Small LDL and its clinical importance as a new CAD risk factor: a female case study

New Advances in Rapid Pretreatment for Small Dense LDL Cholesterol Measurement Using Shear Horizontal Surface Acoustic Wave (SH-SAW) Technology

Atherosclerosis is an inflammatory disease of the arteries associated with alterations in lipid and other metabolism and is a major cause of cardiovascular disease (CVD). LDL consists of several subclasses with different sizes, densities, and physicochemical compositions. Small dense LDL (sd-LDL) is a subclass of LDL. There is growing evidence that sd-LDL-C is associated with CVD risk, metabolic dysregulation, and several pathophysiological processes. In this study, we present a straightforward membrane device filtration method that can be performed with simple laboratory methods to directly determine sd-LDL in serum without the need for specialized equipment. The method consists of three steps: first, the precipitation of lipoproteins with magnesium harpin; second, the collection of effluent from a 100 nm filter; and third, the quantification of sd-LDL-ApoB in the effluent with an SH-SAW biosensor. There was a good correlation between ApoB values obtained using the centrifugation (y = 1.0411x + 12.96, r = 0.82, n = 20) and filtration (y = 1.0633x + 15.13, r = 0.88, n = 20) methods and commercially available sd-LDL-C assay values. In addition to the filtrate method, there was also a close correlation between sd-LDL-C and ELISA assay values (y = 1.0483x - 4489, r = 0.88, n = 20). The filtration treatment method also showed a high correlation with LDL subfractions and NMR spectra ApoB measurements (y = 2.4846x + 4.637, r = 0.89, n = 20). The presence of sd-LDL-ApoB in the effluent was also confirmed by ELISA assay. These results suggest that this filtration method is a simple and promising pretreatment for use with the SH-SAW biosensor as a rapid in vitro diagnostic (IVD) method for predicting sd-LDL concentrations. Overall, we propose a very sensitive and specific SH-SAW biosensor with the ApoB antibody in its sensitive region to monitor sd-LDL levels by employing a simple delay-time phase shifted SH-SAW device. In conclusion, based on the demonstration of our study, the SH-SAW biosensor could be a strong candidate for the future measurement of sd-LDL.

Effect of sprouted whole pearl millet on growth performance, intestinal development, bacterial count, and blood indices of broiler chickens

This study investigated the effects of varying levels of sprouted whole grain pearl millet (SPM) on growth performance, intestinal morphology, microbial count, and blood indices of broiler chickens. A maize-soybean meal basal diet was formulated and fed to broiler chickens as starter (0 to 21 d) and finisher (22 to 42 d) diets. The diets comprised of 0%, 25%, 50%, 75%, and 100% of SPM incorporated as whole grain. On 0 d, 180 unsexed broiler chickens were allocated to experimental diets in a completely randomized design. Each treatment was replicated three times; each replicate had 12 chicks. All diets were isonitrogenous and isocaloric to meet the nutrient requirements of broiler chickens. Diets and water were provided ad libitum for 42 d. Results showed that the body weight gain (BWG) of broiler chickens on SPM compared favorably with those on the control diet. BWG showed trends in increment (P < 0.10) while FCR showed decreased trends (P < 0.10) with partial inclusion of SPM at 42 d and 0 to 42 d. The drumstick weight showed quadratic effect (P = 0.044) while the wing weight showed linear effect (P = 0.047) to treatment diets at 21 d. The liver weights of broiler chickens showed linear response (P = 0.018) at 21 d and (P = 0.004) at 42 d to SPM inclusion in diets. Sprouted whole PM consistently increased low-density lipoprotein concentration and mean corpuscular hemoglobin concentration (P < 0.05). Length and weight of small intestine and ceca showed decreasing trends on SPM levels in the treatment diets. Digesta pH assessment revealed that pH in the crop was lower (P < 0.05) on partial SPM while pH in proventriculus was reduced (P < 0.05) with inclusion of SPM in treatment diets. Lactobacilli count decreased linearly (P = 0.010) with SPM inclusion. This study suggests that SPM could be used as an alternative source of energy in production of broiler chickens. Therefore, partial replacement of maize with SPM in broiler diet had no negative effect on performance, physiological status, and overall health of broiler chickens.

