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

• The 99th percentile value for troponin I was determined with a high-sensitivity assay.
• Application of stringent selection criteria resulted in a decreased 99th percentile.
• Median concentrations were significantly higher in individuals above 50 years.

ObjectivesThis 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 methodsCardio-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).ResultsA 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 ± 10.2 years) 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 50 years and older than in those younger than 50 years old.ConclusionsIn 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.