Visit-to-visit fasting plasma glucose variability is an important risk factor for long-term changes in left cardiac structure and function in patients with type 2 diabetes

Background: To investigate the effect of visit-to-visit fasting plasma glucose (FPG) variability on the left cardiac structure and function in patients with type 2 diabetes mellitus (T2DM). Methods: In this prospective cohort study, 455 T2DM patients were included and follow-up for a median of 4.7 years. FPG measured on every hospital visit was collected. FPG variability was calculated by its coefficient of variation (CV-FPG). Left cardiac structure and function were assessed using echocardiography at baseline and after follow-up. Multivariable linear regression analyses were used to estimate the effect of FPG variability on the annualized changes in left cardiac structure and function. Subgroup analysis stratified by mean HbA1c levels (<7% and >= 7%) were also performed. Result: In multivariable regression analyses, CV-FPG was independently associated with the annualized changes in left ventricle (beta = 0.137; P = 0.031), interventricularseptum (beta = 0.215; P = 0.001), left ventricular posterior wall thickness (beta = 0.129; P = 0.048), left ventricular mass index (beta = 0.227; P < 0.001), and left ventricular ejection fraction (beta = -0.132; P = 0.030). After additionally stratified by mean HbA1c levels, CV-FPG was still independently associated with the annualized changes in the above parameters in patients with HbA1c >= 7%, while not in patients with HbA1c <7%. Conclusions: Visit-to-visit variability in FPG could be a novel risk factor for the long-term adverse changes in left cardiac structure and systolic function in patients with type 2 diabetes.