Rapid changes in plaque composition and morphology after intensive lipid lowering therapy: study with serial coronary CT angiography.

Although intensive lipid lowering by statins can enhance plaque stability, few data exist regarding how early statins change plaque composition and morphology in clinical setting. Therefore, to examine early changes in plaque composition and morphology by intensive lipid lowering with statins, we evaluate coronary plaques from acute coronary syndrome (ACS) before and 3 weeks after lipid lowering by coronary CT angiography. We enrolled 110 patients with suspected ACS and underwent coronary CT. We defined plaque as unstable when CT number of plaque< 50HU and remodeling index (lesion diameter/reference diameter) >1.10. Rosuvastatin (5 mg/day) or atorvastatin (20 mg/day) were introduced to reduce low density lipoprotein cholesterol (LDL-C). Then, CT was again performed by the same condition 3 weeks after lipid lowering therapy. Total 10 patients (8 men, mean age 72.0 years), in whom informed consent regarding serial CT examination was obtained, were analyzed. Among them, 4 patients who denied to have intensive lipid lowering were served as controls. In remaining 6 patients, LDL-C reduced from 129.5±26.9 mg/dl to 68.5±11.1 mg/dl after statin treatment. Under these conditions, CT number of the targeted plaque significantly increased from 16.0±15.9 to 50.8±35.0 HU (p<0.05) and remodeling index decreased from 1.22±0.11 to 1.11±0.06 (p<0.05), although these values substantially unchanged in controls. These results demonstrate that MDCT-determined plaque composition as well as volume could be changed within 3 weeks after intensive lipid lowering. This may explain acute effects of statins in treatment of acute coronary syndrome.

Reassessment of the cutoff values of waist circumference and visceral fat area for identifying Japanese subjects at risk for the metabolic syndrome.

In the new world-wide criteria for metabolic syndrome (MetS) by the International Diabetes Federation (IDF) in 2006, the Japanese is the only ethnicity in which the recommended waist circumference (WC) cutoff value is higher in women (>or=90cm) than in men (>or=85cm), and its validity appears to be controversial. We investigated the optimal cutoff points for the diagnosis of central obesity in Japanese men and women, using the receiver operating characteristic (ROC) curve analysis for both of WC and visceral fat area (VFA) in 1870 middle-aged Japanese. VFA was superior to WC and Body mass index (BMI) for discriminating the subjects with two or more nonadipose components of MetS. The optimal cutoff points of VFA and WC were 132.6cm(2) and 89.8cm for men and 91.5cm(2) and 82.3cm for women. The stratifications of MetS components more than 1.0 in average occurred more steeply by the accumulation of VFA in women than in men. In conclusion, setting the cutoff points of WC and VFA lower values in women than in men for the definition of central obesity is needed to identify the subjects with MetS in Japanese, as in other Asian populations.