The apolipoprotein B/A-1 ratio in practically healthy participants with normolipidemia / Монголын Анагаах Ухаан

Introduction@#Studies demonstrated that the apolipoprotein B/apolipoprotein A-I (Apo B/apo A-I) ratio predicts cardiovascular risk better than any of the cholesterol indexes. Apo B and Apo A-1 are assumed to be superiormarkers for lipoprotein abnormalities [1,2]. The concentrations of Apo B and Apo A-1 are associated with cardiovascular disease more strongly than the corresponding lipoprotein cholesterol fractions, the discriminant value of these apoproteins in absolute terms appears to be less important than of their ratio (the Apo B/Apo A-1 ratio) [3, 5-7]. The Apo B/Apo A-1 ratio reflects the balance of atherogenic and antiatherogenic lipoproteins in plasma [4]. Multiple clinical and epidemiological studies have confirmed that the Apo B/Apo A-1 ratio is a superior marker for cardiovascular disease compared with lipids and lipoproteins or their ratios [8, 9].@*Goal@#We determined the variation limits of the Apo B/Apo A-1 ratio in healthy participants with normolipidemia and the relationship of this ratio with other lipid parameters.@*Material and Methods@#A total of 146 normolipidemic healthy participants aged 25–60 years were included in the study. Anthropometric measurements (height and weight) and other personal information were obtained during the clinical examination and the interview. Participants were included in the study using the following criteria: </br>1. body mass index < 30 kg/m2; </br> </br>2. TC < 5.2mmol/L; </br>3. triglycerides (TG) ≤1.7 mmol/L; </br>4. HDL-C ≥1.03 mmol/L ( woman), ≥ 1.29 mmol/L (male) . </br>The plasma levels of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), apo A-I, Apo B and Apo B/Apo A-1 were determined after a 12 h fasting period. The non-HDL-C was calculated as the difference between the TC and HDL-C. Most research data emphasized that the values for the Apo B/Apo A-1 ratio that define a high cardiovascular risk were proposed to be 0.9 for men and 0.8 for women. Statistical Analysis. The statistical analysis was performed using SPSS 21.0 (USA). Differences between the groups were analyzed using the Mann-Whitney test and the chi-squared test. Correlations between the indices were assessed using the Spearman’s rank correlation. A value of < 0.05 was accepted as statistically significant.@*Results@#The relationship of ratio of apolipoprotein (Apo) B/Apo A-1 with other indicators of lipid metabolism in healthy people with normal lipidemia was analyzed. The Apo B/Apo A-1 ratio in the studied normolipidemic subjects was 0.69 ± 0.17. The percentage of subjects with the Apo B/Apo A-1 ratio exceeding 0.9 (the accepted risk value of cardiovascular disease) was 36.3 %.The subjects with Apo B/Apo A-1>0.9 were characterized by higher HDL-C levels and atherogenic Aпo B, Apo B/Apo A-1 but lower values Apo A-1.@*Conclusion@#The subjects with normolipidemia the unfavorable Apo B/Apo A-I ratio> 0.9 had more atherogenic lipid profile.

Correlation of Apo-A and Apo-B/Apo-A ratio with the degree of coronary artery stenosis in patients with coronary heart disease / 西安交通大学学报(医学版)

