CKD, plasma lipids, and common carotid intima-media thickness: results from the multi-ethnic study of atherosclerosis

Correlation of renal function indicators and vascular damage in T2DM patients with normal renal function

Background

This study aimed to assess the correlation between renal function-related indices and vascular damages among patients with type 2 diabetes mellitus (T2DM) and normal renal function.

Methods

We screened a cohort of eligible patients with T2DM, ultimately including 826 individuals. Utilizing multifactorial logistic regression, we conducted an in-depth analysis to explore the potential associations between renal function-related indices-specifically BUN, Cr, ALB, ACR, and eGFR-and the incidence of diabetic vascular damage. Additionally, to comprehensively understand the relationships, we employed Spearman correlation analysis to assess the connections between these indicators and the occurrence of vascular damage.

Results

In this cross-sectional study of 532 patients with carotid atherosclerosis (CA), the prevalence of CA was positively correlated with Cr (53.1%, 72.3%, 68.0%, P<0.05) and negatively correlated with eGFR (71.6%, 68.5%, 53.1%, P<0.05). the higher the Cr, the higher the predominance ratio of CA (T1: reference; T2:OR. 2.166,95%CI:1.454,3.225; T3:OR:1.677, 95%CI:1.075, 2.616; P<0.05), along with an eGFR of 66.9% and 52.0% in terms of sensitivity and specificity, with a 95% CI of 0.562-0.644.

Conclusion

Within our experimental sample, a noteworthy observation emerged: Creatinine (Cr) exhibited a positive correlation with the prevalence of individuals affected by carotid atherosclerosis (CA), underscoring a potential connection between Cr levels and CA incidence. Conversely, the estimated Glomerular Filtration Rate (eGFR) demonstrated a negative correlation with the occurrence of CA, implying that lower eGFR values might be associated with an increased likelihood of CA development.

The relationship between asymptomatic atherosclerosis and hepcidin-25 in chronic kidney disease patients

BACKGROUND

The most common and lethal consequence of chronic kidney disease (CKD) is atherosclerotic cardiovascular disease. The persistent inflammation present in CKD increases hepcidin levels. Iron accumulates in the arterial wall in atherosclerosis. Hepcidin-25 was thought to accelerate the development of atherosclerotic plaques by blocking iron release from macrophages. Therefore, we sought to determine the relationship between hepcidin-25 and asymptomatic atherosclerosis in non-dialysis CKD patients.

OBJECTIVES

Investigate the relationship between hepcidin-25 and subclinical atherosclerosis in non-dialysis CKD patients.

DESIGN

Cross-sectional SETTINGS: Outpatient clinic for urology and nephrology at a university hospital SUBJECTS AND METHODS: Participants above the age of 18 years included a group of healthy controls and a group of CKD patients who were not routinely maintained on hemodialysis. The latter group was further divided according to eGFR into CKD-3, CKD-4 and CKD-5 subgroups. We excluded patients with comorbidities, patients with chronic liver disease, and other conditions or habits. CBC, kidney function tests, and serum levels of hepcidin-25 (SH-25), TNF-α, IL-6, high-sensitivity C-reactive protein (hs-CRP), TC, TG, LDL-C and HDL-C were assessed. To measure carotid intima media thickness (CIMT) and determine presence of plaques, carotid ultrasonography was performed. The near or far walls of common carotid artery, bulb, and internal carotid artery were used to measure CIMT.

MAIN OUTCOME MEASURES

SH-25 association and indicators of subclinical atherosclerosis.

SAMPLE SIZE

128 participants, the control group (n=25) and the non-hemodialysis CKD patients (n=103) RESULTS: The CKD patients had significantly higher serum levels of markers of inflammation including IL-6, TNF-α, and hs-CRP (P<.001 for each) compared to the controls. There was a significantly higher level of TC, TG and LDL-C (P<.001 for each) and a lower level of HDL-C (P<.001) in the CDK patients compared to controls. SH-25 was considerably higher in all CKD subgroups, especially with progression of CKD. CIMT was increased in CKD patients especially CKD-4 and CKD-5 subgroups when compared to healthy participants (P<.001 for each). In the patient group, CIMT showed a positive correlation with SH-25, (r=.65 and P<.001), IL-6 (r=.65, P<.001), TNF-α (r=.71, P<.001), and hs-CRP (r=.52, P<.001). The ROC curve study showed that SH-25 (AUC=.86, P<.001), IL-6 (AUC=.83, P<.001), hs-CRP (AUC=.72, P<.001), TNF-α (AUC=.82, P<.001) were strong predictors of subclinical atherosclerosis in the CKD patients.

