Association of hypertension with small, dense low-density lipoprotein in patients without metabolic syndrome

Elevated small dense low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio is associated with an increased risk of metabolic dysfunction associated fatty liver disease in Chinese patients with type 2 diabetes mellitus

INTRODUCTION

It is demonstrated that elevated small dense low-density lipoprotein cholesterol (sdLDL-C), and reduced high-density lipoprotein cholesterol (HDL-C) is associated with Metabolic dysfunction-associated fatty liver disease (MAFLD). This study aims to explore the relationship between sdLDL-C to HDL-C ratio (SHR) and MAFLD in Chinese patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

A cross-sectional study was performed among 1904 patients with T2DM. Weighted multivariable logistic regression analysis was conducted to explore the relationship between the SHR and the risk of MAFLD. In addition, this study used a two-part linear regression model to identify threshold effects. Subgroup analysis, interaction tests and receiver operating characteristic (ROC) curve analysis were also carried out.

RESULTS

The overall MAFLD prevalence reached 48.1%. Multiple logistic regression analysis showed that SHR was positively correlated with the risk of MAFLD (OR = 2.37, 95% CI = 1.80-3.12). Subgroup analysis stratified by age, gender, hypertension and BMI showed that there was a consistent positive correlation. A non-linear relationship and saturation effect between SHR and MAFLD risk were identified, with an inverted L shaped curve and an inflection point at 1.02. The area under the curve (AUC) for SHR in the ROC analysis was significantly greater than sdLDL-C and HDL-C, with a sensitivity of 71.2% and a specificity of 62.1%.

CONCLUSIONS

Elevated levels of SHR is independently associated with an increased risk of MAFLD in patients with T2DM. SHR may be taken as practical indicators to assess the risk of MAFLD in T2DM patients.

An increase in calculated small dense low-density lipoprotein cholesterol predicts new onset of hypertension in a Japanese cohort

A disorder of lipid metabolism is involved in cardiovascular diseases including hypertension. A high level of small dense low-density lipoprotein cholesterol (sdLDL-C) is a strong risk factor for atherosclerotic cardiovascular disease. However, the association between sdLDL-C and hypertension has not been fully investigated. We investigated the associations between the development of hypertension during a 10-year period and levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglycerides (TG), and LDL-C and sdLDL-C calculated by using the Sampson equations in 28,990 Japanese subjects who received annual health examinations. After exclusion of subjects with missing data, those with hypertension, and those with TG ≥ 800 mg/dL at baseline, a total of 15,177 subjects (men/women: 9374/5803, mean age: 46 years) were recruited. During the 10-year period, 2379 men (25.4%) and 724 women (12.5%) had new onset of hypertension. Multivariable Cox proportional hazard model analyses showed that levels of HDL-C, non-HDL-C, TG and sdLDL-C, but not levels of TC and LDL-C, were independent risk factors for the development of hypertension after adjustment of age, sex, family history of hypertension, systolic blood pressure, obesity, current smoking habit, alcohol drinking habit, estimated glomerular filtration rate, diagnosis of diabetes mellitus and use of lipid-lowering drugs and that the adjusted risk of sdLDL-C (per 1-standard deviation) was highest (hazard ratio [95% confidence interval: 1.09 [1.05-1.13]). The addition of sdLDL-C to traditional risk factors for hypertension significantly improved the discriminatory capability, which was better than that of other lipid fractions. In conclusion, a high level of calculated sdLDL-C predicts the development of hypertension.

Small dense low-density lipoprotein: Analytical review

BACKGROUND

The causal relationship between low-density lipoprotein (LDL) and atherosclerotic cardiovascular disease (CVD) has been firmly substantiated. LDL consists of a heterogeneous group of particles with different physicochemical and metabolic properties. Among them, small dense LDL (sdLDL) particles are considered an emerging CVD risk factor and a promising CVD risk biomarker. This paper reviews published analytical and calculation-based methods for sdLDL determination in plasma, present their principles, strengths, and weaknesses, and examine the challenges arising from method comparison.

