History of diabetes mellitus is associated with elevated cardiac troponin I levels in patients with chest pain but no coronary heart disease

BACKGROUND: The factors and the mechanism contributing to an increase in cardiac troponin I (cTnI) in patients with chest pain, at least one cardiovascular risk factor, and no evidence of coronary heart disease remains elusive. METHODS: Excluding patients with acute coronary syndrome and chronic myocardial isch-emia, we selected 362 consecutive patients with normal coronary angiography or computed tomography coronary angiography results or lesions causing < 50% stenosis in any of the coronary arteries from January 2012 to June 2015. Using a cut-off value of 0.01 ng/mL, patients with cTnI levels ≥ 0.01 ng/mL (164 patients) were compared with those with cTnI levels < 0.01 ng/mL. Logistic regression analysis was used to evaluate associations between elevated cTnI and patient characteristics. RESULTS: Other than history of diabetes mellitus (DM) (18.90% vs. 8.08%, p = 0.002), the characteristics of the patients with and without elevated cTnI levels were similar. History of DM predicted elevation of cTnI level (OR 3.34, 95% CI 1.55-7.20, p = 0.002) in logistic regression analysis. CONCLUSIONS: In total, 45.30% of patients with chest pain had elevated cTnI levels with a mean level of 0.07 ± 0.10 ng/mL. History of DM rather than blood glucose level itself was associated with elevated cTnI levels, whereas female gender was protective against increases in cTnI levels.