CONCLUSIONS

SH-25 and CIMT had a positive relationship in CKD patients. The ROC curve showed that SH-25 is a reliable predictor of carotid atherosclerosis. Therefore, we suggest that SH-25 is a vital biomarker of asymptomatic atherosclerosis.

LIMITATIONS

Single-center.

The Role of Dyslipidemia in Atherogenesis in Peritoneal Dialysis Patients

Background

To evaluate atherosclerotic changes in carotid arteries (CCA) in uremic patients before and after 18 months of continuous ambulatory peritoneal dialysis (CAPD) treatment, and to evaluate the impact of dyslipidemia and CAPD treatment on vascular remodeling.

Materials and Methods

We conducted a longitudinal, prospective study during 2020 and 2021 at the Clinic for Nephrology, Clinical Center University of Sarajevo. Patients with end-stage renal disease were included and were followed during 18 months of CAPD treatment. All patients were treated using commercially prepared biocompatible balanced dialysis solutions. Carotid intima-media thickness (IMT) and atherosclerotic plaques on the common carotid artery (CCA) were measured by echotomography.

Results

A total of 50 patients were included and were followed during 18 months of CAPD treatment. Lipid values in the serum of patients with CAPD were significantly lower after 18 months of CAPD treatment compared to the values before treatment, while the value of high-density lipoprotein (HDL) was significantly increased after 18 months of CAPD treatment. The values of IMT and the diameter of the CCA compared to the basal values were significantly lower (P < 0.001).

Conclusion

We demonstrated significantly lower lipid values and higher HDL levels following CAPD treatment. Correct selection of the targeted pharmacological intervention can substantially impact the regression of vascular changes in patients on peritoneal dialysis.

Small Dense Low-Density Lipoprotein Cholesterol and Carotid Intimal Medial Thickness Progression

AIM

The association between small dense low-density lipoprotein cholesterol (sdLDL-C) levels and carotid intimal medial thickness (cIMT) progression has not been evaluated fully. We assessed specialized lipoproteins, including sdLDL-C, with regard to cIMT progression in a prospective observational study in Japan.

METHODS

Plasma total cholesterol, direct LDL-C, sdLDL-C, LDL-triglycerides (LDL-TG), high-density lipoprotein cholesterol (HDL-C), HDL2-C, HDL3-C, triglycerides, Lp(a), and adiponectin were measured in 2,030 men and women (median age 59 years, free of cardiovascular disease (CVD) and off cholesterol lowering medication). At both baseline and after a five-year follow-up, cIMT was assessed. Univariate, multivariate regression, and least square analyses were performed to examine the relationships between direct LDL-C, sdLDL-C, and other lipoproteins with cIMT progression.

RESULTS

The median cIMT at baseline was 0.63 mm and five-year progression was 0.18 mm. After adjustment for standard CVD risk factors, including age, gender, systolic blood pressure, total cholesterol, HDL-C, smoking, diabetes, and hypertension treatment, only direct LDL-C, sdLDL-C, and the sdLDL-C/LDL-C ratio were associated with cIMT progression. Even in subjects with direct LDL-C ＜100 mg/dL, who were considered at low CVD risk, elevated sdLDL-C were associated with cIMT progression (P for trend=0.009) in a model with established CVD risk factors, although the sdLDL-C/LDL-C ratio did not. Those correlations did not change by including triglycerides as a controlling factor or excluding premenopausal women from the analyzed population.

CONCLUSIONS

Small dense LDL-C has a stronger relationship with cIMT progression than LDL-C does; therefore, measuring sdLDL-C may allow for the formulation of optimal therapy for CVD prevention.

Lipid management in patients with chronic kidney disease

An increased risk of cardiovascular disease, independent of conventional risk factors, is present even at minor levels of renal impairment and is highest in patients with end-stage renal disease (ESRD) requiring dialysis. Renal dysfunction changes the level, composition and quality of blood lipids in favour of a more atherogenic profile. Patients with advanced chronic kidney disease (CKD) or ESRD have a characteristic lipid pattern of hypertriglyceridaemia and low HDL cholesterol levels but normal LDL cholesterol levels. In the general population, a clear relationship exists between LDL cholesterol and major atherosclerotic events. However, in patients with ESRD, LDL cholesterol shows a negative association with these outcomes at below average LDL cholesterol levels and a flat or weakly positive association with mortality at higher LDL cholesterol levels. Overall, the available data suggest that lowering of LDL cholesterol is beneficial for prevention of major atherosclerotic events in patients with CKD and in kidney transplant recipients but is not beneficial in patients requiring dialysis. The 2013 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for Lipid Management in CKD provides simple recommendations for the management of dyslipidaemia in patients with CKD and ESRD. However, emerging data and novel lipid-lowering therapies warrant some reappraisal of these recommendations.

