Estimated small dense low-density lipoprotein-cholesterol and the risk of kidney and cardiovascular outcomes in diabetic kidney disease.

AIMS: This study aimed to investigate the correlations between estimated small dense low-density lipoprotein-cholesterol (esd-LDL-c) and the development of end-stage kidney disease (ESKD), cardiovascular mortality, and all-cause mortality in individuals with diabetic kidney disease (DKD) or diabetes mellitus (DM) concomitant chronic kidney disease (CKD). METHODS: We analyzed the data from a biopsy-proven DKD cohort conducted at West China Hospital of Sichuan University between 2009 and 2021 (the DKD cohort) and participants with DM and CKD in the National Health and Nutrition Examination Survey (NHANES) 2011-2014 (the NHANES DM-CKD cohort). Cox regression analysis was also used to estimate associations between esd-LDL-c and the incidence of ESKD, cardiovascular mortality, and all-cause mortality. RESULTS: There were 175 ESKD events among 338 participants in the DKD cohort. Patients were divided into three groups based on esd-LDL-c tertiles (T1 < 33.7 mg/dL, T2 ≥ 33.7 mg/dL to <45.9 mg/dL, T3 ≥ 45.9 mg/dL). The highest tertile of esd-LDL-c was associated with ESKD (adjusted HR 2.016, 95% CI 1.144-3.554, p = .015). Furthermore, there were 99 deaths (39 cardiovascular) among 293 participants in the NHANES DM-CKD cohort. Participants were classified into three groups in line with the tertile values of esd-LDL-c in the DKD cohort. The highest tertile of esd-LDL-c was associated with cardiovascular mortality (adjusted HR 3.95, 95% CI 1.3-12, p = .016) and all-cause mortality (adjusted HR 2.37, 95% CI 1.06-5.32, p = .036). CONCLUSIONS: Higher esd-LDL-c was associated with increased risk of ESKD in people with biopsy-proven DKD, and higher cardiovascular and all-cause mortality risk among those with DM-CKD.

The Relationship Between Small Dense Low-Density Lipoprotein Cholesterol and Metabolic Syndrome.

Background: Prior research has established an association between small dense low-density lipoprotein cholesterol (sdLDL-C) and dyslipidemia, serving as a significant marker for predicting cardiovascular diseases. Nevertheless, the connection between sdLDL-C and metabolic syndrome (MetS) remains unclear. Methods: This study retrospectively analyzed 23,187 individuals who underwent health checkups at Taizhou Hospital's health management center. Here, we investigated the relationship between sdLDL-C and MetS, along with its components, utilizing Spearman correlation analysis, receiver operating characteristic (ROC) curve analysis, logistic regression, and mediation analysis. Results: The MetS group exhibited significantly higher level of sdLDL-C compared to the non-MetS group (P<0.001). We observed a strong correlation between sdLDL-C and several key factors: TG (r = 0.711), TC (r = 0.672), LDL-C (r = 0.781), GGT (r = 0.420), and HDL-C (r = -0.417). After adjusting for age and gender, the odds ratio (OR) (95% confidence interval [CI]) for MetS incidence in the second, third, and fourth quartiles versus the first quartile of sdLDL-C concentration were 2.264 (95% CI: 1.851, 2.770), 4.053 (95% CI: 3.350, 4.903), and 9.034 (95% CI: 7.531, 10.837). The optimal cut-off value for diagnosing MetS using sdLDL-C was determined to be 0.98 mmol/L, with an area under the ROC curve (AUC) of 0.716 (95% CI: 0.705, 0.726). Additionally, mediation analysis revealed that sdLDL-C mediated a 12.8% correlation between GGT and TG concentration. Conclusion: The sdLDL-C is correlated with MetS and it can successfully mediate the relationship between GGT and TG. Our data suggests that sdLDL-c and GGT are suitable parameters for preventing and monitoring MetS.

Small dense low-density lipoprotein cholesterol and coronary artery calcification in the Multi-Ethnic Study of Atherosclerosis.

