Dyslipidemia in patients with type 2 diabetes. relationships between lipids, kidney disease and cardiovascular disease

Atorvastatin ameliorates diabetic nephropathy through inhibiting oxidative stress and ferroptosis signaling

Clinically, statins have long been used for the prevention and treatment of chronic renal diseases, however, the underlying mechanisms are not fully elucidated. The present study investigated the effects of atorvastatin on diabetes renal injury and ferroptosis signaling. A mouse model of diabetes was established by the intraperitoneal injection of streptozotocin (50 mg/kg/day) plus a high fat diet with or without atorvastatin treatment. Diabetes mice manifested increased plasma glucose and lipid profile, proteinuria, renal injury and fibrosis, atorvastatin significantly lowered plasma lipid profile, proteinuria, renal injury in diabetes mice. Atorvastatin reduced renal reactive oxygen species (ROS), iron accumulation and renal expression of malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), transferrin receptor 1 (TFR1), and increased renal expression of glutathione peroxidase 4 (GPX4), nuclear factor erythroid 2-related factor (NRF2) and ferritin heavy chain (FTH) in diabetes mice. Consistent with the findings in vivo, atorvastatin prevented high glucose-induced ROS formation and Fe2+ accumulation, an increase in the expression of 4-HNE, MDA and TFR1, and a decrease in cell viability and the expression of NRF2, GPX4 and FTH in HK2 cells. Atorvastatin also reversed ferroptosis inducer erastin-induced ROS production, intracellular Fe2+ accumulation and the changes in the expression of above-mentioned ferroptosis signaling molecules in HK2 cells. In addition, atorvastatin alleviated high glucose- or erastin-induced mitochondria injury. Ferroptosis inhibitor ferrostatin-1 and antioxidant N-acetylcysteine (NAC) equally reversed the expression of high glucose-induced ferroptosis signaling molecules. Our data support the notion that statins can inhibit diabetes-induced renal oxidative stress and ferroptosis, which may contribute to statins protection of diabetic nephropathy.

Mendelian randomization indicates that atopic dermatitis contributes to the occurrence of diabetes

BACKGROUND

An association has been indicated between atopic dermatitis (AD), a prevalent chronic inflammatory skin disease, and diabetes mellitus. However, the exact causal relationship between AD and both type 1 diabetes (T1D) and type 2 diabetes (T2D) remains controversial. This study aimed to explore the causal association between AD and diabetes by Mendelian Randomization (MR) approaches.

METHODS

Public genetic summary data for AD was obtained from EAGLE study. Single nucleotide polymorphisms of diabetes were retrieved from four genome-wide association studies that had been performed in European populations. Inverse variance weighted (IVW) in MR analysis was used as the primary means of causality estimation. Several complementary analyses and sensitivity analyses were performed to calculate MR estimates and to enhance the causal inference, respectively. The R package 'TwoSampleMR' was used for analysis.

RESULTS

Genetically predicted AD led to a higher risk of T1D (OR, 1.19; 95% CI, 1.05, 1.34; P = 0.006) and T2D (OR, 1.07; 95% CI, 1.02, 1.11; P = 0.003) based on random-effect IVW method. The complementary analyses provided similar positive results. Cochran's Q test and I2 statistics indicated moderate heterogeneity between AD and both T1D and T2D. No significant horizontal pleiotropy was detected by MR-Egger Intercept p except summary data from FinnGen consortium.

CONCLUSION

Genetically predicted AD is a risk factor for both T1D and T2D. These findings imply potential shared pathological mechanisms between AD and diabetes, thus suggesting the significance of early clinical diagnosis and prevention of AD in reducing the incidence of diabetes.

Combined spectroscopic, biochemical and chemometric approach toward finding of biochemical markers of obesity

BACKGROUND

Early-stage detection of subclinical obesity-driven systemic changes is a challenging area of medical diagnostics, where the most popular existing measures - such as body mass index - BMI - often fall short of providing a realistic estimate of adiposity and, therefore, of ongoing pathologies at the systemic, tissue and cellular level. In the quest for identifying new more robust diagnostic markers, whole-organ analysis of chemical elements is a promising approach for identifying candidate proxies of obesity status in the system.

METHODS

Total Reflection X-ray fluorescence (TXRF) coupled with biochemical assays, chemometrics and statistical validation was used as a new integrated pipeline for marker identification in external ear samples of obese animals. The specimens were taken from obese animals fed a high calorie diet as well as from lean intact animals fed a standard diet.

RESULTS

The most significant differences in the content of K, Fe, Br, and Rb between the studied groups of the animals were identified. However, with the methodology applied Rb was found the most robust biochemical discriminator of early-stage obesity effects, as validated by the logistic regression model. We observed no relationship between the levels of the elements consumed by the animals and their apparent content in the earlobe tissue samples.

CONCLUSIONS

Our preliminary study confirms that obesity alters tissue trace metal metabolism and shows the proposed new approach as an accurate and reliable methodology for detecting tissue elemental obesity-related alterations.

GENERAL SIGNIFICANCE

This result can be of practical significance for designing new point-of-care systems for obesity screening tests, taking advantage of direct/indirect Rb measurements.

