Small Dense Low-Density Lipoprotein Cholesterol and Ischemic Stroke

Systematic analysis of the burden of ischemic stroke attributable to high LDL-C from 1990 to 2021

Background

Low-density lipoprotein cholesterol (LDL-C) is a public health concern linked to ischemic stroke. The study aimed to describe the epidemiological characteristics of ischemic stroke attributable to high LDL-C from 1990 to 2021.

Methods

In this study, we analyzed data from the Global Burden of Disease 2021 to present trends in ischemic stroke related to high LDL-C over the past 30 years. The relationship between disease burden and the Socio-Demographic Index (SDI) was examined. To assess international health disparities, we applied the Slope Index of Inequality (SII) and the Concentration Index (CI). Furthermore, we conducted a frontier analysis to identify areas for improvement and developmental gaps among nations, and employed the Bayesian Age-Period-Cohort (BAPC) model to forecast the disease burden for the next 15 years.

Results

In 2021, the incidence of ischemic stroke attributed to high LDL-C significantly increased compared to 1990, with a more pronounced growth rate in males. The burden mainly affects individuals aged 70 to 84. Analysis using the age-period-cohort model indicates that mortality rates and DALYs rise with age, while period and cohort effects exhibit a gradual decline. Across different SDI regions, trends generally follow a similar downward path, with a narrowing gap in disease burden among regions with varying SDI levels. However, the disease burden in high SDI countries remains significant, indicating potential for reduction. Predictions for the next 15 years suggest that while the global disease burden will decrease, there may be an increase among individuals under 55.

Conclusion

Compared to 1990, the overall age-standardized burden of ischemic stroke related to high LDL-C has been controlled. However, disparities persist across different SDI regions. We have observed an increasing burden among younger populations. Consequently, countries and regions must adopt new measures tailored to their SDI levels, with a specific emphasis on younger individuals. It is essential to develop prevention and treatment strategies aimed at high-risk groups.

"Are new lipid lowering agents a good option for achieving lipid goals in people living with HIV? A case report"

The dyslipidemia in people living with HIV differs from the general population because combination antiretroviral therapy may not only induce dyslipidemia but also interact with lipid-lowering agents.Monoclonal antibodies that target proprotein convertase subtilisin/kexin type 9 (PCSK9) have recently been demonstrated to dramatically reduce LDL-C level (>60%) in the majority of cases, and another interesting new option is inclisiran, a first-in-class, cholesterol-lowering small interfering RNA (siRNA) targeting PCSK9 mRNA and conjugated to triantennary N-acetylgalactosamine carbohydrates (GalNAc).We present the clinical case of a 62-year-old man living with HIV and dyslipidemia in whom new hypolipidemic drugs were fundamental in achieving adequate LDL values to prevent cardiovascular events.

Correlation of sdLDL-C and Apob with the degree of cerebral artery stenosis in posterior circulation stroke

Small and dense LDL cholesterol (sdLDL-C) and apolipoprotein B (ApoB) have important roles in promoting the development of atherosclerosis and are highly correlated with the degree of atherosclerosis. Several studies have found differences in anterior and posterior circulation strokes and in the mechanisms of their atherosclerosis, but little research has been done on the relationship of sdLDL-C and ApoB to atherosclerotic stenosis in anterior and posterior circulation strokes. We analyzed the correlation between sdLDL-C and ApoB and the degree of arterial stenosis in patients with posterior circulation stroke. We included 230 anterior circulation stroke (ACS) patients and 170 posterior circulation stroke (PCS) patients. Blood specimens were collected at admission, serum ApoB and sdLDL-C concentrations were measured, and the degree of arterial stenosis was determined on the basis of vascular imaging. We analyzed the predictive value of ApoB and sdLDL-C for the degree of cerebral artery stenosis in patients with PCS. For patients with nonmild stenosis, sdLDL-C and ApoB levels were higher in the PCS group than in the ACS group (P < 0.05). SdLDL-C (P < 0.001) and ApoB (P < 0.05) were independent risk factors for increased intracranial artery stenosis in the posterior circulation group. Binary logistic regression analysis showed that sdLDL-C (P < 0.05) and ApoB (P < 0.05) were independent risk factors for non-mild stenosis of the intracranial arteries in patients with PCS after correction for confounders. In the posterior circulation group, there was an interaction between the effects of sdLDL and ApoB on intracranial artery stenosis, P < 0.05. Plotting the ROC curve showed that the AUC of the combined detection of sdLDL-C and ApoB was 0.791, which was better than that of the single index. We built nomogram model, the DCA curves, calibration curves, NRI index, and IDI index of both the modeling and validation groups indicated that the diagnostic efficacy and clinical benefit of the combined sdLDL-C and ApoB assay were greater than those of single-indicator assays for cerebral artery stenosis in posterior circulation stroke. Risk factors contributing to the increased degree of intracranial arterial stenosis in ACS and PCS vary somewhat. SdLDL-C and ApoB may be of value in clinical decision making as predictors of cerebral arterial stenosis in patients with PCS.

