Effect of ezetimibe add-on therapy over 52 weeks extension analysis of prospective randomized trial (RESEARCH study) in type 2 diabetes subjects.

BACKGROUND: Lowering cholesterol levels decreases the risk of atherosclerotic diseases. Effective ways to stably reduce LDL-C level are warranted in type 2 diabetic patients, a high-risk population for CVD, with various anti-diabetic therapeutic background. The RESEARCH study focuses on LDL-C reduction in this population along with modifications of the lipid profiles. We evaluated long-term ezetimibe add-on therapy in T2DM patients with hypercholesterolemia. METHODS: In a randomized, multicenter, open-label, prospective study, a total of 109 T2DM patients not attaining LDL-C target value despite first-line dose statin (10 mg of atorvastatin or 1 mg of pitavastatin) therapy in Japan were recruited. We investigated the difference in cholesterol lowering effect between ezetimibe (10 mg) add-on statin (EAT) group and double-dose statin (DST) group. Changes of parameters related to atherosclerotic event risks were assessed. RESULTS: The reduction of LDL-C was larger in the EAT group (28.3%) than in the DST group (9.2%) at 52 weeks as well as the primary endpoint of 12 weeks. EAT achieved significant lower levels of TC and apo B, respectively. Both treatments attained significant reduction in sd-LDL-C or hsCRP on this long-term basis. Notably, sd-LDL-C in EAT reduced as low as 36.1 ± 14.9 mg/dl to reach near the threshold (35.0 mg/dl) for atherosclerosis with significantly higher achievement rate (55.6%) than DST treatment. Simultaneously, hsCRP reduction by EAT attained as low value as 0.52 ± 0.43 mg/l. CONCLUSIONS: In the present 52-week long-term period, ezetimibe add-on therapy showed a robust advantage in lowering LDL-C and in attaining target LDL-C values compared with the doubling of statin dose. Moreover, it's meaningful that sd-LDL, powerfully atherogenic lipoprotein, exhibited prominent decrease consistently prominently by ezetimibe add-on therapy. DM patients with hypercholesterolemia are at high risk for CAD, and adding ezetimibe onto usual-dose statin treatment in Japan has been suggested as the first-line therapy for those DM patients who failed to attain the target LDL-C value (UMIN000002593).

Effect of Ezetimibe on LDL-C Lowering and Atherogenic Lipoprotein Profiles in Type 2 Diabetic Patients Poorly Controlled by Statins.

BACKGROUND: There exists a subpopulation of T2DM in whom first-line doses of statin are insufficient for optimally reducing LDL-C, representing a major risk of CVD. The RESEARCH study focuses on LDL-C reduction in this population along with modifications of the lipid profiles leading to residual risks. METHODS: Lipid changes were assessed in a randomized, multicenter, 12-week, open-label study comparing a high-potency statin (10mg of atorvastatin or 1mg of pitavastatin) plus ezetimibe (EAT: n = 53) with a double dose of statin (20mg of atorvastatin or 2mg of pitavastatin) (DST: n = 56) in DM subjects who had failed to achieve the optimal LDL-C targets. Lipid variables were compared with a primary focus on LDL-C and with secondary focuses on the percentage of patients who reached the LDL-C targets and changes in the levels of RLP-C (remnant like particle cholesterol) and sd-LDL-C, two characteristic atherogenic risks of DM. RESULTS: The reduction of LDL-C (%), the primary endpoint, differed significantly between the two groups (-24.6 in EAT vs. -10.9 in DST). In the analyses of the secondary endpoints, EAT treatment brought about significantly larger reductions in sd-LDL-C (-20.5 vs. -3.7) and RLP-C (-19.7 vs. +5.5). In total, 89.4% of the patients receiving EAT reached the optimized treatment goal compared to 51.0% of the patients receiving DST. The changes in TC (-16.3 vs. -6.3) and non-HDL-C (-20.7 vs. -8.3) differed significantly between the two groups. CONCLUSION: Ezetimibe added to high-potency statin (10 mg of atorvastatin or 1 mg of pitavastatin) was more effective than the intensified-dose statin (20 mg of atorvastatin or 2 mg of pitavastatin) treatment not only in helping T2DM patients attain more LDL-C reduction, but also in improving their atherogenic lipid profiles, including their levels of sd-LDL-C and RLP-C. We thus recommend the addition of ezetimibe to high-potency statin as a first line strategy for T2DM patients with insufficient statin response. TRIAL REGISTRATION: The UMIN Clinical Trials Registry UMIN000002593.

