[Differences in Measured Values among Homogenous Assay Reagents of LDL-C in LP-X Positive Serum Samples].

The LDL-C level measures with homogeneous (direct) assays in almost of clinical laboratories. Several reports however showed differences in measured values among the assay reagents. We investigated the differences in LDL-C values among direct assays and Friedewald formula (F-f) in 58 LP-X positive serum samples from jaundice patients by comparing LDL-C values measured by anion-exchange chromatography (AEX-HPLC), largely comparable to ultracentrifugation method. Changes in LDL-C values during the treatment of 8 patients were also investigated. Direct assay reagents from Sekisui Medical (S-r), Denka-Seiken (D-r), Wako Chemical (W-r), and Kyowa Medics (K-r) were used for comparison. F-f, S-r, and D-r correlated with AEX-HPLC with r values < 0.6 while W-r and K-r correlated with AEX-HPLC with r-vales > 0.6. Two samples in which F-f values provided 500 mg/dL plus bias to AEX-HPLC (LDL-C value of 220 mg/dL) demonstrated increased levels of IDL-C before treatment. LDL-C values (S-r and D-r) of the 2 samples were relatively high and near to F-f data while LDL-C values (W-r and K-r) were relatively low and close to AEX-HPLC data. The jaundice treatment decreased LDL-C values (S-r and D-r) and converged to 220 mg/dL, indicating that S-r and D-r might react markedly to IDL. These changes were consistent with decreases in serum free cholesterol and phospholipid in support of LP-X. By contrast, W-r and K-r data showed upward tendency and also converged to 220 mg/dL. These results suggest that LDL-C direct assay reagents would be classified into 2 groups with respect to the reagent reactivity to LP-X.

Clinical Significance of Intermediate-Density Lipoprotein Cholesterol Determination as a Predictor for Coronary Heart Disease Risk in Middle-Aged Men.

Background: Not only low-density lipoprotein (LDL) cholesterol but also non-high-density lipoprotein cholesterol (non-HDL-C), very low-density lipoprotein (VLDL) cholesterol (VLDL-C), and intermediate-density lipoprotein (IDL) cholesterol (IDL-C) are reported to be significant risk markers for coronary heart disease (CHD). We reported the relevance of IDL-C to Framingham risk score (F-score), but the present study addressed the relevance of IDL-C to Suita score (S-score), a risk score for coronary heart disease (CHD) developed for the Japanese individuals in addition to F-score. Methods: The cholesterol levels of lipoproteins, including triglyceride (TG)-rich lipoproteins (IDL and VLDL), were measured by an anion exchange high-performance liquid chromatography (AEX-HPLC). This study enrolled 476 men, aged mean 51 years and free of CHD and stroke. Results: Non-HDL-C, IDL-C, and VLDL-C significantly correlated with F-score and S-score. In the multiple stepwise regression analysis, IDL-C as well as body mass index (BMI) significantly correlated with both F-score and S-score in both the total subjects and the subjects without drug therapy. The multivariate logistic analysis with the model composed of BMI and IDL-C as the predictor variables demonstrated that 1 SD increase in IDL-C was an independent predictor for 10-year CHD risk >10% of F-score (OR 1.534, 95% CI 1.266-1.859, p < 0001) and that of S-score (OR 1.372, 95% CI 1.130-1.667, p = 0.0014) in the total subjects. Even in the subjects without the drug therapy, the increased IDL-C, as well as BMI, were significant predictors for 10-year CHD risk >10% of S-score as well as F-score. Conclusion: These results suggest the significant relevance of the increased IDL-C for CHD risk scores in middle-aged men free of CHD and stroke. Further investigations are needed in women and elderly subjects.