Objective: To investigate the correlation of Apo-A and Apo-B/Apo-A ratio with the degree of coronary artery stenosis (CHD) in patients with coronary heart disease. Methods: Totally 234 patients with coronary heart disease examined with coronary angiography were collected. We collected blood lipid and calculated blood lipid ratio, such as non-HDL-C, TG/HDL-C, TC/HDL-C, LDL-C/HDL-C, and Apo-B/Apo-A. Gensini score was calculated according to the result of CAG. We analyzed the correlation between the blood lipid indicators and the Gensini score with the Spearman correlation analysis. Linear regression analysis was made of the correlation between those meaningful indicators and the Gensini score. Results: There were no significant differences in age, hypertension, diabetes or smoking index between all Gensini score groups. The illness course in middle-score group was longer than that in low-score group and high-score group (P=0.023, P=0.002). There was a significant difference in Apo-A between the groups (P=0.009, P<0.001, P=0.013). The levels of TC, Apo-B and LPα in high-score group were lower than those in low-score group (P=0.008, P=0.001, P=0.002). The levels of HDL-C and Apo-B/Apo-A ratio in both middle-score and high-score group were lower than those in low-score group (P=0.008, P=0.001). The Spearman correlation analysis between various risk factors and Gensini score found that HDL-C and Apo-A had negative correlation with Gensini score (r=-0.166, r=-0.294), the ratios of LDL-C/HDL-C and Apo-B/Apo-A were positively correlated with Gensini score (r=0.159, r=0.170). By multi-factor linear regression, Apo-A was negatively related with Gensini score (β=-62.249), and Apo-B/Apo-A ratio was positively associated with Gensini score (β =31.311). Conclusion: Apo-A and Apo-B/Apo-A ratios are the independent risk factors for the stenosis degree of coronary artery in patients with CHD. They are reliable predictors for the risk of CHD.

Assessment of Apo-B and TG/HDL-C Ratio as Indicators of Insulin Resistance in Patients with Metabolic Syndrome

The aim of the present study was to assess Apolipoprotein B (Apo-B) and Triglyceride/High Density Lipoprotein Cholesterol (TG/HDL-C) ratio as indicators of insulin resistance (IR) with Homeostasis Model of assessment of insulin resistance (HOMA IR)) in metabolic syndrome patients . Study Design: Observational and prospective. Place and Duration of Study: The study was carried out in Department of Biochemistry and Department of Medicine, MGM Medical College, Navi-Mumbai from March 2012 to June 2013. Methodology: Total 110 normal subjects and patients were recruited in the study after obtaining informed written consent. They were divided in to two groups. Group I was healthy controls (n=50) and Group II included subjects with MS (n=60) as per NCEP ATP III criteria. Anthropometric measurements & biochemical analysis was performed in all subjects. IR was defined by HOMA IR. Simple & multiple regression analysis were used to obtain relationship between IR (HOMA IR) using TG/HDL-C (model -1) and Apo-B (Model- 2) as independent variables. Result: There were statistically significant differences in anthropometric, glycemic and lipid parameters between the control and study group (p<0.0001).The regression model between HOMA IR and TG/HDL-C ratio showed a positive correlation, (r=0.29, p < 0.05). HOMA IR & Apo-B also showed a significantly positive correlation (0. 41, p < 0.001). But combined multivariate analysis indicated that Apo-B is a better predictor of IR compared to TG/HDL-C ratio. Conclusion: We concluded in our study that Apo-B may be a better predictor of IR than TG/HDL-C and hence could be adopted in routine laboratory practice as a lipid marker for prediction of insulin resistance (IR) in metabolic syndrome patients at an early stage. Keywords: Insulin resistance; Apo B; metabolic syndrome; Insulin resistance indicators; lipid

Effect of rosuvastatin on obesity-induced cardiac oxidative stress in Wistar rats—A preliminary study.

The prevalence of obesity has been rising alarmingly and it has now become a global concern causing an enormous economic burden on the health care system. Obesity is generally linked to complications in lipid metabolism and oxidative stress. The aim of the present study was to investigate the effect of rosuvastatin (10 mg/kg, po) on obesity-induced oxidative stress in high fat-fed Wistar rats. Oral administration of rosuvastatin (10 mg/kg) for 21 days along with high fat diet brought about significant elevation in serum high density lipoprotein and cardiac antioxidant enzymes levels (superoxide dismutase, catalase, glutathione, glutathione peroxidase, glutathione peroxidase-, glutathione reductase- and glutathione-S-transferase) while decreasing in serum lactate dehydrogenase, apolipoprotein-B, lipids (triglycerides, total cholesterol, low density lipoprotein-cholesterol, very low density lipoprotein-cholesterol and atherogenic index) and cardiac thiobarbituric acid reactive substances levels. The results were comparable with orlistat, a standard antiobesity drug. These preliminary results for the first time demonstrate that administration of rosuvastatin can be beneficial for the suppression of obesity-induced oxidative stress and dyslipidemia in high fat-fed Wistar rats.