Association of the atherogenic index of plasma with frailty in U.S. adults: a cross-sectional study based on NHANES

BACKGROUND

Frailty is a multifactorial syndrome associated with adverse health outcomes. The metabolic underpinnings of frailty, particularly lipid metabolism, are not fully understood. Unlike isolated lipid fractions or inflammatory markers, atherogenic index of plasma (AIP) integrates atherogenic lipid profiles and systemic inflammation. However, its association with frailty has not been extensively studied.

METHODS

Six thousand four hundred participants from the National Health and Nutrition Examination Survey (NHANES) were enrolled. Frailty was calculated with the frailty index (FI), with scores ≥ 0.21 indicating frailty. Logistic regression adjusted for demographic, socioeconomic, and lifestyle factors evaluated the association between AIP and frailty. Restricted cubic splines (RCS) explored nonlinear associations, and subgroup analyses assessed interactions across age, sex, race, poverty income ratio, smoking status, drinking status, and marital status.

RESULTS

This study demonstrated a strong dose-response relationship between AIP and frailty. After full adjustment, Individuals in quartile 3 and 4 showed higher odds of frailty than those in lowest quartile, with ORs (95% CI) of 1.26(1.01,1.57) and 1.73(1.34,2.23), respectively. Continuous AIP measures also exhibited significant associations (OR: 1.82, 95% CI: 1.34-2.47). RCS analysis showed that AIP exhibited a nonlinear association with the risk of frailty. Subgroup analyses showed the associations were more pronounced in the females. The sensitivity analyses substantiated the stability and strength of the results.

CONCLUSIONS

Our findings suggest that elevated AIP levels are independently associated with frailty risk, particularly in females, highlighting its potential as a cost-effective biomarker for risk stratification. Future longitudinal studies are needed to validate AIP's predictive utility and uncover the underlying mechanisms.

Alterations in LDL and HDL after an ischemic stroke associated with carotid atherosclerosis are reversed after 1 year

Approximately, 20% of ischemic strokes are attributed to the presence of atherosclerosis. Lipoproteins play a crucial role in the development of atherosclerosis, with LDL promoting atherogenesis and HDL inhibiting it. Therefore, both their concentrations and their biological properties are decisive factors in atherosclerotic processes. In this study, we examined the qualitative properties of lipoproteins in ischemic stroke patients with carotid atherosclerosis. Lipoproteins were isolated from the blood of healthy controls (n = 27) and patients with carotid atherosclerosis (n = 64) at 7 days and 1 year postischemic stroke. Compared to controls, patients' LDL 7 days poststroke showed increased levels of apoC-III, triacylglycerol, and ceramide, along with decreased cholesterol and phospholipid content. LDL from patients induced more inflammation in macrophages than did LDL from controls. HDL isolated from patients 7 days after stroke showed alterations in the apolipoprotein cargo, with reduced levels of apoA-I and increased levels of apoA-II, and apoC-III compared to controls. Patients' HDL also showed a higher electronegative charge than that of controls and partially lost its ability to counteract the modification of LDL and the inflammatory effects of modified LDL. One year after stroke onset, the composition of patients' LDL and HDL resembled those of the controls. In parallel, LDL and HDL gained positive charge, LDL became less prone to oxidation and aggregation, and HDL regained protective properties. In conclusion, LDL and HDL in ischemic stroke patients with carotid atherosclerosis exhibited alterations in composition and function, which were partially reversed 1 year after stroke.