METHODS

A literature survey was conducted using the PubMed database. Subject headings and keywords facilitated the search strategy. Titles and abstracts were initially assessed, and the full-text article of the pre-selected ones was reviewed.

RESULTS

A range of methods is currently available for the analysis of LDL subfractions and the measurement of sdLDL particle size, number, and cholesterol concentration. Ultracentrifugation (UC), vertical auto profile, gradient gel electrophoresis (GGE), nuclear magnetic resonance (NMR) spectroscopy, high-performance liquid chromatography, ion mobility analysis, and a homogeneous assay are the most prevalent. To date, there is no "gold standard". UC and GGE are the most established techniques, albeit significantly sophisticated. NMR and the homogeneous assay are options with potential clinical use as they yield results rapidly and can be high-throughput. None of the proposed equations for the calculated sdLDL determination has been sufficiently validated to serve as a clinical tool.

CONCLUSIONS

Many analytical procedures have been developed for the study of sdLDL particles. Their use remains largely restricted to research laboratories since their analytical and clinical performance, along with the clinical- and cost-effectiveness of sdLDL determination have not been fully established.

Association of small dense LDL-cholesterol with disease severity, hypertension status and clinical outcome in patients with coronary artery disease

OBJECTIVE

Previous studies have demonstrated that small dense LDL-cholesterol (sdLDL-C) is related to the pathogenesis of coronary artery disease (CAD). However, its prognostic role in hypertensive patients with CAD has been undetermined. The aim of the study was to investigate the association between sdLDL-C with disease severity, hypertensive status and clinical outcome in patients with CAD.

METHODS

A total of 4594 patients with angiography-proven CAD were consecutively enrolled and categorized into subgroups according to blood pressure status. Serum sdLDL-C levels were measured by direct quantitative measurement using automated chemistry analyzers. The severity of coronary artery lesions were determined by Gensini score, Syntax score and the number of lesion vessels. The associations of sdLDL-C with disease severity, hypertensive status and cardiovascular events (CVEs) were evaluated.

RESULTS

Patients with hypertension had higher sdLDL-C levels than ones without (P = 0.010). In hypertensive patients, sdLDL-C was positively associated with the severity of CAD (P < 0.05). In addition, hypertensive patients with poorly controlled hypertension had higher sdLDL-C levels than those with well controlled (P < 0.05). Moreover, 149 CVEs occurred in patients with poorly controlled hypertension and Cox regression analysis indicated that elevated sdLDL-C levels were independently associated with CVEs in hypertensive patients with poorly controlled hypertension (adjusted hazard ratio: 1.673, 95% confidence interval: 1.105-2.535, P = 0.015).

CONCLUSION

The current data, for the first time, showed that serum sdLDL-C levels were correlated with hypertension control, disease severity and worse outcomes in hypertensive patients with CAD, suggesting that paying more attention on sdLDL-C in these patients were warranted.

Lipid Abnormalities in Patients With Cushing's Disease and Its Relationship With Impaired Glucose Metabolism

PURPOSE

Dyslipidemia has been frequently reported and associated with increased cardiovascular risk in patients with Cushing's disease (CD). Few studies are available regarding the relationships between lipid abnormalities and other preoperative metabolic comorbidities in CD, and the data on alterations of the lipid profile after surgery is quite variable. We aimed to investigate the associations between hyperlipidemia and other baseline metabolic and hormonal parameters and the impact of surgical remission on lipid metabolism in patients with CD.

METHODS

This retrospective study included 104 patients diagnosed with CD. Baseline hormonal and metabolic parameters were compared between the hyperlipidemia (HLP) group and non-hyperlipidemia (NLP) group, and their relationships with hyperlipidemia at diagnosis were evaluated. Alterations in lipid profiles after surgical remission of CD were evaluated in 65 patients with available follow-up data.

RESULTS

Upon baseline, logistic regression analysis showed that impaired glucose metabolism (IGM) (OR=4.68, 95%CI:1.38-15.91) and morning cortisol levels (per 10 μg/dl change) (OR=1.81, 95%CI:1.11-2.95) are both independent risk factors of preoperative occurrence of hyperlipidemia in patients with CD. The baseline triglyceride (TG) level was positively correlated with systolic blood pressure (SBP) (r=0.297, p=0.003). Lipid abnormalities had improvement but may persist after surgical remission, and the persisted hyperlipidemia is associated with higher baseline total cholesterol (TC) levels (r=0.505, p=0.033).