Coronary heart disease risk associated with the dyslipidaemia of chronic kidney disease

OBJECTIVE

This study sought to characterise the main dyslipidaemic phenotypes present in chronic kidney disease (CKD) and their association with coronary heart disease (CHD) risk.

METHODS

Analyses included 6612 individuals in the multiethnic study of atherosclerosis free of CHD at baseline. CKD was defined as an estimated glomerular filtration rate (eGFR) of 15 to <60 mL/min/1.73 m² (stages 3-4). Principal component analyses were used to characterise the main dyslipidaemic phenotypes of CKD accounting for the correlation among different lipoproteins and lipoprotein particles. CHD was defined as incident myocardial infarction, angina followed by revascularisation, resuscitated cardiac arrest or CHD death.

RESULTS

CHD developed in 303 individuals (5%) with eGFR ≥60 and in 72 individuals (12%) with CKD (p for difference <0.001). A dyslipidaemic phenotype (principal component 1 (PC1)) consisting of elevations in triglycerides, triglyceride-rich lipoproteins (VLDL particles), small LDL particles and reductions in HDL particles, was more common in those with CKD, compared with those without CKD (p for difference <0.001). This phenotype was also more strongly associated with CHD in those with CKD: adjusted HRs (95% CIs) per SD increase in PC1 1.13 (95% CI 1.00 to 1.27; P=0.05) and 1.51 (95% CI 1.17 to 1.94; P<0.001) in eGFR ≥60 and CKD, respectively (P for interaction=0.05).

CONCLUSION

In individuals with mainly stage 3 CKD, a dominant lipid phenotype consisting of triglyceride-rich lipoproteins and other closely correlated lipoproteins is strongly associated with CHD risk. Future studies should investigate whether modification of the components of this phenotype leads to a reduction in the CHD burden in individuals with CKD.

Mineral metabolism factors predict accelerated progression of common carotid intima-media thickness in chronic kidney disease: the NEFRONA study

Background

The leading cause of premature death in chronic kidney disease (CKD) is cardiovascular disease (CVD), but risk assessment in renal patients is challenging. The aim of the study was to analyse the factors that predict accelerated progression of common carotid intima-media thickness (CCIMT) in a CKD cohort after 2 years of follow-up (2010-12).

Methods

The study included 1152 patients from the NEFRONA cohort with CKD stages 3-5D and without a clinical history of CVD. CCIMT was measured at the far wall on both common carotids. CCIMT progression was defined as the change between CCIMT at baseline and at 24 months for each side, averaged and normalized as change per year. Accelerated progressors were defined as those with a CCIMT change ≥75th percentile.

Results

The median CCIMT progression rate was 0.0125 mm/year, without significant differences between CKD stages. The cut-off value for defining accelerated progression was 0.0425 mm/year. After adjustment, age was a common factor among all CKD stages. Traditional cardiovascular risk factors, such as diabetes and systolic blood pressure, were predictors of progression in CKD stages 4-5, whereas high-density lipoprotein and low-density lipoprotein cholesterol predicted progression in women in stage 3. Mineral metabolism factors predicting accelerated progression were serum phosphorus in stages 3 and 5D; low 25-hydroxyvitamin D and parathyroid hormone levels >110 pg/mL in stages 4-5 and intact parathyroid hormone levels out of the recommended range in stage 5D.

Conclusions

Mineral metabolism parameters might predict accelerated CCIMT progression from early CKD stages.

Signs of subclinical atherosclerosis in asymptomatic patients at increased risk of type 2 diabetes mellitus

AIMS

We aimed to study carotid intima media thickness (CIMT) in asymptomatic patients with an increased risk of type 2 diabetes mellitus (T2DM) and in a pre-diabetic state.

METHODS

Diabetes risk assessment was performed in 2420 participants in a voluntary screening program between 2011 and 2013. The risk of T2DM was estimated by the Findrisc scoring system (FR). A FR≥12 was considered as increased risk. HbA1c% between 5.7 and 6.4% signified a pre-diabetic state. Carotid duplex scan was performed and CIMT above 0.9 mm was regarded as pathological. Patients with T2DM or a history of cardiovascular disease were excluded.

