Diabetes and dyslipidemia: characterizing lipoprotein metabolism

Discovery of the selective and nanomolar inhibitor of DPP-4 more potent than sitagliptin by structure-guided rational design

Various therapeutic targets and approaches are commonly employed in the management of Type 2 Diabetes. These encompass diverse groups of drugs that target different mechanisms involved in glucose regulation. Inhibition of the DPP-4 enzyme has been proven an excellent target for antidiabetic drug design. Our previous work on discovering multitarget antidiabetic drugs led to the identification of a gallic acid-thiazolidinedione hybrid as a potent DPP4 inhibitor (IC50 = 36 nM). In current research, our efforts resulted in a new dihydropyrimidine-based scaffold with enhanced DPP4 inhibition potential. After virtual evaluation, the designed molecules with excellent interaction patterns and binding energy values were synthesized in the wet laboratory. The inhibition potential of synthesized compounds was assessed against the DPP-4 enzyme. Compound 46 with single digit IC50 value 2 nM exhibited 4-fold and 18-fold higher activity than Sitagliptin and our previously reported hybrid respectively. Moreover, compounds 46, 47 and 50 have shown manyfold selectivity against DPP8 and DPP9. Further pretreatment with compounds 43, 45-47 and 50 (at doses of 10 and 20 mg/kg) in OGTT conducted on rats resulted in a significant decrease in the serum glucose levels compared to the control group. In the long-term STZ-induced diabetic rats, tested compound 50 performed similarly to the reference drug. Molecular dynamics simulations and in-silico molecular docking studies were employed to elucidate the time-dependent interactions of inhibitors within the active sites of DPP4. The compounds examined in this work might serve as a possible lead in the development of effective diabetic mellitus treatments.

The еffects of low mineral content water on microbiota, metabolic, and oxidative stress parameters in patients with type 2 diabetes mellitus

Although scientific evidence has shown that natural mineral waters have potential beneficial metabolic effects, there is still very scarce data on their influence on type 2 diabetes mellitus (T2DM). The study was designed to investigate the effects of low mineral water from the "Sneznik-1/79″ source in Serbia on microbiota, metabolic, and oxidative stress parameters in patients with T2DM. In total, 60 patients with confirmed T2DM were included in the study, and they consumed "Sneznik-1/79″ water for 28 days. To examine the positive effects of "Sneznik-1/79″ water, we compared the results before and after the four weeks of "Sneznik-1/79″ water intake. Standard biochemical analyses were carried out, such as glucose level, lipid profile, and stool tests. The blood samples were collected to evaluate the effects of "Sneznik-1/79″ water on the redox status. At the end of the monitoring period, the total cholesterol concentration significantly dropped compared to the initial value. A significant improvement in intestinal peristalsis was observed, which was reflected in the fact that after four weeks, all patients established regular, daily bowel movements. Moreover, consumption of "Sneznik-1/79″ water eliminated the appearance of dysbiosis in 50% of patients. Additionally, the antioxidant capacity was improved by increasing the concentration of superoxide dismutase and reduced glutathione. The result of our study pointed out that the intake of "Sneznik-1/79″ water could be a promising adjuvant therapy for improving intestinal peristalsis as well as reducing the appearance of dysbiosis in T2DM patients.

Interactions between genetic and lifestyle factors on cardiometabolic disease-related outcomes in Latin American and Caribbean populations: A systematic review

Introduction

The prevalence of cardiometabolic diseases has increased in Latin American and the Caribbean populations (LACP). To identify gene-lifestyle interactions that modify the risk of cardiometabolic diseases in LACP, a systematic search using 11 search engines was conducted up to May 2022.

Methods

Eligible studies were observational and interventional studies in either English, Spanish, or Portuguese. A total of 26,171 publications were screened for title and abstract; of these, 101 potential studies were evaluated for eligibility, and 74 articles were included in this study following full-text screening and risk of bias assessment. The Appraisal tool for Cross-Sectional Studies (AXIS) and the Risk Of Bias In Non-Randomized Studies-of Interventions (ROBINS-I) assessment tool were used to assess the methodological quality and risk of bias of the included studies.

Results

We identified 122 significant interactions between genetic and lifestyle factors on cardiometabolic traits and the vast majority of studies come from Brazil (29), Mexico (15) and Costa Rica (12) with FTO, APOE, and TCF7L2 being the most studied genes. The results of the gene-lifestyle interactions suggest effects which are population-, gender-, and ethnic-specific. Most of the gene-lifestyle interactions were conducted once, necessitating replication to reinforce these results.

Discussion

The findings of this review indicate that 27 out of 33 LACP have not conducted gene-lifestyle interaction studies and only five studies have been undertaken in low-socioeconomic settings. Most of the studies were cross-sectional, indicating a need for longitudinal/prospective studies. Future gene-lifestyle interaction studies will need to replicate primary research of already studied genetic variants to enable comparison, and to explore the interactions between genetic and other lifestyle factors such as those conditioned by socioeconomic factors and the built environment. The protocol has been registered on PROSPERO, number CRD42022308488.

Systematic review registration

https://clinicaltrials.gov, identifier CRD420223 08488.

Is type 2 diabetes associated dementia a microvascular early-Alzheimer's phenotype induced by aberrations in the peripheral metabolism of lipoprotein-amyloid?