Efficacy and safety of sitagliptin for the treatment of diabetes mellitus complicated by chronic liver injury.

AIM: To investigate the efficacy and safety of a dipeptidyl peptidase-4 inhibitor, sitagliptin, for treating diabetes mellitus complicated by chronic liver injury. METHODS: Sitagliptin was administered for 13.7 ± 10.1 months to 122 patients with DM complicated by chronic liver injury (including 19 patients with liver cirrhosis), and changes in hemoglobin A1c (HbA1c) and liver enzymes (transaminases, etc.) were evaluated. RESULTS: HbA1c was reduced from 8.48 ± 1.43% to 7.87 ± 1.35% (P < 0.001). Among liver enzymes, alanine aminotransferase (ALT) levels improved from 75.1 ± 45.2 to 65.8 ± 35.8 IU/L (P = 0.012) and gamma-glut amyl-trans peptidase from 155.2 ± 161.1 to 133.2 ± 127.4 IU/L (P = 0.044). Among the causes of liver injury, non-alcoholic fatty liver disease and alcoholic liver disease both showed the reductions in HbA1c with no deterioration of liver enzymes. An analysis of 19 patients with liver cirrhosis also showed reductions in HbA1c with no deterioration of liver enzymes. CONCLUSION: It is suggested that sitagliptin can be administered effectively and safely to patients with diabetes mellitus complicated by chronic liver injury, including liver cirrhosis.

A Case of Rathke's Cleft Cyst Associated with Transient Central Adrenal Insufficiency and Masked Diabetes Insipidus.

A 73-year-old woman admitted to our hospital because of headache, poor appetite, malaise, weight loss, and vomiting was found to have central adrenal insufficiency and thyrotoxicosis due to silent thyroiditis. Polyuria developed after replacement with glucocorticoid (masked diabetes insipidus), which was controlled with nasal administration of desmopressin. Magnetic resonance imaging of the brain showed a large cystic pituitary mass (18 × 18 × 12 mm) extending suprasellarly to the optic chiasm. Transsphenoidal surgery revealed that the pituitary tumor was Rathke's cleft cyst. Following surgery, replacement with neither glucocorticoid nor desmopressin was needed any more. Therefore, it is suggested that Rathke's cleft cyst is responsible for the masked diabetes insipidus and the central insufficiency. Furthermore, it is speculated that thyrotoxicosis with painless thyroiditis might induce changes from subclinical adrenal insufficiency to transiently overt insufficiency.

Well-defined iron complexes as efficient catalysts for "green" atom-transfer radical polymerization of styrene, methyl methacrylate, and butyl acrylate with low catalyst loadings and catalyst recycling.

Environmentally friendly iron(II) catalysts for atom-transfer radical polymerization (ATRP) were synthesized by careful selection of the nitrogen substituents of N,N,N-trialkylated-1,4,9-triazacyclononane (R3 TACN) ligands. Two types of structures were confirmed by crystallography: "[(R3 TACN)FeX2 ]" complexes with relatively small R groups have ionic and dinuclear structures including a [(R3 TACN)Fe(µ-X)3 Fe(R3 TACN)](+) moiety, whereas those with more bulky R groups are neutral and mononuclear. The twelve [(R3 TACN)FeX2 ]n complexes that were synthesized were subjected to bulk ATRP of styrene, methyl methacrylate (MMA), and butyl acrylate (BA). Among the iron complexes examined, [{(cyclopentyl)3 TACN}FeBr2 ] (4 b) was the best catalyst for the well-controlled ATRP of all three monomers. This species allowed easy catalyst separation and recycling, a lowering of the catalyst concentration needed for the reaction, and the absence of additional reducing reagents. The lowest catalyst loading was accomplished in the ATRP of MMA with 4 b (59 ppm of Fe based on the charged monomer). Catalyst recycling in ATRP with low catalyst loadings was also successful. The ATRP of styrene with 4 b (117 ppm Fe atom) was followed by precipitation from methanol to give polystyrene that contained residual iron below the calculated detection limit (0.28 ppm). Mechanisms that involve equilibria between the multinuclear and mononuclear species were also examined.

