Longitudinal study of circulating oxidized LDL and HDL and fatty liver: the Cardiovascular Risk in Young Finns Study

Lipid Oxidation Products and the Risk of Cardiovascular Diseases: Role of Lipoprotein Transport

Cholesterol has for decades ruled the history of atherosclerotic cardiovascular diseases (CVDs), and the present view of the etiology of the disease is based on the transport of cholesterol by plasma lipoproteins. The new knowledge of the lipoprotein-specific transport of lipid oxidation products (LOPs) has introduced another direction to the research of CVD, revealing strong associations between lipoprotein transport functions, atherogenic LOP, and CVD. The aim of this review is to present the evidence of the lipoprotein-specific transport of LOP and to evaluate the potential consequences of the proposed role of the LOP transport as a risk factor. The associations of cholesterol and lipoprotein LOP with the known risk factors of CVD are mostly parallel, and because of the common transport and cellular intake mechanisms it is difficult to ascertain the independent effects of either cholesterol or LOP. While cholesterol is known to have important physiological functions, LOPs are merely regarded as metabolic residues and able to initiate and boost atherogenic processes. It is therefore likely that with the increased knowledge of the lipoprotein-specific transport of LOP, the role of cholesterol as a risk factor of CVD will be challenged.

Hypertriglyceridemic hyperapoB and the development and resolution of nonalcoholic fatty liver disease: a cohort study

Hypertriglyceridemic hyperapoB is an adverse lipoprotein phenotype characterized by low high density lipoprotein (HDL) cholesterol, high triglycerides, high apolipoprotein B (ApoB), and low low density lipoprotein (LDL) cholesterol to ApoB ratio. We investigated whether and to what extent hypertriglyceridemic hyperapoB associates with the incidence and resolution of nonalcoholic fatty liver disease (NAFLD). This prospective cohort study included 9,019 Chinese participants 40 years or older, from 2010 to 2015. Logistic regression models were used to examine the odds ratios (ORs) for the incidence and resolution of NAFLD associated with the hypertriglyceridemic hyperapoB lipoprotein phenotype and individual lipid and lipoprotein parameters. During a median 4.3 years of follow-up, compared with participants with optimal phenotype, the fully adjusted ORs (95% CIs) for participants with hypertriglyceridemic hyperapoB were 2.75 (1.91, 3.95) and 0.57 (0.33, 1.00) for incidence and resolution of NAFLD, respectively. These associations were consistent across subgroup participants with varied demographic, lifestyle, and metabolic status. Individually, each unit increase in HDL cholesterol (OR: 0.98; 95% CI: 0.97, 0.99), natural logarithm-transformed triglycerides (1.89; 1.52, 2.36), and ApoB (1.006; 1.002, 1.011) was independently associated with NAFLD incidence, and only triglycerides (0.77; 0.60, 0.99) was independently associated with NAFLD resolution. Our findings suggest that Chinese adults with hypertriglyceridemic hyperapoB have a higher risk of NAFLD incidence and a lower likelihood of NAFLD resolution. These associations were stable among adults with different demographic, lifestyle, and metabolic status, supporting hypertriglyceridemic hyperapoB as a valuable clinical marker for the prevention and control of NAFLD.

The fatty acid composition of serum phospholipids in adolescents is associated with body composition in early adulthoods: an eight-year follow-up study

The fatty acid composition is associated with obesity. Omega 3 polyunsaturated fatty acid (PUFA) could have a beneficial role in the prevention and treatment of many disorders, including cardiometabolic diseases. A cohort of 84 men and 131 women were examined in adolescence and after 8 years. Body weight (BW) and fat mass (FM) were measured. The composition of fatty acids (FAs) of serum phospholipids was assessed using gas chromatography. Statistics: PLS method. Aim: to determine the relationships between FAs in adolescence and FM (explanatory variable 1, EV1) and BW (explanatory variable 2, EV2) in adulthood. In the predictive models, a cluster of FAs in boys explained 47.2 % of EV1 and a cluster of 6 FAs in girls explained 32.3 % of EV1 measured in adulthood. FAs measured in adolescents explained 23.7 % of EV2 in early adults regardless of gender. A significant negative association was found between 18:1n-9c and EV1 in males and EV2 in both genders. We found a significant negative association between 18:2n-6 and 20:0 and both EV1 and EV2. In all analyses, we found a significant negative association of 20:1n-9 and 18:3n-3 with EV1-2 in both genders. A significant positive association was found in 20:3n-6 with EV1 and EV2 in males. 20:4n-6 was positively associated with EV1 in females and EV2 in both genders. A positive association between FM and very long chain n- 6 PUFAs was also observed. It is concluded that serum MUFAs and essential PUFAs in adolescence are associated with lower BW and FM in adulthood.

