Abstract
BACKGROUND: Carotid plaque and osteoporosis commonly coexist in type 2 diabetes mellitus (T2DM), but whether their association differs by sex remains unclear. We examined sex-specific differences in bone measures and the adjusted association between carotid plaque and osteoporosis status in patients with T2DM. METHODS: This retrospective cross-sectional study included 1,224 patients with T2DM (794 women and 430 men). Carotid plaque was assessed by ultrasound. Lumbar spine bone mineral density (BMD) and T-scores were measured by dual-energy X-ray absorptiometry (DXA), and osteoporosis status was categorized as normal bone mass, osteopenia, or osteoporosis. Clinical characteristics, bone measures, and osteoporosis prevalence were compared between patients with and without carotid plaque within each sex. Sex-stratified ordinal logistic regression models were used to evaluate the adjusted association between carotid plaque and osteoporosis categories with stepwise adjustment for BMI, diabetes duration, lipid parameters, and glycemic indices. RESULTS: In men, patients with carotid plaques showed a modestly higher lumbar spine BMD (P = 0.013); however, lumbar spine T-scores and osteoporosis prevalence were similar between plaque and non-plaque groups, and no adjusted association with osteoporosis category was observed across models. In women, lumbar spine BMD, T-scores, and osteoporosis prevalence were similar between plaque and non-plaque groups in unadjusted comparisons. However, in women, carotid plaques were independently associated with higher odds of worse osteoporosis category after adjustment (Model 1: odds ratio (OR) 1.40 [95% confidence interval (CI) 1.05-1.85]; Model 2: OR 1.45 [95% CI 1.09-1.92]; Model 3: OR 1.50 [95% CI 1.12-1.99]; all P < 0.05). CONCLUSION: Among patients with T2DM, carotid plaque was independently associated with worse osteoporosis category in women but not in men. These findings indicate sex-specific associations between carotid atherosclerosis and skeletal health; however, given the cross-sectional design and unavailable key confounders (e.g., lifestyle factors, central adiposity measures, medication patterns, and fracture outcomes), the results should be interpreted as associative and require confirmation in prospective studies.