AIMS: Elevated small dense LDL cholesterol (sd-LDL-C) increases atherosclerotic cardiovascular disease (CVD) risk. Although coronary artery calcification (CAC) is widely used for predicting CVD events, few studies have examined the relationship between sd-LDL-C and CAC. METHODS AND RESULTS: This study included 4672 individuals with directly measured baseline sd-LDL-C and CAC from the Multi-Ethnic Study of Atherosclerosis [mean (standard deviation) age: 61.9 (10.4) years; 52.5% women; 47.3% with baseline CAC (mean score >0)]. We used multi-variable general linear models and restricted cubic splines with the goodness of fit testing to evaluate the association of sd-LDL-C with the presence of CAC. Odds ratios [OR (95% confidence interval)] were adjusted for demographics and cardiovascular risk factors, including estimated total LDL-C. Higher quartiles of sd-LDL-C were associated with the presence of CAC, even after accounting for total LDL-C. Compared with the lowest quartile of sd-LDL-C, participants in Quartiles 2, 3, and 4 had higher odds for the presence of baseline CAC [Quartile 2 OR: 1.24 (1.00, 1.53); Quartile 3 OR: 1.51 (1.19, 1.93); and Quartile 4 OR 1.59 (1.17, 2.16)]. Splines suggested a quadratic curvilinear relationship of continuous sd-LDL-C with CAC after adjustment for demographics and CVD risk factors (quadratic vs. first-order sd-LDL-C terms likelihood ratio test: P = 0.015), but not after accounting for total LDL-C (quadratic vs. first-order terms: P = 0.156). CONCLUSION: In a large, multi-ethnic sample without known CVD, higher sd-LDL-C was associated with the presence of CAC, above and beyond total LDL-C. Whether selective direct measurement of sd-LDL-C is indicated to refine cardiovascular risk assessment in primary prevention warrants further investigation.

Higher levels of small dense particles of LDL cholesterol, better known as the 'bad cholesterol', are associated with a greater risk for the presence of coronary artery calcium, a strong marker for heart disease, even when accounting for estimated total (small dense + large body particles) LDL cholesterol.This risk is stronger in older individuals.Peak risk seems to occur between 49 and 71 mg/dL and does not increase further at higher levels.

Validation of Estimated Small Dense Low-Density Lipoprotein Cholesterol Concentration in a Japanese General Population.

AIM: A high level of directly measured small dense low-density lipoprotein cholesterol (sdLDL-C) is a strong risk factor for atherosclerotic cardiovascular disease. A method for estimating sdLDL-C by using Sampson's equation that includes levels of total cholesterol, high-density lipoprotein cholesterol (HDL-C), non-HDL-C and triglycerides (TG) has recently been proposed. We investigated the validation and exploration of estimated sdLDL-C level. METHODS: The associations between measured and estimated sdLDL-C levels were investigated in 605 Japanese subjects (men/women: 280/325; mean age: 65±15 years) who received annual health check-ups in the Tanno-Sobetsu Study, a population-based cohort. RESULTS: Estimated sdLDL-C level was highly correlated with measured sdLDL-C level in all subjects (R2=0.701), nondiabetic subjects without any medication (n=254, R2=0.686) and subjects with diabetes mellitus (n=128, R2=0.721). Multivariable regression analysis showed that levels of non-HDL-C, TG and γ-glutamyl transpeptidase (γGTP) were independent predictors of measured sdLDL-C level. In a stratification of the LDL window, all of the subjects with a combination of high non-HDL-C (≥ 170 mg/dL) and high TG (≥ 150 mg/dL) had high levels of measured and estimated sdLDL-C (≥ 35 mg/dL). Furthermore, machine learning-based estimation of sdLDL-C level by artificial intelligence software, Prediction One, was substantially improved by using components of Sampson's equation (R2=0.803) and by using those components with the addition of γGTP and deletion of TC (R2=0.929). CONCLUSIONS: sdLDL-C level estimated by Sampson's equation can be used instead of measured sdLDL-C level in general practice. By building multiple machine learning models of artificial intelligence, a more accurate and practical estimation of sdLDL-C level might be possible.

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.

Calculated Small Dense Low-Density Lipoprotein Cholesterol Level is A Predominant Predictor for New Onset of Ischemic Heart Disease.