Lean non-alcoholic fatty liver disease and associated metabolic disturbance: A Saudi Arabian cross-sectional study

Non-alcoholic liver disease (NAFLD) is a metabolic liver disease associated with visceral adiposity and insulin resistance. Recently, NAFLD has been described in lean individuals who additionally have impaired metabolic parameters similar to their non-lean counterparts. We aimed to explore this further in Saudi Arabia. From 2016 to 2019, we prospectively studied a group of newly diagnosed NAFLD patients at a tertiary hospital in Saudi Arabia. Patients were classified into three groups: lean (body mass index [BMI] <25), overweight (BMI ≥25 and <30), and obese (BMI ≥30). We made comparisons between these groups on basic clinical, demographic, and laboratory parameters. In total, 1753 patients were recruited and 1262 patients met the inclusion criteria. Altogether, 159 (12.6%), 365 (29%), and 737 (58.4%) patients were in the lean, overweight, and obese categories, respectively. Lean NAFLD patients were, on average, younger than those in the overweight group (mean 49.95 ± 15.3) and had a significantly higher high-density lipoprotein value (HDL) (mean 52.56 ± 16.27). Sex, hyperlipidemia, type 2 diabetes, and hypertension were significantly associated with BMI. Lean NAFLD patients displayed the features of metabolic syndrome including elevated glycosylated hemoglobin and abnormal lipid profile but had higher serum HDL. This is in contrast to the widely held belief that lean individuals have no dysmetabolic changes compared to overweight individuals. Recognition of this problem is essential so that lean NAFLD patients can be screened for metabolic changes and managed appropriately to prevent complications.

Cholesterol-Induced M4-Like Macrophages Recruit Neutrophils and Induce NETosis

The liver is the central organ for cholesterol synthesis and homeostasis. The effects of dietary cholesterol on hepatic injury, mainly of oxidized low-density lipoproteins (OxLDL), are not fully understood. Here, we show that the degree of cholesterol oxidation had different impacts on the global gene expression of human M2-like macrophages, with highly oxidized LDL causing the most dramatic changes. M2-like macrophages and Kupffer cells undergo M4-like polarization, decreasing the expression of important markers, such as IL10, MRC1, and CD163. These cells also displayed functional changes, with reduced phagocytic capacity, increased neutrophil recruitment, and more effective neutrophil extracellular traps (NETs) induction. Our findings provide a link between LDL oxidation and modification of peripheral and liver macrophage function.

Hypolipidemic and antioxidant activities of Trichosanthes kirilowii maxim seed oil and flavonoids in mice fed with a high-fat diet

Trichosanlhes kirilowii Maxim seed oil (TSO) is rich in conjugated linolenic acids, and the flavonoids (FLA) combined with n-3 fatty acids can effectively change the plasma antioxidant capacity. Hyperlipidemia and oxidative stress are one of the most important risk factors for cardiovascular disease. This study aims to evaluate the effect of the TSO, FLA, and TSO combined with FLA (TSOFLA) intake on hyperlipemia mice. TSO and TSOFLA administration resulted in a significant decline in serum levels of total cholesterol, triglycerides, and low density lipoprotein-cholesterol. TSOFLA improved the hepatic and serum antioxidant status as assessed by superoxide dismutase, glutathione peroxidase activities, and reduced the levels of lipid peroxidation. Hematoxylin-eosin staining of liver and aorta tissue has shown a marked reduction of the hyperlipidemia-induced lesions by gavage TSOFLA. Compared with TSO and FLA, TSOFLA has more significant hypolipidemic and antioxidant activities, which effects may be correlated to the synergy between TSO and FLA. PRACTICAL APPLICATIONS: Dyslipidemia is a common metabolic disorder, which is characterized by triglyceride levels increased, total cholesterol, and low-density lipoprotein cholesterol. Lipid-lowering treatment can reduce the expansion of coronary atherosclerosis, and particular the dietary lipids have important roles in controlling the concentrations of these risk factors. This is the first study evaluating the hypolipidemic and antioxidant activities effects of Trichosanlhes kirilowii Maxim seed oil (TSO), flavonoids (FLA), and TSO combined with FLA (TSOFLA) intake on hyperlipemia mice caused by a high-fat diet. The pharmacological effects of dietary TSOFLA are correlated to its high content of unsaturated fatty acids and flavonoids. This information can be of interest to the development of food supplements in the field of diseases associated with high-fat intakes such as cardiovascular diseases and adiposis.

