Diabetic dyslipidemia: evaluation and mechanism

Real-world effectiveness of imeglimin in patients with type 2 diabetes: A retrospective longitudinal study in Japan

OBJECTIVE

To examine the real-world effects of imeglimin on glycemic control and other metabolic factors in patients with type 2 diabetes (T2DM).

METHODS

A retrospective longitudinal study was conducted based on a chart review. We recruited patients with T2DM who took imeglimin continuously for at least 3 months. Data on various metabolic parameters were collected at the first prescription of imeglimin and at 3, 6 and 12 months after the initiation of imeglimin. Statistical comparisons were performed using paired t-tests.

RESULTS

68 patients were eligible for this study. HbA1c decreased by 0.7 % at 3 months, 1.1 % at 6 months and 1.0 % by 12 months after the initiation of imeglimin. The decreases in HbA1c were observed regardless of age, gender, body mass index, duration of diabetes, renal function and concomitant use of hypoglycemic agents. There were also significant decreases in body weight, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C) and non-HDL-C during imeglimin treatment.

CONCLUSIONS

This is the first report showing the long-term effects of imeglimin in a real-world setting. We confirmed the glucose-lowering effects of imeglimin. Furthermore, favorable effects of imeglimin on body weight and serum lipids were also suggested.

Silicon as a Functional Meat Ingredient Improves Jejunal and Hepatic Cholesterol Homeostasis in a Late-Stage Type 2 Diabetes Mellitus Rat Model

Silicon included in a restructured meat (RM) matrix (Si-RM) as a functional ingredient has been demonstrated to be a potential bioactive antidiabetic compound. However, the jejunal and hepatic molecular mechanisms by which Si-RM exerts its cholesterol-lowering effects remain unclear. Male Wistar rats fed an RM included in a high-saturated-fat high-cholesterol diet (HSFHCD) combined with a low dose of streptozotocin plus nicotinamide injection were used as late-stage type 2 diabetes mellitus (T2DM) model. Si-RM was included into the HSFHCD as a functional food. An early-stage TD2M group fed a high-saturated-fat diet (HSFD) was taken as reference. Si-RM inhibited the hepatic and intestinal microsomal triglyceride transfer protein (MTP) reducing the apoB-containing lipoprotein assembly and cholesterol absorption. Upregulation of liver X receptor (LXRα/β) by Si-RM turned in a higher low-density lipoprotein receptor (LDLr) and ATP-binding cassette transporters (ABCG5/8, ABCA1) promoting jejunal cholesterol efflux and transintestinal cholesterol excretion (TICE), and facilitating partially reverse cholesterol transport (RCT). Si-RM decreased the jejunal absorptive area and improved mucosal barrier integrity. Consequently, plasma triglycerides and cholesterol levels decreased, as well as the formation of atherogenic lipoprotein particles. Si-RM mitigated the dyslipidemia associated with late-stage T2DM by Improving cholesterol homeostasis. Silicon could be used as an effective nutritional approach in diabetic dyslipidemia management.

Specificities of primary and secondary prevention of lower extremity artery disease in patients with diabetes mellitus

Diabetes mellitus (DM) is a major risk factor for lower extremity arterial disease (LEAD) and about 20% of symptomatic patients with LEAD have DM. In subjects with DM, LEAD is a cause of morbidity and mortality. DM typically causes complications in the form of macro- and microangiopathy. In these patients, macroangiopathy manifests as atherosclerosis like in non-diabetic patients. However, its course is accelerated due to accompanying risk factors like hyperlipidemia and hypertension, with cumulative effects. Other factors are also relevant such as inflammation, endothelial dysfunction, platelet activation, blood rheological properties, hypercoagulability, and factors stimulating vascular smooth muscle cell proliferation. Additionally, DM is a risk factor for restenosis and amputation. DM is strongly associated with femoral-popliteal and tibial LEAD, which manifests earlier in patients with DM and may progress more rapidly to critical limb ischemia. Diabetic microangiopathy is characterized by arteriolosclerosis and interstitial fibrosis which additionally affects progression and outcomes of angiopathy of lower limbs. Glycemic control particularly decreases microangiopathic complications, while prevention of macrovascular complications requires treatment of accompanying risk factors like hypertension and dyslipidemia.