AIM: A high level of directly measured small dense low-density lipoprotein cholesterol (sdLDL-C) is a strong risk factor for ischemic heart disease (IHD). However, it remains unclear whether estimated sdLDL-C level is a predictor for IHD. We investigated the associations of new onset of IHD with levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglycerides (TG), LDL-C and calculated sdLDL-C by Sampson's equation. METHODS: After exclusion of subjects with IHD or those with TG ≥ 800 mg/dL, a total of 18,176 subjects (men/women: 11,712/6,464, mean age: 46 years) were recruited among 28,990 Japanese individuals who received annual health checkups. RESULTS: During the 10-year follow-up period, 456 men (3.9%) and 121 women (1.9%) newly developed IHD. Multivariable Cox proportional hazard analyses after adjustment of age, sex, obesity, smoking habit, family history of IHD, estimated glomerular filtration rate, hypertension and diabetes mellitus at baseline showed that the hazard ratio (HR) (1.38 [95% confidence interval: 1.03-1.85]) for new onset of IHD in subjects with the 4th quartile (Q4) of sdLDL-C (≥ 42 mg/dL) was significantly higher than that in subjects with the 1st quartile (Q1) (≤ 24 mg/dL) as the reference, though the adjusted HRs in subjects with Q2-Q4 of TC, HDL-C, non-HDL-C, LDL-C and TG were comparable with those in subjects with Q1 of the respective lipid fractions. The adjusted HR with a restricted cubic spline increased with a higher level of calculated sdLDL-C as a continuous value at baseline. CONCLUSIONS: sdLDL-C level calculated by Sampson's equation is a predominant predictor for the development of IHD in a general Japanese population.

Role of Small Dense Low-density Lipoprotein Cholesterol in Cardiovascular Events in Patients with Coronary Artery Disease and Type 2 Diabetes Mellitus Receiving Statin Treatment.

AIM: There is little information on the relationships of serum small dense low-density lipoprotein cholesterol (sdLDL-C) levels and serum triglyceride (TG) levels with cardiovascular events in patients with coronary artery disease (CAD) and type 2 diabetes mellitus (DM) who are receiving statins. The aim of this study was to evaluate the relationships of serum TG levels and sdLDL-C levels as residual risks for cardiovascular events in patients with CAD and type 2 DM who were being treated with statins. METHODS: The subjects were divided into four groups based on TG levels and sdLDL-C levels: sdLDL-C of ＜40.0 mg/dL and TG of ＜150 mg/dL, sdLDL-C of ≥ 40.0 mg/dL and TG of ＜150 mg/dL, sdLDL-C of ＜40.0 mg/dL and TG of ≥ 150 mg/dL, and sdLDL-C of ≥ 40.0 mg/dL and TG of ≥ 150 mg/dL. During a median follow-up period of 1419 days, cardiovascular events occurred in 34 patients. RESULTS: The incidences of cardiovascular events were significantly higher in patients with sdLDL-C of ≥ 40.0 mg/dL and TG of ＜150 mg/dL and in patients with sdLDL-C of ≥ 40.0 mg/dL and TG of ≥ 150 mg/dL, but not in patients with sdLDL-C of ＜40.0 mg/dL and TG of ≥ 150 mg/dL, than in patients with sdLDL-C of ＜40.0 mg/dL and TG of ＜150 mg/dL. CONCLUSIONS: Under the condition of treatment with statins, patients with CAD and type 2 DM who had sdLDL-C levels of ≥ 40.0 mg/dL had a high risk for cardiovascular events even though serum TG levels were controlled at ＜150 mg/dL.

Estimated small dense low-density lipoprotein cholesterol and nonalcoholic fatty liver disease in nonobese populations.

AIMS/INTRODUCTION: To explore the association between estimated small dense low-density lipoprotein cholesterol (sdLDL-C) and the risk of incident nonalcoholic fatty liver disease (NAFLD) in nonobese populations. MATERIALS AND METHODS: This study included participants who underwent health checkups in 2014 and were followed up until 2019. We carried out Cox proportional hazards regression analyses to evaluate the association of estimated sdLDL-C with NAFLD. Discordance analyses were carried out to estimate the relative NAFLD risk in estimated sdLDL-C versus low-density lipoprotein cholesterol (LDL-C) discordant/concordant groups. Estimated sdLDL-C was calculated by equations based on LDL-C and triglycerides. The diagnosis of NAFLD was based on the presence of abdominal ultrasonography after excluding other causes of chronic liver disease. RESULTS: Over a mean follow-up period of 26,694 person-years, 844 incident NAFLD cases were recorded. Compared with the first quartile of estimated sdLDL-C, the fourth quartile was associated with a 2.933-fold increased risk of NAFLD (95% confidence interval 2.095-4.107). With the increase in estimated sdLDL-C, the risk of NAFLD gradually increased both in participants within the normal range of LDL-C (hazard ratio 2.854, 95% confidence interval 1.650-5.617) and beyond the normal range of LDL-C (hazard ratio 2.636, 95% confidence interval 1.263-5.502). In addition, the inconsistent high estimated sdLDL-C/low LDL-C group was associated with an increased risk of NAFLD, but not the low estimated sdLDL-C/high LDL-C group. CONCLUSIONS: Estimated sdLDL-C was positively associated with the risk of incident NAFLD in a nonobese population, independent of LDL-C.

