Objective <p>Bone mass abnormalities (osteopenia/osteoporosis) are highly prevalent in patients with type 2 diabetes mellitus (T2DM), yet identifying the systemic metabolic indicators of skeletal deterioration remains a critical clinical challenge. This study aimed to investigate the independent association between fasting plasma glucagon levels and osteopenia/osteoporosis in Chinese T2DM patients, and to evaluate whether elevated glucagon acts as an independent risk indicator for osteopenia/osteoporosis.</p> Methods <p>A retrospective study was conducted in which medical records were collected from 218 patients with T2DM, and plasma glucagon levels were obtained to assess the association with osteoporosis/osteoporosis. Bone mineral density (BMD) was evaluated by dual-energy x-ray absorptiometry (DXA).</p> Results <p>T2DM patients with bone mass abnormalities (osteopenia/osteoporosis) exhibited significantly higher fasting plasma glucagon levels. Glucagon levels were inversely associated with BMD T-scores at the total hip and femoral neck. After adjusting for age, BMI, diabetes duration, and antidiabetic therapies, multivariable logistic regression confirmed that elevated fasting glucagon was independently associated with a higher risk of osteopenia/osteoporosis (OR = 1.112, 95%CI:1.032–1.198, <i>P</i> = 0.006). ROC curve analysis indicated that fasting glucagon possessed a moderate predictive capacity for identifying bone loss, with an area under the curve of 0.614. The optimal cutoff value was 12.205 pmol/L, yielding a sensitivity of 76.3% and a specificity of 43.6%.</p> Conclusions <p>Elevated fasting plasma glucagon is independently associated with reduced bone mass and serves as an independent associated factor for osteopenia/osteoporosis in Chinese patients with T2DM.</p> Clinical trial number <p>Not applicable.</p>