Health benefits of high-density lipoproteins in preventing cardiovascular diseases

High Concentrations of Circulating 2PY and 4PY-Potential Risk Factor of Cardiovascular Disease in Patients with Chronic Kidney Disease

Recently published data indicate that elevated circulating concentrations of N1-methyl-2-pyridone-5-carboxamide (2PY, also described as Met2PY) and N1-methyl-4-pyridone-5-carboxamide (4PY, also described as Met4PY), terminal catabolites of nicotinamide adenine dinucleotide (NAD+), are associated with cardiovascular disease (CVD) risk in humans. Previously, we and the others have shown that patients with advanced stages of chronic kidney disease (CKD) exhibit several-fold higher circulating 2PY and 4PY concentrations compared to healthy subjects or patients in the early stages of the disease. It is also well documented that patients with advanced CKD stages exhibit markedly elevated CVD risk, which is the main cause of premature death (in these patients). Therefore, we hypothesize that high concentrations of circulating 2PY and 4PY are important factors that may contribute to cardiovascular events and, ultimately, premature death in CKD patients. However, further, accurately controlled clinical research is needed to provide definitive answers concerning the role of 2PY and 4PY in CVD risk in CKD patients. Moreover, we are dealing with some issues related to the use of NAD+ precursors (NAD+ boosters) as drugs (also in CKD patients) and/or supplements. Due to the increase in circulating 2PY and 4PY levels during treatment with NAD+ boosters, these precursors should be used with caution, especially in patients with increased CVD risk.

Association of the platelet-to-high-density lipoprotein cholesterol ratio (PHR) with metabolic syndrome and metabolic overweight/obesity phenotypes: A study based on the Dryad database

BACKGROUND

Overweight/obesity and metabolic syndrome (MetS) are major global public health challenges. The platelet-to-high-density lipoprotein cholesterol ratio (PHR) has emerged as a potential biomarker reflecting both inflammatory status and lipid metabolism; however, its association with MetS and metabolic overweight/obesity phenotypes is not well understood. The present study aims to investigate the association of the PHR with MetS and metabolic overweight/obesity phenotypes.

METHODS

We derived data from the Dryad data repository. This retrospective study included 1,592 physical examination participants in Wuhan Union Hospital from 2020 to 2021. Based on BMI categories and metabolic status, we defined and distinguished four metabolic overweight/obesity phenotypes: metabolically healthy with normal weight (MHNW), metabolically unhealthy with normal weight (MUNW), metabolically healthy with overweight/obesity (MHO), and metabolically unhealthy with overweight/obesity (MUO). PHR was calculated as the ratio of platelets to HDL cholesterol. Logistic regression analysis was used to test the independent association between PHR with MetS and metabolic overweight/obesity phenotypes. In addition, we performed smooth curve fitting and subgroup analyses.

RESULTS

Logistic regression analysis, after adjusting for covariates, indicated that each 10-unit increase in PHR was associated with elevated risks of MetS (OR = 1.29, 95% CI: 1.24-1.35). There was a significant positive association between PHR and the occurrence of both MHO (OR = 1.15, 95% CI: 1.11-1.19) and MUO (OR = 1.16, 95% CI: 1.12-1.20), while the association with MUNW remained unclear (P = 0.73). In addition, we found a nonlinear relationship between PHR and the incidence of MetS, MHO, and MUO.

CONCLUSION

PHR demonstrates strong associations with MetS, MHO, and MUO, indicating its potential utility as an early biomarker for metabolic dysfunction.

Apolipoprotein CIII correlates with lipoproteins in the fed state and is not regulated by leptin administration in states of hypoleptinemia induced by acute or chronic energy deficiency: Results from two randomised controlled trials

BACKGROUND

Medications targeting the leptin and Apolipoprotein CIII (APOC3) pathways are currently under development for the treatment of hypertriglyceridaemia. Given that both pathways are implicated in triglyceride regulation, it is unknown whether they function independently or interact under physiological conditions and under acute or long-term energy deficiency.

METHODS

APOC3 levels and their association with circulating lipids and lipoproteins were evaluated in the context of two randomised controlled studies. In Study-1, 15 healthy individuals were examined under three distinct conditions, each lasting 72 h: isocaloric feeding, fasting with placebo administration and fasting with leptin administered at replacement doses. In Study-2, 20 females with hypoleptinemia due to relative energy deficiency in sport (REDs) for a minimum of 6 months were treated with either leptin or a placebo for 36 weeks.

RESULTS

In Study-1, APOC3 levels remained stable across all arms and were unaffected by leptin administration. In the fed state, APOC3 levels presented positive correlations with various VLDL, IDL, LDL and HDL sizes, and free fatty acids (FFA), most of which were not replicated in fasting. During complete energy deprivation, APOC3 was correlated with HDL molecules, glutamine and FFA, whereas its levels were positively associated only with FFA under leptin treatment. In Study-2, APOC3 levels were lower in the leptin group, but this was not a leptin-dependent effect. A positive correlation between APOC3 levels and HDL was observed in the leptin group.