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.

Association between triglyceride-glucose index and low-density lipoprotein particle size in korean obese adults.

BACKGROUND: Small dense low-density lipoprotein cholesterol (sdLDL-C) is the lipoprotein marker among the various lipoproteins that is most strongly related to atherosclerosis. Insulin resistance (IR) can alter lipid metabolism, and sdLDL-C is characteristic of diabetic dyslipidemia. Therefore, this study sought to inspect the relationship between the triglyceride-glucose (TyG) index and mean low-density lipoprotein (LDL) particle size. METHODS: In this study, a total of 128 adults participated. The correlation coefficients between various lipoproteins and the TyG index were compared using Steiger's Z test and the Spearman correlation. The independent link between the TyG index and mean LDL particle size was demonstrated by multiple linear regression analysis. To identify the TyG index cutoff value for the predominance of sdLDL particles, receiver operating characteristic curves were plotted. RESULTS: Mean LDL particle size correlated more strongly with the TyG index than did very low-density lipoprotein, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. Regression analysis demonstrated that mean LDL particle size had a strong association with the TyG index (ß coefficient = -0.038, P-value < 0.001). The TyG index optimal cutoff value for sdLDL particle predominance and the corresponding area under the curve (standard error: 0.028, 95% confidence interval: 0.842-0.952) were 8.72 and 0.897, respectively, which were close to the cutoff value of diabetes risk in Koreans. CONCLUSIONS: Mean LDL particle size is more strongly correlated with the TyG index than do other lipid parameters. After correcting for confounding variables, mean LDL particle size is independently linked with the TyG index. The study indicates that the TyG index is strongly related to atherogenic sdLDL particles predominance.

Association of Urinary Lead and Cadmium Levels, and Serum Lipids with Subclinical Arteriosclerosis: Evidence from Taiwan.

BACKGROUND: Exposure to lead and cadmium has been linked to changes in lipid metabolism and the development of arteriosclerosis, but the role of lipoprotein profiles in this relationship is not well understood, including the potential role of novel lipid biomarkers. METHODS: In this study, we enrolled 736 young Taiwanese subjects aged 12 to 30 years to assess the correlation between urine levels of lead and cadmium, lipoprotein profiles, and carotid intima-media thickness (CIMT). RESULTS: Higher levels of lead and cadmium were significantly associated with higher levels of low-density lipoprotein cholesterol (LDL-C), small dense LDL-C (sdLDL-C), LDL-triglyceride (LDL-TG), and CIMT. Participants with higher levels of lead and cadmium had the highest mean values of CIMT, LDL-C, sdLDL-C, and LDL-TG. In a structural equation model, lead had a direct and indirect association with CIMT through LDL-C and sdLDL-C, whereas cadmium had a direct association with CIMT and an indirect association through LDL-C. CONCLUSION: Our results suggest higher levels of lead and cadmium are associated with abnormal lipid profiles and increased CIMT. These heavy metals could have additive effects on lipids and CIMT, and the relationship between them may be mediated by lipoprotein levels. Further research is needed to determine the causal relationship.

Small dense low-density lipoprotein cholesterol compared to other lipoprotein biomarkers for predicting coronary heart disease among individuals with normal fasting glucose: The Multi-Ethnic Study of Atherosclerosis.

