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Background: Growth hormone (GH) replacement therapy improves hypercholesterolemia in patients with GH deficiency, suggesting that GH modulates cholesterol metabolism., Objectives: We examined GH effects on lipid profiles and cholesterol-related markers reflecting hepatic and cerebral cholesterol metabolism in small-for-gestational age (SGA) children without catch-up growth., Methods: This study examined SGA children without catch-up growth (n = 22) and healthy children (controls, n = 11). Based on parents' choice, 11 SGA children received GH at 0.23 to 0.25 mg/kg/d for 6 months, and at 0.34 to 0.36 mg/kg/d for the subsequent 6 months (GH (+) group). The other SGA children received no GH (GH (-) group, n = 11). We ascertained baseline and posttreatment lipid profiles and cholesterol-related markers reflecting hepatic and cerebral cholesterol metabolism., Results: Baseline lipid profiles of SGA children and controls were similar. Serum 24S-hydroxycholesterol (marker for cerebral cholesterol metabolism) concentration was 19% lower in SGA children than in controls (P < .05). Compared with baseline, the GH (+) group low-density lipoprotein-cholesterol concentration had decreased by 6.6% during 6 months and 8.8% during 12 months (P < .01), whereas the high-density lipoprotein-cholesterol concentration had increased by 1.7% (P = .07) and 3.3% (P < .01). Serum 7α-hydroxycholesterol (marker for hepatic cholesterol elimination) concentration had increased by 34% at 6 months and 35% at 12 months (P < .01). In addition, 24S-hydroxycholesterol increased by 25% and 26% (P < .001). No marker for cholesterol synthesis or absorption changed. The GH (-) group lipid profiles and oxysterols remained unchanged during the observation period., Conclusion: GH activates hepatic and cerebral cholesterol metabolism in SGA children without catch-up growth., (Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.)

Recent lifestyle and social environment changes in Japan have been accompanied by increasing incidencerates of metabolic disorders, such as dyslipidemia and diabetes. Therefore, the rates of cardiovascular disease due to the progression of atherosclerosis are also increasing, and cardiovascular disease remains the leading cause of death in Japan. In particular, dyslipidemia, represented by hypercholesterolemia, hypertriglyceridemia, and hypoalphalipoproteinemia, is closely related to the onset and progression of atherosclerosis. Total cholesterol, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol have been used as quantitative markers of lipids to evaluate cardiovascular risks. However, these markers are not sufficient to fully assess the risks. Therefore, we focused on qualitative markers that represent lipid abnormalities, and examined the utility of qualitative lipids evaluation as clinical markers of atherosclerotic disorders. Previously, we reported that HDL and LDL subclasses and sterol markers are clinically important for evaluating the pathogenesis and risks of cardiovascular disorders. Moreover, lipoprotein subclasses may be useful as therapeutic markers for cardiovascular disorders, and oxysterols may also be useful as diagnostic markers for dementing disorders and diseases of the central nervous system. These issues remain to befully elucidated in the future.

Objective: Cholesterol and diet-derived oxidized cholesterol are absorbed in the small intestine and eliminated by bile acids. We determined whether ezetimibe, a selective cholesterol absorption inhibitor, changes serum oxidized cholesterol levels., Methods: We measured levels of plant sterols, cholesterol precursors, and oxysterols by gas chromatography-mass spectrometry in 47 hypercholesterolemics and 32 controls. Twenty-four hypercholesterolemics received 10 mg ezetimibe/day for 4 weeks., Results: Plant sterols were 30-42% higher in hypercholesterolemics than in controls and positively correlated with low-density lipoprotein-cholesterol (LDL-C). Ezetimibe decreased plant sterols by 21-53%, but did not change bile acid synthesis markers. 7β-hydroxycholesterol, a marker for non-enzymatic oxidation of cholesterol, was 66% higher in hypercholesterolemics than controls. Ezetimibe decreased 7β-hydroxycholesterol levels by 15% regardless of LDL-C reduction., Conclusions: Ezetimibe decreases serum oxidized cholesterol generated by non-enzymatic reactions without impairing bile acid synthesis. Ezetimibe may maintain cholesterol excretion into bile and alleviate the diet-derived oxidative burden., (© 2013 Elsevier Ireland Ltd. All rights reserved.)

