Abstract
This study aimed to investigate the association between serum 25-hydroxyvitamin D (25[OH]D) levels and metabolic dysfunction-associated steatotic liver disease (MASLD) in older patients with type 2 diabetes mellitus. This retrospective cross-sectional study included 1044 older patients with T2DM who were treated at the Department of Endocrinology of Gansu Provincial Hospital between April 2021 and June 2024. MASLD was diagnosed by abdominal ultrasonography. Demographic, metabolic, and biochemical data were collected, including high-sensitivity C-reactive protein (hs-CRP), sialic acid (SA), and homocysteine (HCY). Binary logistic regression analysis was performed to assess the independent association between 25(OH)D levels and the presence of MASLD. MASLD was present in 64.0% of participants. Serum 25(OH)D levels were significantly lower in the MASLD group than in the non-MASLD group. After adjusting for age, sex, diabetes duration, body mass index, glycemic parameters, lipid profiles, and inflammatory markers, each 1 ng/mL decrease in 25(OH)D level was associated with 27.6% higher odds of MASLD (odds ratio [OR] = 0.724, 95% confidence interval [CI]: 0.686-0.765, P < 0.001). Receiver operating characteristic (ROC) analysis demonstrated the discriminatory performance of 25(OH)D for MASLD, yielding an area under the curve of 0.856 (95% CI: 0.828-0.884, P < 0.001) and an optimal cutoff value of 19.95 ng/mL. Low serum 25(OH)D levels were independently associated with higher odds of MASLD in older patients with T2DM. Vitamin D status may have potential value for MASLD risk stratification, but prospective studies are required before treatment recommendations can be made.