Measurement of cholesterol levels of lipoprotein subclasses in human serum using anion-exchange high-performance liquid chromatography with a linear concentration gradient of sodium perchlorate

BACKGROUND

Relationships between the subclasses of high-density lipoprotein (HDL) or low-density lipoprotein (LDL) and the risk of atherosclerotic cardiovascular disease have been studied, and using various methods, such as ultracentrifugation, electrophoresis, and nuclear magnetic resonance, for analysing lipoprotein subclasses. We established a method for HDL and LDL subclasses using anion-exchange high-performance liquid chromatography (AEX-HPLC) with a linear concentration gradient of sodium perchlorate (NaClO4).

METHOD

In the AEX-HPLC, the subclasses of HDL and LDL were separated, and detected using a post-column reactor with an enzymatic cholesterol reagent, that contained cholesterol esterase, cholesterol oxidase, and peroxidase as major ingredients. LDL subclasses were divided based on the absolute value of first-derivative chromatogram.

RESULT

Three HDL subclasses, HDL-P1, HDL-P2, and HDL-P3, and three LDL subclasses, LDL-P1, LDL-P2, and LDL-P3, were separated by AEX-HPLC, and detected in order. The major components of HDL-P2 and HDL-P3 were HDL3 and HDL2, respectively. The linearity was determined for each lipoprotein subclass. The coefficients of variation of cholesterol concentration of the subclasses for within-day assay (n = 10) and between-day assay (n = 10) ranged between 3.08-8.94% and 4.52-9.97%, respectively. Cholesterol levels in HDL-P1 of diabetic patients were positively correlated with oxidized LDL levels (r = 0.409, p = 0.002). Moreover, cholesterol levels in LDL-P2 and LDL-P3 were positively correlated with oxidized LDL levels (r = 0.393, p = 0.004 and r = 0.561, p < 0.001, respectively).

CONCLUSION

AEX-HPLC may be highly suitable as an assay to clinically assess lipoprotein subclasses.

The Antihyperglycemic Effect of Crude Liang (Gnetum gnemon var. tenerum) Leaves Powder on Wistar Rats

Chlorophyll and chlorophyllin (CHL) demonstrated antidiabetic activity by inhibiting gluconeogenesis and increasing glucose uptake in rats' muscle cells. Liang leaves contain high amounts of chlorophyll and chlorophyllin and may provide an antidiabetic effect. The antidiabetic activity of chlorophyll and CHL contained in Liang leaves, Cu-chlorophyllin (CCL) Liang leaves treated with CuSO4, and untreated crude Liang leaves (CLL) were compared using commercial chlorophyllin (CHL) as a reference. Twelve Wistar male rats were separated into 4 groups (3 rats/group); the first was a normal one (based line group), the second were the diabetic rats treated with CHL, while the third and the fourth were the diabetic rats treated with 0.97 g/kg of CCL and CLL, respectively. Diabetic rats were induced by a high fructose diet, before being taken to administer commercial CHL, CCL, and CLL for 7 days. Nonfasting blood glucose and body weight were checked daily. After euthanasia, organ weight, biochemical, hematological, and histopathological properties were evaluated. CCL treatment showed no antihyperglycemic activity in the rat model but caused some biochemical abnormalities and thrombocytopenia. Commercial CHL gave a higher reduction of nonfasting blood glucose (NFBG) than Liang leaves powder CCL or CLL but also showed some signs of abnormal biochemical parameters. CLL exhibited an antihyperglycemic effect, with higher body weight and increased HDL/LDL ratio and thus could be a promising alternative natural source for diabetes treatment.

Prevalence of dyslipidemia and its associated factors among university academic staff and students in Bangladesh

BACKGROUND

Dyslipidemia is one of the important contributors to cardiovascular disease and type 2 diabetes. There is little or no information on dyslipidemia among academic staff and students in Bangladesh. Therefore, this study aimed to investigate the prevalence and factors related to dyslipidemia among university academic staff and students in Bangladesh.

METHODS

A total of 533 participants (302 academic staff and 231 students) were enrolled in this cross-sectional study. A simple random sampling technique was used to enrol the participants. Fasting blood samples were obtained from the participants, and serum levels of triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured using the standard methods. Dyslipidemia was defined according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP-III) model guideline. Multivariable logistic regression was conducted to identify the factors related to lipid marker abnormalities.