Background: Phenylketonuria (PKU) possibly leads to hypocholesterolemia and lowered vitamin D (VD) status. Metabolism of oxysterols linking with those of cholesterol and VD has never been examined in PKU., Methods: Blood oxysterols along with blood phenylalanine, lipids and VD were examined for 33 PKU adults aged 21-38 years and 20 age-matched healthy controls., Results: Total- and low-density cholesterols, and 25-hydroxy VD(3) were decreased significantly in the PKU group (cholesterols, 10% decrease; 25-hydroxy VD(3) 35% decrease vs. the control group). 24S-hydroxycholesterol (24S-OHC) eliminating brain cholesterol, and 27-OHC and 7α-hydroxycholesterol (7α-OHC) representing peripheral and hepatic cholesterol elimination, respectively, were significantly decreased in PKU group: 24S-OHC, 25% decrease, p<.01; 27-OHC and 7α-OHC, 35-40% decrease, p<.001. 7β-Hydroxycholesterol (7β-OHC) reflecting oxidative stress was increased significantly in PKU group (p<.05). 7α-OHC and 27-OHC levels in PKU group always showed similar values, regardless of other parameters while the 24S-OHC and 7β-OHC levels decreased and increased, respectively, showing significant correlations with phenylalanine level (p<.005). 27-OHC level showed a significant positive correlation with the 25-hydroxy VD(3) level in this group (p<.001)., Conclusion: Blood oxysterol changes predominate over blood cholesterol changes and influence on VD status in adult PKU patients., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or "statins", are used as cholesterol-lowering agents worldwide. Statins inhibit cholesterol biosynthesis, leading to enhanced uptake of low-density lipoprotein (LDL) from the circulation via LDL receptors. This strong cholesterol-lowering action contributes to the beneficial effects of statins. For example, large clinical trials have demonstrated that statins significantly reduce cardiovascular risk. Recent research has shown that statins have other multiple actions involved in endothelial function, cell proliferation, inflammatory response, immunological reactions, platelet function, and lipid oxidation. These "pleiotropic actions" of statins probably provide a significant contribution to the reduction of cardiovascular events. This review summarizes the pleiotropic actions of statins in both basic and clinical studies. It also considers the potential for statin therapy in the treatment of stroke and dementia.

Abstract: Background: Postprandial hypertriglyceridemia is a risk factor for atherosclerotic disease. However, the postprandial triglyceride (PTG) concentration fluctuates markedly and is poorly reproducible. The aim of this study was to determine whether the mean PTG (mean-PTG) concentration is a risk factor for carotid atherosclerosis in patients with type 2 diabetes. Methods: We measured the fasting and postprandial lipid concentrations, and the maximum intima-media thickness (max IMT) of carotid arteries by ultrasound in 115 diabetic patients. A carotid plaque was defined as max IMT of >1.0mm. The mean-PTG concentration was calculated from several PTG concentrations measured on different days during a 1-year follow-up period. Results: PTG concentrations showed marked intra-individual variability, and ranged from 0.29 to 6.03mmol/l. Patients with carotid plaques had higher mean-PTG concentrations than those without carotid plaques (1.51±0.57 vs. 1.29±0.47mmol/l, p =0.025). Neither fasting triglycerides nor one-point PTG concentrations differed between the two groups. Multivariate stepwise logistic regression analysis revealed that the mean-PTG concentration was significantly associated with carotid plaques [OR 1.20 (95% CI, 1.05–1.37), p =0.009], even after adjusting for traditional risk factors including HDL-cholesterol, LDL-cholesterol, age, hypertension, and duration of diabetes. Conclusions: The mean-PTG concentration is an independent risk factor for carotid atherosclerosis in patients with type 2 diabetes. [Copyright &y& Elsevier]

Abstract: Although low-density lipoprotein cholesterol (LDL-C) is a strong risk factor for coronary artery disease (CAD), LDL-C levels are not always elevated in CAD patients. LDL consists of several subclasses with distinct sizes, densities, and physicochemical compositions. Thus, LDL subclasses can be separated by various laboratory procedures. Among them, ultracentrifugation and electrophoresis have been used most frequently for determining LDL subclasses. Accumulating evidence has shown that a predominance of small dense LDL (sd-LDL) is closely associated with CAD. Moreover, sd-LDL-cholesterol (sd-LDL-C) concentrations are elevated in groups at a high risk for CAD, such as patients with type 2 diabetes and metabolic syndrome. Therefore, sd-LDL concentration is recognized as a surrogate marker for CAD. However, some studies failed to show therapeutic modulation of sd-LDL, likely because separating methods and sd-LDL particle definitions have not yet been standardized. Recently, a detergent-based homogenous assay for sd-LDL-C has been developed. This method does not require any pretreatment, and the measured values are highly reproducible with an automated analyzer. These features are suitable for large-scale clinical studies. This homogeneous assay is a useful tool for clarifying whether sd-LDL-C is a superior marker to LDL-C, and whether sd-LDL-C lipid-lowering therapies decrease the incidence of CAD. [Copyright &y& Elsevier]