RESULTS

Overall 1475 subjects were included. Four groups were compared: "control" (normal HbA1c, FR<12), "HbA1c only" (HbA1c: 5.7-6.4%, FR<12), "Findrisc only" (normal HbA1c, FR≥12) and "combined" (HbA1c: 5.7-6.4%, FR≥12). Frequency of pathological maximal CIMT was 9.4%, 19.7%, 27.4% and 36.4% in the groups, respectively (p<0.001). Logistic regression analysis revealed that compared to control subjects, sex and risk factor-adjusted Odds Ratios for the presence of pathological maximal CIMT were 2.2 (p<0.001), 3.4 (p<0.001) and 5.1 (p<0.001) for the groups, respectively.

CONCLUSIONS

Evaluation of Findrisc score and HbA1c at population level may facilitate early recognition of subclinical vascular complications even in the pre-diabetic state.

Renal function and carotid atherosclerosis in adults with no known kidney disease

BACKGROUND AND AIMS

A high prevalence of atherosclerotic lesions characterizes patients with chronic kidney disease, though there is little data on the relationship between kidney function and atherosclerotic changes in the healthy population or in people with no known renal impairment. The aim of our study was to analyze, in a comprehensive general population with no known kidney disease, the relationship between renal function and subclinical carotid atherosclerotic damage.

METHODS AND RESULTS

A general real-life population of 611 participants (233 males and 378 females; age ≥18 years) with no known kidney failure was selected for the study. The glomerular filtration rate (GFR) was estimated according to the CKD-EPI equation. Carotid intima-media thickness (c-IMT) and plaques were assessed by duplex Doppler ultrasonography of the carotid vessels. The main laboratory and metabolic parameters were evaluated in all participants. When we divided the overall study population into tertiles according to GFR values (I tertile <85; II tertile: 85-99; III tertile >99 ml/min/1.73 m²), the c-IMT mean values and the prevalence of carotid plaques decreased with the increasing tertile of GFR. On univariate analysis, c-IMT was significantly correlated with eGFR (r = -0.33; p < 0.001), serum creatinine (r = 0.17; p < 0.001), and other variables such as age, systolic blood pressure, waist circumference, fasting or random glycemia, and glycated hemoglobin (HbA₁c). On multiple regression analysis, serum creatinine was associated with c-IMT (β = 0.069; p = 0.017), independent of other covariates.

CONCLUSION

Our study seems to suggest the importance of early identification of people with near normal or mildly decreased renal function due to its association with carotid atherosclerosis.

Association of High-Density Lipoprotein Subclasses with Chronic Kidney Disease Progression, Atherosclerosis, and Klotho

BACKGROUND

Atherosclerosis is often a complication of chronic kidney disease (CKD) because of dyslipidemia and CKD-mineral and bone disorder. High-density lipoproteins (HDLs) are grouped into various subclasses composed of multiple proteins and lipids, and their transformation is altered in CKD. We investigated the roles of lipoprotein subclasses in CKD progression, and atherosclerosis, and the relationships with Klotho and fibroblast growth factor (FGF) 23.

METHODS

Seventy-one CKD patients were enrolled in this prospective cohort study in Japan. The proportions of cholesterol level to total cholesterol level (cholesterol proportion) and lipoprotein particle numbers in 20 lipoprotein fractions were measured by a newly developed high-performance gel permeation chromatography.

RESULTS

Diabetic nephropathy was observed in 23.9% of the patients. The mean age was 75.0 years and estimated glomerular filtration rate (eGFR) was 17.2 ml/min./1.73m2. The lipoprotein particle numbers in small HDLs were higher in Stage 4 group than in Stage 5 group (p = 0.002). Multivariate regression analysis adjusted for baseline characteristics showed that the cholesterol proportions in very small HDLs were associated with eGFR change rate [F19 β = -17.63, p = 0.036] and ABI [F19 β = 0.047, p = 0.047] in Stage 4 group, and that serum soluble α-Klotho level was associated with the lipoprotein particle numbers in very small HDLs [F19 β = 0.00026, p = 0.012; F20 β = 0.00041, p = 0.036] in Stage 5 group.

CONCLUSIONS

This study showed that HDL subclasses are associated with CKD progression, ABI, and Klotho level in CKD-stage-specific manner.

High Density Lipoprotein Cholesterol and the Risk of All-Cause Mortality among U.S. Veterans

BACKGROUND AND OBJECTIVES

The relationship between HDL cholesterol and all-cause mortality in patients with kidney disease is not clear. We sought to characterize the relationship of HDL cholesterol and risk of death and examine the association by eGFR levels.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We built a cohort of 1,764,986 men who were United States veterans with at least one eGFR between October of 2003 and September of 2004 and followed them until September of 2013 or death.