Objective: This study compared small dense low-density lipoprotein cholesterol (sdLDL-C) with apolipoprotein B (apo B), and low-density lipoprotein particles (LDL-P) in predicting CHD risk in generally healthy adults with normal fasting glucose (NFG). Methods: This study was conducted among participants with NFG in the Multi-Ethnic Study of Atherosclerosis (MESA) prospective cohort with measurements of sdLDL-C, LDL-P, and apo B available at baseline (2000-2002) and follow-up CHD data (through 2015) (N = 3,258). Biomarkers were evaluated as quartiles, and in categories using clinically and 75th percentile-defined cut-points. Discordance/concordance of sdLDL-C relative to other biomarkers was calculated using 75th percentile cut-points and linear regression residuals. Associations between individual biomarkers, sdLDL-C discordance and CHD incidence were evaluated using Cox proportional hazards regression. Results: There were 241 incident CHD events in this population through 2015. Higher sdLDL-C, apo B, LDL-P were similarly associated with increased CHD in individuals with NFG. Discordance of sdLDL-C with apo B or LDL-P by 75th percentiles was not significantly associated with CHD. Residuals discordantly higher/lower sdLDL-C relative to apo B (discordant high HR=1.26, 95% CI: 0.89, 1.78; discordant low HR=0.94, 95% CI: 0.68, 1.29) and LDL-P (discordant high HR=1.25, 95% CI: 0.88, 1.75; discordant low HR=0.84, 95% CI:0.60, 1.16), compared to those with concordant measures, had non-statistically significant higher/lower risk of CHD. Conclusions: Results suggest sdLDL-C, apo B and LDL-P are generally comparable for predicting CHD events in normoglycemic individuals. Larger studies are needed to confirm findings and to investigate whether measurement of sdLDL-C may be beneficial to evaluate as an additional risk-enhancing factor.

N-3 fatty acid supplementation mediates lipid profile, including small dense LDL, when combined with statins: a randomized double blind placebo controlled trial.

BACKGROUND: Epidemiological and clinical evidence suggests that high-dose intake of omega 3 fatty acids (n-3 FA) have a favorable role in altering serum triglycerides (TG) and non-high density lipoprotein cholesterol (non-HDL-C) when combined with statins in hyperlipidemic patients. Their efficacy in altering low-density lipoprotein cholesterol (LDL-C) particle size is yet to be established. AIM: This study evaluated the effects of supplementing 4 g/day Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) on serum blood lipids, including small, dense LDL-C particle concentration, in hyperlipidemic patients receiving stable statin therapy. METHODS: In this randomized, placebo-controlled, double-blind parallel group study, 44 patients on statin therapy for > 8 weeks with non-HDL-C concentrations above 130 mg/dL were randomized into two groups. For 8 weeks, together with their prescribed statin, the intervention group received 4 g/day EPA + DHA (3000 mg EPA + 1000 mg DHA in ethyl ester form) and the placebo group received 4 g/day olive oil (OO). Measurements of serum non-HDL-C, TG, total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), LDL-C (including large - LDL I; intermediate - LDL II; and small - LDL III subclasses), very-low-density lipoprotein cholesterol (VLDL-C) concentration, were taken at baseline and post-intervention. Dietary intake was assessed with a weighed intake, 3-day food diary at week 4. Primary outcome measures were percent change in LDL III, non-HDL-C and LDL particle number. RESULTS: At the end of treatment, the median percent change in serum LDL III concentration was significantly greater in the n-3 FA group plus atorvastatin compared to placebo (- 67.5% vs - 0%, respectively; P < 0.001). Supplementation with n-3 FA plus atorvastatin led to significant reductions in serum non-HDL-C (- 9.5% vs 4.7%, P < 0.01), TG (- 21.5% vs 6.2%, P < 0.001) and VLDL-C (- 36.9% vs 4.0%, P < 0.001) and TC (- 6.6% vs 2.1%, P < 0.001). Between the groups, no significant difference in percent change in the serum concentration of LDL-C, HDL-C, as well as in the LDL I and LDL II subclasses was observed. CONCLUSION: In this group of hyperlipidemic patients on a stable statin prescription, OM3 plus atorvastatin improved small dense LDL concentrations, non-HDL-C, VLDL-C and TG to a greater extent than atorvastatin alone. Further studies are warranted in this area. TRIAL REGISTRATION: This trial was retrospectively registered on 23 May 2019 on ClinicalTrials.gov with ID: NCT03961763.

Impact of small dense low-density lipoprotein cholesterol and triglyceride-rich lipoproteins on plaque rupture with ST-segment elevation myocardial infarction.