Small dense LDL and its Association with Hypertension: a Case-Control Study.

Hypertension is one of the most common diseases affecting humans throughout the world. The commonest variety of hypertension is benign essential hypertension. Cardiovascular risk is more in hypertensive patients as their lipid profile is more atherogenic than normotensive subjects. Traditionally, estimation of total serum cholesterol and LDL-C are used as an indicator of atherogenicity. But subjects may develop hypertension and CHD with normal levels of LDL cholesterol. So assessment of LDL cholesterol concentration may not entirely reflect its atherogenic potential. Because LDL-C is not a single entity rather it consists of seven distinct subclasses of different particle size. The size of the LDL particle is inversely correlated to their atherogenicity. Smaller LDL particles are more atherogenic despite their less cholesterol content than the larger more buoyant LDL particles containing more cholesterol. Therefore individuals having smaller LDL particles are more atherogenic and more at risk to develop hypertension inspite of even normal LDL cholesterol concentration. So measurement of small dense LDL particle is more important than any other lipid measure. With this aim 122 subjects were included in this study, among them 82 were diagnosed cases of essential hypertension with the mean age of 42.56±9.98 years and 40 were healthy controls. Serum apo-B was measured in all study subjects. The amount of apoB is almost similar in every LDL subtypes but the amount of cholesterol increases with the increasing particle size. So the ratio of cholesterol to apo-B decreases as the particle size decreases, thus LDL cholesterol / apo-B £ 1 indicates the presence of atherogenic small dense LDL. So the prevalence of small dense LDL was evaluated by calculating the ratio of LDL-C/apo B. The ratio was significantly lower in hypertensive cases (0.093±0.18) compared to controls, indicating presence of sd LDL in hypertensive patients. When the risk ratio was calculated, the patients having small dense LDL in their plasma were found to have 2.87 times more risk for developing CVD then the persons who doesn't have small dense LDL in their plasma.

Insulin resistance and apolipoprotein B as a metabolic syndrome risk factor in normal glucose tolerance / 대한내과학회지

BACKGROUND: Insulin resistance is associated with greatly increased risk of coronary artery disease. Serum apolipoprotein B and the ratio of apo A-1/Apo B are important markers of the coronary artery disease. The aim of this study was to assess the association of serum apolipoprotein B and the ratio of apo A-1/Apo B with insulin resistance in normal glucose tolerance. METHODS: From individual, who participated in medical screening at health promotion center in Kangbuk Samsung Hospital from Jan. to Dec. 2002, total 7427 participants (4356 men, 3071 women) were enrolled in this study. All participants was no personal history of diabetes and normal fasting glucose. We assess the clinical characteristics and biochemical parameters of subjects. RESULTS: Apolipoprotein B, total cholesterol/HDL-C and LDL-C/HDL-C show an positive correlation with metabolic syndrome and insulin resistance (p<0.001). Apo A-I, Apo A-I/Apo B, LDL/Apo B and HDL/Apo A-I show an negative correlation with metabolic syndrome and insulin resistance (p<0.001). CONCLUSION: These data suggest that insulin resistance are associated with serum apolipoprotein B and the ratio of apo A-1/Apo B in normal glucose tolerance. And early diagnosis and tight control of insulin resistance in normal glucose tolerance should be administered for the prevention of coronary artery disease.