CONCLUSIONS

These results contribute towards our better understanding of the intricate nature of lipid regulation under energy deficiency, suggesting that medications targeting the leptin and APOC3 pathways act through different metabolic pathways and thus may have independent effects from each other in regulating triglycerides.

Cardiometabolic Trajectories Preceding Dementia in Community-Dwelling Older Individuals

Importance

Poor cardiometabolic health is a risk factor associated with cognitive impairment in later life, but it remains unclear whether cardiometabolic trajectories can serve as early markers associated with dementia.

Objective

To compare cardiometabolic trajectories that precede dementia diagnosis with those among individuals without dementia.

Design, Setting, and Participants

This case-control study analyzed a sample drawn from community-dwelling participants in the Aspirin in Reducing Events in the Elderly (ASPREE) study. Recruitment through primary care physicians occurred between March 2010 and December 2014, with participants followed up for a maximum of 11 years. Dementia cases were matched on sociodemographic characteristics and time of diagnosis to dementia-free controls. Data analysis was performed between February and June 2024.

Exposures

Body mass index (BMI), waist circumference, systolic and diastolic blood pressure, glucose levels, high- and low-density lipoprotein (HDL and LDL) and total cholesterol levels, and triglyceride levels were measured repeatedly between 2010 and 2022.

Main Outcomes and Measures

Dementia (Diagnostic and Statistical Manual of Mental Disorders [Fourth Edition] criteria) was adjudicated by an international expert panel.

Results

Among 5390 participants (mean [SD] age, 76.9 [4.8] years; 2915 women [54.1%]), there were 2655 individuals (49.3%) with less than 12 years of education. The study included 1078 dementia cases and 4312 controls. Up to a decade before diagnosis, dementia cases compared with controls had lower BMI for all years from -7 years (marginal estimate, 27.52 [95% CI, 27.24 to 27.79] vs 28.00 [95% CI, 27.86 to 28.14]; contrast P = 002) to 0 years (marginal estimate, 26.09 [95% CI, 25.81 to 26.36] vs 27.22 [95% CI, 27.09 to 27.36]; contrast P < .001) and lower waist circumference for all years from -10 years (marginal estimate, 95.45 cm [95% CI, 94.33 to 96.57 cm] vs 97.35 cm [95% CI, 96.79 to 97.92 cm]; contrast P = .003) to 0 years (marginal estimate, 93.90 [95% CI, 93.15 cm to 94.64 cm] vs 96.67 cm [95% CI, 96.30 to 97.05 cm]; contrast P < .001); cases also had a faster decline in BMI (linear change β, -0.13 [95% CI, -0.19 to -0.08]) and waist circumference (linear change β, -0.30 cm [95% CI, -0.51 to -0.08 cm]). Compared with controls, cases generally had higher HDL levels, in particular from 5 years (marginal estimate, 62.57 mg/dL [95% CI, 61.59 to 63.56 mg/dL] vs 60.84 mg/dL [95% CI, 60.35 to 61.34 mg/dL]; contrast P = .002) to 3 years (marginal estimate, 62.78 mg/dL [95% CI, 61.82 to 63.74 mg/dL] vs 61.08 mg/dL [95% CI, 60.60 to 61.56 mg/dL]; contrast P = .002) before dementia but with a decline in levels just before diagnosis (linear change β, -0.47 mg/dL [95% CI, -0.86 to -0.07 mg/dL]). Dementia cases had lower systolic blood pressure and triglyceride levels in the decade before diagnosis and higher LDL and total cholesterol levels, but these were not significantly different from controls.

Conclusions and Relevance

In this study of older individuals, decline in BMI, waist circumference, and HDL occurred up to a decade before dementia diagnosis. These findings provide insights into cardiometabolic changes preceding dementia and the potential for early monitoring and intervention.

The Predictive Role of Hematological Parameters in Hypertension

Hypertension (HT) is a common chronic disease that often causes target-organ damage and severe complications, contributing to cardiovascular morbidity and mortality worldwide. Accumulating evidence suggests that inflammation plays a prominent role in the initiation and progression of HT. Multiple inflammatory biomarkers have been proposed to predict HT. Several new hematological parameters can reflect the inflammatory response and platelet activation. The major advantage of hematological parameters over conventional inflammatory markers is that they are relatively inexpensive and easily obtained from routine blood tests. Numerous studies have investigated several hematological parameters for their utility as predictive biomarkers for the diagnosis and prognosis of HT. Among them, the neutrophil to lymphocyte ratio (NLR), monocyte to high density lipoprotein cholesterol ratio (MHR), red cell distribution width (RDW), platelet to lymphocyte ratio (PLR), mean platelet volume (MPV), platelet distribution width (PDW), and systemic immune-inflammation index (SII) have recently received attention. We searched PubMed and Embase databases (up to September 18, 2022) to assess the relationships between hematological parameters and HT. This review discusses the diagnostic and prognostic value of these hematological parameters in HT, providing an important basis for early screening, risk stratification, and optimal management of hypertensive patients.

