To examine whether bone mineral density (BMD) mediates the association between geriatric nutritional risk index (GNRI) and sarcopenia in hospitalized adults with type 2 diabetes mellitus (T2DM). Nutritional risk, low BMD, and sarcopenia frequently coexist in T2DM, but their interrelationship remains insufficiently understood. This single-center, cross-sectional study included 362 hospitalized patients with T2DM. The GNRI was calculated using serum albumin and anthropometric data. Femoral neck BMD was measured using dual-energy X-ray absorptiometry and sarcopenia was defined according to the 2019 criteria of the Asian Working Group for Sarcopenia. Group comparisons, Pearson correlation analyses and bootstrap-based mediation analyses were performed with covariate adjustment. Sarcopenia was identified in 73 patients (20.2%), while osteoporosis was identified in 104 patients (28.7%). Patients with sarcopenia had significantly lower GNRI and BMD than those without sarcopenia (both P < 0.001). GNRI was positively correlated with BMD (r = 0.382) and skeletal muscle index (r = 0.216), while BMD was positively correlated with skeletal muscle index (r = 0.285) (all P < 0.01). In adjusted models, a higher GNRI score was associated with a higher BMD score (β = 0.004, 95% CI 0.002–0.006), while a higher BMD score was associated with a lower odds of sarcopenia (OR = 0.100, 95% CI 0.012–0.859). BMD partially mediated the association between GNRI and sarcopenia (indirect effect = − 0.001, 95% CI − 0.002 to − 0.000), accounting for 6.6% of the total association. This mediation effect was significant in men, but not in women. A lower GNRI was associated with sarcopenia, both directly and indirectly via lower BMD, in hospitalized patients with T2DM. Further longitudinal studies are needed to confirm temporality.
Wu et al. (Wed,) studied this question.