Lowering LDL cholesterol, but not raising LDL receptor activity, by ezetimibe.

BACKGROUND: Ezetimibe, an inhibitor of intestinal cholesterol absorption, is effective in lowering serum low-density lipoprotein (LDL) cholesterol with or without coadministration of statin. Ezetimibe-plus-statin therapy enhances LDL receptor activity, but it is still unclear whether ezetimibe alone enhances LDL receptor activity, resulting in LDL cholesterol decrease. OBJECTIVE: We investigated whether ezetimibe lowers serum LDL cholesterol by raising LDL receptor activity in humans. METHODS: Patients with hypercholesterolemia (n = 28; age [mean ± SD], 61.6 ± 13.0 years; 57% men) were treated with ezetimibe (10 mg/d) for 4 months. Before and after the treatment, serum LDL cholesterol, apolipoprotein B (apo B), and apolipoprotein C-II (apo C-II) were measured. LDL receptor activities were estimated with the equation we reported previously as follows: LDL receptor activity (represented as a percentage of normocholesterolemic subjects) = 63.595 + apo C-II (in mg/dL) × 13.459-apo B (in mg/dL) × 0.366. RESULTS: By the treatment of ezetimibe, LDL cholesterol (176.8 ± 17.9 vs 138.0 ± 19.7 mg/dL) was lowered 21.9% significantly (P < .01). The estimated LDL receptor activities before and after the ezetimibe treatment were 86.8% ± 21.4% and 89.6% ± 19.7%, respectively, with no significant difference between them (P = .13). CONCLUSION: Ezetimibe lowered LDL cholesterol significantly in patients with hypercholesterolemia without raising LDL receptor activity. The enhancement of LDL receptor activity is less involved in the pharmacologic action of ezetimibe.

RESEARCH (Recognized effect of Statin and ezetimibe therapy for achieving LDL-C Goal), a randomized, doctor-oriented, multicenter trial to compare the effects of higher-dose statin versus ezetimibe-plus-statin on the serum LDL-C concentration of Japanese type-2 diabetes patients design and rationale.

AIMS: Hypercholesterolemia coexisting with diabetes still requires clinical intervention to manage the high risk of cardiovascular disease it poses. No second-step strategy is established, however, for cases where strong statins fail to bring cholesterol down to target levels. In this study we seek to demonstrate the superior effect of ezetimibe in combination with strong statins to reduce LDL-C in Japanese patients suffering from both T2DM and hyper LDL-cholesterolemia. METHODS: T2DM outpatients (109 patients from 16 institutes) who failed to achieve the target LDL-C value were recruited and randomly assigned to two groups, a double-dose-statin group and ezetimibe-plus-statin group. Follow-ups were scheduled at 0, 12, 26, and 52 weeks. The primary endpoint was the percentage change in the level of LDL-C from baseline to 12 weeks. INTERIM RESULTS: We could successfully create randomized (gender, age, LDL-C, HbA1c, etc.) two groups except for slight differences in apolipoprotein-B and sd-LDL. CONCLUSIONS: RESEARCH is the first prospective, parallel-group, multicenter study comparing a double dose of strong statin with ezetimibe plus strong statin for T2DM patients. The RESEARCH study will provide reliable evidence with which to establish a clinical strategy for diabetics who fail to achieve the target LDL-C value.

Statin-induced Ca(2+) release was increased in B lymphocytes in patients who showed elevated serum creatine kinase during statin treatment.

AIM: Statins are effective in lowering cholesterol levels, but cause fatal rhabdomyolysis in susceptible individuals. Because it has been hypothesized that muscle damage could result from alterations in Ca(2+) homeostasis in muscle cells, we tested whether measuring statin-induced changes in intracellular calcium ([Ca(2+)](i)) is useful for predicting susceptibility to statin-muscle damage, using human CD19+ primary B lymphocytes. METHODS: Statin-induced alterations in [Ca(2+)](i) were studied using the human THP-1 cell line and CD19+ primary B lymphocytes. Changes in [Ca(2+)](i) were measured directly in fluo-3- loaded cells using either single or dual-color flow cytometry. RESULTS: The Ca(2+) release study suggested that statin-induced changes in [Ca(2+)](i) were due to Ca(2+) release from ryanodine-sensitive Ca(2+) stores and mitochondrial compartments. Further, statin users who experienced elevated creatine kinase (n=8) exhibited significantly greater statin-induced Ca(2+) release in B cells than healthy volunteers (n=45) and statin users without elevated creatine kinase (n=16), while no difference was seen between the latter two groups. CONCLUSION: Statin-induced Ca(2+) release from ryanodine-sensitive stores and mitochondria may contribute to myotoxicity. The laboratory test for Ca(2+) release using CD19+ primary B lymphocytes may be useful to predict susceptibility to statin-induced muscle toxicity prior to statin use.