There is increasing evidence of a positive association of type 2 diabetes with Alzheimer's disease (AD), the most prevalent form of dementia. Suggested pathways include cerebral vascular dysfunction; central insulin resistance, or exaggerated brain abundance of potentially cytotoxic amyloid-β (Aβ), a hallmark feature of AD. However, contemporary studies find that Aβ is secreted in the periphery by lipogenic organs and secreted as nascent triglyceride-rich lipoproteins (TRL's). Pre-clinical models show that exaggerated abundance in blood of TRL-Aβ compromises blood-brain barrier (BBB) integrity, resulting in extravasation of the TRL-Aβ moiety to brain parenchyme, neurovascular inflammation and neuronal degeneration concomitant with cognitive decline. Inhibiting secretion of TRL-Aβ by peripheral lipogenic organs attenuates the early-AD phenotype indicated in animal models, consistent with causality. Poorly controlled type 2 diabetes commonly features hypertriglyceridemia because of exaggerated TRL secretion and reduced rates of catabolism. Alzheimer's in diabetes may therefore be a consequence of heightened abundance in blood of lipoprotein-Aβ and accelerated breakdown of the BBB. This review reconciles the prevailing dogma of amyloid associated cytotoxicity as a primary risk factor in late-onset AD, with substantial evidence of a microvascular axis for dementia-in-diabetes. Consideration of potentially relevant pharmacotherapies to treat insulin resistance, dyslipidaemia and by extension plasma amyloidemia in type 2 diabetes are discussed.

Periodontitis and implant complications in diabetes

Epidemiologic evidence indicates that periodontitis is more frequent in patients with uncontrolled diabetes mellitus than in healthy controls, suggesting that it could be considered the "sixth complication" of diabetes. Actually, diabetes mellitus and periodontitis are two extraordinarily prevalent chronic diseases that share a number of comorbidities all converging toward an increased risk of cardiovascular disease. Periodontal treatment has recently been shown to have the potential to improve the metabolic control of diabetes, although long-term studies are lacking. Uncontrolled diabetes also seems to affect the response to periodontal treatment, as well as the risk to develop peri-implant diseases. Mechanisms of associations between diabetes mellitus and periodontal disease include the release of advanced glycation end products as a result of hyperglycemia and a range of shared predisposing factors of genetic, microbial, and lifestyle nature. This review discusses the evidence for the risk of periodontal and peri-implant disease in diabetic patients and the potential role of the dental professional in the diabetes-periodontal interface.

Treatment with omega-3 PUFAs does not increase the risk of CYP2E1-dependent oxidative stress and diabetic liver pathology

An increase in CYP2E1 expression is a key factor in the development of diabetic oxidative liver damage. Long-term treatment with omega-3 PUFAs, which are CYP2E1 substrates, may affect CYP2E1 expression in the liver. In this work, we performed Western blot analysis, biochemical methods, and microscopic ultrastructural studies of the liver in a streptozotocin-induced rat model of type 1 diabetes to investigate whether long-term treatment with omega-3 PUFAs could induce CYP2E1-dependent oxidative stress and diabetic liver pathology. Significant hyperglycemia and lack of natural weight gain were observed in the diabetic rats compared to non-diabetic controls. A 2.5-fold increase in CYP2E1 expression (protein content and activity) was also observed in the diabetic rats. In addition, signs of oxidative stress were found in the liver of the diabetic rats. A significant increase in transaminases and GGT level in blood serum was also observed, which could indicate marked destruction of liver tissue. Diabetic dyslipidemia (increased triacylglycerol levels and decreased HDL-C levels) was found. Treatment of the diabetic animals with an omega-3-enriched pharmaceutical composition of PUFAs had no effect on CYP2E1 levels but contributed to a two-fold decrease in enzyme activity. The intensity of lipid peroxidation also remained close to the diabetic group. However, at the same time, antioxidant protection was provided by induction of antioxidant enzyme activity. Examination of the liver ultrastructure revealed no characteristic signs of diabetic pathology. However, omega-3 PUFAs did not normalize blood glucose levels and serum lipid profile. Thus, long-term treatment of diabetic rats with omega-3 PUFAs does not increase the risk of CYP2E1-dependent oxidative stress and development of liver pathology but prevents some diabetic ultrastructural damage to hepatocytes.

Clinical Aspects of Genetic and Non-Genetic Cardiovascular Risk Factors in Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is the most common monogenic metabolic disorder characterized by considerably elevated low-density lipoprotein cholesterol (LDL-C) levels leading to enhanced atherogenesis, early cardiovascular disease (CVD), and premature death. However, the wide phenotypic heterogeneity in FH makes the cardiovascular risk prediction challenging in clinical practice to determine optimal therapeutic strategy. Beyond the lifetime LDL-C vascular accumulation, other genetic and non-genetic risk factors might exacerbate CVD development. Besides the most frequent variants of three genes (LDL-R, APOB, and PCSK9) in some proband variants of other genes implicated in lipid metabolism and atherogenesis are responsible for FH phenotype. Furthermore, non-genetic factors, including traditional cardiovascular risk factors, metabolic and endocrine disorders might also worsen risk profile. Although some were extensively studied previously, others, such as common endocrine disorders including thyroid disorders or polycystic ovary syndrome are not widely evaluated in FH. In this review, we summarize the most important genetic and non-genetic factors that might affect the risk prediction and therapeutic strategy in FH through the eyes of clinicians focusing on disorders that might not be in the center of FH research. The review highlights the complexity of FH care and the need of an interdisciplinary attitude to find the best therapeutic approach in FH patients.