Plasma LDL Particle Sizes Affect the Blood Lipid Profile and Dietary Intakes among Korean Adults / 대한지역사회영양학회지

The purpose of this research was to examine the relationship between the plasma LDL particle size and blood lipid profile, dietary factors and anthropometric values (body mass index, waist circumference and waist/hip ratio). The subjects were 173 adults aged 23 to 81 years, selected from the Outpatient Clinic and Cardiovascular Department of the Seoul Municipal Hospital. Dietary data were obtained using a 3-day food record and analyzed using Korean and US nutrient databases. The subjects were divided into three groups by LDL particle size:type A (large buoyant LDL, > 25.5 nm, n = 96), type I (Intermediate LDL, 25.2 < or = - < or = 25.5 nm, n = 18), and type B (small dense LDL, < 25.2 nm, n = 59) groups. The type B group had higher age, waist circumference, and waist/hip ratio (WHR) than the type A and type I groups. Serum concentration of triglyceride, Apo B, LDL/HDL cholesterol ratio and atherogenic index were significantly higher in the type B group as compared to those in the other two groups. HDL cholesterol level and Apo A-I/Apo B ratio were significantly lower in the type B group than the other two groups. The plasma LDL particle size was highly correlated with triglyceride (r = -0.450), Apo B (r = -0.402) and HDL cholesterol (r = 0.418). However, there was no correlation between plasma LDL particle size and dietary intakes. This study showed that small dense LDL was an important biochemical risk factor that was associated with other risk factors.

Quantificação das apoliproteínas A-I e B em soros normo e hipertrigliceridêmicos, conservados em condições de diferentes temperaturas / Measurement of apolipoproteins A-I and B in normal and hypertriglyceridemic serum stored under different conditions

1.) Utilizando método de imunoturbidimetria, nós medimos as concentrações das apolipoproteínas A-I e B, em amostras de soros normo e hipertrigliceridêmicos, estocados por um período de 94 dias. Alíquotas desses soros foram estocadas a 4°C, -20°C ou em nitrogênio líquido (-170°C). Três “pools” de soros foram usados, contendo respectivamente, 148, 491 e 964 mg/dl de triglicérides (TG). 2.) Nossos resultados mostraram que tanto soros normo quanto hipergliceridêmicos podem ser estocados a 4°C por um período de 8 dias, antes da determinação de apo A-I e apo B por imunoturbidimetria. Com o congelamento a -20°C ou no nitrogênio líquido (-170°C) , as determinações apo A-I foram imediatamente alteradas em 14% no “pool” de soros que continha valores altos de triglicérides, enquanto os outros dois “pools” não mostraram alterações significativas. Os valores de apo B aumentaram em todos os “pools” de soros após o congelamento a -20°C, enquanto no nitrogênio líquido houve significante alteração somente no soro com valores médios e altos de TG.

Níveis de LDL-C, HDL-C e de apolipoproteínas B e A-I em indivíduos normo e hiperlipidêmcos e suas correlações com os níveis de triglicérides / Levels of LDL-C, HDL-C and apolipoproteins B and A-I normo and hyperlipidemic indiviuals and their correlations with triglyceride levels

Os níveis plasmáticos de LDL-colesterol (LDL-C), HDL-colesterol (HDL-C), apolipoproteínas B (apo B) e A-I (apo A-I) foram estimados em 38 indivíduos hiperlipidêmicos (HL) e 42 normolipidêmicos (NL). Coeficientes de correlação, entre essas variáveis e os níveis de TG, foram calculados, em cada grupo. O teor de LDL-C, apo B e as razões LDL-C/HDL-C e apo B/apo A-I apresentaram-se significativamente maiores (p>0,001) nos HL do que nos NL. Entretanto, utilizando-se análise discriminante, observamos que a discriminação mais acentuada, nos hl, foi obtida pela razão apo B/apo A-I, que classificou 87% dos pacientes no grupo correto. O teor de HDL-C foi significativamente menor no grupo dos HL do que no de NL (p0,05). No grupo de NL, os resultados da correlação entre os níveis de TG com as outras variáveis fora: a) positiva e significativa com os níveis de LDL-C e apo B; b) negativa e significativa com os níveis de HDL-C; c) não significativa com o nível de apo A-I. No grupo de HL, encontramos correlações negativas entre os níveis de TG com os de LDL-C, HDL-C, não havendo correlação significativa com apo B e apo A-I.