RESULTS

Patients with low HDL cholesterol and low eGFR had a higher burden of comorbid illnesses. Over a median of 9.1 years (interquartile range, 7.7-9.4 years), 26,247 (40.1%), 109,222 (32.3%), 152,625 (29.2%), 113,785 (28.5%), and 139,803 (31.8%) participants with HDL cholesterol ≤25, >25 to <34, ≥34 to ≤42, >42 to <50, and ≥50 mg/dl died. In adjusted survival models, compared with the referent group of patients with low HDL cholesterol (≤25 mg/dl), intermediate HDL cholesterol levels (>25 to <34, ≥34 to ≤42, and >42 to <50 mg/dl) were associated with lower risk of death across all levels of eGFR. The lower risk was partially abrogated in those with high HDL cholesterol (≥50 mg/dl), and the risk of death was similar to the referent category among those with eGFR<30 or ≥90 ml/min per 1.73 m2. Analysis by HDL cholesterol deciles and spline analyses suggest that the relationship between HDL cholesterol and death follows a U-shaped curve. There was a significant interaction between eGFR and HDL cholesterol in that lower eGFR attenuated the salutary association of HDL cholesterol and risk of death (P for interaction <0.01). Presence of coronary artery disease attenuated the lower risk of high HDL cholesterol and all-cause mortality in those with eGFR≥60 ml/min per 1.73 m2 (P for interaction <0.05).

CONCLUSIONS

Our results show a U-shaped relationship between HDL cholesterol and risk of all-cause mortality across all eGFR categories. The risk is modified by eGFR and cardiovascular disease.

Chronic Kidney Disease and Carotid Atherosclerosis in Patients With Acute Stroke

BACKGROUND AND PURPOSE

Chronic kidney disease (CKD) is increasingly recognized as an independent risk factor for cardiovascular disease and stroke. Our aim was to examine the association between estimated glomerular filtration rate (eGFR) and carotid plaques, stenosis and occlusions, and to assess whether CKD and its severity affect carotid atherosclerosis in a cohort of unselected patients with acute stroke.

METHODS

A total of 249 consecutive patients with acute stroke (ischemic or hemorrhagic) were included in this study and baseline eGFR, carotid intima-media thickness (cIMT), and carotid stenosis were evaluated. The eGFR was calculated using the modified Modification of Diet in Renal Disease equation, which was adjusted for data from Chinese CKD patients. An eGFR rate of <60 mL/min/1.73 m was defined as CKD. The cIMT and carotid plaques were detected by carotid ultrasound.

RESULTS

CKD, defined as eGFR<60 mL/min/1.73 m, was found in 66 individuals (26.50%). Among the 5 subtypes, the level of low-density lipoprotein cholesterol was significantly higher in the moderate and severe stenosis groups compared with the normal, elevated cIMT and mild stenosis groups (P<0.01). The value of eGFR gradually decreased with increasing degree of carotid stenosis, and the differences between the groups were statistically significant (P<0.01). On linear regression analysis, eGFR was negatively correlated with the degree of carotid stenosis (r=0.03; P<0.05). On ordinal logistic regression analysis, eGFR was an independent risk factor associated with carotid atherosclerosis (1.05; 95% confidence interval, 0.47-1.63).

CONCLUSIONS

There was a significant burden of atherosclerosis among individuals with CKD. CKD is an independent predictor of carotid plaques, stenoses, and occlusions in patients with acute stroke.

High-sensitivity C-reactive protein, apolipoproteins, and residual diuresis in chronic kidney disease patients undergoing hemodialysis

BACKGROUND

Residual diuresis (RD) is the simplest method for measuring renal residual function in patients with chronic kidney disease (CKD). A reduction in RD is associated with intensification of the inflammatory process caused by uremia. However, little is known regarding the relation between RD and inflammatory markers in these patients. We verify possible associations among the hs-CRP, atherogenic factors, and RD, in patients with CKD undergoing hemodialysis.

METHODS

This study enrolled 80 patients with CKD undergoing hemodialysis. Patients were stratified according to RD in anuric (RD-) group (n = 47) and non-anuric (RD+) group (n = 33). Urine volumes were collected in a 24 h period during the interdialytic period. Serum high-sensitivity C-reactive protein (hs-CRP), and apolipoprotein (Apo) A1 and B levels were measured after fasting for 12 h.

RESULTS

Serum hs-CRP levels were higher in the RD- group than in the RD+ group (P = 0.015). In the total group, hs-CRP was significantly correlated with RD (r = - 0.25, P = 0.025) and Apo AI (r = - 0.25, P = 0.024). A greater proportion of patients had reduced plasma concentrations of Apo AI in the RD- group (31.9 %) compared with the RD+ group (9.1 %) (P = 0.014).