CONCLUSIONS

Persistence of post-surgery hyperlipidemia is associated with severe baseline lipid abnormalities. Surgical remission with concomitant control of impaired glucose metabolism at diagnosis may have significant implications for controlling hyperlipidemia and reducing cardiovascular risk in CD.

Evaluation of lipid profile and its relationship with blood pressure in patients with Cushing's disease

INTRODUCTION

The purpose of the study was to describe lipid profile and explore pathogenetic role of LDL-c on hypertension in patients with Cushing's disease (CD). Hypertension is a common feature in patients with CD. Previous study found low-density lipoprotein cholesterol (LDL-c) uptake in vascular cells might be involved in vascular remodeling in patients with CD. Therefore, we evaluated the relationship between lipid profile and the blood pressure in patients with CD.

METHODS

This retrospective study included 84 patients referred to Huashan Hospital for the evaluation and diagnosis of CD from January 2012 to December 2013. All subjects had detailed clinical evaluation by the same group of endocrinology specialists to avoid subjective influences.

RESULTS

We found that high LDL-c patients had significant higher body mass index (BMI), systolic blood pressure (SBP), cholesterol (CHO), triglyceride (TG), and apolipoproteinB (apoB) (P < 0.05). An association was detected between SBP values and lipids profile including CHO, TG, LDL-c, apolipoproteinA (apoA), apoB and lipoprotein(a) (LP(a)). After adjustment for all covariates, the LDL-c remained positively associated with SBP. In patients with or without taking statins, patients with LDL-c ≥3.37 mmol/L had higher SBP than patients with LDL-c <3.37 mmol/L. Then, LDL-c was coded using restricted cubic splines (RCS) function with three knots located at the 5th, 50th and 95th percentiles of the distribution of LDL-c. Compared to individuals with 3.215 mmol/L of LDL-c, individuals with 4.0, 4.5 and 5.0 mmol/L of LDL-c had differences of 3.86, 8.53 and 14.11 mmHg in SBP, respectively.

CONCLUSIONS

An independent association between LDL-c and SBP was found in patients with CD. We speculate that LDL-c may be a pathogenic factor for hypertension in those patients.

EPHA6 rs4857055 C > T polymorphism associates with hypertension through triglyceride and LDL particle size in the Korean population

BACKGROUND

Erythropoietin-producing human hepatocellular (Eph) receptors might contribute to the development of atherosclerosis. A genome-wide association study indicated that the Eph receptor A6 gene (EPHA6) associated with at least 1 blood pressure (BP) phenotype. The objective of the present study was to determine whether EPHA6 is a novel candidate gene for hypertension in a Korean population.

METHODS

A total 2146 study participants with normotension and hypertension were included. Genotype data were obtained using a Korean Chip. To assess the association between single-nucleotide polymorphisms (SNPs) and BP, we performed a linear regression analysis, which showed that rs4850755 in the EPHA6 gene was the SNP most highly associated with both systolic and diastolic BP.

RESULTS

The presence of the TT genotype of the EPHA6 rs4857055 C > T SNP was associated with a higher risk of hypertension after adjusting for age, sex, body mass index (BMI), smoking, and drinking [odds ratio 1.533, P = 0.001]. In the control group, significant associations were observed between systolic BP and the rs4857055 polymorphism and between diastolic BP and the rs4857055 polymorphism. In the hypertension group, a significant association was observed between systolic BP and the rs4857055 polymorphism. In the hypertension group, subjects with the TT genotype showed significantly higher systolic BP than CC subjects. Additionally, in the hypertension group, TT carriers showed a higher tendency of serum triglyceride (P = 0.069) and significantly higher apolipoprotein B (P = 0.015) and smaller low-density lipoprotein (LDL) particle size (P < 0.001) than either TC or CC subjects.