The Association between Plant-Based Diets and Dietary Patterns with Cardiometabolic Risk in a Sample of Commercial Taxi Drivers in South Africa

The consumption of unhealthy foods and a sedentary lifestyle predispose individuals to non-communicable diseases. This study investigated the distribution and the association of plant-based diets (PBDs) and dietary patterns in relation to the cardiometabolic risks in commercial taxi drivers. A cross-sectional analysis was conducted among males (≥19 years) who consumed street foods sold by vendors in the Cape Metropole. A validated questionnaire was administered, including a quantified 24 h dietary recall, and fasting blood samples were collected for biochemical analyses. Statistical analyses were performed to investigate the association between dietary habits and cardiometabolic risks, while adjusting for confounding variables. The analytic sample consisted of 189 males with a median age of 38 years. The taxi drivers who ranked in the top-third of the healthy plant-based diet index (hPDI) had a 1–4% lower likelihood of having raised triglycerides (TG). Furthermore, consumption patterns including refined grains and meat conferred a 33% lower likelihood of dysglycaemia (p = 0.049), while fish/seafood, potatoes, and vegetables conferred a 43% greater likelihood of low high-density lipoprotein cholesterol (HDL-C) (p = 0.026) and 44% greater probability of raised low-density lipoprotein cholesterol (LDL-C) (p = 0.027). Consumption patterns, including sugar-sweetened beverages and eggs, conferred a 37% greater probability of hypertension (p = 0.047) and 53% greater likelihood of subclinical inflammation (p = 0.017). These preliminary findings require larger and more elaborate studies to explore the associations between PBDs and dietary patterns in at-risk African populations, with or without sedentary lifestyles, and exposure to unhealthy food environments.

Obesogenic environment around schools is associated with atherogenic risk in Brazilian children

INTRODUCTION

Cardiometabolic risk factors often emerge in childhood, increasing the risk of cardiovascular diseases in adulthood. The school environments represent an important active space in a child's routine and may influence their health status.

METHODS

In this cross-sectional study, we aimed to evaluate the clustering of cardiometabolic risk factors and its association with the obesogenic and leptogenic environment around schools. A total of 378 children (181 boys; 197 girls) aged 8 and 9 years, enrolled in all urban schools of Viçosa, Minas Gerais, Brazil, were evaluated. Concentrations of high-density lipoprotein-cholesterol (HDL-c) and triglycerides (TG), and the insulin resistance (HOMA-IR), waist circumference (WC), and mean arterial pressure (MAP) were measured. The neighborhood income, walkability index, predominantly ultra-processed food stores, public spaces for leisure and/or physical activities, traffic accidents, crime and green spaces densities were assessed in 400 road network buffers around schools. To test association of the obesogenic and leptogenic environment around schools with cardiometabolic risk clustering, binary logistic regression models were performed with generalized estimating equations.

RESULTS

"Obesogenic school environments" had greater densities of ultra-processed food stores, crime and traffic accidents, and higher walkability. The "↓ Atherogenic risk" cluster consisted of higher HDL-c values. There was an inverse association between the obesogenic environment around schools and a child's "↓ atherogenic risk" clustering (OR = 0.63; p < 0.001).

CONCLUSION

We concluded that public policies aimed at modifying the environment around schools, by providing healthier food options and safe conditions for active mobility, are essential to prevent child's atherogenic risk.

Trivalent chromium supplementation ameliorates adjuvant induced rheumatoid arthritis through up-regulation of FOXP3 and decrease in synovial Cathepsin G expression

BACKGROUND

Rheumatoid arthritis (RA) is a known debilitating autoimmune disease. Immune-suppressants that are used for disease treatment have serious side effects, therefore, trivalent chromium (Cr (III)); which has shown evidence of its influences on some inflammatory pathways and cytokines; was used in this study for the first time to be assessed for its therapeutic effect in RA rat model and was compared to prednisolone in a trial to find a treatment with lesser side effects.

METHODS

Adult male albino rats were randomly divided into four groups: normal, untreated RA, prednisolone treated RA (1.25 mg/kg/day) and Cr (III) treated RA groups (80 μg/kg/day), induction of RA was done by subcutaneous complete Freund adjuvant injection. Study duration was 4 weeks throughout which arthritis scoring and weight measurement were pursued. Histopathological examination and immunohistochemical FOXP3 assessment were done for joint biopsies. Serum inflammatory markers (interleukin 17, interleukin 10, CRP) and synovial erosive arthritis marker (Cathepsin G) were measured. HDL and non-HDL cholesterol were estimated as well.

RESULTS

Cr (III) treatment showed marked clinical and histopathological improvement, also astonishing anti-inflammatory effects (increase in FOXP3 expression and interleukin 10, with decrease in interleukin 17, CRP and synovial Cathepsin G) to the extent that Cr (III) effects on inflammation abolishment were comparable to that of prednisolone and even better at some aspects. Moreover, Cr (III) was protective from side effects, i.e., weight gain and dyslipidemia that were seen with prednisolone treatment.

CONCLUSIONS

Cr (III) is promising in treating RA and it lacks some side effects of accustomed immune-modulatory agents including prednisolone. Further experimental studies and clinical trials should be held to see the efficacy of Cr (III) in different doses and to assess its long term side effects when used for rheumatoid arthritis and other autoimmune diseases treatment.