Fatty acids of type 2 diabetic serum decrease the stemness properties of human adipose-derived mesenchymal stem cells

In type 2 diabetes, dyslipidemia and increased serum free fatty acids (FFAs) exacerbate the development of the disease through a negative effect on insulin secretion. Adipose-derived mesenchymal stem cells (AdMSCs) play a key role in regenerative medicine, and these cells can potentially be applied as novel therapeutic resources in the treatment of diabetes. In this study, AdMSCs were treated with diabetic or nondiabetic serum FFAs isolated from women of menopausal age. Serum FFAs were analyzed using gas-liquid chromatography. The expression level of the stemness markers CD49e and CD90 and the Wnt signaling target genes Axin-2 and c-Myc were evaluated using real-time PCR. The proliferation rate and colony formation were also assessed using a BrdU assay and crystal violet staining, respectively. The level of glutathione was assessed using cell fluorescence staining. Compared to nondiabetic serum, diabetic serum contained a higher percentage of oleate (1.5-fold, p < 0.01). In comparison with nondiabetic FFAs, diabetic FFAs demonstrated decreasing effects on the expression of CD90 (-51%, p < 0.001) and c-Myc (-48%, p < 0.05), and proliferation rate (-35%, p < 0.001), colony formation capacity (-50%, p < 0.01), and GSH levels (-62%, p < 0.05). The negative effect of the FFAs of diabetic serum on the stemness characteristics may impair the regenerative capabilities of AdMSCs.

Association of the APOA-5 Genetic Variant rs662799 with Metabolic Changes after an Intervention for 9 Months with a Low-Calorie Diet with a Mediterranean Profile

In cross-sectional studies, the genetic variant rs662799 of the APOA5 gene is associated with high serum triglyceride concentrations, and in some studies, the effect of short-term dietary interventions has been evaluated. The aim of the present investigation was to evaluate the role of this genetic variant in metabolic changes after the consumption of a low-calorie diet with a Mediterranean pattern for 9 months. A population of 269 Caucasian obese patients was recruited. Adiposity and biochemical parameters were measured at the beginning (basal level) and after 3 and 9 months of the dietary intervention. The rs662799 genotype was assessed with a dominant analysis (TT vs. CT + CC). The APOA5 variant distribution was: 88.1% (n = 237) (TT), 11.5% (n = 31) (TC) and 0.4% (n = 1) (CC). There were significant differences only in triglyceride levels at all times of the study between the genotype groups. After 3 and 9 months of dietary intervention, the following parameters improved in both genotype groups: adiposity parameters, systolic pressure, total cholesterol, LDL cholesterol, leptin, adiponectin and the leptin/adiponectin ratio. The intervention significantly decreased insulin levels, HOMA-IR and triglyceride levels in non-C allele carriers (Delta 9 months TT vs. TC + CC). i.e., insulin levels (delta: −3.8 + 0.3 UI/L vs. −1.2 + 0.2 UI/L; p = 0.02), HOMA-IR levels (delta: −1.2 + 0.2 units vs. −0.3 + 0.1 units; p = 0.02), triglyceride levels (delta: −19.3 + 4.2 mg/dL vs. −4.2 + 3.0 mg/dL; p = 0.02). In conclusion, non-C allele carriers of rs662799 of the APOA5 gene showed a decrease of triglyceride, insulin and HOMA-IR levels after consuming a low-calorie diet with a Mediterranean pattern; we did not observe this effect in C allele carriers, despite a significant weight loss.

Metabolic and Metabo-Clinical Signatures of Type 2 Diabetes, Obesity, Retinopathy, and Dyslipidemia

Macro- and microvascular complications of type 2 diabetes (T2D), obesity, and dyslipidemia share common metabolic pathways. In this study, using a total of 1,300 metabolites from 996 Qatari adults (57% with T2D) and 1,159 metabolites from an independent cohort of 2,618 individuals from the Qatar BioBank (11% with T2D), we identified 373 metabolites associated with T2D, obesity, retinopathy, dyslipidemia, and lipoprotein levels, 161 of which were novel. Novel metabolites included phospholipids, sphingolipids, lysolipids, fatty acids, dipeptides, and metabolites of the urea cycle and xanthine, steroid, and glutathione metabolism. The identified metabolites enrich pathways of oxidative stress, lipotoxicity, glucotoxicity, and proteolysis. Second, we identified 15 patterns we defined as "metabo-clinical signatures." These are clusters of patients with T2D who group together based on metabolite levels and reveal the same clustering in two or more clinical variables (obesity, LDL, HDL, triglycerides, and retinopathy). These signatures revealed metabolic pathways associated with different clinical patterns and identified patients with extreme (very high/low) clinical variables associated with extreme metabolite levels in specific pathways. Among our novel findings are the role of N-acetylmethionine in retinopathy in conjunction with dyslipidemia and the possible roles of N-acetylvaline and pyroglutamine in association with high cholesterol levels and kidney function.

Emerging Insights on the Diverse Roles of Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) in Chronic Liver Diseases: Cholesterol Metabolism and Beyond

Chronic liver diseases are commonly associated with dysregulated cholesterol metabolism. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a serine protease of the proprotein convertase family that is mainly synthetized and secreted by the liver, and represents one of the key regulators of circulating low-density lipoprotein (LDL) cholesterol levels. Its ability to bind and induce LDL-receptor degradation, in particular in the liver, increases circulating LDL-cholesterol levels in the blood. Hence, inhibition of PCSK9 has become a very potent tool for the treatment of hypercholesterolemia. Besides PCSK9 limiting entry of LDL-derived cholesterol, affecting multiple cholesterol-related functions in cells, more recent studies have associated PCSK9 with various other cellular processes, including inflammation, fatty acid metabolism, cancerogenesis and visceral adiposity. It is increasingly becoming evident that additional roles for PCSK9 beyond cholesterol homeostasis are crucial for liver physiology in health and disease, often contributing to pathophysiology. This review will summarize studies analyzing circulating and hepatic PCSK9 levels in patients with chronic liver diseases. The factors affecting PCSK9 levels in the circulation and in hepatocytes, clinically relevant studies and the pathophysiological role of PCSK9 in chronic liver injury are discussed.