Abstract: Background: Small dense low-density lipoprotein (sd-LDL) is an atherogenic LDL subfraction and often increased in metabolic syndrome (MetS). This study aimed to determine whether sd-LDL cholesterol (sd-LDL-C) is a therapeutic marker of statin treatment in patients with acute coronary syndrome (ACS) and MetS. Methods: We examined 71 patients with ACS and 50 non-ACS subjects with normal coronary arteries (controls). The patients with ACS were treated with life-style modifications (n=36) or those plus 20mg atorvastatin daily (n=35) for 6months. We measured sd-LDL-C by a novel detergent-based homogenous assay and calculated buoyant LDL-C (b-LDL-C). Results: The patients with ACS had higher sd-LDL-C than did the controls (30±14 vs. 22±8mg/dl, p<0.001). Furthermore, sd-LDL-C was higher in the patients with ACS and MetS (n=31) than in those without MetS (n=40) (35±17 vs. 27±11mg/dl, p<0.05). Atorvastatin reduced LDL-C and sd-LDL-C by 31% (102±23 to 70±28mg/dl, p<0.0001) and 24% (29±15 to 22±13mg/dl, p<0.01). The reduction in sd-LDL-C by atorvastatin was 5.5-fold greater in the patients with ACS and MetS than in those without MetS (p<0.001). Contrary, that in b-LDL-C was similar between the groups. Conclusions: sd-LDL-C is a superior therapeutic marker of statin treatment in patients with ACS and MetS. [Copyright &y& Elsevier]

Abstract: Background: Influence of hyperphenylalaninemia on lipoproteins in early life remains unclear. Methods: We enrolled 24 phenylalanine hydroxylase (PAH)-deficient children who were classified into a phenylketonuria (PKU) group (n =12) lacking PAH activity and a benign hyperphenylalaninemia (HPA) group (n =12) having partial PAH activity, and their 11 non-affected siblings. We measured serum total-cholesterol, low-density lipoprotein (LDL)-cholesterol, and high-density lipoprotein (HDL)-cholesterol levels together with apolipoproteins for the first year of life, and compared them with those of 30 age-matched healthy controls. Results: The affected groups invariably had lower cholesterol levels than non-affected groups. At birth, HDL-cholesterol decrease was greatest and predominated over the LDL-cholesterol decrease: total cholesterol, 28/36% decrease to the control level in HPA/PKU; HDL-cholesterol, 33/51%; LDL-cholesterol, 20/28%. At 3months, the opposite changes were observed: total cholesterol, 16/28%; HDL-cholesterol, 13/23%; LDL-cholesterol, 16/33%. At 12months, LDL were still significantly lower in both groups (8/18%, p <.05 and .001), although HDL was significantly decreased only in the PKU group (15%, p <.05). Apolipoprotein A-I/A-II and B changed respectively in accordance with HDL-cholesterol and LDL-cholesterol changes. Despite similar phenylalanine levels, the PKU group invariably had lower cholesterol concentrations than the HPA group had. Conclusion: Irrespective of phenylalanine concentrations, lipoprotein synthesis in PAH-deficient children, particularly in PKU children, was suppressed in early life. [Copyright &y& Elsevier]