Efeitos da pravastatina nas lipoproteínas, Lp(a), apo B e apo A-I em pacientes com hipercolesterolemia primária / Effects of Pravastatin on Lipoproteins, Lp(a), apo B and apo A-I in Patients with Primary Hypercholesterolemia

PURPOSE--To evaluate the effects of pravastatin on lipoproteins, Lp (a), apo B and apo A-I and its tolerability in primary hypercholesterolemic patients in our outpatient lipid clinic. METHODS--Twenty-two primary hypercholesterolemic patients were evaluated. They had all been treated previously with other hypocholesterolemic drugs, including the statins, forming a specific and homogeneous group with hypercholesterolemia and definite coronary risk. After 7 weeks with American Heart Association phase I diet and placebo drug, pravastatin was administered during 12 weeks. All patients received an initial daily dose of 10 mg for six weeks. After this period, this dose was increased to 20 mg. The levels of cholesterol, triglycerides, high-density lipoprotein, lipoprotein (a) and apolipoproteins A-1 and B were determined. RESULTS--No changes occurred with diet and placebo, but pravastatin at a daily dose of 10 mg, reduced significantly cholesterol level (7.22 per cent) LDL-cholesterol (13.08 per cent) and increased HDL-cholesterol (7.8 per cent). The results were better with 20 mg, achieving a reduction of (28.21 per cent) in cholesterol, (36.88 per cent) in LDL-cholesterol, (17.06 per cent) in apo B level and an increase of (10.06 per cent) in HDL-cholesterol. The smaller effect observed with the more commonly used dosage (10 mg/day) was most probably due to the characteristics of the sample with already established hypercholesterolemia, being thus dependent of higher concentrations of medications, as observed in previous treatments in our outpatient clinic. Side affects with this drug were rare. No biochemical changes were observed that would interrupt the continuation of therapy. CONCLUSION--Pravastatin was well tolerated and promoted favorable changes in the total cholesterol, LDL, apo B and cholesterol/HDL and LDL/HDL ratios of primary hypercholesterolemic patients

Investigations on the mechanism of hypercholesterolemia observed in copper deficiency in rats.

The mechanism of hypercholesterolemia effect of Cu2+ deficiency was studied in rats. There was increased activity of hepatic hydroxymethylglutaryl-coenzyme A reductase and increased incorporation of labelled acetate into free cholesterol of liver in the Cu2+ deficient rats. Incorporation of label into ester cholesterol was however decreased in the liver. Concentration of bile acids in the liver was not significantly altered. Increase in the incorporation of labelled acetate into serum cholesterol and increase in the concentration of cholesterol and apo B in the low density lipoproteins + very low density lipoproteins fractions were observed. Activity of lipoprotein lipase of the extrahepatic tissues decreased in the Cu 2+ deficient rats.

A Simplified Colorimetric Assay of Nonenzymatic Glycosylation of Human low Density Lipoproteins in Normal and Diabetes Mellitus

A simplified colorimetric method for measurement of the levels of glycosylation of proteins was developed by a modification of an existing method. Employing this method, the extent of nonenzymatic glycosylation of apolipoprotein B subspecies(B-100, B-74, B-26), LDL, VLDL and total serum proteins in human plasma obtained from patients with diabetes mellitus and control subjects was compared. Plasma LDL (1.019 < d < 1.063) and VLDL(d < 1.006) were separated using the sequential ultracentrifugation method, and the subspecies of apolipoprotein B were isolated by extracting them from polyacrylamide gels after they were separated by preparative SDS-polyacrylamide gel electrophoresis. Increases in the level of glycosylation of serum proteins, LDL, VLDL, and apo B subspecies obtained from diabetic patients were observed. Among them, the increases of glycosylated LDL and apo B-26 were most significant (p < .001). Also, good correlations were found between glycosylations of apo B-26 and LDL (r=.88), and glycosylation of LDL and LDL cholesterol level(r=.79). The results also showed an excellent correlation between levels of HbA1c and glycosylated apo B-26(r=.93).