CONCLUSION

This study shows a relationship between RD and the hs-CRP in patients undergoing hemodialysis. Although the inflammatory state was verified in a large part of the CKD population, patients without RD had more elevated hs-CRP serum levels than those with RD.

Predictors of Subclinical Atheromatosis Progression over 2 Years in Patients with Different Stages of CKD

BACKGROUND AND OBJECTIVES

Ultrasonographic detection of subclinical atheromatosis is a noninvasive method predicting cardiovascular events. Risk factors predicting atheromatosis progression in CKD are unknown. Predictors of atheromatosis progression were evaluated in patients with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our multicenter, prospective, observational study included 1553 patients with CKD (2009-2011). Carotid and femoral ultrasounds were performed at baseline and after 24 months. A subgroup of 476 patients with CKD was also randomized to undergo ultrasound examination at 12 months. Progression of atheromatosis was defined as an increase in the number of plaque territories analyzed by multivariate logistic regression.

RESULTS

Prevalence of atheromatosis was 68.7% and progressed in 59.8% of patients after 24 months. CKD progression was associated with atheromatosis progression, suggesting a close association between pathologies. Variables significantly predicting atheromatosis progression, independent from CKD stages, were diabetes and two interactions of age with ferritin and plaque at baseline. Given that multiple interactions were found between CKD stage and age, phosphate, smoking, dyslipidemia, body mass index, systolic BP (SBP), carotid intima-media thickness, plaque at baseline, uric acid, cholesterol, 25-hydroxy vitamin D (25OH vitamin D), and antiplatelet and phosphate binders use, the analysis was stratified by CKD stages. In stage 3, two interactions (age with phosphate and plaque at baseline) were found, and smoking, diabetes, SBP, low levels of 25OH vitamin D, and no treatment with phosphate binders were positively associated with atheromatosis progression. In stages 4 and 5, three interactions (age with ferritin and plaque and plaque with smoking) were found, and SBP was positively associated with atheromatosis progression. In dialysis, an interaction between body mass index and 25OH vitamin D was found, and age, dyslipidemia, carotid intima-media thickness, low cholesterol, ferritin, and uric acid were positively associated with atheromatosis progression.

CONCLUSIONS

Atheromatosis progression affects more than one half of patients with CKD, and predictive factors differ depending on CKD stage.

Correlation between small dense low-density lipoprotein cholesterol and carotid artery intima-media thickness in a healthy Chinese population

BACKGROUND

Small dense low-density lipoprotein cholesterol (sdLDL-C) concentration was useful in the assessment of the presence of cardiovascular diseases (CVD) and its severity. We examined whether SdLDL-C is more closely associated with carotid artery intima-media thickness (CA-IMT), a surrogate measure of atherosclerosis, than LDL-C and traditional CVD risk factors in Chinese healthy subjects.

METHODS

We measured CA-IMT, blood pressure (BP), sdLDL-C, glucose metabolism and lipid in 183 native Chinese healthy subjects. CA-IMT was assessed by ultrasonography, and sdLDL-C concentrations were measured by a homogenous assay. Pearson's correlation coefficient analyses and Multiple regression analyses were used to examine the relationships between CA-IMT values and other clinical variables.

RESULTS

The sdLDL-C level was significantly higher in males than in females (p <0.05) and there was an age effect on sdLDL-C (p <0.05). When the effects of age, gender and other traditional CVD risk factors were adjusted using multiple regression analysis. CA-IMT remained significantly associated with sdLDL-C(β = 0.437, p <0.001).

CONCLUSIONS

There are gender and age differences in sdLDL-C levels among a healthy Chinese population. Moreover, we found adjusted traditional CVD risk factors such as higher age, male sex, and other traditional CVD risk factors, the association between CA-IMT and SdLDL-C remained significant. sdLDL-C is may be a useful predictor in the assessment of CA-IMT in Chinese population.

High-Density Lipoprotein Subfractions and Their Oxidized Subfraction Particles in Patients with Chronic Kidney Disease

AIM

Chronic kidney disease (CKD) may lead to reduced concentrations of high-density lipoprotein (HDL) and its subfractions (HDL2 and HDL3), and damage them via inflammation and oxidative stress. The present study aimed to determine the contribution of such changes to cardiovascular disease (CVD) in patients with CKD.

METHODS

The levels of total cholesterol, low-density lipoprotein cholesterol, HDL-C, HDL2, HDL3, apolipoproteins, malondialdehyde-modified LDL (MDA-LDL), oxidized (ox) HDL, oxHDL2, and oxHDL3 were measured in blood samples from patients with CKD (stages 2-5, n=86) who were not on dialysis and from patients undergoing hemodialysis (CKD stage 5D, n=25). The patients were followed up for 28±9 months after baseline examinations and CVD events were recorded.