Elevated monocyte-to-HDL cholesterol ratio predicts post-stroke depression

OBJECTIVES

Inflammation plays an important role in the development of depression after stroke. Monocyte-to-HDL Cholesterol Ratio (MHR) recently emerged as a novel comprehensive inflammatory indicator in recent years. This study aimed to investigate whether there is a relationship between MHR levels and post-stroke depression (PSD).

METHODS

From February 2019 to September 2021, patients with acute ischemic stroke (AIS) were recruited within 7 days post-stroke from the two centers and blood samples were collected after admission. The 17-item Hamilton Depression Scale (HAMD-17) was used to measure depressive symptoms at 3 months after stroke. Patients were given the DSM-V criteria for diagnosis of PSD.

RESULTS

Of the 411 enrolled patients, 92 (22.38%) patients were diagnosed with PSD at 3-months follow-up. The results also showed significantly higher level of MHR in patients with depression [0.81 (IQR 0.67-0.87) vs. 0.61 (IQR 0.44-0.82), P < 0.001] at admission than patients without depression. Multivariate logistic regression revealed that MHR (OR 6.568, 95% CI: 2.123-14.565, P = 0.015) was an independent risk factor for the depression at 3 months after stroke. After adjustment for potential confounding factors, the odds ratio of PSD was 5.018 (95% CI: 1.694-14.867, P = 0.004) for the highest tertile of MHR compared with the lowest tertile. Based on the ROC curve, the optimal cut-off value of MHR as an indicator for prediction of PSD was projected to be 0.55, which yielded a sensitivity of 87% and a specificity of 68.3%, with the area under the curve at 0.660 (95% CI: 0.683-0.781; P = 0.003).

CONCLUSION

Elevated level of MHR was associated with PSD at 3 months, suggesting that MHR might be a useful Inflammatory markers to predict depression after stroke.

Is a High HDL-Cholesterol Level Always Beneficial?

The specific interest concerning HDL cholesterol (HDL-C) is related to its ability to uptake and return surplus cholesterol from peripheral tissues back to the liver and, therefore, to its role in the prevention of cardiovascular diseases, such as atherosclerosis and myocardial infarction, but also transient ischemic attack and stroke. Previous epidemiological studies have indicated that HDL-C concentration is inversely associated with the risk of cardiovascular disease and that it can be used for risk prediction. Some genetic disorders are characterized by markedly elevated levels of HDL-C; however, they do not translate into diminished cardiovascular risk. The search of the potential causative relationship between HDL-C and adverse events has shifted the attention of researchers towards the composition and function of the HDL molecule/subfractions. HDL possesses various cardioprotective properties. However, currently, it appears that higher HDL-C is not necessarily protective against cardiovascular disease, but it can even be harmful in extremely high quantities.

A neuroimaging investigation into the role of peripheral metabolic biomarkers in the anticipation of reward in alcohol use

BACKGROUND

The relationship between alcohol use and metabolism has focused on the effects of alcohol use on metabolic factors. Metabolic factors, such as triglycerides, cholesterol, and glucose, have been shown to be associated with increased risk for heavy alcohol consumption and alcohol use disorder (AUD). It's been suggested that changes in metabolic factors may play a role in reward seeking behaviors and pathways. Studies on feeding behavior and obesity revealed the role of triglycerides in neural response to food cues in neurocircuitry regulating reward and feeding behaviors. This study aimed to explore the relationship of peripheral metabolism, alcohol use, and reward processing in individuals that use alcohol.

METHODS

Ninety participants from a previously collected dataset were included in the analysis. Participants were treatment seeking, detoxified individuals with AUD and healthy individuals without AUD, with the following metabolic biomarkers: triglyceride, glucose, high- and low-density cholesterol, and HbA1c levels. Participants completed a neuroimaging version of the Monetary Incentive Delay task (MID).

RESULTS

Correlations on peripheral metabolic biomarkers, alcohol use, and neural activity during reward anticipation and outcome during the MID task were not significant. Mediation models revealed triglycerides and high-density cholesterol had significant effects on left anterior insula during anticipation of potential monetary loss and this effect was not mediated by alcohol use.

CONCLUSION

Limbic recruitment by anticipation of monetary rewards revealed an independent relationship with peripheral metabolism and was not affected by individual differences in alcohol use, despite the effects of alcohol use on metabolic markers and reward processing neural circuitry.

The Lipid Paradox as a Metabolic Checkpoint and Its Therapeutic Significance in Ameliorating the Associated Cardiovascular Risks in Rheumatoid Arthritis Patients

While the most common manifestations associated with rheumatoid arthritis (RA) are synovial damage and inflammation, the systemic effects of this autoimmune disorder are life-threatening, and are prevalent in 0.5–1% of the population, mainly associated with cardiovascular disorders (CVDs). Such effects have been instigated by an altered lipid profile in RA patients, which has been reported to correlate with CV risks. Altered lipid paradox is related to inflammatory burden in RA patients. The review highlights general lipid pathways (exogenous and endogenous), along with the changes in different forms of lipids and lipoproteins in RA conditions, which further contribute to elevated risks of CVDs like ischemic heart disease, atherosclerosis, myocardial infarction etc. The authors provide a deep insight on altered levels of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TGs) in RA patients and their consequence on the cardiovascular health of the patient. This is followed by a detailed description of the impact of anti-rheumatoid therapy on the lipid profile in RA patients, comprising DMARDs, corticosteroids, anti-TNF agents, anti-IL-6 agents, JAK inhibitors and statins. Furthermore, this review elaborates on the prospects to be considered to optimize future investigation on management of RA and treatment therapies targeting altered lipid paradigms in patients.

