Illicit drug use is associated with lower bone mineral density and bone strength

Objectives: To evaluate the association of illicit drug use with bone mineral density (BMD) and hip geometric parameters at the narrow neck.Methods: This is a cross-sectional matched cohort study conducted in the Hong Kong Chinese population. Associations with illicit drug use were estimated using linear regression for BMD (lumbar spine and femoral neck) and hip geometrical parameters (cross-sectional area [CSA], cross-sectional moment of inertia [CSMI], section modulus [SM], average cortical thickness [ACT] and BMD at the narrow neck) after adjusting for age, body mass index (BMI), smoking status, drinking status, physical activity, and history of antipsychotic and antidepressant use. Mean difference and 95% confidence intervals (95% CI) were calculated between 108 illicit drug users and 108 controls using an adjusted linear model and cluster-robust standard errors after matching by age and sex. The false discovery rate was used to correct for multiple testing.Results: Illicit drug users had a significantly lower BMD (g/cm2) at the lumbar spine (mean difference: -0.062; 95% CI: -0.108 to -0.015), and femoral neck (mean difference: -0.058; 95% CI: -0.106 to -0.010) in the fully adjusted model. Illicit drug users also had a significantly lower CSA (mean difference: -0.238 cm2; 95% CI: -0.462 to -0.013), ACT (mean difference: -0.018 cm; 95% CI: -0.030 to -0.006) and BMD (mean difference: -0.070 g/cm2; 95% CI: -0.128 to -0.012) at the narrow neck.Conclusions: Illicit drug use is associated with lower BMD and bone strength. Future studies evaluating the risk of illicit drug use with fragility fracture are warranted.