Probiotic Bifidobacterium breve in Improving Cognitive Functions of Older Adults with Suspected Mild Cognitive Impairment: A Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Probiotics use has been associated with modulation of inflammation and considered as a possible intervention for CNS diseases such as mild cognitive impairment (MCI) and dementia. OBJECTIVE: We aimed to test the effect of the probiotic strain, Bifidobacterium breve A1 (MCC1274), to restore cognition in a physically healthy, suspected MCI population. METHODS: In this randomized, double-blind, placebo-controlled trial, 80 healthy older adults suffering from MCI were divided into two even groups to receive once daily either probiotic (B. breve A1, 2×1010 CFU) or placebo for 16 weeks using a computer-generated algorithm. Cognitive functions were assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and the Japanese version of the MCI Screen (JMCIS) tests before and after the study as primary and secondary endpoints, respectively. RESULTS: 79 participants completed the study, and no adverse events were observed. RBANS total score was significantly improved in probiotic group compared with placebo (mean between-group difference 11.3 [95% CI 6.7 to 15.8]; p < 0.0001) after 16 weeks of consumption, in particular with significant improvement in domain scores of immediate memory, visuospatial/constructional, and delayed memory (p < 0.0001), in both intention-to-treat (ITT) analysis and per-protocol (PP) analysis. JMCIS score was also improved versus placebo in ITT analysis (p = 0.052) and PP analysis (p = 0.036). CONCLUSION: Study results indicate B. breve A1 is a safe and effective approach for improving memory functions of suspected MCI subjects.

Reference Intervals of Serum Non-Cholesterol Sterols by Gender in Healthy Japanese Individuals.

AIMS: The present study was conducted to establish a practical method for measuring non-cholesterol sterols and reference intervals of serum levels. METHODS: Healthy subjects (109 men and 151 women), four patients with sitosterolemia, and 10 heterozygous mutation carriers of ABCG5/ABCG8 genes were investigated. Then, three non-cholesterol sterols (sitosterol, campesterol, and lathosterol) of fasting serum samples were measured via a practical and highly sensitive gas chromatography (GC) method with 0.2 µg/mL as the lower limit of quantification. The coefficient of variation (CV) values for within-run reproducibility were 3.06%, 1.89%, and 1.77% for lathosterol, campesterol, and sitosterol, respectively. The CV values for between-run reproducibility were 2.81%, 2.06%, and 2.10% for lathosterol, campesterol, and sitosterol, respectively. RESULTS: The serum levels of sitosterol and campesterol were significantly higher in women than in men, whereas the serum levels of lathosterol were significantly higher in men than in women. Because of these gender difference, the determination of reference intervals of the three sterol values was performed by considering gender. The reference intervals of sitosterol, campesterol, and lathosterol were 0.99-3.88, 2.14-7.43, and 0.77-3.60 µg/mL in men and 1.03-4.45, 2.19-8.34, and 0.64-2.78 µg/mL in women, respectively. The serum levels of sitosterol and campesterol were higher in patients with sitosterolemia (94.3±47.3 and 66.3±36.6 µg/mL, respectively) than in healthy subjects. CONCLUSION: These results demonstrate a practical and highly sensitive GC method to measure non-cholesterol sterol levels and gender-segregated reference intervals of sitosterol, campesterol, and lathosterol in Japanese healthy subjects.

Amount of Collagen in the Meat Contained in Japanese Daily Dishes and the Collagen Peptide Content in Human Blood after Ingestion of Cooked Fish Meat.

Objectives of the present study were to evaluate amounts of collagen in Japanese daily dishes and contents of food-derived collagen peptides in human blood. The meat in one serving of most Japanese daily dishes contains 0.2-2.5 g of collagen, except for beef tendon, eel with skin, and skinned shark tail (7.6-13.3 g). After ingestion of cooked shark meat, nine collagen di- and tripeptides were detected in plasma and the area under the curve of most peptides, except for Hyp-Gly and Pro-Hyp-Gly, was ∼30% of that after ingestion of collagen hydrolysate containing an equivalent amount of collagen. Likewise, only ∼30% of the total collagen in the meat was liberated into solution by pepsin and pancreatin digestion. Thus, ingestion of collagen-rich meat increases the collagen peptides in blood, which depends on not only the collagen content in the meat but also the susceptibility of the collagen/gelatin to digestive endoproteinases.