OX-HDL: A Starring Role in Cardiorenal Syndrome and the Effects of Heme Oxygenase-1 Intervention

In this review, we will evaluate how high-density lipoprotein (HDL) and the reverse cholesterol transport (RCT) pathway are critical for proper cardiovascular-renal physiology. We will begin by reviewing the basic concepts of HDL cholesterol synthesis and pathway regulation, followed by cardiorenal syndrome (CRS) pathophysiology. After explaining how the HDL and RCT pathways become dysfunctional through oxidative processes, we will elaborate on the potential role of HDL dysfunction in CRS. We will then present findings on how HDL function and the inducible antioxidant gene heme oxygenase-1 (HO-1) are interconnected and how induction of HO-1 is protective against HDL dysfunction and important for the proper functioning of the cardiovascular-renal system. This will substantiate the proposal of HO-1 as a novel therapeutic target to prevent HDL dysfunction and, consequently, cardiovascular disease, renal dysfunction, and the onset of CRS.

Dysfunctional High-Density Lipoproteins Are Associated With a Greater Incidence of Acute Coronary Syndrome in a Population at High Cardiovascular Risk: A Nested Case-Control Study

BACKGROUND

Studies have failed to establish a clear link between high-density lipoprotein (HDL) cholesterol and cardiovascular disease, leading to the hypothesis that the atheroprotective role of HDL lies in its biological activity rather than in its cholesterol content. However, to date, the association between HDL functional characteristics and acute coronary syndrome has not been investigated comprehensively.

METHODS

We conducted a case-control study nested within the PREDIMED (Prevención con Dieta Mediterránea) cohort, originally a randomized trial in which participants followed a Mediterranean or low-fat diet. Incident acute coronary syndrome cases (N=167) were individually matched (1:2) to control patients by sex, age, intervention group, body mass index, and follow-up time. We investigated 2 individual manifestations (myocardial infarction, unstable angina) as secondary outcomes. We measured the following functional characteristics: HDL cholesterol concentration (in plasma); cholesterol efflux capacity; antioxidant ability, measured by the HDL oxidative-inflammatory index; phospholipase A2 activity; and sphingosine-1-phosphate, apolipoproteins A-I and A-IV, serum amyloid A, and complement 3 protein (in apolipoprotein B-depleted plasma). We used conditional logistic regression models adjusted for HDL cholesterol levels and cardiovascular risk factors to estimate odds ratios (ORs) between 1-SD increments in HDL functional characteristics and clinical outcomes.

RESULTS

Low values of cholesterol efflux capacity (OR1SD, 0.58; 95% CI, 0.40-0.83) and low levels of sphingosine-1-phosphate (OR1SD, 0.70; 95% CI, 0.52-0.92) and apolipoprotein A-I (OR1SD, 0.58; 95% CI, 0.42-0.79) were associated with higher odds of acute coronary syndrome. Higher HDL oxidative inflammatory index values were marginally linked to acute coronary syndrome risk (OR1SD, 1.27; 95% CI, 0.99-1.63). Low values of cholesterol efflux capacity (OR1SD, 0.33; 95% CI, 0.18-0.61), sphingosine-1-phosphate (OR1SD: 0.60; 95% CI: 0.40-0.89), and apolipoprotein A-I (OR1SD, 0.59; 95% CI, 0.37-0.93) were particularly linked to myocardial infarction, whereas high HDL oxidative-inflammatory index values (OR1SD, 1.53; 95% CI, 1.01-2.33) and low apolipoprotein A-I levels (OR1SD, 0.52; 95% CI, 0.31-0.88) were associated with unstable angina.

CONCLUSIONS

Low cholesterol efflux capacity values, pro-oxidant/proinflammatory HDL particles, and low HDL levels of sphingosine-1-phosphate and apolipoprotein A-I were associated with increased odds of acute coronary syndrome and its manifestations in individuals at high cardiovascular risk.

CLINICAL TRIAL REGISTRATION

URL: https://www.controlled-trials.com/ISRCTN35739639. Unique identifier: ISRCTN35739639.

Synergistic and Non-synergistic Associations for Cigarette Smoking and Non-tobacco Risk Factors for Cardiovascular Disease Incidence in the Atherosclerosis Risk In Communities (ARIC) Study

INTRODUCTION

Cigarette smoking, various metabolic and lipid-related factors and hypertension are well-recognized cardiovascular disease (CVD) risk factors. Since smoking affects many of these factors, use of a single imprecise smoking metric, for example, ever or never smoked, may allow residual confounding and explain inconsistencies in current assessments of interactions.

