Impact of Direct Measurement of Small Dense Low-Density Lipoprotein Cholesterol for Long-Term Secondary Prevention in Patients with Stable Coronary Artery Disease.

BACKGROUND: This study investigated whether directly measured small dense low-density lipoprotein cholesterol (D-sdLDL-C) can predict long-term coronary artery disease (CAD) events compared with low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), apolipoprotein B (apoB), and estimated small dense low-density lipoprotein cholesterol (E-sdLDL-C) determined by the Sampson equation in patients with stable CAD. METHODS: D-sdLDL-C measured at Showa University between 2010 and 2022, and E-sdLDL-C were evaluated in 790 male and 244 female patients with stable CAD. CAD events, defined as sudden cardiac death, onset of acute coronary syndrome, and/or need for coronary revascularization, were monitored for 12 years. Cutoff lipid levels were determined by receiver operating characteristic curves. RESULTS: CAD events were observed in 238 male and 67 female patients. The Kaplan-Meier event-free survival curves showed that patients with D-sdLDL-C ≥32.1 mg/dL (0.83 mmol/L) had an increased risk for CAD events (P = 0.007), whereas risk in patients with E-sdLDL-C ≥36.2 mg/dL (0.94 mmol/L) was not increased. In the group with high D-sdLDL-C, the multivariable-adjusted hazard ratio (HR) was 1.47 (95% CI, 1.15-1.89), and it remained significant after adjustment for LDL-C, non-HDL-C, or apoB and in patients treated with statins. HRs for high LDL-C, non-HDL-C, or apoB were not statistically significant after adjustment for high D-sdLDL-C. Higher D-sdLDL-C was associated with enhanced risk of high LDL-C, non-HDL-C, and apoB (HR 1.73; 95% CI, 1.27-2.37). CONCLUSIONS: Higher D-sdLDL-C can predict long-term recurrence of CAD in stable CAD patients independently of apoB and non-HDL-C. D-sdLDL-C is an independent risk enhancer for secondary CAD prevention, whereas E-sdLDL-C is not. UMIN-CTR Clinical Trial Number: UMIN000027504.

Managing hypertriglyceridemia for cardiovascular disease prevention: Lessons from the PROMINENT trial.

BACKGROUND: Numerous epidemiological studies have shown that hypertriglyceridemia is a significant risk factor for cardiovascular diseases (CVD). However, large clinical studies on triglyceride-lowering therapy have yielded inconsistent results. In the current review, we reassess the importance of triglyceride-lowering therapy in preventing CVD based on previous literature and the recently published findings of the PROMINENT trial. METHODS: This narrative review is based on literature and public documents published up to November 2023. RESULTS: Meta-analyses of trials on peroxisome proliferator-activated receptor α agonists and triglyceride-lowering therapy, including the PROMINENT trial, have indicated that triglyceride-lowering therapy can reduce CVD events. Mendelian randomization studies have also indicated that triglyceride is indeed a true risk factor for coronary artery disease, leaving no doubt about its relationship to CVD. Meanwhile, the negative results from the PROMINENT trial were likely due to the insufficient triglyceride-lowering effect, slight increases in low-density lipoprotein cholesterol and apolipoprotein B, and the inclusion of mostly high-intensity statin users as target patients. It is unlikely that adverse events counteracted the effectiveness of pemafibrate on outcomes. Additionally, pemafibrate has shown positive effects on non-alcoholic fatty liver disease and peripheral artery disease. CONCLUSION: Although the PROMINENT trial did not demonstrate the significance of pemafibrate as a triglyceride-lowering therapy in a specific population, it does not necessarily negate the potential benefits of treating hypertriglyceridemia in reducing CVD events. It is necessary to explore appropriate populations that could benefit from this therapy, utilize data from the PROMINENT trial and other databases, and validate findings in real-world settings.

Specific Increase in Small Dense Low-Density Lipoprotein-Cholesterol Levels beyond Triglycerides in Patients with Diabetes: Implications for Cardiovascular Risk of MAFLD.

