Determination of high-sensitivity cardiac troponin I 99th percentile upper reference limits in a healthy Korean population.

Objectives: This study aimed to determine the 99th percentile upper reference limit (URL) concentration of cardiac troponin I (cTnI) with a high-sensitivity assay in a Korean population.

Design And Methods: Cardio-healthy males and females were enrolled between March 2014 and March 2015. Participants with possible subclinical conditions were excluded on the basis of laboratory measures (primary: estimated glomerular filtration rate and glycated hemoglobin; secondary: B-type natriuretic peptide). Serum cTnI was measured using ARCHITECT STAT High-Sensitive Troponin-I Assay (Abbott Diagnostics, USA).

Results: A total of 1204 participants completed a self-reporting questionnaire for inclusion in the study. Of these, we excluded 349 (29.0%) participants on the basis of primary (n=283) and secondary (n=66) laboratory measures. Ultimately, we included 854 participants (mean age, 49.8±10.2years) in the final analysis. The 99th percentiles of cTnI concentrations were 18 (90% confidence interval [CI], 14-35) ng/L for all participants, 20 (90% CI, 15-69) ng/L for males and 19 (90% CI, 11-41) ng/L for females. In both males and females, the median cTnI concentrations were significantly higher in participants aged 50years and older than in those younger than 50years old.

Conclusions: In this study, the reference population with Korean ethnicity had lower overall and male 99th percentile URLs than other reference populations. Our data suggest that 99th percentile URLs may be influenced by factors such as ethnicity, age distribution of participants, and selection criteria used to define a healthy reference population.