Sex-Specific Associations Between Area-Level Poverty and Cardiometabolic Dysfunction Among US Adolescents

OBJECTIVE

Cardiometabolic disease is the leading cause of mortality in the United States. Cardiometabolic function during adolescence predicts future cardiometabolic disease, yet few studies have examined early determinants of cardiometabolic function. Informed by evidence of sex differences in the prevalence and severity of cardiometabolic disorders and evidence of sexual dimorphism in the stress response, we examined sex differences in the association between living in poverty and cardiometabolic function during adolescence, a precursor of later cardiometabolic disorders.

METHODS

We linked data from 10 415 adolescents aged 12-19 in the National Health and Nutrition Examination Survey (1999-2012) with US Census-tract data on area-level poverty (percentage of the population living in poverty, grouped into quartiles). We parameterized cardiometabolic dysfunction by summing the z scores of 6 cardiometabolic biomarkers, grouped into quintiles. Hierarchical ordinal models estimated associations.

RESULTS

Compared with residents in low-poverty areas, residents in high-poverty areas had elevated odds of cardiometabolic dysfunction (highest quartile of poverty odds ratio [OR] = 1.27; 95% confidence interval [CI], 1.08-1.50). This association was more pronounced among boys than girls (highest quartile of poverty for boys: OR = 1.36; 95% CI, 1.10-1.70; highest quartile of poverty for girls: OR = 1.17; 95% CI, 0.94-1.47).

CONCLUSION

Our study supports the existence of sex-specific associations. These results highlight the potential for community-based programs, such as housing assistance, to improve population health.

Quantitative Lipoprotein Subclass and Low Molecular Weight Metabolite Analysis in Human Serum and Plasma by 1H NMR Spectroscopy in a Multilaboratory Trial

We report an extensive 600 MHz NMR trial of quantitative lipoprotein and small-molecule measurements in human blood serum and plasma. Five centers with eleven 600 MHz NMR spectrometers were used to analyze 98 samples including 20 quality controls (QCs), 37 commercially sourced, paired serum and plasma samples, and two National Institute of Science and Technology (NIST) reference material 1951c replicates. Samples were analyzed using rigorous protocols for sample preparation and experimental acquisition. A commercial lipoprotein subclass analysis was used to quantify 105 lipoprotein subclasses and 24 low molecular weight metabolites from the NMR spectra. For all spectrometers, the instrument specific variance in measuring internal QCs was lower than the percentage described by the National Cholesterol Education Program (NCEP) criteria for lipid testing [triglycerides <2.7%; cholesterol <2.8%; low-density lipoprotein (LDL) cholesterol <2.8%; high-density lipoprotein (HDL) cholesterol <2.3%], showing exceptional reproducibility for direct quantitation of lipoproteins in both matrixes. The average relative standard deviations (RSDs) for the 105 lipoprotein parameters in the 11 instruments were 4.6% and 3.9% for the two NIST samples, whereas they were 38% and 40% for the 37 commercially sourced plasmas and sera, respectively, showing negligible analytical compared to biological variation. The coefficient of variance (CV) obtained for the quantification of the small molecules across the 11 spectrometers was below 15% for 20 out of the 24 metabolites analyzed. This study provides further evidence of the suitability of NMR for high-throughput lipoprotein subcomponent analysis and small-molecule quantitation with the exceptional required reproducibility for clinical and other regulatory settings.

