The effect of gestational age, birth weight, and disease on troponin I andcreatine kinase MB in the first year of life

Objectives: To determine the effect of gestational age and birth weight (BW ) on troponin I (Tnl) and creatine kinase MB fraction (CKMB) levels during the first year of life. Methods: Troponin I and CKMB levels were determined in infants less than 1 year of age using the Immune I (Bayer Corp.). Results: Troponin I fractions were greatest in the preterm infant; the leve ls decreased significantly with increasing gestational age and BW, (p = 0.0 08 and p = 0.005, respectively). The CKMB levels did not exhibit a signific ant difference between the preterm and term infant groups when assessed for the effects of gestational age or BW (p = 0.12 vs. p = 0.35). Neither Tnl nor CKMB levels were significantly different between preterm survivors and nonsurvivors (p = 0.31; p = 0.34, respectively). Tnl levers were elevated i n critically ill patients without documented myocardial infarction, and wit hout a comparable rise in CKMB. Conclusion: The higher Tnl levels during the first 3 months of life may ind icate programmed cell death, or apoptosis. This may be especially true in t he preterm infant in which the greatest values were documented. Copyright ( C) 1999 The Canadian Society of Clinical Chemists.