AIMS: Small dense (sd) low-density lipoprotein (LDL)-cholesterol (C) is the most powerful predictor of cardiovascular (CV) disease among lipid biomarkers and is generated by hypertriglyceridemia and insulin resistance. Metabolic dysfunction-associated fatty liver disease (MAFLD) is a newly proposed liver disease with a high CV risk. We investigated the specific association of sdLDL-C with MAFLD beyond triglycerides (TG) and obesityMethods: Participants were 839 non-alcoholic drinkers with type 2 diabetes enrolled in a regional diabetes cohort. Fatty liver (FL) and visceral fat area (VFA) was detected by computed tomography scan. sdLDL-C and LDL-TG were measured by our established homogeneous assay. TG rich lipoprotein (TRL) was calculated by subtracting LDL-C plus HDL-C from total-C. Grade of sdLDL-C (≤ 24, 25-34, 35-44, and ≥ 45 mg/dL) was classified according to the Hisayama study. RESULTS: Compared to non-FL counterparts, FL subjects were younger, predominantly male and smokers; and had higher body mass index (BMI), VFA, hemoglobin A1c, C-peptide, TG, and sdLDL-C, while had similar levels of LDL-C, LDL-TG, and TRL-C. Multivariate logistic analysis revealed that sdLDL-C was the most powerful lipid parameter for identifying FL, independent of TG, HDL-C, BMI, and VFA. The independent association between TG and FL was lost when sdLDL-C was added to the analysis. These results remained the same when lipid-lowering drug users were excluded. After adjustment for confounders, the odds ratio for FL was 2.4-2.7 at sdLDL ≥ 35 mg/dL based on sdLDL ≤ 24 mg/dL. CONCLUSIONS: sdLDL-C levels are specifically elevated in patients with diabetes and MAFLD, independent of TG and VFA, suggesting liver-centered metabolic abnormalities.

Prospective randomized comparative study of the effect of pemafibrate add-on or double statin dose on small dense low-density lipoprotein-cholesterol in patients with type 2 diabetes and hypertriglyceridemia on statin therapy.

AIMS/INTRODUCTION: Small dense low-density lipoprotein (sdLDL) is a more potent atherogenic lipoprotein than LDL. As sdLDL-cholesterol (C) levels are determined by triglyceride and LDL-C levels, pemafibrate and statins can reduce sdLDL-C levels. However, it remains unclear whether adding pemafibrate or increasing statin doses would more effectively reduce sdLDL-C levels in patients receiving statin therapy. MATERIALS AND METHODS: A total of 97 patients with type 2 diabetes and hypertriglyceridemia who were treated with statins were randomly assigned to the pemafibrate 0.2 mg/day addition or statin dose doubled, and followed for 12 weeks. sdLDL-C was measured by our established homogenous assay. RESULTS: The percentage and absolute reductions of sdLDL-C levels were significantly greater in the pemafibrate add-on group than the statin doubling group (-32.8 vs -8.1%; -16 vs -3 mg/dL, respectively). Triglyceride levels were reduced only in the pemafibrate add-on group (-44%), and LDL-C levels were reduced only in the statin doubling group (-8%), whereas levels of non-high-density lipoprotein-C and apolipoprotein B were similarly decreased (7-9%) in both groups. The absolute reductions of sdLDL-C levels were closely associated with decreased triglyceride, LDL-C, non-high-density lipoprotein-C and apolipoprotein B. In the subgroup analysis, the effect of pemafibrate add-on on sdLDL-C reductions was observed irrespective of baseline lipid parameters or statin type. No serious adverse effects were observed in both groups. CONCLUSIONS: In patients with type 2 diabetes and hypertriglyceridemia, the addition of pemafibrate to a statin is superior to doubling a statin in reducing sdLDL-C without increasing adverse effects.

Hypertriglyceridemia contributes significantly to high prevalence of small dense LDL-cholesterol in patients with type 2 diabetes, even when LDL-C targets are achieved.

