Coronary artery calcification (CAC) is a common complication of type 2 diabetes mellitus(T2DM), which can significantly increase all-cause mortality and the incidence of serious cardiovascular events, and increase the burden of the national economy. The epidemiological characteristics and the clinical progress of CAC are still not clear. Moreover, the pathogenesis of CAC has not yet been fully elucidated, and lack of specific diagnostic indicators. Arterial calcification is an active, reversible, and multifactorial biological process like bone formation. It is generally believed that early detection of calcification lesions and active targeted treatment may be the key to prevention and treatment of vascular calcification. In addition, statins are commonly used in patients with dyslipidemia and can stabilize CAC plaque. However, the timing, dosage and effect of statins are controversial. Moreover, our previous study found that the expression of miR-32 is significantly elevated in patients with CAC, and can promoting vascular calcification. Herein, this study is to conduct a prospective cohort study on T2DM patients with CAC in Hunan province through a multidisciplinary and multi-center cooperation model, the main research objectives include the following three parts: ① To identify the prevalence, incidence, and characteristics of CAC in T2DM patients in Hunan province, and to build a risk assessment model. ② To observe the effects of statins on the occurrence and development of CAC in patients with T2DM, and to provide clinical data for the improvement of medication guidelines; ③To observe the dynamic changes of serum miR-32 in the progression of CAC in patients with T2DM, and to explore its possibility as a serological diagnosis or prognostic bio-maker of CAC. The completion of this research project is expected to bring a new breakthrough in the field of early diagnosis, prognosis evaluation, and intervention treatment of patients with T2DM combined with CAC, and provide an important reference for the formulation of cardiovascular disease prevention and control strategy.

The prospective cohort study of type 2 diabetes mellitus(T2DM) with coronary artery calcification (CAC) is a multi-center, observational clinical study. The study included a baseline survey and 8-year follow-up survey of hospitalized patients with T2DM in seven third-class hospital in Hunan Province (the follow-up is divided into two stages, the first stage is the first 4 years, and the second stage is the last 4 years). The first phase is conducted in three affiliated hospitals of University of South China in Hengyang City, Hunan Province, and the second phase is conducted in four representative Grade-A hospitals according to the geographical location of Hunan Province. The sample size of each center is set to be at least 200 cases, and that of a single center is at most 500 cases. The diagnosis of T2DM is made according to the criteria of the WHO in 1999, and the hyperglycemia caused by type 1 diabetes, gestational diabetes, special type diabetes and other factors are excluded. The volume and density of coronary artery calcification are evaluated by low dose prospectively triggered sequential dual-source CT coronary angiography. The coronary artery calcification score (CACS) is calculated by CAS coring software. MiR-32 is detected by PCR. All in all, this clinical trial is aiming to establishing a prospective long-term follow-up cohort of patients with T2DM complicated with CAC in Hunan Province, to observing the effect of statins on the occurrence and development of CAC in patients with T2DM, and to exploring the dynamic changes of serum miR-32 in this process to determine whether it can be used as an early diagnosis and prognostic marker of vascular calcification.

Inclusion Criteria:

• Age ≥ 18 years old
• Type 2 diabetes is diagnosed according to WHO diagnostic criteria
• Low dose prospectively triggered sequential dual-source CT coronary angiography can be performed at baseline investigation
• Those subjects are able to understand the purpose and procedure of this study and sign the informed consent voluntarily

Exclusion Criteria:

• Those have received coronary artery stenting or coronary artery bypass grafting
• Those with severe lung (respiratory failure), liver (ALT or AST 3 times normal value or bilirubin increase), renal dysfunction[GFR < 45ml/(min.1.73m2) or dialysis patients
• Malignant tumor
• Mental illness or mental retardation
• Pregnant or lactating women or those with fertility planning
• Concomitant diseases (hyperparathyroidism, sarcoidosis, amyloidosis) affecting calcium balance and soft tissue calcification
• Contraindications of contrast agents
• Based on the judgment of the researcher, the compliance is poor and the study could not be completed according to the requirements](streamdown:incomplete-link)

The prospective cohort study of type 2 diabetes mellitus with coronary artery calcification is a multicenter, observational clinical study for patients with type 2 diabetes mellitus. The study included a baseline survey and an 8-year follow-up survey of hospitalized patients with type 2 diabetes mellitus in seven third-class hospital in Hunan Province. The first phase is conducted in three affiliated hospitals of University of South China in Hengyang City, Hunan Province, and the second phase is conducted in four representative Grade-A hospitals according to the geographical location of Hunan Province. The sample size of each center is set to be at least 200 cases, and that of a single-center is at most 500 cases.