BACKGROUND: Plaque rupture (PR), characterized by a disruption of the fibrous cap of lipid-rich plaques, is the major etiology of ST-segment elevation myocardial infarction (STEMI). Dyslipidemia is a well-known risk factor for PR. Nonetheless, the impact of detailed atherogenic lipid profiles, including small dense low-density lipoprotein cholesterol (sd-LDL-C) and triglyceride-rich lipoproteins (TRLs), on PR has not yet been investigated. OBJECTIVE: To elucidate the impact of sd-LDL-C and TRL levels on PR in patients with STEMI using optical coherence tomography (OCT). METHODS: A total of 106 consecutive statin-naive patients with STEMI were enrolled. The PR in culprit lesions was assessed on pre-intervention OCT images, and serum samples were collected immediately before coronary angiography. Sd-LDL-C was directly measured using a homogeneous assay. TRL-cholesterol (TRL-C) was estimated by subtracting the LDL-C level from the non-high-density lipoprotein cholesterol level. Clinical characteristics and lipid profiles were compared between the PR and intact fibrous cap (IFC). RESULTS: No difference in LDL-C levels was observed between the PR (n=64) and IFC (n=42) groups (120.0 mg/dL vs. 129.5 mg/dL, p=0.97); however, sd-LDL-C levels were significantly higher in the PR group (38.9 mg/dL vs. 32.4 mg/dL, p=0.04). Similarly, the PR group had higher TRL-C (24.0 mg/dL vs. 18.0 mg/dL, p=0.01) and triglyceride (130.0 mg/dL vs. 100.3 mg/dL, p=0.03) levels than the IFC group. Multivariate logistic regression analysis showed that sd-LDL-C was an independent factor determining PR (odds ratio, 1.53 per 10 mg/dL; p=0.04). CONCLUSION: Only sd-LDL-C levels were significantly associated with PR in culprit lesions in patients with STEMI.

Comparisons of the Relationships Between Multiple Lipid Indices and Diabetic Kidney Disease in Patients With Type 2 Diabetes: A Cross-Sectional Study.

Background: Dyslipidemia is a well-recognized risk factor for diabetic kidney disease (DKD) in patients with type 2 diabetes (T2D). Growing evidences have shown that compared with the traditional lipid parameters, some lipid ratios may provide additional information of lipid metabolism. Thus, the present study aimed to investigate which lipid index was most related to DKD. Methods: This study was a cross-sectional study that enrolled patients with T2D from January 2021 to October 2021. Each participant was screened for DKD, and the diagnostic criterion for DKD is estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2 or urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g for 3 months. Fasting blood was collected to determine lipid profiles by an automatic biochemical analyzer, and lipid ratios were calculated based on corresponding lipid parameters. Spearman's correlation analyses were conducted to assess the correlations between lipid indices and kidney injury indices, and binary logistic regression analyses were conducted to explore the relationship between lipid indices and the risk of DKD. Results: A total of 936 patients with T2D were enrolled in the study, 144 (15.38%) of whom had DKD. The LDL-C/Apo B ratios were positively correlated with eGFR (r = 0.146, p < 0.05) and inversely correlated to cystatin C and UACR (r = -0.237 and -0.120, both p < 0.001). Multiple logistic regression demonstrated that even after adjusting for other clinical covariates, the LDL-C/Apo B ratios were negatively related to DKD, and the odds ratio (95% confidence interval) was 0.481 (0.275-0.843). Furthermore, subgroup analyses revealed that compared with patients with normal lipid profiles and a high LDL-C/Apo B ratio, the odds ratio of DKD in patients with normal lipid metabolism and a low LDL-C/Apo B ratio was 2.205 (1.136-4.280) after adjusting for other clinical covariates. Conclusion: In patients with T2D, the LDL-c/Apo B ratio was most closely associated with DKD among various lipid indices, and a lower LDL-C/Apo B ratio was associated with increased risks of DKD among patients with T2D.

Impact of small dense low-density lipoprotein cholesterol on cholesterol crystals in patients with acute coronary syndrome: An optical coherence tomography study.