CONCLUSIONS

These results could suggest that the EPHA6 rs4857055 C > T SNP is a novel candidate gene for hypertension in the Korean population. Additionally, the TT genotype could be associated with hypertriglyceridemia and small LDL particle size in hypertension.

Hypertriglyceridemia is a major factor associated with elevated levels of small dense LDL cholesterol in patients with metabolic syndrome

BACKGROUND

We aimed to determine the major contributing component of metabolic syndrome (MetS) that results in an elevated small dense LDL cholesterol (sdLDL-C) concentration and sdLDL-C/LDL-C ratio.

METHODS

Four hundred and forty-seven subjects (225 men; 222 women) with MetS were randomly selected from the Korean Metabolic Syndrome Research Initiatives-Seoul cohort study. Age- and sex-matched healthy controls (181 men; 179 women) were also randomly selected from the same cohort.

RESULTS

A comparison of the median values of the sdLDL-C concentration between subgroups, divided according to whether subjects met or did not meet the criteria for each MetS component in patients with MetS, revealed a significant difference in the sdLDL-C concentration only between subgroups divided according to whether subjects met or did not meet the triglyceride (TG) criteria (P<0.05 for each gender). The TG level showed a good correlation with sdLDL-C concentration (correlation coefficients [r]=0.543 for men; 0.653 for women) and the sdLDL-C/LDL-C ratio (r=0.789 for men; 0.745 for women). Multiple linear regression analyses conducted for the MetS group concordantly identified TG as one of the most significant contributors to sdLDL-C concentration (β=0.1747±0.0105, P<0.0001) and the sdLDL-C/LDL-C ratio (β=6.9518±0.3011, P<0.0001).

CONCLUSIONS

Among five MetS components, only the abnormal TG level was a differentiating factor for sdLDL-C concentration and sdLDL-C/LDL-C ratio. These results were reproducible in both genders, with or without MetS.

Distribution of High-Density Lipoprotein Subfractions and Hypertensive Status: A Cross-Sectional Study

The exact mechanisms of hypertension contributing to atherosclerosis have not been fully elucidated. Although multiple studies have clarified the association with low-density lipoprotein (LDL) subfractions, uncertainty remains about its relationship with high-density lipoprotein (HDL) subfractions. Therefore, we aimed to comprehensively determine the relationship between distribution of HDL subfractions and hypertensive status.A total of 953 consecutive subjects without previous lipid-lowering drug treatment were enrolled and were categorized based on hypertension history (with hypertension [n = 550] or without hypertension [n = 403]). Baseline clinical and laboratory data were collected. HDL separation was performed using the Lipoprint System.Plasma large HDL-cholesterol (HDL-C) and large HDL percentage were dramatically lower whereas the small HDL-C and small HDL percentage were higher in patients with hypertension (all P < 0.05). The antihypertensive drug therapy was not associated with large or small HDL subfractions (on treatment vs not on treatment, P > 0.05; combination vs single drug therapy, P > 0.05). However, the blood pressure well-controlled patients have significantly lower small HDL subfraction (P < 0.05). Moreover, large HDL-C and percentage were inversely whereas small HDL percentage was positively associated with incident hypertension after adjusting potential confounders (all P < 0.05). In the multivariate model conducted in patients with and without hypertension separately, the cardio-protective value of large HDL-C was disappeared in patients with hypertension (OR 95%CI: 1.011 [0.974-1.049]).The distribution of HDL subfractions is closely associated with hypertensive status and hypertension may potentially impact the cardio-protective value of large HDL subfraction.

LDL-migration index (LDL-MI), an indicator of small dense low-density lipoprotein (sdLDL), is higher in non-alcoholic steatohepatitis than in non-alcoholic fatty liver: a multicenter cross-sectional study

Background

Non-alcoholic fatty liver disease (NAFLD) is associated with increased risks of atherosclerotic diseases, including cardiovascular disease. However, the difference in risk between patients with non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH) has not yet been determined. Accumulating evidence has shown that high amounts of small dense low-density lipoprotein (sdLDL) are closely associated with atherosclerotic diseases. This study investigated differences in risk factors for atherosclerotic diseases, especially LDL-migration index (LDL-MI), an indicator of sdLDL, between patients with NAFL and NASH.

