Serum leptin and tissue doppler evaluation of myocardial function in Egyptian children living with type 1 diabetes mellitus

Background To evaluate biventricular myocardial function using tissue Doppler imaging (TDI) in children with type 1 diabetes mellitus (T1DM), and to examine the relationship between serum leptin and echocardiographic indices of ventricular performance. Methods Forty children with T1DM (19 male; mean age 12.80 ± 2.35 years; mean disease duration 6.23 ± 2.29 years) were compared with 30 healthy controls (15 male; mean age 13.57 ± 1.95 years). All participants underwent M-mode echocardiography, pulsed-wave Doppler, and pulsed-wave TDI at the lateral mitral, lateral tricuspid, and medial septal annuli. The myocardial performance index (MPI, Tei index) was computed for both ventricles. Serum leptin was measured in all 70 participants (40 patients and 30 controls). Between-group leptin comparison used the Mann-Whitney U test. Spearman rank correlations with 95% confidence intervals were computed between leptin and echocardiographic parameters within the patient group. Results The two groups were comparable in age, BMI, height, and sex distribution (all P > 0.05). No significant differences were found in any M-mode structural parameter, fractional shortening, or LV mass index. Left atrial dimension was significantly greater in patients (26.76 ± 3.42 vs. 23.80 ± 5.49 mm; P = 0.01). Conventional Doppler confirmed Grade I diastolic dysfunction at both mitral and tricuspid valves. TDI demonstrated significantly reduced S’ and E’ velocities at all three annular sites and significantly elevated LV MPI (0.52 ± 0.12 vs. 0.29 ± 0.05) and RV MPI (0.54 ± 0.09 vs. 0.32 ± 0.05; both P < 0.001). Serum leptin was significantly higher in patients than controls (median 2.75 vs. 1.45 ng/mL; P = 0.026). Within the patient group, leptin correlated significantly and negatively with mitral S’ ( r = − 0.371; P = 0.002), mitral E’ ( r = − 0.268; P = 0.025), tricuspid S’ ( r = − 0.281; P = 0.018), and tricuspid E’ ( r = − 0.298; P = 0.012), and positively with LV MPI (r = + 0.416; P < 0.001) and RV MPI (r = + 0.452; P < 0.001; Fig. 1). Conclusion Children with T1DM demonstrate significant subclinical biventricular myocardial dysfunction on TDI with preserved conventional systolic parameters. Serum leptin is significantly elevated in T1DM children compared with controls and correlates significantly with impaired TDI velocities and elevated biventricular MPI, suggesting adipokine-associated pathways as potential contributors in early diabetic cardiomyopathy.