The underlying mechanisms for development of hypertension in the metabolic syndrome.

High blood pressure is an important constituent of the metabolic syndrome. However, the underlying mechanisms for development of hypertension in the metabolic syndrome are very complicated and remain still obscure. Visceral/central obesity, insulin resistance, sympathetic overactivity, oxidative stress, endothelial dysfunction, activated renin-angiotensin system, increased inflammatory mediators, and obstructive sleep apnea have been suggested to be possible factors to develop hypertension in the metabolic syndrome. Here, we will discuss how these factors influence on development of hypertension in the metabolic syndrome.

Characteristic comparison of triglyceride-rich remnant lipoprotein measurement between a new homogenous assay (RemL-C) and a conventional immunoseparation method (RLP-C).

BACKGROUND: Increased serum remnant lipoproteins are supposed to predict cardiovascular disease in addition to increased LDL. A new homogenous assay for remnant lipoprotein-cholesterol (RemL-C) has been developed as an alternative to remnant-like particle-cholesterol (RLP-C), an immunoseparation assay, widely used for the measurement of remnant lipoprotein cholesterol. METHODS: We evaluated the correlations and data validation between the 2 assays in 83 subjects (49 men and 34 women) without diabetes, hypertension and medications for hyperlipidemia, diabetes, and hypertension, and investigated the characteristics of remnant lipoproteins obtained by the two methods (RLP-C and RemL-C) and their relationships with IDL-cholesterol determined by our developed HPLC method. RESULTS: A positive correlation was significantly found between the two methods (r = 0.853, 95%CI 0.781-0.903, p < 0.0001). Bland & Altman analysis revealed that RemL-C values were likely to be significantly higher than RLP-C values, particularly in samples with high levels of remnant lipoproteins. Several data dissociations between the RemL-C and RLP-C were also observed. The HPLC chromatograms show high concentrations of chylomicron cholesterol in serum samples with RemL-C level < RLP-C level, but high concentrations of IDL-cholesterol in samples with RemL-C level > RLP-C level. RemL-C (r = 0.339, 95%CI 0.152-0.903; p = 0.0005) significantly correlated with IDL-cholesterol, but not RLP-C (r = 0.17, 95%CI -0.047-0.372; p = 0.1237) in all the samples (n = 83). CONCLUSION: These results suggest that there is generally a significant correlation between RemL-C and RLP-C. However, RemL-C assay is likely to reflect IDL more closely than RLP-C.

Diacylglycerol oil for the metabolic syndrome.

Excess adiposity has been shown to play a crucial role in the development of the metabolic syndrome. The elevated fasting and postprandial triglyceride-rich lipoprotein levels is the central lipid abnormality observed in the metabolic syndrome. Recent studies have indicated that diacylglycerol (DAG) is effective for fasting and postprandial hyperlipidemia and preventing excess adiposity by increasing postprandial energy expenditure. We will here discuss the mechanisms of DAG-mediated improvements in hyperlipidemia and in postprandial energy expenditure, and effects of DAG oil on lipid/glucose metabolism and on body fat. Further, the therapeutic application of DAG for the metabolic syndrome will be considered.

Evaluation of the effect of salmon nasal proteoglycan on biomarkers for cartilage metabolism in individuals with knee joint discomfort: A randomized double-blind placebo-controlled clinical study.