Background: Small-dense (sd)LDL-cholesterol (C) is a potent risk factor for atherosclerotic cardiovascular disease (ASCVD) beyond LDL-C, and 35 mg/dL has been proposed as a cut-off value for high-sdLDL-C. sdLDL-C levels are strongly regulated by triglycerides (TG) and LDL-C levels. LDL-C has detailed targets for the prevention of ASCVD, while TG is only defined as abnormal at ≥ 150 mg/dL. We investigated the effect of hypertriglyceridemia on the prevalence of high-sdLDL-C in patients with type 2 diabetes and explored the optimal TG levels that would suppress high-sdLDL-C. Methods: Fasting plasma was obtained from 1569 patients with type 2 diabetes who were enrolled in the regional cohort study. sdLDL-C concentrations were measured by the homogeneous assay established by us. High-sdLDL-C was defined as ≤ 35 mg/dL according to the Hisayama Study. Hypertriglyceridemia was defined as ≥ 150 mg/dL. Results: All lipid parameters except HDL-C were higher in the high-sdLDL-C group than in the normal-sdLDL-C group. The receiver operating characteristic (ROC) curves revealed that high sdLDL-C was identified sensitively by TG and LDL-C, with cut-off values of 115 mg/dL for TG and 110 mg/dL for LDL-C. The presence of hypertriglyceridemia increased the prevalence of high-sdLDL-C sixfold more than the normotriglyceridemic counterpart, regardless of statin use. This substantial influence of hypertriglyceridemia was found even within the control target of LDL-C levels (70-120 mg/dL) for diabetic subjects. Conclusions: The TG cut-off for high-sdLDL-C was well below 150 mg/dL in a diabetic population. Amelioration of hypertriglyceridemia is needed even when LDL-C targets for diabetes are achieved.

The influence of triglycerides on small dense low-density lipoprotein cholesterol levels is attenuated in low low-density lipoprotein-cholesterol range: Implications for the negative results of the PROMINENT trial.

The Pemafibrate to Reduce Cardiovascular Outcomes by Reducing Triglycerides in Patients with Diabetes (PROMINENT) trial failed to show the preventive effects of pemafibrate, a triglyceride (TG)-lowering drug, on atherosclerotic cardiovascular disease in patients with type 2 diabetes and dyslipidemia. We recently reported that TG-lowering with pemafibrate did not decrease the calculated small dense (sd) low-density lipoprotein cholesterol (LDL-C), and speculated that the effect of TG on sdLDL-C is attenuated in low LDL-C levels. This report examined this possibility in 1,508 patients with type 2 diabetes and 670 healthy controls. LDL-C ranges were classified as ≤69, 70-99, 100-139 and 140≤ mg/dL. The slope of the regression curve between sdLDL-C and TG was found to flatten as LDL-C decreased; 0.18, 0.13, 0.10 and 0.04 for controls, and 0.18, 0.13, 0.09 and 0.07 for diabetes patients. Correspondingly, the lower the LDL-C range, the lower the sdLDL-C/TG ratio. These results suggest that when LDL-C is tightly controlled, TG-lowering has only a weak inhibitory effect on sdLDL-C.

Clinical significance of skin autofluorescence for diabetic macroangiopathy and comparison with conventional markers of atherosclerosis: a cross-sectional and prospective study.