BACKGROUND: The presence of cholesterol crystals (CCs) is recognized as a component of vulnerable atherosclerotic plaques at risk of rupture. The phagocytosis of atherogenic lipid factors by macrophages precedes and promotes the formation of vulnerable plaques, but it is not clear how these factors affect the formation of CC. OBJECTIVE: This study aimed to evaluate the relationship between lipid biomarkers such as small dense low-density lipoprotein cholesterol (sd-LDL-c) and CC detected by optical coherence tomography (OCT) in patients with acute coronary syndrome (ACS). METHODS: Serum samples were collected immediately before coronary angiography in consecutive 174 patients with ACS who did not take statins and underwent OCT imaging of the culprit lesion. The sd-LDL-c levels were measured using a direct homogenous assay. CC was defined as a thin linear structure with high reflectivity and low signal attenuation on the OCT images. RESULTS: CC was identified in 85 patients (48.9%). The prevalence of CC was significantly higher in lesions with ruptured plaques and greater macrophage grade. The sd-LDL-c levels were significantly higher in the patients with CC (41.6 vs. 31.2 mg/dL, p = 0.01) although there were no significant differences in the levels of LDL-c and apolipoprotein B. The CC group also had higher levels of apolipoprotein C3 and HbA1c levels. In multiple logistic regression analysis, sd-LDL-c was an independent risk factor of CC (odds ratio, 1.19 per 10 mg/dL; p = 0.03). CONCLUSIONS: sd-LDL may play an important role in the presence of CC in patients with ACS.

Reference interval for serum concentration of small dense low-density lipoprotein cholesterol in the healthy Japanese population.

BACKGROUND: Small dense low-density lipoprotein a smaller and denser subfraction among whole low density lipoprotein particles is known to be highly atherogenic. The reference interval (RI) is not strictly defined for serum concentration of sdLDL-cholesterol (sdLDL-C) in Japan. The purpose of this study is to set the reference interval for sdLDL-C in healthy subjects. METHODS: The population of this cross-sectional study was consisted of 40,862 individuals who had annual health checkups, and healthy subjects were extracted based on exclusion criteria such as medical history, social history, and blood sampling test results. Their serum sdLDL-C values were statistically analyzed and the RIs were set in men, premenopausal women, and postmenopausal women separately. RESULTS: The mean values of serum sdLDL-C in healthy subjects were 23.9 mg/dL in men, 20.0 mg/dL in premenopausal women and 23.7 mg/dL in postmenopausal women, and the RIs were 12.6-45.3 mg/dL in men, 11.4-35.1 mg/dL in premenopausal women and 14.6-38.6 mg/dL in postmenopausal women. Serum sdLDL-C values were significantly higher in men than in women. Besides, sdLDL-C values were significantly higher in postmenopausal women than in premenopausal women. In both genders, sdLDL-C values tended to increase with age. CONCLUSION: These results suggest that the RIs for sdLDL-C are recommended as follows: 13-45 mg/dL in men, 11-35 mg/dL in premenopausal women, and 15-39 mg/dL in postmenopausal women, respectively. Aside from these RIs, it is also necessary to define clinical cutoff values graded according to individual risk levels for atherosclerotic cardiovascular diseases.

Small Dense Low-Density Lipoprotein Cholesterol is a Potential Marker for Predicting Laser Treatment for Retinopathy in Diabetic Patients.

AIM: We explored the superiority of small dense low-density lipoprotein cholesterol (sdLDL-C) as a marker for predicting not only the occurrence of cardiovascular (CV) events but also the need for laser treatment in patients with hypercholesterolemia and diabetic retinopathy. METHODS: We performed a sub-analysis of the intEnsive statin therapy for hyper-cholesteroleMic Patients with diAbetic retinopaTHY (EMPATHY) study (n=5042), in which patients were assigned randomly to intensive or standard statin therapy targeting low-density lipoprotein cholesterol ＜70 mg/dl or 100-120 mg/dl. Using the survival analysis, the risks for CV events and the need for laser treatment were evaluated according to the lipids one year after registration. RESULTS: The patients were 63±11 years old. LDL-C and sdLDL-C levels were 98±25 and 32±14 mg/dl, respectively, one year after registration. The sdLDL-C level had a strong positive correlation with apolipoprotein B level (r=0.83 at registration). SdLDL-C was a sensitive marker for predicting CV events when comparing among the quartiles according to sdLDL-C levels (hazard ratios: HR for quartiles 1-4 were 1.0, 1.4, 1.6, and 2.5, respectively; p for trend ＜0.01). Also, sdLDL-C was a sensitive marker for predicting the need for laser treatment among lipids (log rank, p=0.009), especially in patients with elderly (≧65 yrs) and obesity (BMI ≧25 kg/m2). CONCLUSIONS: SdLDL-C is a sensitive target marker to predict cardiovascular events as well as the need for laser treatment in patients with hypercholesterolemia and diabetic retinopathy.