RESULT

The levels of HDL3 and ApoA1 in HDL3 fraction decreased according to CKD severity, whereas those of HDL2 and ApoA1 in HDL2 fraction did not differ. The levels of oxHDL were similar across CKD stages. The levels of oxHDL3 and MDA-LDL were decreased, whereas those of oxHDL2 increased according to CKD severity. Multivariate analyses using the Cox proportional hazards model selected high levels of oxHDL and its subfractions, and those adjusted with HDL-C and HDL subfractions or ApoA1 in HDL fractions respectively, compared with HDL-C and HDL subfractions or ApoA1 in HDL fractions alone as independent risk factors for CVD events.

CONCLUSION

The levels of HDL subfractions and their oxidized subfraction particles differed among patients with CKD. The increasing levels of oxHDL subfractions might cause a high frequency of CVD events in such patients.

Residual Cardiovascular Risk in Chronic Kidney Disease: Role of High-density Lipoprotein

Although reducing low-density lipoprotein-cholesterol (LDL-C) levels with lipid-lowering agents (statins) decreases cardiovascular disease (CVD) risk, a substantial residual risk (up to 70% of baseline) remains after treatment in most patient populations. High-density lipoprotein (HDL) is a potential contributor to residual risk, and low HDL-cholesterol (HDL-C) is an established risk factor for CVD. However, in contrast to conventional lipid-lowering therapies, recent studies show that pharmacologic increases in HDL-C levels do not bring about clinical benefits. These observations have given rise to the concept of dysfunctional HDL where increases in serum HDL-C may not be beneficial because HDL loss of function is not corrected by or even intensified by the therapy. Chronic kidney disease (CKD) increases CVD risk, and patients whose CKD progresses to end-stage renal disease (ESRD) requiring dialysis are at the highest CVD risk of any patient type studied. The ESRD population is also unique in its lack of significant benefit from standard lipid-lowering interventions. Recent studies indicate that HDL-C levels do not predict CVD in the CKD population. Moreover, CKD profoundly alters metabolism and composition of HDL particles and impairs their protective effects on functions such as cellular cholesterol efflux, endothelial protection, and control of inflammation and oxidation. Thus, CKD-induced perturbations in HDL may contribute to the excess CVD in CKD patients. Understanding the mechanisms of vascular protection in renal disease can present new therapeutic targets for intervention in this population.

Relationship between carotid artery intima-media thickness and small dense low-density lipoprotein cholesterol concentrations measured by homogenous assay in Japanese subjects

BACKGROUND

Small dense low-density lipoprotein cholesterol (sdLDL-C) concentrations correlate more strongly with coronary heart disease than other LDL-C and large LDL particle concentrations. We investigated the association between carotid artery intima-media thickness (IMT) and sdLDL-C concentrations in Japanese subjects.

METHODS

Carotid artery IMT, blood pressure (BP), fasting plasma sdLDL-C, glucose metabolism, lipid, and C-reactive protein concentrations were measured in 97 native Japanese subjects. Carotid artery IMT was assessed by ultrasonography, and sdLDL-C concentrations were measured by a homogenous assay. Pearson's correlation coefficient analyses and multiple regression analyses were used to examine the relationships between carotid artery IMT values, sdLDL-C values, and other clinical variables.

RESULTS

After multiple regression analysis, including age, sex, body mass index, systolic BP, diastolic BP, fasting plasma glucose, HbA1c, estimated glomerular filtration rate (eGFR), total-C, high-density lipoprotein (HDL)-C, triglyceride, LDL-C, non-HDL-C, large buoyant LDL-C, and sdLDL-C, carotid artery IMT remained significantly associated with age, systolic BP, diastolic BP, and sdLDL-C, whereas sdLDL-C remained significantly associated with age, total-C, HDL-C, triglycerides, and carotid artery IMT.

CONCLUSIONS

When measured by a homogenous assay, carotid artery IMT may have a closer relationship with sdLDL-C concentrations than other lipid parameters in Japanese subjects. sdLDL-C may be a potentially useful risk marker when assessing carotid artery IMT in Japanese subjects.

Importance of high-density lipoprotein quality: evidence from chronic kidney disease

PURPOSE OF REVIEW

This review will examine advances in our understanding of the association between high-density lipoprotein (HDL) function and cardiovascular disease (CVD) in patients with chronic kidney disease (CKD).