Methods

LDL-MI was analyzed in a primary cohort of 156 patients with NAFLD, including 53 with NAFL and 103 with NASH, and a validation cohort of 69 patients with NAFLD, including 25 with NAFL and 44 with NASH.

Results

In the primary cohort, NASH was associated with elevated LDL-MI (p = 0.039). Multiple regression analysis showed that NASH and the non-use of lipid lowering medications were independently correlated with higher LDL-MI in all patients with NAFLD. Among patients not on lipid lowering medications, those with NASH had significantly higher LDL-MI than those with NAFL (p = 0.001). These findings were confirmed in a validation cohort, in that LDL-MI was significantly higher in patients with NASH than with NAFL (p = 0.043).

Conclusion

This study is the first to show that LDL-MI, an indicator of sdLDL, was higher in patients with NASH than with NAFL, suggesting that the risk of atherosclerotic diseases may be higher in NASH than NAFL. Patients with NASH should be followed closely, especially for the progression of liver pathology and atherosclerotic diseases.

Trial Registration

UMIN000009614

Lipoprotein subfractions in metabolic syndrome and obesity: clinical significance and therapeutic approaches

Small, dense low density lipoprotein (sdLDL) represents an emerging cardiovascular risk factor, since these particles can be associated with cardiovascular disease (CVD) independently of established risk factors, including plasma lipids. Obese subjects frequently have atherogenic dyslipidaemia, including elevated sdLDL levels, in addition to elevated triglycerides (TG), very low density lipoprotein (VLDL) and apolipoprotein-B, as well as decreased high density lipoprotein cholesterol (HDL-C) levels. Obesity-related co-morbidities, such as metabolic syndrome (MetS) are also characterized by dyslipidaemia. Therefore, agents that favourably modulate LDL subclasses may be of clinical value in these subjects. Statins are the lipid-lowering drug of choice. Also, anti-obesity and lipid lowering drugs other than statins could be useful in these patients. However, the effects of anti-obesity drugs on CVD risk factors remain unclear. We review the clinical significance of sdLDL in being overweight and obesity, as well as the efficacy of anti-obesity drugs on LDL subfractions in these individuals; a short comment on HDL subclasses is also included. Our literature search was based on PubMed and Scopus listings. Further research is required to fully explore both the significance of sdLDL and the efficacy of anti-obesity drugs on LDL subfractions in being overweight, obesity and MetS. Improving the lipoprotein profile in these patients may represent an efficient approach for reducing cardiovascular risk.

Lipoprotein subfractions in metabolic syndrome and obesity: clinical significance and therapeutic approaches

Small, dense low density lipoprotein (sdLDL) represents an emerging cardiovascular risk factor, since these particles can be associated with cardiovascular disease (CVD) independently of established risk factors, including plasma lipids. Obese subjects frequently have atherogenic dyslipidaemia, including elevated sdLDL levels, in addition to elevated triglycerides (TG), very low density lipoprotein (VLDL) and apolipoprotein-B, as well as decreased high density lipoprotein cholesterol (HDL-C) levels. Obesity-related co-morbidities, such as metabolic syndrome (MetS) are also characterized by dyslipidaemia. Therefore, agents that favourably modulate LDL subclasses may be of clinical value in these subjects. Statins are the lipid-lowering drug of choice. Also, anti-obesity and lipid lowering drugs other than statins could be useful in these patients. However, the effects of anti-obesity drugs on CVD risk factors remain unclear. We review the clinical significance of sdLDL in being overweight and obesity, as well as the efficacy of anti-obesity drugs on LDL subfractions in these individuals; a short comment on HDL subclasses is also included. Our literature search was based on PubMed and Scopus listings. Further research is required to fully explore both the significance of sdLDL and the efficacy of anti-obesity drugs on LDL subfractions in being overweight, obesity and MetS. Improving the lipoprotein profile in these patients may represent an efficient approach for reducing cardiovascular risk.