Background: Skin autofluorescence (SAF) is a marker for the accumulation of advanced glycation end products (AGEs), and is associated with diabetic macroangiopathy. However, whether SAF is superior to conventional markers of atherosclerosis such as carotid intima-media thickness (IMT) and pulse wave velocity (PWV) in detecting macroangiopathy remains unclear. Methods: We recruited 845 patients with type 2 diabetes enrolled in a community diabetes cohort (ViNA cohort) who had SAF, IMT, and PWV measured at baseline. The prevalence of macroangiopathy at baseline and new cardiovascular events during the 2-year follow-up period was investigated. SAF was measured using an AGE reader. Coronary artery calcification (CAC) was measured by computed tomography in 485 patients. Peripheral artery disease (PAD) was defined as the ankle-brachial blood pressure ratio of ≤ 0.9. Results: SAF, IMT, and PWV were significantly correlated with each other, and age, diabetes duration, and estimated glomerular filtration rate were their strong confounders. SAF was associated with baseline stroke and new stroke after adjusting for confounders, but not with coronary artery disease (CAD) or PAD. The nonsignificant relationship between SAF and CAD was consistent with the relationship between SAF and CAC. Multivariate analysis showed a significant association of SAF with baseline and new stroke independent of IMT and PWV. Maximum-IMT was significantly associated with baseline CAD, PAD, and stroke, but not with a new stroke, whereas PWV was associated with a new stroke. Conclusion: Among diabetic macroangiopathies, SAF is a good stroke biomarker, but not for CAD and PAD. Supplementary Information: The online version contains supplementary material available at 10.1007/s13340-022-00608-8.

Accuracy of Small Dense Low-density Lipoprotein-cholesterol Concentration Estimated via Sampson's Equation in Healthy Subjects and Patients with Diabetes.

AIM: Sampson et al. proposed a method to calculate small dense low-density lipoprotein-cholesterol (sdLDL-C) concentrations using common lipid measurements, but its accuracy remains unresolved. We examined the difference between Sampson's equation and direct measurement in patients with diabetes. METHODS: sdLDL-C was measured directly by our established homogeneous assay and estimated by Sampson's equation in patients with diabetes (n=1542) and healthy control subjects (n=673). Large-buoyant (lb)LDL-C was estimated using triglycerides and LDL-C, and sdLDL-C was obtained by subtracting lbLDL-C from LDL-C. The effect of fasting/nonfasting state or lipid-lowering drug therapy on sdLDL-C values was also examined in 30 and 43 patients with diabetes, respectively. RESULTS: The coefficient of determination (R2) between calculated sdLDL-C and direct measurement was 0.73 and 0.61 for healthy controls and patients with diabetes, respectively. The R2 between calculated sdLDL-C and nonHDL-C or apolipoprotein B was 0.64 and 0.65, respectively. Calculated sdLDL-C was 4-5 mg/dl or 17%-18% higher than the direct measurement. The lower the plasma lipids, especially sdLDL-C, the greater the dissociation between the two methods. Sampson sdLDL-C was also found to give a positive bias when calculated for the nonfasting samples. Statins and pemafibrate significantly reduced sdLDL-C, but their therapeutic effect was underestimated by 5 mg/dl (24%) via Sampson's equation. CONCLUSIONS: The correlation between Sampson's equation and direct measurements of sdLDL-C was reduced in patients with diabetes. Furthermore, the correlations with nonHDL-C and apolipoprotein B were even higher than those with direct sdLDL-C. The accuracy of Sampson's equation decreased with lower sdLDL-C concentrations and was also influenced by diet.

Two Cases of Acquired High-Density Lipoprotein Deficiency with Immunoglobulin G4-Related Lecithin-Cholesterol Acyltransferase Autoantibody.

Lecithin-cholesterol acyltransferase (LCAT) plays a significant role in the progression from premature to mature high-density lipoprotein (HDL) in circulation. Consequently, primary or secondary LCAT deletion or reduction naturally results in low serum HDL cholesterol levels. Recently, rare cases of acquired HDL deficiency with LCAT autoantibodies have been reported, mainly from Japan, where LCAT autoantibodies of immunoglobulin G (IgG) caused the HDL deficiency. Here to our knowledge, we report for the first time two cases of acquired HDL deficiency caused by IgG4 linked LCAT autoantibodies with or without a high serum IgG4 level. Furthermore, these cases can extend to a new concept of "IgG4 autoimmune disease" from the viewpoint of verifying the serum autoantibody and/or renal histopathology.

Circadian Rhythm of Subspecies of Low-Density Lipoprotein-Cholesterol and High-Density Lipoprotein-Cholesterol in Healthy Subjects and Patients with Type 2 Diabetes.