Laboratory data clustering in defining population cohorts: Case study on metabolic indicators

The knowledge on the general population health is important for creating public policies and organization of medical services. However, personal data are often limited, and mathematical models are employed to achieve a general overview. Cluster analysis was used in this study to assess general trends in population health based on laboratory data. Metabolic indicators were chosen to test the model and define population cohorts. Data on blood analysis of 33,049 persons, namely the concentrations of glucose, total cholesterol, and triglycerides, were collected in a public health laboratory and used to define metabolic cohorts employing computational data clustering (CLARA method). The population was shown to be distributed in 3 clusters: persons with hypercholesterolemia with or without changes in the concentration of triglycerides or glucose, persons with reference or close to reference concentrations of all three analytes and persons with predominantly elevated all three parameters. Clustering of biochemical data, thus, is a useful statistical tool in defining population groups in respect to certain health aspect.

Genetic mutations of APOEε4 carriers in cardiovascular patients lead to the development of insulin resistance and risk of Alzheimer's disease

Type 2 diabetes mellitus and Alzheimer's disease (AD), both are chronic and progressive diseases. Many cardiovascular and genetic risk factors are considered responsible for the development of AD and diabetes mellitus (DM). Genetic risk factor such as apolipoprotein E (APOE) plays a critical role in the progression of AD. Specifically, APOEε4 is genetically the strongest isoform associated with neuronal insulin deficiency, altered lipid homeostasis, and metabolism, decreased glucose uptake, impaired gray matter volume, and cerebrovascular functions. In this article, we have summarized the mechanisms of cardiovascular disturbances associated with AD and DM, impact of amyloid-β aggregation, and neurofibrillary tangles formation in AD. Moreover, cardiovascular risk factors leading to insulin resistance (IR) and amyloid-β aggregation are highlighted along with the effects of APOE risk alleles on cerebral, lipid, and cholesterol metabolism leading to CVD-mediated IR. Correspondingly, the contribution of IR, genetic and cardiovascular risk factors in amyloid-β aggregation, which may lead to the late onset of AD and DM, has been also discussed. In short, IR is related to significantly lower cerebral glucose metabolism, which sequentially forecasts poorer memory performance. Hence, there will be more chances for neural glucose intolerance and impairment of cognitive function in cardiac patients, particularly APOEε4 carriers having IR. Hence, this review provides a better understanding of the corresponding crosstalk among different pathways. This will help to investigate the rational application of preventive measures against IR and cognitive dysfunction, specifically in APOEε4 carriers' cardio-metabolic patients.

APOA-5 Genetic Variant rs662799: Role in Lipid Changes and Insulin Resistance after a Mediterranean Diet in Caucasian Obese Subjects

Background and Aims

This APOA5-1131C allele is related with a higher serum triglyceride levels and perhaps a different metabolic response to a dietary intervention. The aim of the present investigation was to evaluate SNP rs662799 in the APOA5 gene and its associations with metabolic effects after a hypocaloric diet with Mediterranean pattern.

Methods

A population of 363 Caucasian obese patients was enrolled. Anthropometric parameters and serum parameters (lipid profile, insulin, homeostasis model assessment (HOMA-IR), glucose, C reactive protein, adiponectin, resistin, and leptin levels) were measured, at basal time and after 3 months. All patients were genotyped in the rs662799 polymorphism.

Results

The APOA5 variant distribution was as follows: 89.3% (n = 324) (TT) were homozygous for the T allele, 10.5% (n = 38) (TC) were heterozygous, and 0.2% (n = 1) (CC) were homozygous for the C allele. Triglyceride levels were higher in patients with the C allele. After dietary intervention, BMI, weight, fat mass, waist circumference, systolic blood pressure, adiponectin, leptin, and adiponectin/leptin ratio improved significantly in both genotype groups TT and TC+CC. After dietary intervention, insulin levels (delta: −3.6 ± 0.8 UI/L vs. −1.5 ± 0.6 UI/L; P = 0.03), HOMA-IR (delta: −1.5 ± 0.4 units vs. −0.3 ± 0.2 units; P = 0.02), and triglyceride levels (delta: −19.3 ± 4.2 mg/dL vs. −3.2 ± 3.1 mg/dL; P = 0.02) decreased in non-C allele carriers.

Conclusions

C allele carriers of rs662799 of the APOA5 gene did not show an improvement in triglyceride, insulin, and HOMA-IR levels after a significant weight loss due to a hypocaloric diet with a Mediterranean pattern.

APOA5 Variant rs662799, Role in Cardiovascular Traits and Serum Adipokine Levels in Caucasian Obese Subjects

BACKGROUND AND AIMS

This ApoA5-1131C allele of rs662799 variant is related with a higher serum triglyceride levels, and it contributes to increase risk of cardiovascular disease. The aim of the present investigation was to evaluate single nucleotide polymorphism rs662799 in APOA5 gene and its associations with cardiovascular risk factors, MS, and serum adipokine levels.

METHODS

The study involved a population of 1,002 Caucasian obese subjects. Measurements of body weight, waist circumference, fat mass, arterial blood pressure, blood glucose, C-reactive protein, insulin levels, insulin resistance (HOMA-IR), lipid profile, and adipokines levels were recorded. Genotype of ApoA5 gene polymorphism (rs662799) and prevalence of metabolic syndrome (MS) were evaluated.

RESULTS

The distribution of the rs662799 polymorphism in this adult population (n = 1,002) was 88.3% (n = 885) (TT), 11.4% (n = 114) (TC), and 0.3% (n = 3) (CC). No significant differences were found between the 2 genotypes in the anthropometric data, MS, or blood pressure. Triglyceride levels were higher in C-allele carriers (delta total group: 19.7 ± 2.1 mg/dL: p = 0.02) than non C-allele carriers. HDL-cholesterol levels were lower in C-allele carriers (delta total group: -6.7 ± 1.1 mg/dL: p = 0.02) than non C-allele carriers. Adiponectin levels were lower in C-allele carriers (delta total group: -11.6 ± 1.0 mg/dL: p = 0.02) too. In C-allele carriers, logistic regression analysis showed an increased risk of hypertriglyceridemia (odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.2-3.4, p = 0.001) and percentage of low-HDL-C (OR = 2.2, 95% CI = 1.3-3.7, p = 0.002) after adjusting by body mass index and age.