METHODS

Using a comprehensive model in pack-years and cigarettes/day for the complex smoking-related relative risk (RR) of CVD to reduce residual confounding, we evaluated interactions with non-tobacco risk factors, including additive (non-synergistic) and multiplicative (synergistic) forms. Data were from the prospective Atherosclerosis Risk in Communities (ARIC) Study from four areas of the United States recruited in 1987-1989 with follow-up through 2008. Analyses included 14 127 participants, 207 693 person-years and 2857 CVD events.

RESULTS

Analyses revealed distinct interactions with smoking: including statistical consistency with additive (body mass index [BMI], waist to hip ratio [WHR], diabetes mellitus [DM], glucose, insulin, high density lipoproteins [HDL] and HDL(2)); and multiplicative (hypertension, total cholesterol [TC], low density lipoproteins [LDLs], apolipoprotein B [apoB], TC to HDL ratio and HDL(3)) associations, as well as indeterminate (apolipoprotein A-I [apoA-I] and triglycerides) associations.

CONCLUSIONS

The forms of the interactions were revealing but require confirmation. Improved understanding of joint associations may help clarify the public health burden of smoking for CVD, links between etiologic factors and biological mechanisms, and the consequences of joint exposures, whereby synergistic associations highlight joint effects and non-synergistic associations suggest distinct contributions.

IMPLICATIONS

Joint associations for cigarette smoking and non-tobacco risk factors were distinct, revealing synergistic/multiplicative (hypertension, TC, LDL, apoB, TC/HDL, HDL(3)), non-synergistic/additive (BMI, WHR, DM, glucose, insulin, HDL, HDL(2)) and indeterminate (apoA-I and TRIG) associations. If confirmed, these results may help better define the public health burden of smoking on CVD risk and identify links between etiologic factors and biologic mechanisms, where synergistic associations highlight joint impacts and non-synergistic associations suggest distinct contributions from each factor.

High density lipoprotein (HDL) reverses palmitic acid induced energy metabolism imbalance by switching CD36 and GLUT4 signaling pathways in cardiomyocyte

In our previous study palmitic acid (PA) induced lipotoxicity and switches energy metabolism from CD36 to GLUT4 in H9c2 cells. Low level of high density lipoprotein (HDL) is an independent risk factor for cardiac hypertrophy. Therefore, we in the present study investigated whether HDL can reverse PA induced lipotoxicity in H9c2 cardiomyoblast cells. In this study, we treated H9c2 cells with PA to create a hyperlipidemia model in vitro and analyzed for CD36 and GLUT4 metabolic pathway proteins. CD36 metabolic pathway proteins (phospho-AMPK, SIRT1, PGC1α, PPARα, CPT1β, and CD36) were decreased by high PA (150 and 200 μg/μl) concentration. Interestingly, expression of GLUT4 metabolic pathway proteins (p-PI3K and pAKT) were increased at low concentration (50 μg/μl) and decreased at high PA concentration. Whereas, phospho-PKCζ, GLUT4 and PDH proteins expression was increased in a dose dependent manner. PA treated H9c2 cells were treated with HDL and analyzed for cell viability. Results showed that HDL treatment induced cell proliferation efficiency in PA treated cells. In addition, HDL reversed the metabolic effects of PA: CD36 translocation was increased and reduced GLUT4 translocation, but HDL treatment significantly increased CD36 metabolic pathway proteins and reduced GLUT4 pathway proteins. Rat neonatal cardiomyocytes showed similar results. In conclusion, HDL reversed palmatic acid-induced lipotoxicity and energy metabolism imbalance in H9c2 cardiomyoblast cells and in neonatal rat cardiomyocyte cells.

Human paraoxonase 1 overexpression in mice stimulates HDL cholesterol efflux and reverse cholesterol transport

This study was aimed to investigate the effect of human PON1 overexpression in mice on cholesterol efflux and reverse cholesterol transport. PON1 overexpression in PON1-Tg mice induced a significant 3-fold (p<0.0001) increase in plasma paraoxonase activity and a significant ~30% (p<0.0001) increase in the capacity of HDL to mediate cholesterol efflux from J774 macrophages compared to wild-type mice. It also caused a significant 4-fold increase (p<0.0001) in the capacity of macrophages to transfer cholesterol to apoA-1, a significant 2-fold (p<0.0003) increase in ABCA1 mRNA and protein expression, and a significant increase in the expression of PPARγ (p<0.0003 and p<0.04, respectively) and LXRα (p<0.0001 and p<0.01, respectively) mRNA and protein compared to macrophages from wild-type mice. Moreover, transfection of J774 macrophages with human PON1 also increased ABCA1, PPARγ and LXRα protein expression and stimulates macrophages cholesterol efflux to apo A1. In vivo measurements showed that the overexpression of PON1 significantly increases the fecal elimination of macrophage-derived cholesterol in PON1-Tg mice. Overall, our results suggested that the overexpression of PON1 in mice may contribute to the regulation of the cholesterol homeostasis by improving the capacity of HDL to mediate cholesterol efflux and by stimulating reverse cholesterol transport.