Clinical significance of neutrophil gelatinase-associated lipocalin and sdLDL-C for coronary artery disease in patients with type 2 diabetes mellitus aged ≥ 65 years

BACKGROUND AND AIMS

Although type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD) share many common pathological and physiological characteristics, there are few studies assessing the predictive capacity of novel biomarkers in occurrence and development of CAD in T2DM patients aged ≥ 65 years. In addition, T2DM patients aged ≥ 65 years are prone to CAD. Therefore, it is of great significance to find novel biomarkers for the development CAD in T2DM.

METHODS

In this retrospective cohort study, 579 T2DM patients aged ≥ 65 years were consecutively enrolled in this work, and 177 of whom had major adverse cardiovascular and cerebrovascular events (MACCE: cardiovascular or cerebrovascular death, acute coronary syndrome, coronary stent implantation, and stroke) during the follow up. Univariate and multivariate factors were employed to analyze the correlation between each variable and the occurrence of MACCE, and the Spearman's rank correlation analysis was performed to assess the relationships between Neutrophil gelatinase-associated lipocalin (NGAL) and small dense low-density lipoprotein-cholesterol (LDL-C) (sdLDL-C). The receiver operating characteristic (ROC) curve was adopted to determine the predictive value of NGAL and sdLDL-C elevation for MACCE in T2DM patients aged ≥ 65 years.

RESULTS

After a median 48 months follow-up [19, (10 ~ 32) ], the levels of NGAL, sdLDL-C, hemoglobin A1c (HbA1c), LDL-C, and apolipoprotein B (ApoB) were significantly higher while those of high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A I (ApoA-I) were lower in MACCE positive group. NGAL correlated to body mass index (BMI) (r = 0.391, P = 0.001) and triglyceride (TG) (r = 0.228, P = 0.032), and high-sensitivity CRP (hsCRP) (r = 0.251, P = 0.007), and neutrophils (r = 0.454, P = 0.001), sdlDL-C level was found to be positively correlated with LDL-C (r = 0.413, P = 0.001), TG (r = 0.432, P = 0.001), and ApoB (r = 0.232, P = 0.002); and it was negatively correlated with HDL-C (r = -0.362, P = 0.031) and ApoA-I (r = -0.402, P = 0.001). Age-adjusted Cox regression analysis showed that NGAL (HR = 1.006, 95% confidence interval (CI): 1.005-1.008, P < 0.001) and sdLDL-C (HR = 1.052, 95% CI: 1.037-1.066, P < 0.001) were independently associated with occurrence of MACCE. ROC curve analysis showed that NGAL (area under ROC (AUC) = 0.79, 95% CI: 0.75-0.84, P < 0.001) and sdlDL-C (AUC = 0.76, 95% CI: 0.72-0.80, P < 0.001) could predict the occurrence of MACCE (area under ROC. NGAL combined with sdlDL-C could predict the occurrence of MACCE well (AUC = 0.87, 95% CI: 0.84-0.90, P < 0.001).

CONCLUSION

The higher NGAL and sdLDL-C in T2DM patients aged ≥ 65 years were significantly and independently associated with the risk of MACCE, and showed higher clinical values than other lipid biomarkers or other chronic inflammation, so they were expected to be the most effective predictors of MACCE assessment.

Comparative effects of ethanol leaf and stem bark extracts of Irvingia gabonensis (BUSH MANGO) on sodium arsenite-induced lipid profile perturbtions in wistar rats

Background

Exposure to arsenic orchestrates a myriad of noxious health effects, including cancer. Different parts ofIrvingia gabonensisare used as herbal remedies in traditional medicine. In this study, the comparative effects of the ethanol leaf (ELEIG) and stem bark extracts (ESEIG) ofIrvingia gabonensison sodium arsenite (SA)-induced lipid profile disturbances in Wistar rats were investigated.

