Relationship between LDL-C reduction after coronary revascularization and prevention of recurrence of cardiovascular events.

PURPOSE: The purpose of our study was to optimize lipid-lowering therapy in patients undergoing coronary revascularization and to determine whether the percentage change in low-density lipoprotein-cholesterol (LDL-C) level in the 3 months after coronary revascularization could be used as a predictor of the time to recurrence of coronary artery disease (CAD). METHODS: Biochemical values of patients undergoing lipid-lowering therapy after receiving coronary revascularization at the Nippon Medical School Chiba Hokusoh Hospital, Japan, were retrospectively investigated. Recurrence of a cardiovascular event (CVE) was defined by death, myocardial infarction, or angina caused by coronary revascularization more than 3 months after the first event. RESULTS: Of 171 patients under secondary preventive care who had at least one recurrence of a CVE, 75 showed evidence of objective stenotic lesions on coronary angiography. Among these 75 patients, exclusion of those in whom coronary revascularization had not been performed at disease onset, balloon dilatation had been used, serum lipid levels had not been measured, or coronary revascularization had been applied to restenosis left 44 patients suitable for inclusion in the study group. Although the mean value of high density lipoprotein-cholesterol did not change in the 3 months after coronary revascularization, that of (LDL-C) significantly decreased. A significant positive correlation was identified between % decrease in LDL-C and number of days to CVE recurrence. The average LDL-C value (102.8+/-21.7 mg/dL) in the group of patients with no recurrence within 5 years was significantly lower than that (135.3+/-46.1 mg/dL) in the recurrence group (P = 0.0088). The % of patients achieving the LDL-C target level (non-recurrence group vs. recurrence group: 50.0% vs. 16.7%; P = 0.032) and the % decrease in LDL-C (31.0%+/-12.6% vs. 9.6+/-21.0%, P = 0.0012) were significantly greater in the non-recurrence group than in the recurrence group. CONCLUSIONS: From our present study, a decrease in LDL-C 3 months after revascularization surgery reduces the rate of CVE relapse. The % LDL-C decrease could serve as a useful predictor of CVE recurrence, in addition to LDL-C values and achievement of the LDL-C target level.

Long-term exercise down-regulates leptin receptor mRNA in the arcuate nucleus.

The purpose of this study was to investigate the effects of exercise on blood leptin concentrations and expression of leptin receptor subtype-b (Ob-Rb) mRNA in the arcuate nucleus of hypothalamus (ARC). Male Wistar rats (26 weeks old) underwent regular wheel exercise for 12 weeks. The expression of Ob-Rb mRNA in the ARC decreased at the end of the study period despite reductions of abdominal fat-pad weight and serum leptin concentration. Serum 1,5-anhydroglucitol levels were higher in exercising rats, suggesting lower serum insulin levels in exercising rats. Our results suggested that 12-week wheel exercise reduced the expression of Ob-Rb mRNA in the ARC probably through improvement in insulin resistance.

Evaluation of Rhubarb using antioxidative activity as an index of pharmacological usefulness.

We attempted to estimate the pharmacological activity by measuring the concentrations of a composition ingredient using a multivariate statistical analysis method. Medicinal herb of Rhubarb has been many largely unrecognized biochemical and pharmacological effect components. Therefore, we attempted to estimate the antioxidative activity of Rhubarb on low-density lipoprotein (LDL) of its components. Thirty specimens of Rhubarb from various origins were used, chose nine components of anthraquinones, two components of anthrones, two components of flavan-3-ols, one component of procyanidin, one component of naphthalene, two components of phenylbutanones and one component of stilbene. Quantitative analysis of 18 components was performed with high-performance liquid chromatography (HPLC) and antioxidative activities were measured with plasma taken from spontaneous familial hypercholesterolemia model rabbits. There was considerable variation among the specimens in the concentration of components and antioxidative activities on LDL. As a result of multiple regression analysis, significant multiple correlation coefficient for antioxidative activities on LDL (R=0.914, P<0.01) was found in relation to the concentrations of five components: aloe-emodin, chrysophanol, emodin 1-O-beta-D-glucoside, lindleyin and 6-hydroxymusizin 8-O-beta-D-glucoside. Three of the five components were not active in promoting antioxidative activity and there was no significant correlation between the concentrations of the most active component and the activity. We consider this a useful method for selecting of Rhubarb and propose a new scientific approach for the selection of natural medicines.

Effects of Dai-saiko-to (Da-Chai-Hu-Tang) on plasma lipids and atherosclerotic lesions in female heterozygous heritable Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbits.

We investigated the antihypercholesterolemic effects of traditional Japanese herbal medicine Dai-saiko-to (Da-Chai-Hu-Tang in Chinese) in female heritable Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbits. The plasma total cholesterol levels increased for up to 12 weeks after beginning a diet containing 0.1% cholesterol then reached a plateau of about 603 mg dl(-1). Dai-saiko-to was administered at doses of 0.5-1.0 g kg(-1) per day or pravastatin 10 mg kg(-1) per day for 24 weeks. Plasma total cholesterol levels were significantly decreased in the groups administered Dai-saiko-to 1.0 g kg(-1) per day or pravastatin for 4-24 weeks, whereas there were no change with plasma phospholipid and triglyceride levels. However, Dai-saiko-to 1.0 g kg(-1) per day significantly decreased plasma LDL cholesterol levels, but had no effect on either VLDL- or HDL-cholesterol levels. Moreover, LDL-receptor mRNA levels in the liver were significantly increased in the Dai-saiko-to 1.0 g kg(-1) per day group compared with those of animals receiving the 0.1% cholesterol diet. In addition, both groups receiving Dai-saiko-to 1.0 g kg(-1) per day and pravastatin showed a significantly reduced percentage of intimal surface area of thoracic aorta involved with atheromatous plaques in the thoracic aorta at 24 weeks. These results indicated that Dai-saiko-to 1.0 g kg(-1) per day significantly decreased the plasma cholesterol levels and atheromatous plaque area due to expression of the LDL mRNA gene in the liver.