Association of Lipoprotein-Associated Phospholipase A2 with the Prevalence of Nonalcoholic Fatty Liver Disease: A Result from the APAC Study

Nonalcoholic fatty liver disease (NAFLD) is a worldwide chronic liver disease. Few studies have investigated the association between NAFLD and Lipoprotein-associated phospholipase A₂ (Lp-PLA₂), a unique enzyme correlated with oxidative stress. The aim of this study was to assess the relationship between Lp-PLA₂ and NAFLD in a Chinese community-based cohort. A total of 1587 adults aged ≥40 years were enrolled in the current study. Participants underwent a standardized evaluation. The serum Lp-PLA2 concentration was measured by ELISA and NAFLD was diagnosed by ultrasonography. Multivariable logistic regression was used to assess the association between Lp-PLA2 and NAFLD. Increased Lp-PLA2 levels were significantly associated with decreased NAFLD prevalence after adjusting for other potential confounders. The adjusted ORs of NAFLD in Q2, Q3 and Q4 compared with Q1 were 0.88 (0.64–1.21), 0.71 (0.51–0.98) and 0.67 (0.48–0.95), respectively (P < 0.05). Furthermore, the adjusted ORs of moderate and heavy NAFLD in Q2, Q3 and Q4 compared to Q1 were 0.64 (0.41–1.01), 0.48 (0.29–0.80) and 0.47 (0.28–0.79), respectively (P < 0.01). In conclusions, increased Lp-PLA2 levels were independently associated with decreased NAFLD prevalence.

New findings of oxidative stress biomarkers in nutritional research

PURPOSE OF REVIEW

The aim of this article is to present a brief overview of recently published articles assessing oxidative stress markers in nutritional studies.

RECENT FINDINGS

Intervention and observational studies were carried out in both, healthy subjects and patients and describe the association of foodstuffs as well as isolated nutrients with biomarkers of oxidative stress. The results from human intervention studies on healthy participants and patients are controversial. Long-term interventions (>8 weeks) seem to be more effective than short-term or single-dose interventions. Results are difficult to compare because not only the methods used, also the assessed biomarkers and outcomes were very diverse. In addition, studies vary in the compounds and doses used, duration, participants and so on. Different biomarkers (damaged molecules together with antioxidants from different compartments) should be assessed to evaluate the true 'redox-status' of an individual and the impact of a nutritional intervention.

SUMMARY

Both observational and interventional studies performed in healthy participants and patients show possible beneficial effects of nutrients and foodstuffs by improving oxidative stress markers and antioxidant enzyme activities. Biomarkers should be standardized to allow better comparison of results of antioxidant intervention studies.

Association between circulating oxidized low-density lipoprotein and atherosclerotic cardiovascular disease

Atherosclerosis is a chronic, progressive disease which eventually leads to coronary heart disease (CHD), ischemic stroke and other atherosclerotic cardiovascular disease (ASCVD). Numerous studies have demonstrated an atherogenic role of oxidized low-density lipoprotein (ox-LDL) in the progression of ASCVD. This article briefly reviews the atherogenic mechanism of ox-LDL, the methods of measuring ox-LDL in the circulation, effect of medical therapy and life-style modification on ox-LDL level, and the association between circulating ox-LDL and atherosclerosis, including clinical ASCVD events and subclinical atherosclerosis, in observational studies.

Synergistic in vitro antioxidant activity and observational clinical trial of F105, a phytochemical formulation including Citrus bergamia, in subjects with moderate cardiometabolic risk factors

We examined the clinical safety and efficacy of F105 in 11 subjects with moderate dyslipidemia. F105 is a combination of bergamot fruit extract (Citrus bergamia, BFE) and 9 phytoextracts selected for their ability to improve the antioxidant and anti-inflammatory activity of BFE. In vitro F105 exhibited a synergistic inhibition of oxygen radical absorbing capacity, peroxynitrite formation, and myeloperoxidase activity. Following 12 weeks of F105 daily, no treatment-related adverse events or changes in body mass were seen. Statistically significant changes were noted in total cholesterol (-7.3%), LDL-cholesterol (-10%), non-HDL cholesterol (-7.1%), cholesterol/HDL (-26%), and apolipoprotein B (-2.8%). A post hoc analysis of 8 subjects with HbA1c > 5.4 and HOMA-IR score > 2 or elevated triglycerides revealed additional statistically significant changes in addition to those previously observed in all subjects including triglycerides (-27%), oxLDL (-19%), LDL/HDL (-25%), triglycerides/HDL (-27%), oxLDL/HDL (-25%), and PAI-1 (-37%). A follow-up case report of a 70-year-old female patient, nonresponsive to statin therapy and placed on F105 daily, demonstrated improved cardiometabolic variables over 12 weeks similar to the subgroup. In summary, F105 was clinically well-tolerated and effective for ameliorating dyslipidemia in subjects with moderate cardiometabolic risk factors, particularly in the individuals with HbA1c > 5.4%.