CONCLUSIONS

C-allele carriers of rs662799 of APOA5 gene showed high rates of low levels of HDL and hypertriglyceridemia, with differences in triglyceride, HDL cholesterol, and adiponectin levels in Caucasian obese subjects.

Antidiabetic effect of a flavonoid-rich extract from Sophora alopecuroides L. in HFD- and STZ- induced diabetic mice through PKC/GLUT4 pathway and regulating PPARα and PPARγ expression

HEADINGS ETHNOPHARMACOLOGICAL RELEVANCE

Sophora alopecuroides L. is a traditional ethnopharmacological plant, which is widely used in traditional Chinese medicine and Mongolian and Uighur medicine to ameliorate "thirst disease".

AIM OF THE STUDY

This study aimed to investigate the antidiabetic activities and mechanisms of a flavonoid-rich extract from Sophora alopecuroides L. (SA-FRE) both in vivo and vitro.

MATERIALS AND METHODS

The main six chemical constituents of SA-FRE were elucidated based on an off-line semi-preparative liquid chromatography nuclear magnetic resonance (LC-NMR) protocol. Myc-GLUT4-mOrange-L6 cell models and mouse model with diabetes induced by high-fat diet combined with STZ injection were respectively adopted to investigate the antidiabetic effects of SA-FRE both in vitro and vivo.

RESULTS

In vivo, 4-week treatment of SA-FRE ameliorated hyperglycemia, dyslipidemia, and insulin resistance in diabetic mice. Mechanically, SA-FRE regulated PPARα and PPARγ expression in white adipose tissue (WAT) and liver, thereby ameliorating dyslipidemia. Moreover, SA-FRE increased the phosphorylation of PKC and further stimulated the GLUT4 expression in WAT and skeletal muscle, thus increasing the glucose utilization in vivo. In vitro, 50 μg/mL SA-FRE increased GLUT4 translocation to about 1.91-fold and glucose uptake to 1.82-fold in L6-myotubes. SA-FRE treatment increased the GLUT4 expression at both gene and protein levels. Furthermore, only Gö6983, a PKC inhibitor, reversed the SA-FRE-induced GLUT4 translocation and expression at the gene and protein levels.

CONCLUSIONS

Generally, SA-FRE ameliorated hyperglycemia, dyslipidemia, and insulin resistance partly through activating PKC/GLUT4 pathway and regulating PPARα and PPARγ expression.

Associations Between Bioavailable Vitamin D and Remnant Cholesterol in Patients With Type 2 Diabetes Mellitus

Introduction In circulation, 99% vitamin D is transported by binding to vitamin D binding protein (VDBP) and albumin. Vitamin D at free form and vitamin D binding to albumin are defined as bioavailable vitamin D. Vitamin D deficiency is associated with atherogenic lipid profile and insulin resistance. Remnant cholesterol is defined as the cholesterol component of triglyceride-rich lipoproteins and contributes to the atherosclerotic burden. The aim of this study was to investigate the association between bioavailable vitamin D and remnant cholesterol in patients with type 2 diabetes mellitus (T2DM). Methods A total of 198 T2DM patients and 208 non-diabetic subjects underwent biochemical measurements of lipid profiles, 25(OH)D, VDBP, CRP and albumin levels. Their demographic characteristics (age, sex) were questioned. Subjects with thyroid, kidney and liver dysfunction and using lipid-lowering therapy were not included in the study. The diagnosis of T2DM was made according to the American Diabetes Association ADA 2016 criteria. Classification of vitamin D levels was done according to the Endocrine Society. Bioavailable vitamin D concentrations were calculated. Results High-density lipoprotein cholesterol (HDL), 25(OH)D, free vitamin D and bioavailable vitamin D levels were significantly lower in diabetic patients than in non-diabetic patients while triglyceride, remnant cholesterol and CRP levels were found to be significantly higher. VDBP was positively correlated with CRP and remnant cholesterol in diabetic patients, but not in non-diabetic patients. Cut-off values were determined from non-diabetics as 3.56 ng/mL for bioavailable vitamin D and 26.56 mg/dL for remnant cholesterol. Logistic regression analysis in the control group showed that the odds ratio for increasing remnant cholesterol above the cut-off value was determined as 2.01 for low bioavailable vitamin D and 1.1 for elevated CRP. However, in T2DM there was no significant relationship. In all subjects, low bioavailable vitamin D increased the remnant cholesterol above the cut-off by 2.18-fold independent of the presence of T2DM. However, there was no significant risk to increase remnant cholesterol, considering a total 25(OH) D deficiency in all groups. Conclusions Low bioavailable vitamin D was found to be a risk factor for elevated remnant cholesterol. This relationship was not detected in patients with T2DM. We believe that the inflammation observed in Diabetes Mellitus may increase the concentrations of VDBP and a decrease in bioavailable vitamin D levels. Therefore, measuring VDBP and calculating the bioavailable vitamin D may provide additional information about the actual vitamin D status.

Comparing prophylactic effect of exercise and metformin on cognitive brain functions in rats with type 3 diabetes mellitus

Introduction

Type 2 diabetes mellitus (DM) and Alzheimer's disease (AD) are two major medical conditions that constitute a significant financial burden on most healthcare systems. Due to AD sharing "insulin resistance" mechanistic features with DM, some scientists have proposed "type 3 DM" terminology for it. This study aims to compare the prophylactic effect of exercise and metformin on cognitive brain functions in rats with type 3 DM.

