Cardiac troponin I levels and its relation to echocardiographic findings in infants of diabetic mothers

BACKGROUND Cardiomyopathy is noted in up to 40% of infants of diabetic mothers, and the exact mechanisms responsible for it are unknown. The aim of this study was to compare between infants of diabetic mothers (IDM) and infants of non- diabetic mothers (INDM) as regards cardiac troponin I (cTnI) levels (as a marker of cardiac dysfunction) and to examine the relationship between this marker and neonatal echocardiographic changes (cardiac structure and function). METHODS A prospective, comparative study included eighty full term neonates during the first three days of life, during the period from April 2008 to June 2011. They were divided into 2 groups, group I: included 40 infants of diabetic mothers (IDMs)and group II: included 40 infants of non diabetic healthy mothers as a control group. RESULTS 37.5% of the IDMs were large for gestational age and demonstrated a significantly lower blood glucose level than the control group (34.6 ± 11.3mg/dl Vs 77.2 ± 19.8 mg/dl respectively) , respiratory distress and cyanosis were the presenting signs in 67.5% of IDMs. Cardiac TnI on the second day of life increased significantly in infants of diabetic mothers in comparison to INDM (p < 0.006) . IDMs had a significant increase in left atrial thickness ( 11.5 ± 1.8mm in IDM Vs 10.5 ± 0.9mm in INDM P < 0.002*) and a significant increase in septal thickness (5.0 ± 1.2mm in IDM Vs 4.0 ± 0.5mm in INDM P < 0.001*). CTnI correlated positively with interventricular septum thickness (P-value = 0.002*). Cardiac TnI was significantly increased in IDMs with respiratory distress (P -value < 0.05). CONCLUSIONS This study demonstrated a highly significant positive correlation between cTnI level on the second day of life and the left ventricular end diastolic diameter (LVED) and interventricular septum diameter (IVSD). Cardiac troponin I (cTnI) is a useful biochemical marker for monitoring myocardial injury in infants of diabetic mothers. An elevated cTnI concentration in infants of diabetic mothers with respiratory distress was a good predictor for hypertrophic cardiomyopathy and/or left ventricular dysfunction.