Abstract
PURPOSE: Our study aimed to assess whether individuals diagnosed with thyroid cancer face an elevated risk of osteoporosis compared to control subjects in a large-scale study. Additionally, we intended to identify potential risk factors associated with osteoporosis in patients with thyroid cancer. METHODS: We used the National Health Insurance Service-National Sample Cohort of South Korea. We included 1,313 patients diagnosed with thyroid cancer and 3,939 control subjects without cancer. Following propensity score matching at a 1:3 ratio, Cox proportional hazards regression and stratification analyses were used to estimate the risk of osteoporosis in patients with thyroid cancer, incorporating multivariate adjustments. A restricted cubic spline model was employed to evaluate dose-response relationships. RESULTS: Thyroid cancer patients exhibited a higher likelihood of developing osteoporosis than the control group (hazard ratio [HR], 6.59; P < 0.001). In the stratification analyses, younger thyroid cancer patients, females, and those who did not have dyslipidemia were more susceptible to osteoporosis than their counterparts in the control group. Furthermore, the administration of levothyroxine has been linked to an elevated risk of osteoporosis (HR, 2.33; P = 0.044). A restricted cubic spline analysis demonstrated a significant overall association between exposure and outcome (P for total = 0.007, P for nonlinear = 0.573), indicating an essentially linear relationship. CONCLUSION: Thyroid cancer patients showed a higher risk of osteoporosis compared to matched controls. Stratified analyses suggested that levothyroxine therapy may be a risk factor for osteoporosis. These findings highlight the importance of individualized treatment approaches.