The Myocardial Microvascular Effect of Type 2 Diabetes Mellitus Patients Accompanied with Obesity: A Cardiac Magnetic Resonance Study

Purpose: To determine the effect of type 2 diabetes mellitus (T2DM) and obesity on myocardial microcirculation function by cardiac magnetic resonance (CMR) first-pass perfusion imaging, and to clarify the important risk factors contributing to microvascular dysfunction in T2DM patients.   Methods: A total of 120 clinically diagnosed T2DM patients and 79 controls with different body mass index (BMI) underwent CMR examination. All clinical data and perfusion parameters were recorded and analyzed. Univariable analysis was performed to identify the predictors of myocardial microvascular dysfunction in T2DM patients. Variables with a probability value of < 0.1 in the univariable analysis were included in a back ward multivariable linear regression analysis to identify risk factors of microvascular dysfunction.   Results: All perfusion parameters showed that the microvascular function decreased in T2DM patients when compared with controls on the same weight scale. For the T2DM subgroup and controls subgroup, perfusion upslope and max signal intensity (MaxSI) reduced as BMI increased (both P < 0.01). In multivariable linear regression analysis, the BMI (Upslope model, I²=-0.344, P=0.003; MaxSI model, I²=-0.472, P=0.000) and HbA1c (Upslope model, I²=-0.254, P=0.024) had a significant association with microvascular dysfunction.   Conclusions: The microvascular function impaired as the BMI increased both in T2DM patients and controls. The BMI, HbA1c and rest heart rate contribute to the myocardial microvascular dysfunction in T2DM patients, and BMI is one of the most important risk factor.    Funding Statement: This work was financially supported by the National Natural Science Foundation of China (No. 81641169, 81771887, and 81771897), 1·3·5 project for disciplines of excellence, West China Hospital, Sichuan University, Program for New Century Excellent Talents in University (No: NCET-13-0386), Applied Basic Research Program of Science and Technology Commission Foundation in Sichuan Province (2017JY0027) of China and Program for Young Scholars and Innovative Research Team in Sichuan Province (2017TD0005) of China. Declaration of Interests: The authors declare that there are no conflicts of interest. Ethics Approval Statement: All participants provided informed consent, and the institutional ethics committee of our hospital approved this study (No.2016-24).