Distribution of dolichol in the serum and relationships between serum dolichol levels and various laboratory test values.

We examined the correlations between serum dolichol levels and laboratory test parameters in patients affected by disease, as well as the distribution of dolichol in sera from patients with hyperbetalipoproteinemia and hyperalphalipoproteinemia. Serum dolichol was evaluated by a reverse-phase HPLC method. After centrifugation, the serum dolichol found in healthy controls was mainly associated with medium-sized particles of the high-density lipoprotein (HDL) fraction. For patients with hyperbetalipoproteinemia, serum dolichol was also associated with the medium HDL fractions. However, for hyperalphalipoproteinemia patients the levels of large HDL and serum dolichol were increased, and serum dolichol was mainly associated with the large HDL fraction. On laboratory tests of components, the dolichol level was not correlated with the values for markers of the liver and biliary system, with the values of renal function markers, with creatine kinase activity, amylase activity or uric acid concentration, but was correlated with total cholesterol, HDL-cholesterol and apoA-I concentrations, and with lactate dehydrogenase (LDH) activity. These results suggest that serum dolichol exclusively localized in HDL, and in subpopulation, that in normocholesterolemia or hyperbeta-cholesterolemia is associated with HDL(3), which is small sized and high density HDL, however, that in hyperalphacholesterolemia is associated with HDL(2), which is large sized and lower density HDL.

Circulating levels of ganglioside GM3 in metabolic syndrome: A pilot study.

BACKGROUND: Insulin resistance is a characteristic feature of metabolic syndrome. Ganglioside GM3 [α-Neu5Ac-(2-3)-ß-Gal-(1-4)-ß-Glc-(1-1)-ceramide] may impair insulin sensitivity in adipose tissue. We investigated the relationship between serum GM3 levels and adiposity indices, as well as between serum GM3 levels and metabolic risk variables. METHODS: Study 1: we assessed serum GM3 levels in normal subjects and in patients with hyperglycemia and/or hyperlipidemia (HL). Study 2: we investigated the relationship between serum GM3 levels and metabolic risk variables in patients with type 2 diabetes. RESULTS: Study 1: serum GM3 levels were higher in hyperglycemic patients (1.4-fold), hyperlipidemic patients (1.4-fold) and hyperglycemic patients with hyperlipidemia (1.6-fold), than in normal subjects. Study 2: serum GM3 levels were significantly increased in type 2 diabetic patients with severe obesity (visceral fat area (VFA) >200 cm(2), BMI > 30). The GM3 level was positively correlated with LDL-c (0.403, p = 0.012) in type 2 diabetes mellitus, but not affected by blood pressure. In addition, the high levels of small dense LDL (>10 mg/dL) were associated with the elevation of GM3. CONCLUSIONS: Serum GM3 levels was affected by glucose and lipid metabolism abnormalities and by visceral obesity. GM3 may be a useful marker for severity of metabolic syndrome.

Bromocriptine-responsive Cushing's disease; clinical and biochemical remission accompanied by amelioration of impaired ocular movement.

A 73-year-old woman presented with disturbance of right eyelid opening with ptosis and impairment of right ocular movement, and later was found to have Cushingoid features. Endocrine examinations revealed that plasma ACTH and cortisol levels were elevated, lack of circadian rhythm, resistant to low-doses (0.5, 1, 2 mg) and high-dose (8 mg) dexamethasone, and responsive to CRH and DDAVP. Magnetic resonance imaging (MRI) revealed a large pituitary tumor invading the right cavernous sinus. After two months treated with bromocriptine (5 mg/day), she showed clinical improvement with normalization of plasma ACTH and cortisol levels, and improvement of right eyelid opening and ocular movement. MRI, however, revealed no apparent reduction in the size of pituitary tumor. This is a rare case of bromocriptine-responsive Cushing's disease.