Methods

Fifty five Wistar rats weighing between 100 g and 179 g were distributed into eleven groups (n=5). Group 1 (control) received feed and water ad libitum. Group 2 received SA at a dose of 4.1 mg/kg body weight (kgbw) for 14 days. Groups 3–11 were treated with the extracts with or without SA. Treatment was done by oral intubation for 14 days. Serum concentrations of total cholesterol (TC), triacylglycerol (TAG), high density lipoprotein cholesterol (HDL-c), low density lipoprotein cholesterol (LDL-c), very low density lipoprotein cholesterol (VLDL-c), total lipids (TL) and atherogenic index of plasma (AIP) were used to determine the lipid profile effects of the extracts.

Results

Exposure to SA caused significant (p˂ 0.05) increases in all assayed parameters, relative to control. Post-treatment and simultaneous treatment with ELEIG and ESEIG mitigated the effects of SA. In addition, ELEIG alone at various doses produced results comparable with control values. However, ESEIG alone caused significant (p˂ 0.05) increases in all assayed parameters, relative to control.

Conclusion

These results show that ELEIG and ESEIG ameliorate SA-induced lipid profile disturbances in Wistar rats. However, long-term administration of ESEIG alone may be discouraged.

Saturated Fat: Part of a Healthy Diet

PURPOSE OF REVIEW

Despite the American public following recommendations to decrease absolute dietary fat intake and specifically decrease saturated fat intake, we have seen a dramatic rise over the past 40 years in the rates of non-communicable diseases associated with obesity and overweight, namely cardiovascular disease. The development of the diet-heart hypothesis in the mid twentieth century led to faulty but long-held beliefs that dietary intake of saturated fat led to heart disease. Saturated fat can lead to increased LDL cholesterol levels, and elevated plasma cholesterol levels have been shown to be a risk factor for cardiovascular disease; however, the correlative nature of their association does not assign causation.

RECENT FINDINGS

Advances in understanding the role of various lipoprotein particles and their atherogenic risk have been helpful for understanding how different dietary components may impact CVD risk. Numerous meta-analyses and systematic reviews of both the historical and current literature reveals that the diet-heart hypothesis was not, and still is not, supported by the evidence. There appears to be no consistent benefit to all-cause or CVD mortality from the reduction of dietary saturated fat. Further, saturated fat has been shown in some cases to have an inverse relationship with obesity-related type 2 diabetes. Rather than focus on a single nutrient, the overall diet quality and elimination of processed foods, including simple carbohydrates, would likely do more to improve CVD and overall health. It is in the best interest of the American public to clarify dietary guidelines to recognize that dietary saturated fat is not the villain we once thought it was.

LDL Subclasses in Ischemic Stroke: A Risk Factor?

Introduction

Seven low-density lipoprotein (LDL) subclasses are identified, and smaller LDL particles are associated with an increased risk for cardiovascular events. However, there is limited data about the relationship between the acute ischemic stroke (AIS) subtypes and LDL subclasses. The aim of our study is to investigate the relationship between AIS subtypes and LDL subclasses.

Methods

This study consisted of 110 AIS patients and 60 healthy controls. Stroke patients were classified according to the TOAST classification system as cardioembolic infarct (CI), large artery atherosclerosis (LAA), and lacunar infarct (LI). LDL subclasses were distributed as seven bands (LDL-1 and-2 defined as large, and LDL-3 to-7 defined as small-LDL particle), using the LipoPrintª System. Control group and AIS subtypes were compared in terms of LDL subclasses; p<0.05 was considered statistically significant.

Results

AIS patients had higher LDL-2, LDL-3 and LDL-4 subclasses compared to the control groups, while LDL-1 was similar in two groups. In addition, LDL-2 and LDL-3 subclasses were significantly higher in each AIS subtype when compared to the control group. LDL-4 subclasses were significantly higher in LAA and LI subtypes than in the control group, but there was no relationship for CI subtypes. Smaller subclasses LDL-5 to LDL-7 were undetectable in both AIS patients and controls. Using regression analysis; age, LDL-2, LDL-3 and LDL-4 were found to be independent predictors of AIS development.