RESULTS

Overall, the prevalence of dyslipidemia was 81.5%, of which 85% was in staff and 76.5% in students. A significant difference was found in the prevalence of dyslipidemia between males and females only in the student group (p < 0.01). Among staff, hypertriglyceridemia prevalence was 49.7%, hypercholesterolemia 23%, high LDL-C 24.7% and low HDL-C 77.3%. On the other hand, hypertriglyceridemia prevalence was 39%, hypercholesterolemia 25.6%, high LDL-C 26.5% and low HDL-C 69.3% among students. The most common lipid abnormality was low HDL-C in both groups. The prevalence of mixed dyslipidemia was 14.2% and 14.1% in staff and students, respectively. According to the regression analysis, increased age, obesity, diabetes, and inadequate physical activity were significantly associated with dyslipidemia.

CONCLUSIONS

Dyslipidemia was prevalent among the majority of the study participants. Increased age, obesity, diabetes, and inadequate physical activity were significantly associated with dyslipidemia. The study's results highlight the importance of implementing interventions to address the associated risk factors of dyslipidemia among academic staff and students in Bangladesh.

Real-World Efficacy of Glucagon-like Peptide-1 (GLP-1) Receptor Agonist, Dulaglutide, on Metabolic Parameters in Japanese Patients with Type 2 Diabetes: A Retrospective Longitudinal Study

The glucagon-like peptide-1 receptor agonist (GLP-1RA) dulaglutide has been shown to improve body weight and glycemic control and reduce major cardiovascular (CV) events. In Japan, dulaglutide is used at a fixed dose of 0.75 mg, which is lower than that in Europe and North America. However, the reports of real-world efficacy on metabolic parameters in Japanese patients with type 2 diabetes (T2DM) are limited. This study aimed to examine the real-world efficacy of GLP-1RA dulaglutide on metabolic parameters in Japanese patients with T2DM. We retrospectively selected patients with T2DM who had been prescribed dulaglutide continuously for 12 months or longer between September 2015 and December 2020 and compared metabolic parameters at baseline with the data at 12 months after the start of dulaglutide. One hundred twenty-one patients were enrolled in this study. The 12-month dulaglutide treatment reduced body weight by 1.7 kg and hemoglobin A1c by 1.1%. Significant improvements were also observed in serum high-density lipoprotein cholesterol (HDL-C), triglyceride (TG) and non-HDL-C. The change in HbA1c during dulaglutide treatment was significantly correlated with the changes in HDL-C (R = −0.236, p = 0.013), LDL-C (R = 0.377, p = 0.005) and non-HDL-C (R = 0.415, p < 0.001). The improvements in HbA1c, HDL-C, TG and non-HDL-C were greater in patients concurrently treated with SGLT2 inhibitors (SGLT2is) at baseline. In conclusion, the treatment with dulaglutide has beneficial effects on multiple CV risk factors in Japanese patients with T2DM.

Atherogenic Lipoproteins for the Statin Residual Cardiovascular Disease Risk

Randomized controlled trials (RCTs) show that decreases in low-density lipoprotein cholesterol (LDL-C) by the use of statins cause a significant reduction in the development of cardiovascular disease (CVD). However, one of our previous studies showed that, among eight RCTs that investigated the effect of statins vs. a placebo on CVD development, 56–79% of patients had residual CVD risk after the trials. In three RCTs that investigated the effect of a high dose vs. a usual dose of statins on CVD development, 78–87% of patients in the high-dose statin arms still had residual CVD risk. The risk of CVD development remains even when statins are used to strongly reduce LDL-C, and this type of risk is now regarded as statin residual CVD risk. Our study shows that elevated triglyceride (TG) levels, reduced high-density lipoprotein cholesterol (HDL-C), and the existence of obesity/insulin resistance and diabetes may be important metabolic factors that determine statin residual CVD risk. Here, we discuss atherogenic lipoproteins that were not investigated in such RCTs, such as lipoprotein (a) (Lp(a)), remnant lipoproteins, malondialdehyde-modified LDL (MDA-LDL), and small-dense LDL (Sd-LDL). Lp(a) is under strong genetic control by apolipoprotein (a), which is an LPA gene locus. Variations in the LPA gene account for 91% of the variability in the plasma concentration of Lp(a). A meta-analysis showed that genetic variations at the LPA locus are associated with CVD events during statin therapy, independent of the extent of LDL lowering, providing support for exploring strategies targeting circulating concentrations of Lp(a) to reduce CVD events in patients receiving statins. Remnant lipoproteins and small-dense LDL are highly associated with high TG levels, low HDL-C, and obesity/insulin resistance. MDA-LDL is a representative form of oxidized LDL and plays important roles in the formation and development of the primary lesions of atherosclerosis. MDA-LDL levels were higher in CVD patients and diabetic patients than in the control subjects. Furthermore, we demonstrated the atherogenic properties of such lipoproteins and their association with CVD as well as therapeutic approaches.

