SummaryPrevious studies reporting that statin increases coronary artery calcium (CAC) were conducted exclusively on patients with statin as a prevention, regardless of the presence or absence of dyslipidemia. The impact of sex on CAC has not been fully evaluated. We aimed to determine the association of dyslipidemia and sex with CAC using 320-row multi-detector computed tomography (MDCT).Of the 356 consecutive patients who underwent coronary MDCT, 251 patients were enrolled, after excluding those with prior stenting and/or coronary bypass grafting or images showing motion artifacts. The primary outcome measures were the percent calcium volume (PCV) and percent atheroma volume (PAV) per coronary vessel.Multivariable analyses indicated that PCV was significantly higher in dyslipidemia patients without statins than in the subjects without dyslipidemia [partial regression coefficient (PRC): 2.59, 95% confidence interval (CI): 0.83 to 4.34, P = 0.004]. In contrast, PCV was similar in dyslipidemia patients taking statins and those without dyslipidemia (PRC: -1.09, 95% CI: -2.82 to 0.65, P = 0.22). There was no significant difference in PCV between men and women, although women exhibited a significantly lower PAV (PRC: -2.87, 95% CI: -4.54 to -1.20, P = 0.001).In low-risk patients, these results could be translated into hypotheses, which should be tested in future prospective studies. Furthermore, there was no significant difference in CAC between men and women, but women had lower PAV than men.(Int Heart J 2017; 58: 695-703) Key words: Coronary plaque burden, Low-risk, Statin, Multi-detector computed tomography, Sex difference T he presence of calcified plaques in the coronary artery is associated with future adverse coronary events.1-3) Statin therapy was proven efficient for the primary and secondary preventions of coronary adverse events 4,5) through stabilization of unstable plaques and management of low-density lipoprotein (LDL) cholesterol levels.6,7) However, it remains to be elucidated whether there is any association between statin and coronary artery calcium (CAC) formation. 8) Recent intravascular ultrasound (IVUS) studies indicated that high-dose statin therapy leads to a reduction in the necrotic core volume, but to an increase in tissue calcification.9-12) These IVUS studies were conducted on high-risk patients diagnosed with coronary artery disease (CAD) [9][10][11] or STsegment elevation myocardial infarction (STEMI).12) As those patients received statin therapy regardless of the presence or absence of dyslipidemia, we could not differentiate the effect of statins and dyslipidemia on CAC. Furthermore, the region of interest in IVUS was limited to the proximal coronary vessels, instead of the entire coronary vasculature.Multi-detector computed tomography (MDCT) provides images of all coronary arteries with a higher specificity of CAC. The efficiency of MDCT remains controversial as some studies reported a significant impact of statin therapy on coronary plaque burden and/or CAC, 13,14) whereas others re...