Conclusion

Our study showed that examination of LDL subclasses may be important in management of AIS patients. LDL-2, LDL-3, and LDL-4 are independent predictors of AIS development. These findings should be supported by further large studies.

Deleterious effects of potassium bromate administration on renal and hepatic tissues of Swiss mice

Potassium bromate (KBrO₃) is widely used as a food additive and is a major water disinfection by-product. The present study reports the side effects of KBrO₃ administration in Swiss mice. Animals were randomly divided into three groups: control, low dose KBrO₃ (100 mg/kg/day) and high dose KBrO₃ (200 mg/kg/day) groups. Administration of KBrO₃ led to decreased white blood corpuscles (WBCs), red blood corpuscles (RBCs) and platelets count in the animals of both the high and the low dose groups. Altered lipid profile represented as low density lipoprotein (LDL), high density lipoprotein (HDL) and cholesterol levels were observed in plasma samples of both KBrO₃ treated groups of mice. Also, an increased plasma level of LDH was detected in both KBrO₃ treated groups. Histological investigations showed impaired renal and hepatic histology that was concomitant with increased plasma Creatinine level in both of KBrO₃-treated groups. Nevertheless, decreased glutathione (GSH) level in both renal and hepatic tissue of mice after KBrO₃ intake was detected. These results show that KBrO₃ has serious damaging effects and therefore, its use should be avoided.

Effects of palm and sunflower oils on serum cholesterol and fatty liver in rats

Palm oil is a common cooking ingredient used in the commercial food industry as the second largest consumed vegetable oil in the world. Because of its lower cost and highly saturated nature, it usually maintains a solid form at room temperature and is used as a cheap substitute for butter. However, there has been a growing health concern about palm oil because of the link between dietary fats and coronary heart disease. Palm oil contains ∼49% saturated fat, a relatively high concentration compared with other vegetable oils. Consequently, high intakes of saturated fat from palm oil induce a larger increase in plasma concentrations of total cholesterol and low-density lipoproteins. In the present study, we examined the hyperlipidemia of palm oil and the risk of cardiovascular disease (CVD) using a rat model in comparison with sunflower oil with a relatively low level of saturated fat. On in vivo examination using Sprague-Dawley (SD) rats for 22 days, there were no significant differences in serum lipid levels, suggesting that palm oil may not cause hyperlipidemia and elevate CVD risk. However, liver samples obtained from SD rats fed with palm oil showed a lot of large lipid inclusions stained with the Oil Red O working solution, but not much lipid accumulation was observed in rats treated with sunflower oil. In addition, lipid accumulation in the mixed oil group fed the combination of palm and sunflower (1:1) oil was shown to be at an intermediary level between the palm oil group and sunflower oil group. Taken together, these results indicate that palm oil, a highly saturated form of vegetable oil, may induce dysfunction of the liver lipid metabolism before affecting serum lipid levels. On the other hand, sunflower oil, a highly unsaturated vegetable oil, was shown to be well metabolized in liver.

Influence of a high cholesterol regime on epicardial and subcutaneous adipose tissue fatty acids profile in rabbits

BACKGROUND

We have shown that the fatty acid profile of epicardial adipose tissue (EAT) in patients with obstructed coronary vessels is different from that of the subcutaneous adipose tissue (SAT). The diversity and amount of fatty acids in the adipose tissue can be affected by the component of the lipids in diet. As a result, this study investigated the influence of a high cholesterol regime on EAT and subcutaneous adipose tissue fatty acids profile in rabbits.

METHODS

Sixteen New Zealand white rabbits were randomly divided into two equal groups. The control group received a normal standard diet, whereas the test group was fed with the high cholesterol regime for 2 months. At the end of this period, the rabbits were anesthetized, 1-5 mg of EAT and SAT were removed, and their fatty acids content was determined.