A Significant Effect of Oral Semaglutide on Cardiovascular Risk Factors in Patients With Type 2 Diabetes

BACKGROUND

The once-daily glucagon-like peptide 1 (GLP-1) analogue, liraglutide has been shown to reduce major adverse cardiovascular events (MACE) and progression of chronic kidney disease (CKD). The once-weekly GLP-1 analogue, semaglutide also reduced MACE and renal events. Based on the evidence for GLP-1 analogues on MACE and renal events, the guideline recommended to treat high-risk diabetic individuals with GLP-1 analogues to reduce MACE and CKD progression. Recently, a once-daily oral semaglutide was developed and shown to reduce MACE. However, its effects on renal outcome and cardiovascular metabolic risk factors remain unknown.

METHODS

We retrospectively picked up patients who had taken oral semaglutide from March 2021 to June 2022 and compared metabolic parameters at baseline with the data at 3, 6 months after the start of oral semaglutide.

RESULTS

We found 47 patients who had taken oral semaglutide. Body weight significantly decreased at 3 and 6 months after the start of oral semaglutide, and systolic blood pressure significantly decreased after 6 months. Hemoglobin A1c (HbA1c) tended to decrease after 3 months and significantly deceased after 6 months. Serum low-density lipoprotein cholesterol (LDL-C) levels significantly decreased after 6 months and non-high-density lipoprotein-cholesterol (non-HDL-C) levels tended to decrease after 6 months. Urinary albumin to creatinine ratio (UACR) tended to decrease after 3 and 6 months. Such favorable metabolic changes by oral semaglutide were observed more prominently in patients who had not ever used GLP-1 analogues than in patients who switched from subcutaneous GLP-1 analogues.

CONCLUSIONS

Our study showed that oral semaglutide improved body weight, blood pressure, HbA1c, LDL-C, non-HDL-C and UACR, in type 2 diabetic obese patients, especially, in patients who had not ever used GLP-1 analogues.

Molecular Biological and Clinical Understanding of the Statin Residual Cardiovascular Disease Risk and Peroxisome Proliferator-Activated Receptor Alpha Agonists and Ezetimibe for Its Treatment

Several randomized, double blind, placebo-controlled trials (RCTs) have demonstrated that low-density lipoprotein cholesterol (LDL-C) lowering by using statins, including high-doses of strong statins, reduced the development of cardiovascular disease (CVD). However, among the eight RCTs which investigated the effect of statins vs. placebos on the development of CVD, 56-79% of patients had the residual CVD risk after the trials. In three RCTs which investigated the effect of a high dose vs. a usual dose of statins on the development of CVD, 78-87% of patients in the high-dose statin arms still had the CVD residual risk after the trials. An analysis of the characteristics of patients in the RCTs suggests that elevated triglyceride (TG) and reduced high-density lipoprotein cholesterol (HDL-C), the existence of obesity/insulin resistance, and diabetes may be important metabolic factors which determine the statin residual CVD risk. To understand the association between lipid abnormalities and the development of atherosclerosis, we show the profile of lipoproteins and their normal metabolism, and the molecular and biological mechanisms for the development of atherosclerosis by high TG and/or low HDL-C in insulin resistance. The molecular biological mechanisms for the statin residual CVD risk include an increase of atherogenic lipoproteins such as small dense LDL and remnants, vascular injury and remodeling by inflammatory cytokines, and disturbed reverse cholesterol transport. Peroxisome proliferator-activated receptor alpha (PPARα) agonists improve atherogenic lipoproteins, reverse the cholesterol transport system, and also have vascular protective effects, such as an anti-inflammatory effect and the reduction of the oxidative state. Ezetimibe, an inhibitor of intestinal cholesterol absorption, also improves TG and HDL-C, and reduces intestinal cholesterol absorption and serum plant sterols, which are increased by statins and are atherogenic, possibly contributing to reduce the statin residual CVD risk.

