk in military populations. Whether a history of tobacco use is associated with less favorable bone microarchitectural properties in military recruits is unknown. PURPOSE: To examine the influence of prior tobacco use on bone microarchitecture using data from a large prospective field study (789 men and women from a larger planned cohort of 4000 U.S. Army recruits). METHODS: We collected high-resolution peripheral quantitative computed tomography images of the ultradistal tibia at the 4% site during the first week of basic combat training (BCT) from 556 male and 233 female recruits. Also, self-reported history of tobacco use was assessed via questionnaire. Generalized linear models stratified by sex were used to evaluate the relationship between a history of tobacco use and baseline bone microarchitecture. Models were further stratified by tobacco type. All models were adjusted for prior physical activity, recruit and parents’ level of education, race/ethnicity, age, and body mass index (BMI). RESULTS: 21.29% of recruits reported prior tobacco use. Tobacco users were more likely to be male (25.5%, p<0.0001) and white (26.8%, p=0.0007). There were no differences in tobacco use by socioeconomic status, prior physical activity, or BMI. At the ultradistal tibia, tobacco use in female recruits was associated with lower indices of cortical thickness and cortical area, with decrements ranging from -2.53% to -10.46% depending on the method of tobacco consumption (all p<0.05). In male recruits, use of tobacco pipe was associated with a 17.39% lower cortical thickness (p=0.026). There were no significant differences reported in trabecular bone parameters associated with prior tobacco use in male or female recruits. CONCLUSIONS: These data show that recruits, particularly female recruits, with a history of tobacco use may enter BCT with some less favorable microarchitectural properties, potentially placing them at greater risk for stress fracture, although this remains to be determined.