Atherogenic circulating lipoproteins in ischemic stroke

The fundamental role of qualitative alterations of lipoproteins in the early development of atherosclerosis has been widely demonstrated. Modified low-density lipoproteins (LDL), such as oxidized LDL (oxLDL), small dense LDL (sdLDL), and electronegative LDL [LDL(-)], are capable of triggering the atherogenic process, favoring the subendothelial accumulation of cholesterol and promoting inflammatory, proliferative, and apoptotic processes characteristic of atherosclerotic lesions. In contrast, high-density lipoprotein (HDL) prevents and/or reverses these atherogenic effects. However, LDL's atherogenic and HDL's anti-atherogenic actions may result altered in certain pathological conditions. The molecular mechanisms underlying the impaired effects of altered lipoproteins have been studied in numerous in vitro and in vivo studies, and have been extensively analyzed in coronary atherosclerosis, especially in the context of pathologies such as dyslipidemia, diabetes, obesity, and metabolic syndrome. However, the corresponding studies are scarcer in the field of ischemic stroke, despite carotid arteriosclerosis progression underlies at least 20% of ischemic strokes. The present review relates qualitative alterations of LDL and HDL with the development of carotid arteriosclerosis and the occurrence of ischemic stroke.

Trends and Prospects of Low-Density Lipoprotein Cholesterol in Stroke: A Bibliometric Analysis

Management of low-density lipoprotein cholesterol (LDL-C) in stroke is a crucial component of cardiovascular disease care. Recent years have seen substantial progress in understanding and managing LDL-C in the context of stroke. This study utilized bibliometric methods to analyze and synthesize trends in this area over the past decade, incorporating 2,841 publications from the Web of Science database. The analyses included trend topic analysis, co-authorship analysis, and co-citation analysis. The findings indicate that research had predominantly concentrated on epidemiological studies related to pharmacological management strategies. Future research is expected to continue exploring lipid-lowering therapies, including both established treatments like statins and newer drugs such as proprotein convertase subtilisin-kexin type 9 inhibitors. Assessing residual cholesterol and employing Mendelian randomization techniques may become potential research hotspots. The New England Journal of Medicine is the most globally influential journal, while Circulation holds the most influence within the field, and Atherosclerosis ranks as the most prolific. International collaboration in this research area was strong between the USA and England, followed by the USA and China. However, collaboration between productive institutions in the USA and China remains limited, highlighting the need to strengthen partnerships between these institutions to further advance the field.

Combined impact of elevated C-reactive protein levels and dyslipidemia on stroke: a CHNS prospective cohort study

Background

The objective of this study was to examine whether the combination of elevated levels of C-reactive protein (CRP) and dyslipidemia increased the risk of stroke among middle-aged and older adult individuals in China.

Methods

This study utilized longitudinal data from the China Health and Nutrition Survey (CHNS) collected in 2009, 2015, and 2018. A total of 8,023 participants aged ≥40 years (3,595 males and 4,428 females) were included. The Generalized Estimating Equation (GEE) method was employed to examine the association between inflammation, dyslipidemia, their combined effects, and stroke in the Chinese population.

Results

A total of 174 stroke events occurred during follow-up. Compared with those with normal CRP levels (CRP ≤ 3 mg/L), the adjusted ORs and 95%CI were 2.13 (1.25, 3.64) for the female with elevated CRP level. Compared with those with non-dyslipidemia, the adjusted ORs and 95%CI were 1.56 (1.03, 2.37) for the individuals with high LDL cholesterol, 1.93 (1.12, 3.33) for the male with high LDL cholesterol. Compared with those with normal CRP levels and non-dyslipidemia, the adjusted ORs and 95%CI were 1.74 (1.08, 2.78) for the individuals with elevated CRP levels and dyslipidemia, 2.41 (1.29, 4.49) for the male with elevated CRP levels and dyslipidemia. People with the coexistence of elevated CRP levels and dyslipidemia had the highest risk of stroke among male.

Conclusion

In females, higher levels of inflammation are associated with an increased incidence of stroke. In males, individuals with dyslipidemia characterized by high LDL cholesterol levels are more susceptible to stroke. In the general population, the joint effect of inflammation and dyslipidemia predisposes individuals to a higher risk of stroke, particularly among males.

Genetically predicted small dense low-density lipoprotein cholesterol and ischemic stroke subtype: multivariable Mendelian randomization study

Purpose

Small dense low-density lipoprotein cholesterol (S-LDL-C) has been suggested as a particularly atherogenic factor for ischemic stroke (IS) in observational studies, but the causality regarding the etiological subtype remains unclear. This study aims to explore the causal effects of small dense low-density lipoprotein cholesterol (S-LDL-C), medium (M-LDL-C) and large (L-LDL-C) subfractions on the lifetime risk of ischemic stroke (IS) and main subtypes using two-sample Mendelian randomization (TSMR) design.

Methods

We identified genetic instruments for S-LDL-C, M-LDL-C and L-LDL-C from a genome-wide association study of 115 082 UK Biobank participants. Summary-level data for genetic association of any ischemic stroke (AIS), large artery stroke (LAS), small vessel stroke (SVS) and cardioembolic stroke (CES) were obtained from MEGASTROKE consortium. Accounting for the pleiotropic effects of triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C), we conducted multivariable TSMR analysis.

