Objective To investigate the relationship between the levels of peripheral blood irisin, myostatin (MSTN), and 25-hydroxyvitamin D25(OH)Dand the risk and predictive value of sarcopenia in elderly patients with type 2 diabetes mellitus (T2DM) complicated by heart failure.

Methods Elderly patients with T2DM complicated by heart failure who visited Xingtai Central Hospital from March 2023 to March 2024 were selected as the study subjects. The sample size was calculated based on the effect size. Patients were divided into modeling set (n=140) and validation set (n= 60) at a ratio of 7 to 3 using a simple randomization method. Additionally, according to the occurrence of sarcopenia, patients in the modeling set were divided into sarcopenia group and non-sarcopenia group. Clinical data and the levels of peripheral blood irisin, MSTN, and 25(OH)D were compared between the modeling and validation sets. The receiver operating characteristic (ROC) curve was used to analyze the predictive efficacy of peripheral blood irisin, MSTN, and 25(OH)D for sarcopenia. Multivariate logistic regression analysis was employed to identify the influencing factors of sarcopenia in elderly patients with T2DM complicated by heart failure, and a relevant predictive model was constructed using R software.

Results Among 200 elderly patients with T2DM complicated by heart failure, 71 cases developed sarcopenia, with an incidence rate of 35.50%. The proportion of regular exercise, bone mineral content, and the levels of irisin and 25(OH)D in the sarcopenia group were lower than those in the non-sarcopenia group, while the MSTN level was higher in the sarcopenia group, and the differences were statistically significant (P < 0.05). The areas under the curve (AUCs) for predicting sarcopenia by irisin, MSTN, and 25(OH)D were 0.878 (95%CI, 0.812 to 0.927), 0.848 (95%CI, 0.778 to 0.903), and 0.826 (95%CI, 0.753 to 0.885), respectively. The sensitivities were 74.16%, 79.78%, and 88.76%, and the specificities were 74.16%, 79.79%, and 88.76%, respectively. The results of multivariate logistic regression analysis showed that lack of exercise habits (OR=2.489, 95%CI, 1.665 to 3.735), decreased bone mineral content (OR=2.340, 95%CI, 1.596 to 3.595), irisin ≤105.44 ng/mL (OR=3.111, 95%CI, 2.004 to 5.147), MSTN >19.06 μg/L (OR=2.667, 95%CI, 2.015 to 4.693), and 25(OH)D ≤12.23 ng/mL (OR=2.547, 95%CI, 1.285 to 4.492) were all independent risk factors for sarcopenia in these patients (P < 0.05). The results of ROC curve analysis showed that the AUCs of the nomogram model for predicting postoperative recurrence in the modeling and validation sets were 0.875 and 0.853, respectively. The Hosmer-Lemeshow test for the modeling and validation sets showed the following results: χ²=0.715, P=0.510; χ²=0.651, P=0.568. The calibration curves were basically consistent with the standard curves. The threshold probability range of decision curve analysis (DCA) was 0.1 to 0.9. Within this range, both the modeling and validation sets showed good clinical net benefits.

Conclusion Peripheral blood irisin, MSTN, and 25(OH)D all have certain predictive values for the occurrence of sarcopenia in elderly patients with T2DM complicated by heart failure. The nomogram model constructed based on irisin, MSTN, and 25(OH)D can provide a quantitative basis for the early screening of sarcopenia in these patients.