Change in adiponectin explains most of the change in HDL particles induced by lifestyle intervention but not metformin treatment in the Diabetes Prevention Program

OBJECTIVE

In addition to slowing diabetes development among participants in the Diabetes Prevention Program (DPP), intensive lifestyle change and metformin raised HDL-cholesterol (HDL-C) compared to placebo treatment. We investigated the lifestyle and metabolic determinants as well as effects of biomarkers of inflammation, endothelial dysfunction and coagulation and their changes resulting from lifestyle and metformin interventions on the increase in HDL-C in the DPP.

METHODS

The effects of a 1year period of intensive lifestyle change aimed at achieving 7% weight loss or metformin 850mg twice daily versus placebo on HDL-C were assessed in 3070 participants with impaired glucose tolerance, and on HDL particle concentration (HDL-P) and size in a subgroup of 1645 individuals. Treatment-associated changes in lifestyle and metabolic factors as well as in novel biomarkers were investigated for their associations with change in HDL-C using multiple regression analysis.

RESULTS

After adjusting for BMI, insulin resistance, glycemia, dietary saturated fat, alcohol intake, physical activity and nine different biomarkers, only adiponectin accounted for the effect of intensive lifestyle change on HDL-C via an increase in large HDL-P. By contrast baseline and change in BMI and tissue plasminogen activator levels attenuated the effect of metformin on HDL-C, with adiponectin having no specific effect.

CONCLUSION

While both lifestyle and metformin interventions used to prevent diabetes increase HDL-C, the mechanisms involved differ between the two treatments and may have consequences for future risk of cardiovascular disease.

Effect of beta-3 adrenoceptor stimulation on the levels of ApoA-I, PPARα, and PPARγ in apolipoprotein E-deficient mice

The beta-3 adrenoceptor (β3-AR) protects against the progression of atherosclerosis. However, the specific mechanism of this antiatherosclerotic effect is still not clear. Thus, the aim of this study was to understand the antiatherosclerotic effects of β3-AR. Thirty-six male homozygous apolipoprotein E-deficient mice and wild-type C57BL/6J mice were randomized into 6 treatment groups: wild-type, atherosclerotic model, atorvastatin, low-dose β3-AR agonist, high-dose β3-AR agonist, and β3-AR antagonist groups. The serum lipids, aortic-free cholesterol (FC), and cholesteryl ester (CE) concentrations were measured at the end of the treatments. The mRNA expression levels of liver apolipoprotein A-I (apoA-I), peroxisome proliferator-activated receptor-α (PPARα), and peroxisome proliferator-activated receptor-γ (PPARγ) were detected by quantitative real-time PCR. Protein expression levels of apoA1, PPARα, and PPARγ in the liver were determined by western blot analysis. Treatment with β3-AR significantly increased the plasma levels of high-density lipoprotein cholesterol and apoA-I, whereas the levels of total cholesterol, triglycerides, and low-density lipoprotein cholesterol decreased. The β3-AR agonist treatment markedly decreased both the FC and the CE concentrations in the aorta compared with the atherosclerotic model mice. The β3-AR agonist increased the mRNA and protein expression levels of apoA-I, PPARα, and PPARγ in the liver. This study demonstrates that long-term β3-AR activation can regulate lipid metabolic disorders and reduces the aortic FC and the CE concentrations. These effects may be related to apoA-I, PPARα, and PPARγ.

Black-White differences in the relationship between alcohol drinking patterns and mortality among US men and women

OBJECTIVES

We investigated Black-White differences in the association between average alcohol drinking patterns and all-cause mortality.

METHODS

We pooled nationally representative samples of 152 180 adults in the National Health Interview Survey from 1997 to 2002 with mortality follow-up through 2006. Usual drinking days per week and level of alcohol consumed per day were based on self-report. We used race- and gender-specific Cox proportional hazards regression analyses to adjust for physical activity, smoking status, and other potential confounders.

RESULTS

Over 9 years, 13 366 deaths occurred from all causes. For men, the lowest multivariable-adjusted hazard ratio (HR) for total mortality among drinkers was 0.81 among White men who consumed 1 to 2 drinks 3 to 7 days per week (compared with abstainers) and Black men who abstained. For women, the lowest mortality risk was among White women (HR = 0.71) consuming 1 drink per day 3 to 7 days per week and Black women (HR = 0.72) consuming 1 drink on 2 or fewer days per week.

CONCLUSIONS

Risks and benefits of alcohol consumption in relation to mortality risk were dependent on race- and gender-specific drinking patterns.

Strong correlations between circulating chemerin levels and lipoprotein subfractions in nondiabetic obese and nonobese subjects

OBJECTIVE

Chemerin is a recently described adipokine expressed primarily in the white adipose tissue. Compared with lean subjects, circulating chemerin levels are significantly elevated in obese individuals and correlate positively with the prevalence of various cardiovascular risk factors including altered lipoprotein levels. To date, the impact of chemerin on lipoprotein subfractions and its role in atherosclerotic processes are still unclear.

PATIENTS AND METHODS

Fifty nondiabetic obese (NDO) patients and 38 lean controls matched in age and gender were enrolled. Chemerin level was measured by ELISA. Low-density lipoprotein (LDL) and high-density lipoprotein (HDL) subfractions were detected by nongradient polyacrylamide gel electrophoresis (Lipoprint).