Material and methods

Two groups of rats were included in the study: the control group (n = 15) and the streptozotocin-induced type 2 diabetic group (n = 45). The diabetic group was subdivided into three equal subgroups: a sedentary non-treated diabetic group, an exercised group, and a metformin-treated group. We estimated step-down avoidance task latency, serum glucose, insulin, free fatty acids (FFA), cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides (TG), brain Aβ-42 and glucose, histological changes by toluidine blue, and immunohistochemistry for brain Aβ-42 and tau-positive cells.

Results

Serum glucose, FFA, TG, cholesterol, LDL, brain Aβ-42, brain glucose, the number of hippocampal dark and degenerated cells, and brain Aβ-42 and tau-positive cells, were all significantly lower. In contrast, serum insulin and HDL, the number of hippocampal granular cells, and latency of the step-down avoidance task were significantly higher in exercised and metformin-treated groups compared to the diabetic group. There were significantly higher values of serum insulin and brain/plasma glucose ratio and number of brain tau-positive cells in the metformin-treated group than in the exercised group.

Conclusions

We can conclude that exercise can be as effective as metformin regarding prophylaxis against the deleterious effects of type 3 DM on cognitive brain functions.

Progression to type 2 diabetes mellitus and associated risk factors after hyperglycemia first detected in pregnancy: A cross-sectional study in Cape Town, South Africa

BACKGROUND

Global data indicate that women with a history of hyperglycemia first detected in pregnancy (HFDP) are at up to 7 times risk of progressing to type 2 diabetes mellitus (T2DM) compared with their counterparts who have pregnancies that are not complicated by hyperglycemia. However, there are no data from the sub-Saharan African region, which has the highest projected rise in diabetes prevalence globally. The aim of this study was to determine the proportion of women who progress to T2DM and associated risk factors 5 to 6 years after HFDP in Cape Town, South Africa.

METHODS AND FINDINGS

All women with HFDP, at a major referral hospital in Cape Town, were followed up 5 to 6 years later using a cross-sectional study. Each participant had a 75 g oral glucose tolerance test; anthropometric measurements and a survey were administered. A total of 220 participants were followed up. At this time, their mean age was 37.2 years (SD 6.0). Forty-eight percent (95% CI 41.2-54.4) progressed to T2DM, 5.5% (95% CI 3.1-9.4) had impaired fasting glucose, and 10.5% (95% CI 7.0-15.3) had impaired glucose tolerance. Of the participants who progressed to T2DM, 47% were unaware of their diabetes status. When HFDP was categorized post hoc according to WHO 2013 guidelines, progression in the diabetes in pregnancy (DIP) group was 81% (95% CI 70.2-89.0) and 31.3% (95% CI 24.4-39.3) in the gestational diabetes mellitus (GDM) category. Factors associated with risk of progression to T2DM were; at follow-up: waist circumference (odds ratios [OR] 1.1, 95% CI 1.0-1.1, p = 0.007), hip circumference (OR 0.9, 95% CI 0.8-1.0, p = 0.001), and BMI (OR 1.1, 95% CI 1.0-1.3, p = 0.001), and at baseline: insulin (OR 25.8, 95% CI 3.9-171.4, p = 0.001) and oral hypoglycaemic treatment during HFDP (OR 4.1, 95% CI 1.3-12.9, p = 0.018), fasting (OR 2.7, 95% CI 1.5-4.8, p = 0.001), and oral glucose tolerance test 2-hour glucose concentration at HFDP diagnosis (OR 4.3, 95% CI 2.4-7.7, p < 0.001). Our findings have limitations in that we did not include a control group of women without a history of HFDP.

CONCLUSIONS

The progression to T2DM in women with previous HFDP found in this study highlights the need for interventions to delay or prevent progression to T2DM after HFDP. In addition, interventions to prevent HFDP may also contribute to reducing the risk of T2DM.

Serum vitamin D status in type 2 diabetic patients from Gaza Strip

OBJECTIVE

To assess serum vitamin D status and its relations to other biochemical parameters in type 2 diabetic patients from Gaza Strip.

MATERIALS AND METHODS

This case-control study included 58 type 2 diabetic patients as well as 58 non-diabetic controls. Patients and controls were matched for age and gender. Data were obtained from questionnaire interview, and biochemical analysis of blood samples.

RESULTS

Serum vitamin D was significantly lower in diabetic patients compared to non-diabetic controls (25.9 ± 11.0 versus 34.6 ± 13.8 ng/dl, % difference = 28.8%, P < 0.001). The number of patients having vitamin D deficient, insufficient and sufficient were 6 (10.4%), 35 (60.3%) and 17 (29.3%) compared to controls of 3 (5.2%), 16 (27.6%) and 39 (67.2%), respectively (χ² = 14.672, P < 0.001). Serum glucose, glycated hemoglobin (HbA1c), serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and triglycerides were significantly higher in patients than in controls whereas serum insulin, high density lipoprotein cholesterol (HDL-C) and calcium were significantly lower in patients. Serum vitamin D showed significant negative correlations with HbA1c (r = - 0.186, P = 0.046), ALT (r = - 192, P = 0.040) and AST (r = - 0.188, P = 0.044) whereas significant positive correlations were found with HDL-C (r = 0.188, P = 0.044) and calcium (r = 0.239, P = 0.010).

CONCLUSION

The significant negative and positive correlations of vitamin D with HbA1c and calcium, respectively suggests that vitamin D supplementation would be of potential therapeutic value in clinical settings for controlling of type 2 diabetes and more importantly its complications. However, a well-designed clinical trials are needed to define the contribution of vitamin D status and therapy in the global diabetes problem.

