The protective role of appendicular lean mass in osteoporosis development among postmenopausal type 2 diabetes patients.

This study aimed to explore the relationship between appendicular lean mass (ALM), osteoporosis (OP), and fracture risk in postmenopausal patients with type 2 diabetes mellitus (T2DM). A total of 1418 hospitalized postmenopausal patients with T2DM were enrolled. Bone mineral density (BMD) and ALM were measured using dual-energy X-ray absorptiometry (DXA). Based on BMD T-values, patients were categorized into OP and non-OP groups. General demographic data, biochemical markers, and body composition indices were compared between groups. Logistic regression analysis, nomogram construction, and receiver operating characteristic (ROC) curve analysis were performed to identify predictors and assess model performance. The prevalence of OP was significantly higher in patients with sarcopenia (SAC) compared to those without (P < 0.05). Significant between-group differences were observed in age, heart rate, 25-hydroxyvitamin D, height, weight, BMI, systolic blood pressure, presence of peripheral neuropathy, lymphocyte count, LDL cholesterol, total cholesterol, alanine aminotransferase, albumin, uric acid, creatinine, β-CTX, ALM/Ht2, and ALM (P < 0.05). Logistic regression identified ALM [OR = 0.785, 95% CI 0.697-0.884] and BMI [OR = 0.880, 95% CI 0.839-0.923] as protective factors against OP. A nomogram prediction model was developed using multiple independent predictors. ROC analysis showed good predictive performance, with an area under the curve (AUC) of 0.80 (95% CI 0.77-0.82), sensitivity of 82.0%, specificity of 67.8%, and an optimal cut-off value of 0.466. Lower age, BMI, and ALM were significantly associated with increased risk of OP. ALM and BMI emerged as independent protective factors. The developed nomogram can assist healthcare professionals in identifying key risk factors for OP in elderly postmenopausal patients with T2DM and support early screening and intervention strategies to reduce fracture risk.