Association of the metabolic score for insulin resistance with bone mineral density and trabecular bone score in cancer patients: a cross-sectional study.

OBJECTIVE: To investigate the association between the Metabolic Score for Insulin Resistance (METS-IR) and bone mineral density (BMD) and trabecular bone score (TBS) in adult cancer patients. METHODS: This cross-sectional study enrolled 127 patients (median age 63 years, 44.9% female) with histopathologically confirmed malignancies. BMD at the lumbar spine, femoral neck, and total hip and lumbar spine TBS were measured by dual-energy X-ray absorptiometry. METS-IR was calculated using fasting glucose, triglycerides, high-density lipoprotein cholesterol, and body mass index. Multivariable linear regression was used to identify independent associations. RESULTS: After adjustment for confounders, METS-IR was independently and positively associated with BMD at lumbar spine (β = 0.006, 95% CI 0.002-0.011, P = 0.007), femoral neck (β = 0.007, 95% CI 0.003-0.011, P < 0.001), and total hip (β = 0.007, 95% CI 0.003-0.010, P < 0.001). Age was inversely associated with lumbar spine and femoral neck BMD, but not with total hip BMD; bone metastasis was linked to higher lumbar spine and total hip BMD. In contrast, METS-IR showed no significant association with lumbar spine TBS (P = 0.374). For TBS, age and male sex, but not METS-IR, were independent determinants. CONCLUSIONS: In cancer patients, higher METS-IR is independently associated with greater BMD but not with better trabecular microarchitecture. This discordance between bone quantity and quality suggests that insulin resistance may mask impaired bone quality despite preserved BMD. Clinicians should consider bone quality assessments when evaluating fracture risk in metabolically compromised cancer patients. Longitudinal studies are warranted to confirm these findings.