Results

In univariable TSMR, we found a causal association between genetically predicted S-LDL-C and LAS (IVW-FE: odds ratio (OR) = 1.481, 95% confidence interval (CI): 1.117-1.963, P = 0.006, q = 0.076) but not AIS, SVS or CES. No causal effects were observed for M-LDL-C or L-LDL-C in terms of AIS and IS subtype. In multivariable analysis, the causal association between S-LDL-C and LAS remained significant (IVE-MRE: OR = 1.329, 95% CI: 1.106-1.597, P = 0.002).

Conclusions

Findings supported a causal association between S-LDL-C and LAS. Further studies are warranted to elucidate the underlying mechanism and clinical benefit of targeting S-LDL-C.

SGLT2-inhibition increases total, LDL, and HDL cholesterol and lowers triglycerides: Meta-analyses of 60 randomized trials, overall and by dose, ethnicity, and drug type

BACKGROUND AND AIMS

Sodium glucose co-transporter 2 (SGLT2)-inhibitors were developed as glucose-lowering drugs. Surprisingly, SGLT2-inhibitors also reduced risk of cardiovascular disease. The impact of SGLT2-inhibitors on lipids and lipoproteins is unclear, but an effect might contribute to the observed lower cardiovascular risk. We conducted a meta-analysis to examine this, overall and by dose, ethnicity, and drug type.

METHODS

PubMed, EMBASE and Web of Science were searched for randomized controlled trials examining all available SGLT2-inhibitors. Studies with available lipid measurements were included. Quantitative data synthesis was performed using random and fixed effects models.

RESULTS

We identified 60 randomized trials, including 147,130 individuals. Overall, using random effects models, SGLT2-inhibitor treatment increased total cholesterol by 0.09 mmol/L (95% CI: 0.06, 0.13), low-density lipoprotein (LDL) cholesterol by 0.08 mmol/L (0.05, 0.10), and high-density lipoprotein (HDL) cholesterol by 0.06 mmol/L (0.05, 0.07), while it reduced triglycerides by 0.10 mmol/L (0.06, 0.14). Fixed effects estimates were similar but with smaller effect sizes for HDL cholesterol and triglycerides. For higher SGLT2-inhibitor doses, there was a nominally higher non-significant effect on lipids and lipoproteins. In Asian compared to non-Asian populations, a slightly larger increase in HDL cholesterol and a decrease in triglycerides were observed, but with similar results for total and LDL cholesterol. Treatment effects on lipids and lipoproteins were generally robust across different SGLT2-inhibitor drugs.

CONCLUSION

In meta-analyses, SGLT2-inhibition increased total, LDL, and HDL cholesterol and decreased triglycerides. Effect sizes varied slightly by drug dose and ethnicity but were generally robust by drug type.

Metabolic Syndrome and Ischemic Stroke in Iran: Incidence and Disability-Adjusted Life Years 1990 to 2019

Introduction: Metabolic syndrome (MS) is one of the conditions that may increase the risk of ischemic stroke (IS). This study focuses on factors of MS related to the incidence, years of life lost (YLL), and years of life disability (YLD) caused by IS. Materials and Methods: The age-adjusted data (incidence, YLL, and YLD) related to four factors of MS [fasting plasma glucose, body mass index (BMI), low-density lipoprotein, and systolic blood pressure, SBP] were extracted as risk factors for IS during the years 1990 to 2019 from global burden of disease study. ARC GIS V.10 software was used to investigate the geographical distribution and the Cochran-Armitage test was used to investigate the trend of these indices. Results: The highest incidence of IS was reported in Golestan provinces in 2019 [women: 180 (95% UI 153-213), men: 163 (95% UI 141-191), and both genders: 172 (95% UI 149-201)]. High SBP has the highest impact on YLD (96-102 per 100,000 population in some provinces) and YLL (688-824 per 100,000 population in some provinces) in men and women (YLD: 126-156, YLL: 586-785 per 100,000 population in some provinces). High BMI has increased YLD caused by IS from 1990 (35 per 100,000 population) to 2019 (53 per 100,000 population). Conclusion: Considering the importance of IS and the impact that MS has on this disease, it seems that one of the most effective possible measures is to eliminate MS. The factors of MS are mostly related to lifestyle, and MS can be controlled with a suitable plan, which can be considered as primary prevention for IS.