RESULTS

We detected significantly higher serum chemerin levels in NDO patients compared with healthy controls (590·1 ± 190·3 ng/ml vs 405 ± 127·1 ng/ml, P < 0·001). A significant positive correlation was found between chemerin and LDL cholesterol levels, while chemerin showed a significant negative correlation with the level of HDL cholesterol. Significant positive correlation was detected between chemerin and the ratio of small dense LDL, while chemerin correlated negatively with the mean LDL size. Also, a significant negative correlation was found between serum chemerin and the ratio of large HDL subfraction, while there were significant positive correlations between chemerin levels and intermediate and small HDL subfraction ratios, respectively.

CONCLUSION

Chemerin may be involved in the regulation of lipoprotein metabolism in obese patients who do not show apparent abnormalities of glucose metabolism. Early changes in the distribution of the lipoprotein subfractions may contribute to the progression of atherosclerosis, leading to increased cardiovascular risk.

Cardiovascular risk in rheumatoid arthritis: recent advances in the understanding of the pivotal role of inflammation, risk predictors and the impact of treatment

Risk of cardiovascular (CV) disease is increased among RA patients. High inflammatory burden associated with RA appears to be a key driver of the increased cardiovascular risk. Inflammation is linked with accelerated atherosclerosis and associated with a paradoxical inversion of the relationship between CV risk and lipid levels in patients with untreated RA, recently coined the lipid paradox. Furthermore, the inflammatory burden is also associated with qualitative as well as quantitative changes in lipoproteins, with the anti-inflammatory and atheroprotective roles associated with high-density lipoprotein cholesterol significantly altered. RA therapies can increase lipid levels, which may reflect the normalization of lipids due to their inflammatory-dampening effects. However, these confounding influences of inflammation and RA therapies on lipid profiles pose challenges for assessing CV risk in RA patients and interpretation of traditional CV risk scores. In this review we examine the relationship between the increased inflammatory burden in RA and CV risk, exploring how inflammation influences lipid profiles, the impact of RA therapies and strategies for identifying and monitoring CV risk in RA patients aimed at improving CV outcomes.

Effect of niacin on endothelial function: a systematic review and meta-analysis of randomized controlled trials

Endothelial dysfunction is an independent predictor of incident atherosclerotic cardiovascular disease (ACVD). Niacin possesses high-density lipoprotein (HDL)-elevating, antioxidant and anti-inflammatory properties, all potentially contributing to the amelioration of endothelial function. However, controversies exist among trials reporting the effects of niacin on endothelium-dependent flow-mediated dilation (FMD) as a reliable surrogate of endothelial function. The objective of this study was to assess the effect of niacin on brachial artery FMD using a meta-analysis of available evidence. MEDLINE and Scopus databases were searched for randomized controlled trials investigating the impact of niacin therapy on brachial artery FMD. Meta-analysis of eligible studies was conducted using a random-effects model. Pooled effects were measured by weighted mean difference (WMD) and 95% confidence intervals (CIs). Quality assessment, and subgroup, meta-regression and sensitivity analyses were conducted using standard methods. Among 596 citations, 19 full-text articles were read and seven were found to be eligible for inclusion. Eligible studies involved 441 subjects comprising 228 in the niacin and 213 in the control groups. Niacin therapy significantly improved FMD (WMD: 1.98%; 95% CI: 0.91-3.05%; p = 0.0003) and this effect was robust in the sensitivity analysis. The effect size was greater in the subgroup of studies administering higher doses of niacin (≥ 2000 mg/day) as well as those studies administering niacin for primary prevention of ACVD. Meta-regression indicated no association between niacin-induced changes in FMD and changes in plasma HDL-cholesterol, low-density lipoprotein-cholesterol or triglycerides. None of the included studies could find any significant effect of niacin on nitroglycerin-mediated dilation. In conclusion, treatment with niacin improves endothelial function.

Inter-organ communication in the regulation of lipid metabolism: focusing on the network between the liver, intestine, and heart

Recent studies have shown that lipid metabolism is regulated through the orchestration of multiple organs. Gut microbiota influences the metabolism of the liver through the production of fatty acids and phosphatidylcholine as well as the modulation of bile acid profile. Microbiota also affects the cardiovascular system through the production of metabolites from nutrients. MicroRNAs (miRNAs) are non-coding RNAs comprised of around 22 nucleotides in length. MiRNAs are released into blood flow from organs and interfere with the gene expression of target organs. MiRNAs are involved in the regulation of metabolic homeostasis including lipoprotein production and cardiovascular functions. Fatty acids are also circulating and distributed to each organ by fatty acid transporting proteins. Fatty acids can act as a ligand of G protein-coupled receptors, such as GPR41 and GPR43, and nuclear receptor PPARα, which bear crucial roles in the regulation of energy expenditure. Therefore the inter-organ communication plays important roles in the systematic regulation of lipid metabolism. Studies on the inter-organ network system will contribute to the development of diagnostic and therapeutic strategies for metabolic diseases. This review discusses how lipid metabolism is regulated by the inter-organ communication, focusing on the network axis between the liver, intestine, and heart.