Abstract
BACKGROUND: Cardiovascular disease remains the leading cause of morbidity and mortality among individuals with type 1 diabetes mellitus (T1DM). Individuals with hyperglycemia are at great risk of cardiovascular complications. This study investigated the impact of glycemic control on left ventricular (LV) microvascular perfusion and myocardial deformation in uncomplicated pediatric T1DM using cardiac magnetic resonance (CMR) imaging. METHODS: A total of 100 uncomplicated pediatric patients with T1DM and 35 controls were enrolled and underwent 3.0 T CMR examinations. Patients were divided into two groups according to HbA1c levels of 7.0% (HbA1c < 7.0%, n = 25; HbA1c ≥ 7.0%, n = 75). Subclinical systolic and diastolic function were evaluated using peak strain and strain rate based on myocardial deformation analysis. Myocardial perfusion upslope and maximum signal intensity (MaxSI) were assessed via first-pass perfusion imaging at rest. Multivariable linear regression analyses identified the independent factors of reduced myocardial perfusion and deformation in T1DM patients. RESULTS: Among the three groups, longitudinal peak diastolic strain rate (PDSR) deteriorated gradually from controls through patients with HbA1c < 7.0% to patients with HbA1c ≥ 7.0% (all p < 0.05). Upslope in patients with HbA1c ≥ 7.0% was decreased compared to patients with HbA1c < 7.0% (p = 0.007) and controls (p < 0.001). Compared to controls, both MaxSI and circumferential PDSR were reduced in patients with HbA1c ≥ 7.0% (p = 0.025 and 0.016, respectively), but not in patients with HbA1c < 7.0% (p = 0.566 and 0.379, respectively). In multivariable analysis, elevated HbA1c level was independently associated with reduced upslope (β = - 2.53, p < 0.001) and longitudinal PDSR (β = - 0.02, p = 0.007). When the perfusion indices were included in the multivariable analysis for diastolic dysfunction, upslope (β = 0.10, p = 0.016) and MaxSI (β = - 0.02, p = 0.006) were associated with reduced longitudinal PDSR. CONCLUSION: Pediatric T1DM with higher HbA1c showed worse myocardial perfusion and subclinical diastolic dysfunction. Microvascular dysfunction was associated independently with cardiac dysfunction. TRIAL REGISTRATION: retrospectively registered ChiCTR2100043799.