A randomized double-blind placebo-controlled clinical trial was conducted to evaluate the chondroprotective action of salmon nasal cartilage proteoglycan on joint health. The effect of oral administration of proteoglycan (10 mg/day) on cartilage metabolism was evaluated in individuals with knee joint discomfort but without diagnosis of knee osteoarthritis. The average age of patients was 52.6±1.1 years old. The effect of proteoglycan was evaluated by analyzing markers for type II collagen degradation (C1,2C) and synthesis (PIICP), and the ratio of type II collagen degradation to synthesis. The results indicated that the change in C1,2C levels significantly differed in the proteoglycan group compared with the placebo group following 16 weeks intervention among subjects with high levels of knee pain and physical dysfunction (total score of Japan Knee Osteoarthritis Measure ≥41) and subjects with constant knee pain (both P<0.05). There was a greater increase in PIICP levels in the proteoglycan group than the placebo group following intervention, although this difference was not significant in both sets of patients. Thus, the C1,2C/PIICP ratios decreased in the proteoglycan group, whereas they slightly increased in the placebo group following the intervention. Furthermore, no test supplement-related adverse events were observed during the intervention. Therefore, oral administration of salmon nasal cartilage proteoglycan at a dose of 10 mg/day may exert a chondroprotective action in subjects with knee joint discomfort. This effect was achieved by improving cartilage metabolism (reducing type II collagen degradation and enhancing type II collagen synthesis), without causing apparent adverse effects.

Effects of pitavastatin and atorvastatin on lipoprotein oxidation biomarkers in patients with dyslipidemia.

OBJECTIVE: The effects of potent statins on oxidized lipoprotein biomarkers are not well defined. METHODS AND RESULTS: The VISION (Value of oxIdant lipid lowering effect by Statin InterventiON in hypercholesterolemia) Trial randomized patients with hypercholesterolemia to 12-week administration of pitavastatin 2 mg/day (n = 21) or atorvastatin 10 mg/day (n = 21) and a variety of lipoprotein oxidative biomarkers were measured. Between-group analysis did not reveal any differences except in the ratio of malondialdehyde (MDA)-LDL over apolipoprotein B-100 (MDA-LDL/apoB) in pitavastatin vs. atorvastatin group (-13% vs. -0.7%, p = 0.04). Within-group changes from baseline to 12-week revealed significant increases in OxPL/apoB and reductions in small-dense LDL, MDA-LDL, and lipoprotein-associated phospholipase A(2) measured on circulating apoB particles (Lp-PLA(2)/apoB) in both groups and significant reductions in OxPL/apoAI in the atorvastatin group. CONCLUSIONS: The VISION study describes the first comparison on lipoprotein oxidation biomarkers between pitavastatin and atorvastatin and suggests diverse effects on lipoprotein oxidation markers in patients with hypercholesterolemia.

Relevance of intermediate-density lipoprotein cholesterol to Framingham risk score of coronary heart disease in middle-aged men with increased non-HDL cholesterol.

BACKGROUND: Cholesterol levels of non-high-density lipoprotein (non-HDL), which contains low-density lipoprotein (LDL), intermediate-density lipoprotein (IDL), very low-density lipoprotein (VLDL) and chylomicron (CM) remnant, have been proven to perform a significant predictor of coronary heart disease (CHD) better than LDL-cholesterol regardless of triglyceride (TG) levels. The present study investigated the relevance of TG-rich lipoproteins (IDL, VLDL, CM) to Framingham risk score (FRS) predictive of 10-year CHD risk. METHODS: Lipoprotein profiles (cholesterol levels of HDL, LDL, IDL, VLDL, CM) in Japanese men (n = 487) who underwent medical check-up were determined by using our developed anion-exchange high performance liquid chromatography (AEX-HPLC). Total-cholesterol (TC), TG, fasting blood sugar (FBS) and hemoglobin (Hb) A1c were measured by routine methods. The lipoprotein profiles, non-HDL-cholesterol, TC, and TG were examined on these associations with FRS. RESULTS: The lipid levels except for CM-cholesterol were significantly different between two groups (low FRS, < 10%; high FRS, ≥10%) (P < 0.0001), and body mass index (BMI), TC, TG, IDL-, and VLDL-cholesterol were significantly and positively correlated with FRS. Among them, the significant association of non-HDL-cholesterol to FRS was noted (r = 0.411, P < 0.0001). Multiple stepwise regression analysis shows that, in addition to non-HDL-cholesterol, IDL-cholesterol in TG-rich lipoproteins was significantly correlated with FRS in independently of BMI. These correlation results were similarly found even when the part of the study subjects (n = 348) without the drug therapy for hyperlipidemia, diabetes, and hypertension was investigated. CONCLUSIONS: These results suggest that IDL-cholesterol may serve as a useful marker for CHD risk in Japanese men with increased non-HDL-cholesterol.