Gentisic acid, an aspirin metabolite, inhibits oxidation of low-density lipoprotein and the formation of cholesterol ester hydroperoxides in human plasma.

Gentisic acid, an aspirin metabolite, has an antioxidant effect, although its detailed mechanism remains elusive. The present study was designed to determine whether it inhibits low-density lipoprotein (LDL) oxidation and the formation of lipid hydroperoxides in human plasma. The susceptibility of LDL oxidative modification was investigated by a method using 2,2'-azobis or Cu2+. To study the effect of gentisic acid on free radical-induced damage to plasma lipids, cholesterol ester hydroperoxides generated by incubating human fresh plasma with Cu2+ and gentisic acid was analyzed. Gentisic acid inhibited LDL oxidation in a concentration-dependent manner. It significantly inhibited the formation of cholesterol ester hydroperoxides in plasma, and was consumed after the depletion of ascorbic acid and reduced form of coenzyme Q-10 (CoQH2-10), whereas concentrations of other antioxidants remained unchanged. Gentisic acid had a potent free radical scavenging activity with a minimal chelating effect. The potent antioxidant property of gentisic acid may partly account for the anti-atherogenic effects of aspirin.

Enhanced susceptibility of LDL to oxidative modification in a CTX patient:- role of chenodeoxycholic acid in xanthoma formation.

Cerebrotendinous xanthomatosis (CTX) is a rare familial sterol storage disease, causing multiple xanthomas in tendons and the brain. The underlying biochemical defect is a lack of the hepatic mitochondrial cholesterol 27-hydroxylase involved in the normal biosynthesis of bile acid, resulting in reduced biosynthesis of chenodeoxycholic acid (CDCA). It has been reported that administration of CDCA to CTX patients improves neurological disorders and xanthomas of the Achilles tendon. The present study investigated the effect of CDCA on the mechanism of cholesterol accumulation in macrophages, the major cells in xanthoma. The LDL from the patients in this study was significantly more susceptible to oxidative modification than normal LDL, and supplement therapy with CDCA resulted in an improvement in the susceptibility to oxidative modification. In the incubation of CDCA with plasma, 13% of the CDCA added to serum was recovered in the LDL fraction. In addition, supplementation with CDCA enhanced cholesteryl ester transfer protein (CETP) activity and reduced high-density-lipoprotein cholesterol levels in the plasma. This evidence suggests that the multiple xanthomas observed in CTX may be induced by increased oxidized LDL and the low activity of CETP, both of which are caused by a lack of CDCA.

Modulation of HDL metabolism by probucol in complete cholesteryl ester transfer protein deficiency.

Probucol, an antioxidative and hypolipidemic agent, has been postulated to increase reverse cholesterol transport by enhancing cholesteryl ester transfer protein (CETP) activity. However, its clinical implication in CETP deficient patients has not been fully defined. To characterize the effects of probucol in the absence of CETP, we evaluated the changes in lipid profile, lipid peroxidation, and paraoxonase 1 (PON1) activity in two complete CETP deficient patients, caused by treatment with probucol. When the patients were not receiving probucol, low-density lipoprotein (LDL) particles were smaller and high-density lipoprotein (HDL) particles were larger in these patients than in controls. Treatment with probucol (500 mg/day) resulted in the decrease in the levels of HDL-C and apolipoprotein (apo) A-I up to 22%. The size of HDL particles became smaller. LDL cholesterol concentration did not change in one patient, while it decreased by 47% in the other. PON1 activity/HDL-C, which was about 40% lower in the patients before treatment than in controls with the matching PON1 genotype, increased by 30% during the treatment. Lag time for LDL and HDL in both cases became prolonged more than 1.8 times after administration of probucol. This study demonstrated for the first time that probucol reduces HDL-C even in humans with complete CETP deficiency. Probucol treatment in these patients was also associated with protection of lipoproteins against oxidative stress, suggesting a clinical benefit of this drug even in such a state.

Nickel(0)-mediated sequential addition of carbon dioxide and aryl aldehydes into terminal allenes.

