[Application of multi-state Markov model in studying transition of number of chronic complications and influencing factors in type 2 diabetes mellitus patients].

Objective: To establish a multi-state Markov model of type 2 diabetes mellitus (T2DM) patients and explore the transition rule between the cumulative number of different chronic complications, estimate the transition probability and intensity between status, and explore the possible factors affecting the transition between status. Methods: A retrospective cohort study of 33 575 patients with T2DM was conducted. According to the baseline and the cumulative number of chronic complications during the follow-up period, the patients were classified based on five status: T2DM, one complication, two complications, three complications, four and above complication, indicated by S0, S1, S2, S3 and S4, respectively. A time-continuous and state-discrete multi-state irreversible Markov model was used for statistical analysis. Results: The study included 33 575 T2DM patients, and their average age was 60 years old, the median of follow-up length was 8 years. In these patients, 32 653 had no baseline complications. At the end of follow-up, the transition probabilities of S0→S1, S1→S2, S2→S3 and S3→S4 were 16.4%, 32.4%, 45.6% and 25.9%, respectively. The results of multivariate analysis showed that being female (HR=0.919), less than 60 years old (HR=0.929), higher fasting plasma glucose (HR=1.601), lower high-density lipoprotein (HR=1.087), higher total cholesterol (HR=1.090),weekly exercise (HR=0.897), vegetarian diet (HR=0.852) and heavy diet (HR=1.887) were the risk factors for S0 to S1. And being female (HR=0.768), less than 60 years old (HR=0.859) and lower high-density lipoprotein (HR=1.160) were the risk factors for S1 to S2. Conclusions: The probability of multiple complications in T2DM patients increased over time, the transition intensity of S2→S3 was largest, followed by S1→S2. Therefore, we need to conduct both early and long-term indicators monitoring and disease prevention, strengthen the health education to improve patients' daily living habits at early stage of the illness, encourage patients to have moderate exercise and balanced diet, strengthen the monitoring of fasting blood- glucose, cholesterol and high-density lipoprotein levels to prevent the deterioration of the illness.