ACE and diabetes mellitus: The peripheral blood levels of hsa_circ_0069972 (OR = 2.225, 95% CI:1.299–3.810, P = 0.004) and hsa_circ_0021509 (OR = 1.706, 95% CI: 1.111–2.620, P = 0.015) remained significantly associated with CAD after adjusting for the impact of smoking history, hypertension, diabetes mellitus, dyslipidemia, stains use, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use, and antiplatelet therapy.