| Objective To explore the association between the expression level of long non-coding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) in the serum and bone mineral density (BMD) in postmenopausal patients with type 2 diabetes mellitus (T2DM). Methods A total of 210 postmenopausal T2DM patients were included and divided into a normal bone mass group (58 cases), an osteopenia group (71 cases), and an osteoporosis group (81 cases) according to their BMD status. Quantitative real-time polymerase chain reaction (qRT-PCR) technique was used to detect the expression level of lncRNA GAS5 in the serum. Pearson correlation analysis was performed to evaluate the correlation between lncRNA GAS5 and BMD. Multivariate logistic regression analysis was conducted to identify the factors influencing the occurrence of osteoporosis in postmenopausal T2DM patients. The receiver operating characteristic curve (ROC) was used to assess the value of lncRNA GAS5 in predicting osteoporosis. Results Compared to those in the normal bone mass group, age, years since menopause, glycosylated hemoglobin, type A1C (HbA1c), fasting plasma glucose (FPG), N-terminal propeptide of type I procollagen (PINP), and CTX in the osteopenia group and the osteoporosis group increased, and those in the osteoporosis group were higher than those in the osteopenia group (P<0.05). Compared to those in the normal bone mass group, the levels of 25-hydroxyvitamin D3 (25(OH)D3), BMD of L1-4, femoral neck BMD, total hip BMD, and lncRNA GAS5 in the osteopenia group and the osteoporosis group decreased, and those in the osteoporosis group were lower than those in the osteopenia group (P<0.05). BMD of L1-4, femoral neck BMD, and total hip BMD were negatively correlated with age, years since menopause, HbA1c, FPG, and PINP, while positively correlated with 25(OH)D3 and lncRNA GAS5 (P<0.05). lncRNA GAS5 was negatively correlated with CTX (P<0.05). Advanced age, a long duration of menopause, high PINP level, low 25(OH)D3 level, and low lncRNA GAS5 level were risk factors for the occurrence of osteoporosis in postmenopausal T2DM patients. The cut-off value of serum lncRNA GAS5 for predicting the occurrence of osteoporosis in postmenopausal T2DM patients was 0.74, the AUC value was 0.934, the sensitivity was 92.6%, and the specificity was 81.4%. Conclusion Low expression of lncRNA GAS5 in postmenopausal T2DM patients is associated with a decrease in BMD, which is a risk factor for the occurrence of osteoporosis. It has a good predictive ability for osteoporosis. |