RESULTS

The high cholesterol regime caused a significant increase in low-density lipoprotein (LDL) and triglycerides levels and a marked decrease in high-density lipoprotein (HDL) concentration. After 2 months, in the EAT, fatty acids 16:0 and 18:1t and saturated fatty acid (SFA) showed a significant increase (P<0.05), whereas, fatty acids 12:0, 18:1, 18:2, and 18:3, monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), ω3, and ω6 had a significant decrease (P<0.05). In SAT, fatty acids 18:3, 20:4, 22:6, MUFA, and ω3 decreased and PUFA, SFA, and ω6 significantly increased (P<0.05).

CONCLUSION

Consumption of a high cholesterol regime for 2 months resulted in a significant increase in atherogenic fatty acids and a decrease in antiatherogenic ones in the EAT. EAT is very sensitive to lipid changes of the regime comparing to SAT.

Systematic review, meta-analysis and regression of randomised controlled trials reporting an association between an intake of circa 25 g soya protein per day and blood cholesterol

AIMS

To determine the effect of a daily intake of circa 25 g soya protein on blood lipids in adults with normal or mildly elevated cholesterolaemia.

METHODS

Medline and other scientific databases were searched to identify randomised controlled trials (RCTs); these were systematically reviewed against pre-determined criteria. Eligible RCTs evaluated the effect of 25 g (range 15-40 g) soya protein on measures of blood lipids. Results from RCTs were pooled using standard meta-analysis methods.

RESULTS

Thirty studies containing 42 treatment arms (n=2913), with an average soya protein intake of 26.9 g met the inclusion criteria. Soya protein inclusion led to reductions in standard difference in mean low density lipoprotein (LDL), total cholesterol and blood triglycerides of 0.23 mmol/L (95% confidence interval (CI) -0.160 to -0.306, p<0.0001), 0.22 mmol/L (95% CI -0.142 to -0.291, p<0.0001) and 0.08 mmol/L (95% CI -0.004 to -0.158, p=0.04), respectively. There was no effect on mean difference in apolipoprotein A (ApoA), but ApoB was reduced by 0.021 g/L (p=0.01) in the soya group. Meta-regression analysis indicated no dose response relationship between soya protein intake in the range of 15-40 g and standard difference in LDL or HDL. All data were tested for heterogeneity and none identified.

CONCLUSIONS

The inclusion of modest amounts soya protein (ca. 25 g) into the diet of adults with normal or mild hypercholesterolaemia resulted in small, highly significant reductions in total and LDL cholesterol, equivalent to ca. 6% LDL reduction. This practically achievable intake, particularly when combined with other dietary measures, can make a useful contribution to blood cholesterol management.

Saturated fats: what dietary intake?

Public health recommendations for the US population in 1977 were to reduce fat intake to as low as 30% of calories to lower the incidence of coronary artery disease. These recommendations resulted in a compositional shift in food materials throughout the agricultural industry, and the fractional content of fats was replaced principally with carbohydrates. Subsequently, high-carbohydrate diets were recognized as contributing to the lipoprotein pattern that characterizes atherogenic dyslipidemia and hypertriacylglycerolemia. The rising incidences of metabolic syndrome and obesity are becoming common themes in the literature. Current recommendations are to keep saturated fatty acid, trans fatty acid, and cholesterol intakes as low as possible while consuming a nutritionally adequate diet. In the face of such recommendations, the agricultural industry is shifting food composition toward lower proportions of all saturated fatty acids. To date, no lower safe limit of specific saturated fatty acid intakes has been identified. This review summarizes research findings and observations on the disparate functions of saturated fatty acids and seeks to bring a more quantitative balance to the debate on dietary saturated fat. Whether a finite quantity of specific dietary saturated fatty acids actually benefits health is not yet known. Because agricultural practices to reduce saturated fat will require a prolonged and concerted effort, and because the world is moving toward more individualized dietary recommendations, should the steps to decrease saturated fatty acids to as low as agriculturally possible not wait until evidence clearly indicates which amounts and types of saturated fatty acids are optimal?