Effects of Genetic Variants of Nuclear Receptor Y on the Risk of Type 2 Diabetes Mellitus

Nuclear factor-Y (NF-Y) consists of three evolutionary conserved subunits including NF-YA, NF-YB, and NF-YC; it is a critical transcriptional regulator of lipid and glucose metabolism and adipokine biosynthesis that are associated with type 2 diabetes mellitus (T2DM) occurrence, while the impacts of genetic variants in the NF-Y gene on the risk of T2DM remain to be investigated. In the present study, we screened five single-nucleotide polymorphisms (SNPs) with the SNaPshot method in 427 patients with T2DM and 408 healthy individuals. Subsequently, we analyzed the relationships between genotypes and haplotypes constructed from these SNPs with T2DM under diverse genetic models. Furthermore, we investigated the allele effects on the quantitative metabolic traits. Of the five tagSNPs, we found that three SNPs (rs2268188, rs6918969, and rs28869187) exhibited nominal significant differences in allelic or genotypic frequency between patients with T2DM and healthy individuals. The minor alleles G, C, and C at rs2268188, rs6918969, and rs28869187, respectively, conferred a higher T2DM risk under a dominant genetic model, and the carriers of these risk alleles (either homozygotes of the minor allele or heterozygotes) had statistically higher levels of fasting plasma glucose, cholesterol, and triglycerides. Haplotype analysis showed that SNPs rs2268188, rs6918969, rs28869187, and rs35105472 formed a haplotype block, and haplotype TTAC was protective against T2DM (OR = 0.76, 95% CI = 0.33-0.82, P = 0.004), while haplotype GCCG was associated with an elevated susceptibility to T2DM (OR = 2.33, 95% CI = 1.43-3.57, P = 0.001). This study is the first ever observation to our knowledge that indicates the genetic variants of NF-YA might influence a Chinese Han individual's occurrence of T2DM.

NLRP3 inflammasome promotes diabetes-induced endothelial inflammation and atherosclerosis

BACKGROUND

NLRP3 inflammasome can be activated by high glucose and links inflammation and metabolic disease. This study aimed to investigate the role of NLRP3 inflammasome in hyperglycemia-induced endothelial inflammation and diabetic atherosclerosis.

METHODS

NLRP3 levels in peripheral blood mononuclear cell (PBMC) and plasma IL-1β level were measured in diabetes patients. The activation of NLPR3 was detected in diabetic ApoE-/- mice and human umbilical vein endothelial cells (HUVECs).

RESULTS

Compared with healthy controls, NLRP3 expression levels in PBMC and plasma IL-1β level were significantly higher in diabetes patients but considerably decreased after lifestyle interventions and medicine. Moreover, carotid atherosclerosis was significantly related to plasma IL-1β level in diabetes patients. In diabetic atherosclerosis mouse model, NLRP3 knockdown suppressed NLRP3 inflammasome activation, inhibited the expression of adhesion molecules ICAM-1 and VCAM-1 in intima, reduced atherosclerosis and stabilized atherosclerotic plaque. In vitro, the expression of NLRP3 inflammasome components and the secretion of IL-1β were augmented by high glucose in HUVECs. Moreover, either high glucose or IL-1β promoted the expression of adhesion molecules, which were suppressed by NLRP3 knockdown or IL-1β receptor antagonist.

CONCLUSION

These findings provide novel insights into pathological mechanisms of diabetic atherosclerosis and have potential therapeutic implications for cardiovascular complications in diabetes.

Inactivation of MAPK in epididymal fat and amelioration of triglyceride secretion by injection of GRK2 siRNA in ob/ob mice

Abnormal G protein-coupled receptor kinase 2 (GRK2) accumulation has a crucial role in the development of insulin resistance and diabetes. Although GRK2 siRNA transfection in the liver improves insulin resistance-related vascular complications, the effects of GRK2 siRNA in lipid metabolism and obesity remain unknown. To investigate how GRK2 siRNA affects obesity, ob/ob mice were transfected with GRK2 siRNA, mainly in the liver, by using a hydrodynamic-based procedure. Epididymal fat, glucose, triglyceride, non-esterified fatty acid (NEFA), and alanine transaminase activity were higher in the control siRNA-transfected ob/ob mice than in the control siRNA-transfected Lean mice, but these parameters were reduced by GRK2 siRNA transfection into the ob/ob mice. GRK2 expression in epididymal fat was not altered among the 3 groups, although hepatic GRK2 expression was higher in the control siRNA-transfected ob/ob mice than in the control siRNA-transfected Lean mice. Additionally, we found that Akt interacted with GRK2 in the liver. Furthermore, phosphorylation levels of ERK1/2 and JNK were higher in the epididymal fats from the control siRNA-transfected ob/ob mice than in those from the control siRNA-transfected Lean mice, but they were lowered by transfection with GRK2 siRNA. The study results showed that GRK2 siRNA improved blood triglyceride levels and abnormal or excessive activity of mitogen-activated protein kinases in epididymal fat. This effect may be promoted by inhibition of the NEFA production pathway in the liver. Therefore, the interaction of organs (hepatic GRK2-epididymal fat) may help improve insulin resistance and diabetes-associated pathophysiology.

Lipid profile and dyslipidemia among school-age children in urban Ghana

Background

Dyslipidemia during childhood has been associated with higher risk of atherosclerosis later in life. Information on the lipid profile of Ghanaian children is scarce. The aim of this study was to assess the lipid profiles of school children between the ages of 9–15 years, living in urban Ghana.