Dyslipidemia in diabetic kidney disease classified by proteinuria and renal dysfunction: A cross-sectional study from a regional diabetes cohort.

AIMS/INTRODUCTION: Diabetic kidney disease (DKD) exacerbates dyslipidemia and increases the incidence of atherosclerotic cardiovascular disease. DKD is a concept that includes typical diabetic nephropathy and an atypical phenotype without proteinuria. We investigated dyslipidemia in different DKD phenotypes that have not been fully studied. MATERIALS AND METHODS: Fasting plasma was obtained from 1,073 diabetes patients enrolled in the regional diabetes cohort (ViNA cohort). Non-proteinuric and proteinuric DKD were defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2 in the absence or presence of urinary albumin-to-creatinine ratio >300 mg/g. Novel lipid risk factors, low-density lipoprotein (LDL) triglyceride (TG) and small dense LDL cholesterol were measured using our established homologous assay. RESULTS: The proportion of atherosclerotic cardiovascular disease patients was higher in non-proteinuric DKD and even higher in proteinuric DKD than in non-DKD. Increased estimated glomerular filtration rate grade and albuminuric stage were independently correlated with higher TG, TG-rich lipoprotein cholesterol and apolipoprotein CIII. Therefore, proteinuric DKD had the highest of these levels. Small dense LDL cholesterol and LDL-TG were higher in the proteinuria without renal dysfunction group in the lipid-lowering drug-free subset. Lipoprotein(a) was higher in DKD regardless of proteinuria. CONCLUSIONS: Proteinuria was associated with an atherogenic subspecies of LDL, whereas renal dysfunction was associated with increased lipoprotein(a). Proteinuria and renal dysfunction independently exacerbated TG-rich lipoprotein-related dyslipidemia. This is in good agreement with the results of large-scale clinical studies in which proteinuria and renal dysfunction synergistically increased the risk of atherosclerotic cardiovascular disease in populations with diabetes.

Serum concentrations of small dense low-density lipoprotein cholesterol and lipoprotein(a) are related to coronary arteriostenosis in Takayasu arteritis.

BACKGROUND: Serum small dense low-density lipoprotein cholesterol (sdLDL-C) and lipoprotein(a) [Lp(a)] levels are related to coronary disease, but their specific associations with coronary arteriostenosis in Takayasu arteritis (TA) have not been ascertained. This study explored the correlations between serum sdLDL-C and Lp(a) levels and coronary arteriostenosis in TA patients as well as the degree of artery stenosis. METHODS: This retrospective study included 190 TA patients and 154 healthy subjects. TA patients were divided into three categories based on the degree of coronary stenosis: Group I, stenosis >50%; Group II, stenosis 1%-50%; and Group III, stenosis 0%. Independent risk factors for coronary arteriostenosis in TA were identified by logistic regression, followed by receiver operating characteristic curve analysis to determine the specificity and sensitivity of risk factors and Youden's Index score calculation to determine the cutoff points. RESULTS: Takayasu arteritis patients had significantly higher serum levels of sdLDL-C and Lp(a) than healthy controls (p < 0.0001). The total cholesterol, triglyceride, LDL-C, sdLDL-C, and Lp(a) levels and the sdLDL-C/LDL-C ratio in Group I were significantly higher than those in Groups II and III (p < 0.05). An elevated serum sdLDL-C level elevated the risk of coronary arteriostenosis by 5-fold (cutoff value, 0.605 mmol/l). An increased serum Lp(a) level increased the risk of coronary arteriostenosis by 3.9-fold (cutoff value, 0.045 g/l). An elevated sdLDL-C/LDL-C ratio increased the risk of coronary arteriostenosis by 2.1-fold (cutoff value, 0.258). CONCLUSIONS: Serum sdLDL-C and Lp(a) levels and sdLDL-C/LDL-C ratio may be used as diagnostic factors for coronary arteriostenosis in TA patients.