Effects of a Novel Selective Peroxisome Proliferator-Activated Receptor α Modulator, Pemafibrate, on Metabolic Parameters: A Retrospective Longitudinal Study

The modulation of peroxisome proliferator-activated receptors (PPARs), the superfamily of steroid–thyroid–retinoid nuclear receptors, is expected to induce an amazing crosstalk between energy-demanding organs. Here, we aimed to study the effects of the novel selective PPARα modulator, pemafibrate, on metabolic parameters in patients with dyslipidemia. We retrospectively studied patients who had taken pemafibrate and compared metabolic parameters at baseline with the data at 3, 6 and 12 months after the start of pemafibrate. Serum triglyceride significantly decreased and high-density lipoprotein-cholesterol significantly increased at 3, 6 and 12 months after the start of pemafibrate. Serum aspartate aminotransferase levels significantly decreased at 3 and 6 after the start of pemafibrate as compared with baseline. Serum alanine aminotransferase and gamma-glutamyl transferase significantly decreased and albumin significantly increased after 3, 6 and 12 months. HbA1c levels significantly decreased after 3 months. Further, serum uric acid significantly decreased after 12 months. Such metabolic favorable changes due to pemafibrate were significantly correlated with changes in serum lipids. In conclusion, we observed a significant improvement of liver function, HbA1c and serum uric acid along with an amelioration of dyslipidemia after the start of pemafibrate.

A Significant Increase of Estimated Glomerular Filtration Rate After Switching From Fenofibrate to Pemafibrate in Type 2 Diabetic Patients

Background

Dyslipidemia is one of the major risk factors for cardiovascular disease (CVD), along with hypertension, diabetes, smoking and obesity. Approximately 70% of CVD risk remains even after treatment of elevated low-density lipoprotein-cholesterol (LDL-C) by statins. High triglyceride (TG) and low high-density lipoprotein-cholesterol (HDL-C) level are potential therapeutic targets to prevent CVD. Fibrates were associated with a greater reduction in TG, and a greater increase in HDL-C. Fibrates activate specific transcription factors belonging to the nuclear hormone receptor superfamily, termed peroxisome proliferator-activated receptors (PPARs). Fibrates improve atherogenic dyslipidemia by mediating PPARα. Pemafibrate is a novel member of the selective PPARα modulator (SPPARMα) family that was designed to have a higher PPARα agonistic activity and selectivity than previous fibrates. Here, we aimed to study the influences of the switching from fenofibrate to pemafibrate on metabolic parameters in type 2 diabetic patients.

Methods

We retrospectively picked up type 2 diabetic patients who had undergone the switching from fenofibrate to pemafibrate, and compared metabolic parameters before the switching with the data at 3, 6 and 12 months after the switching.

Results

We found 15 patients with type 2 diabetes. Serum alanine aminotransferase significantly decreased at 6 months after the switching as compared with baseline. The estimated glomerular filtration rate (eGFR) significantly increased at 3, 6 and 12 months after the switching from fenofibrate to pemafibrate as compared with baseline. Serum uric acid (UA) levels significantly increased at 3 and 6 months after the switching as compared with baseline. We did not observe changes in other metabolic parameters after the switching.

Conclusion

We observed a significant increase of eGFR and serum UA after the switching from fenofibrate to pemafibrate in type 2 diabetic patients. Recent evidences suggest that the improvement of eGFR is beneficially associated with the development of CVD in type 2 diabetic patients. Considering the impact on eGFR, pemafibrate may effectively reduce CVD as compared with fenofibrate.

Secondary dyslipidemia: its treatments and association with atherosclerosis

Dyslipidemia is classified into primary and secondary types. Primary dyslipidemia is basically inherited and caused by single or multiple gene mutations that result in either overproduction or defective clearance of triglycerides and cholesterol. Secondary dyslipidemia is caused by unhealthy lifestyle factors and acquired medical conditions, including underlying diseases and applied drugs. Secondary dyslipidemia accounts for approximately 30-40% of all dyslipidemia. Secondary dyslipidemia should be treated by finding and addressing its causative diseases or drugs. For example, treatment of secondary dyslipidemia, such as hyperlipidemia due to hypothyroidism, by using statin without controlling hypothyroidism, may lead to myopathy and serious adverse events such as rhabdomyolysis. Differential diagnosis of secondary dyslipidemia is very important for safe and effective treatment. Here, we describe an overview about diseases and drugs that interfere with lipid metabolism leading to secondary dyslipidemia. Further, we show the association of each secondary dyslipidemia with atherosclerosis and the treatments for such dyslipidemia.