Abstract: Background: High-density lipoprotein-cholesterol (HDL-C) is a negative risk factor for cardiovascular events. Although several homogeneous HDL-C assays are available, their accuracy has not been validated, particularly in subjects with disease. We aimed to clarify whether HDL-C concentrations measured by homogeneous assays [HDL-C (H)] agree with those determined by the reference measurement procedures [HDL-C (RMP)] using ultracentrifugation and precipitation with heparin-manganese reagent in fresh clinical samples. Methods: HDL-C concentrations in samples from 48 healthy subjects and 119 subjects with disease were determined using 12 homogeneous assays and RMPs. Results: All reagents showed excellent intra- and inter-assay CVs (<2.23%) for two pooled sera. Furthermore, the mean bias was within ±1.0% in nine reagents using samples from healthy subjects and in eight reagents using samples from subjects with disease. In a single HDL-C (H) determination, the total error requirement of the National Cholesterol Education Program (95% of results < 13%) was fulfilled in nine reagents using samples from healthy subjects and six reagents in those from subjects with disease. Error component analysis revealed that only one reagent exceeded ±10% total error in samples from healthy subjects, whereas four reagents exceeded this error in samples from subjects with disease. Correlations between HDL-C (H) and HDL-C (RMP) revealed that the slopes were within 1.00 ± 0.06 in six reagents in healthy subjects, and eight reagents in subjects with disease. Conclusions: Except for three reagents, HDL-C (H) agrees well with HDL-C (RMP) in subjects with common disease, but not in those with extremely low HDL-C or abnormal HDL composition. [Copyright &y& Elsevier]

Abstract: Background: Homogeneous assays for low-density lipoprotein-cholesterol (LDL-C) have good precision and are pretreatment-free procedures. However, their accuracies have been questioned, especially in diseased subjects. In this study, we aimed to verify whether LDL-C levels determined by homogeneous assays [LDL-C (H)] agree with those determined by a beta-quantification method [LDL-C (BQ)] in fresh clinical samples. Methods: We determined LDL-C levels in 49 non-diseased and 124 diseased subjects whose triglyceride (TG) levels were less than 11.29 mmol/L (1000 mg/dL) using 12 homogeneous assays and a BQ method simultaneously. Results: In total, 30.6% of non-diseased subjects and 46.0% of diseased subjects were in the postprandial state. The maximum inter- and intra-assay CVs were 1.8% and 1.5%, and 8 reagents had a CV of 1.0% or less. The mean bias ranged from −0.5% to 1.8% for non-diseased subjects and from −0.7% to 1.6% for diseased subjects. For non-diseased subjects, all but one reagent achieved the National Cholesterol Education Program (NCEP) total error requirement in more than 90% of samples. However, for diseased subjects, the number of reagents that met this requirement was low. With some reagents, LDL-C (H) was higher than LDL-C (BQ), especially in subjects with hypertriglyceridemia. While for other reagents, the difference between the two methods was not associated with hypertriglyceridemia except for type I (n = 2) and type III hyperlipidemia (n = 1). Postprandial sampling was not the main factor for discordant results. Conclusions: LDL-C (H) agrees with LDL-C (BQ) in non-diseased subjects, but exhibits positive bias for subjects with hypertriglyceridemia in diseased subjects for some reagents. [Copyright &y& Elsevier]

Abstract: Background: Recent studies have demonstrated that non-high-density lipoprotein cholesterol (non-HDL-C) can predict the risk of cardiovascular events among general population without coronary heart disease (CHD). However, few studies have investigated the predictive value of non-HDL-C for long-term prognosis in patients with CHD. The purpose of this study was to investigate whether non-HDL-C can predict long-term cardiovascular events in patients with CHD who underwent coronary artery bypass grafting (CABG). Methods: We enrolled 1074 consecutive patients who underwent CABG at Juntendo University Hospital between 1984 and 1994, and obtained mortality data through 2000. We divided the patients into 2 groups by the median non-HDL-C level at baseline (180mg/dL) and used Kaplan–Meier method with log-rank test for survival analyses. Cox proportional-hazard regression model was used to calculate the relative risk (RR) of cardiac death. Results: The mean follow-up period was 10.6±3.5 years. The survival rate of cardiac death was significantly lower in the high non-HDL-C group than that in the low non-HDL-C group (log-rank test; p =0.006). Furthermore, in proportional regression analysis adjusted for conventional coronary risk factors, metabolic syndrome, statin treatment, and use of artery bypass graft, the increased levels of non-HDL-C were significant and independent predictor of cardiac death beyond other lipid parameters (RR1.22; by 10mg/dL non-HDL-C increasing, 95% confidence interval 1.03–1.44; p <0.05). Conclusions: The increased levels of non-HDL-C were significantly associated with an increased risk of cardiac death. Baseline non-HDL-C levels may be a practical predictor of long-term cardiac death in patients with CHD after CABG. [Copyright &y& Elsevier]