Endothelial and heart dysfunction in children and adolescents with type 1 diabetes

Background/Objectives: Type 1 diabetes (T1D) is an important risk factor for cardiovascular disease (CVD). Even if CVD become mainly manifest in adulthood, the process of atherosclerosis starts in childhood. Ultrasound is a reliable and noninvasive method for detecting early structural and functional atherosclerotic changes in arterial wall and heart. Aim of this study was to determine early ultrasound signs of atherosclerosis and of left ventricular (LV) systolic and diastolic dysfunction in children and adolescents with T1D. Methods: Ninety-four subjects with T1D [12.3±3.53 yrs.; males 59.6%; T1D duration 5.14±3.53 years) were enrolled into the study. Carotid intima-media thickness (cIMT), systolic and diastolic function indices were determined according to standardized scanning protocol and were performed by the same investigator blinded to subjects’ anthropometric (Ht, Wt, BMI, pubertal status, WC, SBP/DBP) and laboratory data (HbA1c, TC, LDL-C, HDL-C, TG). Results: cIMT, LV systolic and diastolic function indices were all in the normal range defined for healthy population. Pubertal subjects, respect to pre-pubertal ones, had significantly higher values of cIMT (0.60±0.09 vs. 0.49±0.08 mm; p<0.001), interventricular septal end-diastole (IVSd) (7.27±1.27 vs. 6.61±1.00 mm; p=0.027), deceleration time (DT) (138.3±31.7 vs. 112.6±20.9 ms; p<0.001), and isovolumetric relaxation time (IVRT) (60.8±14.1 vs. 53.1±9.58 ms; p=0.006). Patients with DKA at T1D onset had significantly higher values of IVSd respect to subjects without DKA 7.40±1.22 vs. 6.80±1.17 mm; p=0.018). Moreover, DBP (Chi-Square=6.13; p=0.047), LV internal dimension at end-iastole (LVIDd) (Chi-Square=7.25; p=0.027), A wave peak (Chi-Square=6.11; p=0.047), and IVRT (Chi-Square=7.29; p=0.026) were significantly different according to mean HbA1c value in the last year. cIMT was higher in subjects with a worse glycemic control (HbA1c ≥9%) (Chi-Square=5.07; p=0.079) and cIMT was significantly correlated with age (R=0.51, p<0.001), WC (R=0.39, p<0.001), SBP (R=0.41, p<0.001), mean HbA1c values of the first 5 years of T1D (R=0.24, p=0.021), TG (R=0.23, p=0.029), and TG/HDL-C ratio (R=0.22, p=0.034). The multivariate regression model was statistically significant for cIMT (R2=0.44, p<0.001) and identify T1D duration (β= -0.23; p=0.024) and LDL-C levels (β=0.20, p=0.031) as predictor factors. Conclusions: cIMT were within normal range but, despite the good glycemic and lipid control, mean values were significantly higher respect to published ones in healthy and T1D children and adolescents. Moreover, LV diastolic function was slightly abnormal. Ultrasound is useful for early detection of subjects with a greater cardiovascular risk who can benefit from targeted therapeutic interventions.