[reaction: see text] Nickel-mediated sequential addition of carbon dioxide and aryl aldehydes into terminal allenes is reported. The reaction proceeded in a diastereoselective manner to afford alpha-methylene-gamma-hydroxy carboxylic acids, which allowed stereoselective preparation of cis-beta, gamma-disubstituted alpha-methylene-gamma-lactones.

Ascorbic acid augments cytotoxicity induced by oxidized low-density lipoprotein.

Although ascorbic acid (ASA) is known as a water-soluble antioxidant, we found that it accelerated the cytotoxicity induced by oxidized low-density lipoprotein (OxLDL) in vitro. This suggests that ASA may enhance the oxidation of LDL to augment the atherogenic activities of OxLDL under certain conditions. Thus, this study was designed to investigate the underlying mechanism that ASA enhances OxLDL-induced cytotoxicity. ASA enhanced the cytotoxicity of macrophage cell line (J774) induced by OxLDL in a dose-dependent manner, whose effect was more apparent in high glucose concentration in the medium. The ASA-induced enhancement in cytotoxicity was inhibited by the presence of lipid-soluble antioxidants, such as alpha-tocopherol and probucol, suggesting that the pro-cytotoxic effect by ASA is likely due to its pro-oxidant property. We also investigated the effects of ASA at different time points on the Cu2+-mediated oxidation of LDL. ASA decreased the rate of conjugated dienes formation when added at the early phase of oxidation, whereas it increased when added at the late phase of oxidation. These data suggest that ASA may act as a pro-oxidant under the condition of extensive LDL oxidation. To prevent oxidation stress, ASA would be better used together with lipid-soluble antioxidants for antioxidant therapies.

Human plasma platelet-activating factor acetylhydrolase binds to all the murine lipoproteins, conferring protection against oxidative stress.

OBJECTIVE: Plasma platelet-activating factor (PAF) acetylhydrolase (AH) is an enzyme bound with lipoproteins that degrades not only PAF but also PAF-like oxidized phospholipids that are proposed to promote atherosclerosis. In this study, we investigated the distribution of PAF-AH protein among lipoprotein classes by using adenovirus-mediated gene transfer in mice, and we examined its effects on lipoprotein oxidation and foam cell formation of macrophages. METHODS AND RESULTS: Adenovirus-mediated overexpression of PAF-AH in mice resulted in a 76- to 140-fold increase in plasma PAF-AH activity. Contrary to the previous report, overexpressed human PAF-AH protein was bound to very low density lipoprotein, intermediate density lipoprotein, low density lipoprotein, and high density lipoprotein (HDL). All the lipoproteins with overexpressed human PAF-AH revealed more resistance against oxidative stress, which was associated with lower levels in autoantibody against oxidized low density lipoprotein in the plasma. In addition, HDL with human PAF-AH inhibited foam cell formation and facilitated cholesterol efflux in macrophages. CONCLUSIONS: These results suggest that human plasma PAF-AH exerts an antiatherogenic effect by binding to all the lipoproteins and thereby protecting them from oxidation, producing less proatherogenic lipoproteins and preserving HDL functions.

Apolipoprotein A-I deficiency with accumulated risk for CHD but no symptoms of CHD.

We evaluated a 69-year-old Japanese woman with apolipoprotein (apo) A-I deficiency, high levels of low-density lipoprotein (LDL)-cholesterol, hypertension and impaired glucose tolerance. The patient had corneal opacity, but neither xanthomas, xanthelasma, nor tonsillar hypertrophy. She was not symptomatic for coronary heart disease (CHD), and had normal electrocardiograms at rest and exercise using a cycle ergometer. She had severely reduced levels of high-density lipoprotein (HDL)-cholesterol (0.10-0.18 mmol/l) and no apo A-I (<0.6 mg/dl). LDL-cholesterol and apo B as well as apo E were increased even under treatment with 10 mg pravastatin per day. Gel filtration chromatography revealed that in addition to VLDL and LDL fractions, she had apo A-II rich and apo E rich fractions, which were present in the HDL fraction separated by ultracentrifugation. A cytosine deletion was identified by genomic DNA sequencing of the apo A-I gene of the patient at the third base of codon 184 in the fourth exon, which led to a frame shift mutation and early termination at codon 200. This patient is the oldest among those with apo A-I deficiency reported in the literature, and she had no symptoms of CHD despite the accumulated risk for the disease.