RECENT FINDINGS

Large randomized statin trials and related meta-analyses confirm that lipid-lowering therapy benefits patients with mild to moderate CKD, leaving a degree of residual cardiovascular risk similar to that documented in the general population. However, patients with advanced CKD on dialysis show little to no cardiovascular benefits from lipid-lowering therapy and have an exaggerated residual cardiovascular risk. HDL quantity and functionality may explain some of the residual risk. CKD modulates the level, composition and functionality of HDL, including impaired cholesterol acceptor function and pro-inflammatory effects. Although these abnormalities prevail in CKD, they do not track together and thus support the idea of separate and distinct mechanistic pathways for each of these critical functions of HDL.

SUMMARY

CKD-induced perturbations in HDL composition, metabolism and functionality may contribute to the excess CVD in patients with CKD and present new therapeutic targets for intervention in this population.

HDL cholesterol is not associated with lower mortality in patients with kidney dysfunction

In the general population, HDL cholesterol (HDL-C) is associated with reduced cardiovascular events. However, recent experimental data suggest that the vascular effects of HDL can be heterogeneous. We examined the association of HDL-C with all-cause and cardiovascular mortality in the Ludwigshafen Risk and Cardiovascular Health study comprising 3307 patients undergoing coronary angiography. Patients were followed for a median of 9.9 years. Estimated GFR (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration eGFR creatinine-cystatin C (eGFRcreat-cys) equation. The effect of increasing HDL-C serum levels was assessed using Cox proportional hazard models. In participants with normal kidney function (eGFR>90 ml/min per 1.73 m(2)), higher HDL-C was associated with reduced risk of all-cause and cardiovascular mortality and coronary artery disease severity (hazard ratio [HR], 0.51, 95% confidence interval [95% CI], 0.26-0.92 [P=0.03]; HR, 0.30, 95% CI, 0.13-0.73 [P=0.01]). Conversely, in patients with mild (eGFR=60-89 ml/min per 1.73 m(2)) and more advanced reduced kidney function (eGFR<60 ml/min per 1.73 m(2)), higher HDL-C did not associate with lower risk for mortality (eGFR=60-89 ml/min per 1.73 m(2): HR, 0.68, 95% CI, 0.45-1.04 [P=0.07]; HR, 0.84, 95% CI, 0.50-1.40 [P=0.50]; eGFR<60 ml/min per 1.73 m(2): HR, 1.18, 95% CI, 0.60-1.81 [P=0.88]; HR, 0.82, 95% CI, 0.40-1.69 [P=0.60]). Moreover, Cox regression analyses revealed interaction between HDL-C and eGFR in predicting all-cause and cardiovascular mortality (P=0.04 and P=0.02, respectively). We confirmed a lack of association between higher HDL-C and lower mortality in an independent cohort of patients with definite CKD (P=0.63). In summary, higher HDL-C levels did not associate with reduced mortality risk and coronary artery disease severity in patients with reduced kidney function. Indeed, abnormal HDL function might confound the outcome of HDL-targeted therapies in these patients.

Biomarkers of dairy fatty acids and risk of cardiovascular disease in the Multi-ethnic Study of Atherosclerosis

BACKGROUND

Evidence regarding the role of dairy fat intake in cardiovascular disease (CVD) has been mixed and inconclusive. Most earlier studies have used self-reported measures of dietary intake and focused on relatively racially homogeneous populations. Circulating biomarkers of dairy fat in a multiethnic cohort provide objective measures of dairy fat intake and facilitate conclusions relevant to populations with different diets and susceptibility to CVD.

METHODS AND RESULTS

In a multiethnic cohort of 2837 US adults aged 45 to 84 years at baseline (2000-2002), phospholipid fatty acids including 15:0, 14:0, and trans-16:1n7 were measured using standardized methods, and the incidence of CVD prospectively adjudicated. Self-reported whole-fat dairy and butter intakes had strongest associations with 15:0, rather than 14:0 or trans-16:1n7. In multivariate models including demographics and lifestyle and dietary habits, each SD-unit of 15:0 was associated with 19% lower CVD risk (hazard ratio [95% CI] 0.81 [0.68 to 0.98]) and 26% lower coronary heart disease (CHD) risk (0.74 [0.60 to 0.92]). Associations were strengthened after mutual adjustment for 14:0 and trans-16:1n-7 and were similar after adjustment for potential mediators. Plasma phospholipid 14:0 and trans-16:1n-7 were not significantly associated with incident CVD or CHD. All findings were similar in white, black, Hispanic, and Chinese American participants.

CONCLUSION

Plasma phospholipid 15:0, a biomarker of dairy fat, was inversely associated with incident CVD and CHD, while no association was found with phospholipid 14:0 and trans-16:1n-7. These findings support the need for further investigation of CVD effects of dairy fat, dairy-specific fatty acids, and dairy products in general.