AIMS: We established automated assay kits for quantifying small dense low-density lipoprotein (sdLDL)-cholesterol (C), LDL-triglyceride (TG), and high-density lipoprotein (HDL)3-C, and apolipoprotein (apo)E-rich HDL-C, and these have been recognized as sensitive biomarkers for predicting coronary artery disease. We investigated the circadian rhythms of these novel lipids to determine if fasting is required to determine basal levels. METHODS: Forty-eight inpatients with type 2 diabetes and 19 healthy volunteers were studied. Blood samples were collected at seven time points, which were obtained after an overnight fast, before and 2 h after each meal, and before the next breakfast. sdLDL-C, LDL-TG, remnant-like particle (RLP)-C, TG-rich lipoprotein (TRL-C), HDL3-C, and apoE-rich HDL-C were measured by the homogeneous methods. NonHDL-C, large buoyant (lb)LDL-C and HDL2-C were calculated by subtracting sdLDL-C from LDL-C or HDL3-C from HDL-C, respectively. RESULTS: Serum TG levels were significantly increased after meals in both healthy participants and patients with diabetes. RLP-C and TRL-C were also increased postprandially. LDL-TG, LDL-C, nonHDL-C, HDL2,3-C, and apoE-rich HDL-C did not exhibit significant fluctuation during the day in healthy participants and patients with diabetes. sdLDL-C was slightly increased postprandially in subjects with diabetes (1-2 mg/dl, 3%-9%), though its increase was not significant compared to the baseline (fasting) level. Significant postprandial reduction was observed with LDL-C and lbLDL-C. There was no influence of statin therapy or oral anti-diabetes drugs on the circadian rhythm of LDL-C subspecies. CONCLUSIONS: Subtle postprandial increase in sdLDL-C is considered a negligible level in general clinical practice. Fasting is not mandatory to measure basal concentrations of LDL and HDL subspecies.

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.

Favorable therapeutic efficacy of low-density lipoprotein apheresis for nephrotic syndrome with impaired renal function.

Many reports have shown the therapeutic efficacy of LDL apheresis (LDL-A) in drug-resistant nephrotic syndrome (NS) for improvement of heavy proteinuria and severely impaired renal function. To obtain comprehensive results in a large number of cases, a post hoc analysis of the Prospective Observational survey on the Long-Term Effects of the LDL-Apheresis on the Drug Resistant Nephrotic Syndrome (POLARIS) study was performed by stratifying enrolled cases according to the pretreatment estimated glomerular filtration rate (eGFR) levels indicating normal (N) (≥60 ml/min/1.73 m2 ), moderately impaired (M) (≥30 to <60 ml/min/1.73 m2 ), and severely impaired (S) (<30 ml/min/1.73 m2 ) renal function. Significant improvements of proteinuria and renal function were found in Group N and, most interestingly, in Group M. A tendency for improvement in proteinuria was found in Group S. Most cases in all groups had not entered end-stage renal disease at 2 years after LDL-A treatment. These results suggest that LDL-A has therapeutic efficacy even in cases in which renal function has declined to 30 ml/min/1.73 m2 .

Metabolic Properties of Lowdensity Lipoprotein (LDL) Triglycerides in Patients with Type 2 Diabetes, Comparison with Small Dense LDL-Cholesterol.