Estimation of lipoprotein profile in patients with type II diabetes and its relevance to remnant lipoprotein cholesterol levels.

BACKGROUND: Remnant lipoprotein (RLP), associated with atherosclerosis progression, is often elevated in diabetes mellitus. The RLP level is estimated by immune-separation method and agarose-gel electrophoresis (AGE). METHODS: The patients were grouped into three groups according to tertile of RLP-cholesterol (RLP-C) levels. The lipoprotein profiles of type II diabetic patients (T2DM) (n=194) were measured by an anion-exchange liquid chromatography (AEX-HPLC) and an AGE with lipid-staining or cholesterol-staining. RESULTS: IDL- and VLDL-cholesterol by the AEX-HPLC, and VLDL-levels by the AGE with lipid-staining and with cholesterol-staining were significantly different in the three groups. In all the subjects, IDL-cholesterol (r=0.531) and VLDL-cholesterol (r=0.880) by the AEX-HPLC method were strongly correlated with RLP-C, but only VLDL levels were correlated with RLP-C in AGE, respectively. CONCLUSION: These results suggest that the AEX-HPLC, which can provide cholesterol levels of not only VLDL but also IDL, is helpful for estimation of lipid profiles in T2DM with high RLP-C.

Administration of natural astaxanthin increases serum HDL-cholesterol and adiponectin in subjects with mild hyperlipidemia.

BACKGROUND: Astaxanthin has been reported to improve dyslipidemia and metabolic syndrome in animals, but such effects in humans are not well known. METHODS: Placebo-controlled astaxanthin administration at doses of 0, 6, 12, 18 mg/day for 12 weeks was randomly allocated to 61 non-obese subjects with fasting serum triglyceride of 120-200mg/dl and without diabetes and hypertension, aged 25-60 years. RESULTS: In before and after tests, body mass index (BMI) and LDL-cholesterol were unaffected at all doses, however, triglyceride decreased, while HDL-cholesterol increased significantly. Multiple comparison tests showed that 12 and 18 mg/day doses significantly reduced triglyceride, and 6 and 12 mg doses significantly increased HDL-cholesterol. Serum adiponectin was increased by astaxanthin (12 and 18 mg/day), and changes of adiponectin correlated positively with HDL-cholesterol changes independent of age and BMI. CONCLUSIONS: This first-ever randomized, placebo-controlled human study suggests that astaxanthin consumption ameliorates triglyceride and HDL-cholesterol in correlation with increased adiponectin in humans.

Effects of supervised aerobic exercise training on serum adiponectin and parameters of lipid and glucose metabolism in subjects with moderate dyslipidemia.

AIM: To examine the effects of supervised aerobic exercise training on serum adiponectin and lipids, including triglyceride (TG)-rich lipoproteins, in moderate dyslipidemic subjects. METHODS: Twenty-five dyslipidemic patients [mean body mass index (BMI)=24.6 kg/m²; mean age= 39 years; mean total cholesterol=226 mg/dL; mean TG=149 mg/dL] without metabolic syndrome, diabetes, and hypertension underwent supervised aerobic exercise training (60 min/day, 2 to 3 times/week) at an intensity of 60-80% of age-predicted maximal heart rate for 16 weeks. Lipoprotein cholesterol levels were measured by our established anion-exchange HPLC method. RESULTS: Aerobic exercise training significantly decreased BMI, cholesterol levels of LDL- and IDL-, and markedly reduced VLDL-cholesterol at week 8 (-45%) and week 16 (-50%), but changes in TG and HDL-cholesterol were not significant. Adiponectin significantly increased by 51% and HOMA-R was significantly decreased at week 16, although changes in these parameters were not significant at week 8. There was no significant relationship between changes in adiponectin and in VLDL- or IDL- cholesterol, but changes in adiponectin were inversely but insignificantly associated with changes in BMI (r=-0.343, p=0.095). CONCLUSIONS: These results suggest that supervised aerobic exercise training two to three times/week in the presence of body weight loss increases serum adiponectin with an improved lipid profile and insulin sensitivity at week 16 in non-obese moderate dyslipidemic patients, and that VLDL-cholesterol is markedly decreased by supervised aerobic exercise training.