Methods

A total of 802 randomly selected school-age children participated in the Ghana School Survey implemented in Kumasi and Accra, Ghana. A structured questionnaire was used to collect information on child and maternal socio-demographic characteristics (including age, education, and occupation), 7-day food frequency, home and school activity, as well as measurement of weight and standing height. Weight, height, and age data were converted into BMI-for-age indices to determine weight status. Finger-prick fasting blood samples were taken from the school-age children. Total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) cholesterol levels were determined using the CardioChek® PA Test System. Reference lipid levels based on the US National Cholesterol Education Program 2001 guidelines were used to determine the proportion of children with dyslipidemia.

Results

The mean TC, LDL-C, HDL-C, and TG levels were 149.0 ± 57.0 mg/dl, 80.1 ± 38.6 mg/dl, 53.5 ± 19.4 mg/dl, and 71.4 ± 54.7 mg/dl, respectively. Mean TC/HDL-C ratio was 3.0 ± 1.0. The proportion of children with abnormal values were 12.1% for TC, 4.5% for TG, 28.4% for HDL-C, 9.2% for LDL-C, and 6.6% for TC/HDL-C ratio. The levels of dyslipidemia (HDL, LDL, and TC/HDL-C ratio) were higher among overweight/obese compared to normal-weight children. More frequent fruit consumption was also linked with lower LDL-C (p = 0.020) while watching television (TV) in the mornings was linked with both higher TC (p = 0.011) and TG (p = 0.006).

Conclusions

Majority of urban-dwelling Ghanaian school children had normal lipid profiles. However, the higher levels of dyslipidemia observed among overweight and obese children suggest the need for population level physical activity and dietary interventions among children to reduce risk of cardiovascular diseases in adult life.

New treatment options for lipid-lowering therapy in subjects with type 2 diabetes

Dyslipidemias represent a variety of quantitative and/or qualitative lipoprotein abnormalities. According to etiology, we distinguish primary dyslipidemias with strictly genetic background and secondary ones with their origin in other disease or pathological states. Diabetic dyslipidemia is a type of secondary dyslipidemia and plays an important role in determining the cardiovascular risk of subjects with type 2 diabetes. In these patients, insulin resistance is responsible for overproduction and secretion of atherogenic very low density lipoprotein. In addition, insulin resistance promotes the production of small dense low-density lipoprotein (LDL) and reduces high-density lipoprotein (HDL) production. Cardiovascular disease remains a leading cause of morbidity and mortality in diabetic patients. Previous results support the role for small, dense LDL particles in the etiology of atherosclerosis and their association with coronary artery disease. Moreover, lowering LDL cholesterol reduces the risk of cardiovascular death. Therefore, the European guidelines for the management of dyslipidemias recommend an LDL cholesterol goal < 100 mg/dL in diabetic subjects without cardiovascular events. Moreover, if triglycerides (TG) are elevated (> 400 mg/dL), they recommend a non-HDL cholesterol goal < 130 mg/dL in diabetic individuals without cardiovascular events. Statins are the first line of LDL-lowering therapy in diabetic patients and combined therapy with ezetimibe and statins could be useful in very high cardiovascular risk diabetic subjects. Furthermore, the effect of a fibrate as an add-on treatment to a statin could improve the lipid profile in diabetic individuals with high TG and low HDL cholesterol. Regarding new therapies, recent data from phase III trials show that proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors considerably decrease LDL cholesterol. Thus, they may be useful in diabetic patients with concomitant diseases such as familial dyslipidemia, recurrent cardiovascular events, and elevated LDL cholesterol after second drug administration in addition to maximal statin dose or statin intolerance.

Apolipoprotein A5 3'-UTR variants and cardiometabolic traits in Koreans: results from the Korean genome and epidemiology study and the Korea National Health and Nutrition Examination Survey

BACKGROUND/OBJECTIVES

This study aimed to test the association between APOA5 3'-UTR variants (rs662799) and cardiometabolic traits in Koreans.

SUBJECTS/METHODS

For this study, epidemiological data, Apolipoprotein A5 (APOA5) genotype information, and lymphoblastoid cell line (LCL) biospecimens from a subset of the Ansung-Ansan cohort within the Korean Genome and Epidemiology study (KoGES-ASAS; n = 7,704) as well as epidemiological data along with genomic DNA biospecimens of participants from a subset of the Korea National Health and Nutrition Examination Survey (KNHANES 2011-12; n = 2,235) were obtained. APOA5 mRNA expression was also measured.

RESULTS

APOA5 rs662799 genotype distributions in both the KoGES-ASAS and KNHANES groups were 50.6% for TT, 41.3% for TC, and 8.1% for CC, which are similar to those in previous reports. In both groups, minor C allele carriers, particularly subjects with CC homozygosity, had lower high-density lipoprotein (HDL) cholesterol and higher triglyceride levels than TT homozygotes. Linear regression analysis showed that the minor C allele significantly contributed to reduction of circulating HDL cholesterol levels [β = −2.048, P < 0.001; β = −2.199, P < 0.001] as well as elevation of circulating triglyceride levels [β = 0.053, P < 0.001; β = 0.066, P < 0.001] in both the KoGES-ASAS and KNHANES groups. In addition, higher expression levels of APOA5 in LCLs of 64 healthy individuals were negatively associated with body mass index (r = −0.277, P = 0.027) and circulating triglyceride level (r = −0.340, P = 0.006) but not significantly correlated with circulating HDL cholesterol level. On the other hand, we observed no significant difference in the mRNA level of APOA5 according to APOA5 rs662799 polymorphisms.

CONCLUSIONS

The C allele of APOA5 rs662799 was found to be significantly associated with cardiometabolic traits in a large Korean population from the KoGES-ASAS and KNHANES. The effect of this genotype may be associated with post-transcriptional regulation, which deserves further experimental confirmation.