AIMS: Abnormal compositional changes in low-density lipoprotein (LDL) particles, such as triglyceride (TG) enrichment and size reduction, are common in patients with diabetes. Several cohort studies have demonstrated that LDL-TG and sdLDL-cholesterol (C) are sensitive biomarkers for predicting atherosclerotic cardiovascular diseases beyond LDL-C. Although sdLDL has been extensively studied, little is known about the properties of LDL-TG. We investigated similarities or differences between LDL-TG and sdLDL-C. METHODS: Fasting plasma was obtained from 1,085 patients with type 2 diabetes who were enrolled in the diabetes regional cohort study (ViNA Cohort). LDL-TG and sdLDL-C concentrations were measured using a homogeneous assay established by us. In a subset of subjects, LDL-TG and sdLDL-C levels were measured postprandially or after treatment with lipid-lowering drugs. RESULTS: In a quartile analysis, higher LDL-TG quartiles were associated with higher frequency of female and fibrate users, whereas sdLDL-C quartiles were associated with frequency of men, drinking, and metabolic syndrome-related measurements. Higher quartiles of LDL-TG/LDL-C were associated with smoking, drinking, fibrate users, and statin users. LDL-TG was significantly correlated with TG, LDL-C, sdLDL-C, and apolipoprotein (apo) B, with apoB being the primary determinant. LDL-TG correlated to high sensitive C-reactive protein (CRP) independently of other lipids. Mean LDL-TG did not change with fasting/non-fasting. Statin treatment reduced LDL-TG, whereas fibrates increased it, but these drugs reduced sdLDL-C equally. CONCLUSIONS: LDL-TG levels were more tightly regulated by the number of LDL particles than plasma TG levels were. SdLDL-C was closely associated with metabolic syndrome-related factors, whereas LDL-TG was associated with low-grade systemic inflammation.

Glucose-Dependent Insulinotropic Polypeptide Suppresses Foam Cell Formation of Macrophages through Inhibition of the Cyclin-Dependent Kinase 5-CD36 Pathway.

Glucose-dependent insulinotropic polypeptide (GIP) has been reported to have an atheroprotective property in animal models. However, the effect of GIP on macrophage foam cell formation, a crucial step of atherosclerosis, remains largely unknown. We investigated the effects of GIP on foam cell formation of, and CD36 expression in, macrophages extracted from GIP receptor-deficient (Gipr-/-) and Gipr+/+ mice and cultured human U937 macrophages by using an agonist for GIP receptor, [D-Ala2]GIP(1-42). Foam cell formation evaluated by esterification of free cholesterol to cholesteryl ester and CD36 gene expression in macrophages isolated from Gipr+/+ mice infused subcutaneously with [D-Ala2]GIP(1-42) were significantly suppressed compared with vehicle-treated mice, while these beneficial effects were not observed in macrophages isolated from Gipr-/- mice infused with [D-Ala2]GIP(1-42). When macrophages were isolated from Gipr+/+ and Gipr-/- mice, and then exposed to [D-Ala2]GIP(1-42), similar results were obtained. [D-Ala2]GIP(1-42) attenuated ox-LDL uptake of, and CD36 gene expression in, human U937 macrophages as well. Gene expression level of cyclin-dependent kinase 5 (Cdk5) was also suppressed by [D-Ala2]GIP(1-42) in U937 cells, which was corelated with that of CD36. A selective inhibitor of Cdk5, (R)-DRF053 mimicked the effects of [D-Ala2]GIP(1-42) in U937 cells. The present study suggests that GIP could inhibit foam cell formation of macrophages by suppressing the Cdk5-CD36 pathway via GIP receptor.

Effects of omarigliptin on glucose variability and oxidative stress in type 2 diabetes patients: A prospective study.

AIMS: To date, no clinical studies have compared once-weekly dipeptidyl peptidase 4 (DPP-4) inhibitors with once-daily DPP-4 inhibitors in terms of glucose variability (GV) and oxidative stress (OS). METHODS: Thirty-six patients with type 2 diabetes mellitus (T2DM) treated with once-daily DPP-4 inhibitors for at least 12 weeks were randomized to either continue once-daily DPP-4 inhibitors or receive omarigliptin, a once-weekly DPP-4 inhibitor, for 24 weeks. The primary end points were changes in the diacron-reactive oxygen metabolite (d-ROMs) test, a marker of OS, and GV using flash glucose monitoring. The secondary end point was changes in the diabetes treatment satisfaction questionnaire (DTSQ) scores. RESULTS: There were no significant group differences in d-ROMs and DTSQ scores after 24 weeks of treatments. However, omarigliptin was superior to once-daily DPP-4 inhibitors in controlling fasting plasma glucose (FPG) and time in range (TIR). Although FPG and TIR were unchanged at 24 weeks after switching to omarigliptin, these parameters increased in the group receiving maintenance therapy with once-daily DPP-4 inhibitors. No statistically significant changes in hemoglobin A1c were observed between the two groups. CONCLUSIONS: Our findings suggest that switching from once-daily DPP-4 inhibitors to omarigliptin may be efficacious for maintaining FPG and TIR in T2DM patients.