A molecular mechanism for diacylglycerol-mediated promotion of negative caloric balance.

AIMS: A substitution of diacylglycerol (DAG) oil for triacylglycerol (TAG) oil in diet has been reported to reduce body fat and body weight, possibly by increasing postprandial energy expenditure (EE). We have previously studied plasma serotonin, which increases EE and exists in the small intestine, in individuals who ingested TAG and DAG oil, and found that DAG ingestion elevates plasma serotonin levels by about 50% compared with TAG ingestion. We studied the molecular mechanisms for DAG-mediated increase in serotonin and EE. METHODS: We studied effects of 1-monoacylglycerol and 2-monoacylglycerol, distinct digestive products of DAG and TAG, respectively, on serotonin release from the Caco-2 cells (the human intestinal cell line, n = 8). Further, we studied effects of 1- and 2-monoacylglycerol, and serotonin on expression of mRNA associated with ß-oxidation, FA metabolism, and thermogenesis, in the Caco-2 cells (n = 5). RESULTS: 1-monoacylglycerol (100 µM 1-monooleyl glycerol [1-MOG]) significantly increased serotonin release from the Caco-2 cells compared with 2-monoacylglycerol (100 µM 2-MOG) by 36.6%. Expression of mRNA of acyl-CoA oxidase (ACO), fatty acid translocase (FAT), and uncoupling protein-2 (UCP-2) were significantly higher in 100 µM 1-MOG-treated Caco-2 cells than 100 µM 2-MOG-treated cells by 12.8%, 23.7%, and 35.1%, respectively. Further, expression of mRNA of ACO, medium-chain acyl-CoA dehydrogenase, FAT, and UCP-2 were significantly elevated in serotonin (400 nM)-treated Caco-2 cells compared with cells incubated without serotonin by 28.7%, 30.1%, and 39.2%, respectively. CONCLUSIONS: Our study demonstrated that 1-monoacylglycerol, a digestive product of DAG, increases serotonin release from the Caco-2 cells, and enhances expression of genes associated with ß-oxidation, FA metabolism, and thermogenesis, and that serotonin increases expression of these genes, proposing a novel molecular mechanism for DAG-mediated promotion of negative caloric balance.

Antihypertensive effects of astaxanthin.

Astaxanthin is a biological antioxidant naturally found in a wide variety of aquatic living organisms, and has shown various pharmacological activities, such as anti-inflammatory and antidiabetic activities. A recent study reported that the administration of astaxanthin induced a significant reduction in blood pressure and delayed the incidence of stroke in stroke-prone spontaneously hypertensive rats, suggesting that astaxanthin also has antihypertensive effect. In a study using aortic rings of spontaneously hypertensive rats, astaxanthin induced a significant reduction of the contractile responses of the aorta to α-adrenergic receptor agonist and angiotensin II, which may contribute to the antihypertensive effect of astaxanthin. In a histopathological study, astaxanthin decreased coronary artery wall thickness compared with the control, indicating the possibility that astaxanthin ameliorates hypertension-induced vascular remodeling. Astaxanthin has anti-inflammatory, antidiabetic, antihypertensive, and antioxidative activities; therefore, we should perform further studies to elucidate an antiatherogenic effect of astaxanthin.