GIP_HUMAN[22-51] is a new proatherogenic peptide identified by native plasma peptidomics.

We recently established a new plasma peptidomic technique and comprehensively identified a large number of low-molecular weight and low-abundance native peptides using a single drop of human plasma. To discover a novel polypeptide that potently modulates the cardiovascular system, we performed a bioinformatics analysis of the large-scale identification results, sequentially synthesized the selected peptide sequences, tested their biological activities, and identified a 30-amino-acid proatherogenic peptide, GIP_HUMAN[22-51], as a potent proatherosclerotic peptide hormone. GIP_HUMAN[22-51] has a common precursor with the glucose-dependent insulinotropic polypeptide (GIP) and is located immediately N-terminal to GIP. Chronic infusion of GIP_HUMAN[22-51] into ApoE-/- mice accelerated the development of aortic atherosclerotic lesions, which were inhibited by co-infusions with an anti-GIP_HUMAN[22-51] antibody. GIP_HUMAN[22-51] increased the serum concentrations of many inflammatory and proatherogenic proteins, whereas neutralising antibodies reduced their levels. GIP_HUMAN[22-51] induced IκB-α degradation and nuclear translocation of NF-κB in human vascular endothelial cells and macrophages. Immunoreactive GIP_HUMAN[22-51] was detected in human tissues but there was no colocalization with the GIP. The plasma GIP_HUMAN[22-51] concentration in healthy humans determined using a stable-isotope tagged peptide was approximately 0.6 nM. This study discovered a novel endogenous proatherogenic peptide by using a human plasma native peptidomic resource.

Glucose Variability is Independently Correlated with Serum Level of Pigment Epithelium-Derived Factor in Type 2 Diabetes.

INTRODUCTION: Pigment epithelium-derived factor (PEDF) may play a role in cardiometabolic disorders. The aim of this study was to investigate which biochemical and clinical parameters are independently associated with serum PEDF levels in patients with type 2 diabetes mellitus (T2DM). METHODS: We performed a cross-sectional analysis of 124 patients with T2DM who underwent continuous glucose monitoring (CGM) and blood chemistry analysis, including the diacron-reactive oxygen metabolites (d-ROMs) test and serum PEDF measurement (study 1). Then we investigated whether the changes in the studied biochemical and clinical parameters after 24 weeks of treatment (Δparameters) with anti-hyperglycemic agents, including sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide 1 receptor agonists, and/or insulin and anti-hypertensive drugs and statins, were independently correlated with change in PEDF (ΔPEDF) in 52 of the patients with T2DM for whom there was sufficient serum samples to perform the post-treatment analysis (study 2). Serum levels of PEDF were measured with an enzyme-linked immunosorbent assay. CGM metrics were calculated on days 2 and 3. Oxidative stress was evaluated using the d-ROMs test. RESULTS: Body mass index (BMI), triglycerides, fasting C-peptide, mean amplitude of glycemic excursions (MAGE), urinary albumin-to-creatinine ratio (UACR), and d-ROMs were positively associated with serum PEDF level, and high-density lipoprotein cholesterol (HDL-C) and estimated glomerular filtration rate (eGFR) were inversely associated with serum PEDF level. Because these parameters were correlated with each other, multivariate stepwise analysis was performed: eGFR, HDL-C, BMI, MAGE, and UACR remained significant (R2 = 0.452). Furthermore, ΔMAGE and Δd-ROMs were positively correlated with ΔPEDF in study 2. CONCLUSIONS: The results of this study suggest that MAGE may be independently correlated with elevations in serum PEDF level in patients with T2DM.