The New Markers of Early Obesity-Related Organ and Metabolic Abnormalities

The objective of our study was to identify new markers related to excessive body adiposity and its early consequences. For this purpose we determined serum FGF-19 and FGF-21 concentrations in obese rats, whose role in the pathogenesis of obesity is not yet established. In addition, a total reflection X-ray fluorescence technique was applied to determine the elemental chemistry of certain tissues affected by obesity. Next, the new biochemical and molecular parameters were correlated with well-known obesity-related markers of metabolic abnormalities. Our obese rats were characterized by increased calorie consumption and body adiposity, hypercholesterolemia, elevated levels of liver enzymes and FGF-21, while the level of FGF-19 was reduced. Strong relationships between new hormones and established metabolic parameters were observed. Furthermore, we demonstrated that obesity had the greatest effect on elemental composition in the adipose tissue and liver and that rubidium (Rb) had the highest importance in distinguishing the studied groups of animals. Tissue Rb strongly correlated with both well-known and new markers of obesity. In conclusion, we confirmed serum FGF-19 and FGF-21 as useful new markers of obesity-related metabolic alternations and we robustly propose Rb as a novel indicator of excessive body adiposity and its early consequences. However, further investigations are encouraged to address this clinical issue.

Prevalence and Pattern of Dyslipidemia and Its Associated Factors Among Patients with Type 2 Diabetes Mellitus in Jordan: A Cross-Sectional Study

Background

Dyslipidemia and type 2 diabetes mellitus (T2DM) are growing health problems, particularly in developing countries. This study aimed to determine the prevalence and pattern of dyslipidemia and its associated factors among patients with T2DM.

Methods

A cross-sectional study was conducted among patients with T2DM attending Family Medicine Clinics in Jordan between August 2017 and March 2019. The socio-demographics, clinical features, medications, and laboratory findings were collected. These laboratory findings included high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and triglycerides (TGs).

Results

A total of 870 patients with T2DM were included. The prevalence of dyslipidemia among patients with T2DM was 91.4%. The most common patterns of dyslipidemia were low HDL-C (66.2%), high LDL-C (62.1%), and hypertriglyceridemia (58.2%). Female gender, obesity, and hypertension were associated with diabetic dyslipidemia patterns. T2DM duration and poor glycemic control were associated with high LDL-C and hypercholesterolemia. Hypertriglyceridemia was associated with poor glycemic control and smoking.

Conclusion

Dyslipidemia is highly prevalent among patients with T2DM. Evidence -based interventions are needed to prevent and control dyslipidemia among patients with T2DM in Jordan.

The Effect of Curcumin in Improving Lipid Profile in Patients with Cardiovascular Risk Factors: A Systematic Review of Clinical Trials

Cardiovascular disease (CVD) is a major cause of death worldwide. Lipid abnormalities are one of the major risk factors for CVD. Curcumin is a natural polyphenol with lipid-lowering properties. Therefore, we carried out a systematic review to summarize the randomized controlled trials (RCTs) investigating the effect of curcumin on lipid profile in patients at risk of CVD. A comprehensive systematic search was conducted in PubMed, Scopus, Web of Science, and Google Scholar up to March 1, 2020, to identify controlled clinical trials assessing the effects of curcumin on lipid profile in patients at risk of CVD. From 1051 initially identified studies, 22 met the eligibility criteria. Curcumin supplementation significantly reduced at least one of the lipid profile indices (triglycerides, total cholesterol, low-density lipoprotein-cholesterol, and high-density lipoprotein-cholesterol) in 15 studies and improved more than one index in five studies. However, curcumin had no effect on any of lipid profile indices in seven studies. Overall, studies using a bioavailable formulation of curcumin had a better impact on the lipid profile. The findings of this systematic review showed that curcumin supplementation significantly reduced at least one of the lipid profile indices in more than two-thirds of the included studies. Curcumin might be used as an accessible, inexpensive, and safe agent to reduce risk of CVD. More randomized, clinical controlled trials are needed to verify these results.

The effect of underlying inflammation on iron metabolism, cardiovascular risk and renal function in patients with type 2 diabetes

Aim

To investigate the impact of inflammation on iron metabolism, cardiovascular risk and renal function in type 2 diabetes (T2D).

Methods

A total of 50 patients with T2D were included in this study. The patients were stratified into two groups based on their levels of C-reactive protein (CRP), namely normal and high levels (n = 25/group). All laboratory tests were measured using standardised methods.

Results

Fasting plasma glucose levels were elevated in patients with high CRP when compared to those with normal levels (p = 0.0413). Total serum iron levels were lower in patients with high CRP levels (12.78 ± 3.50) when compared to those with normal levels (15.26 ± 4.64), p = 0.0381. However, ferritin and transferrin levels were comparable between the groups (p > 0.05). The mean cell volume (MCV) in the high CRP group was lower (87.66 ± 3.62) than the normal level group (90.79 ± 4.52), p = 0.0096, whilst the lipograms were similar (p > 0.05). The estimated glomerular filtration rate (eGFR) was lower in the high CRP group (98.06 ± 11.64) than the normal level group (104.7 ± 11.11), p = 0.046. Notably, CRP levels were negatively associated with serum iron levels (r = -0.38, p = 0.0061), MCV (r = -0.41, p = 0.0031), potassium (r = -0.37, p = 0.0086) and sodium levels (r = -0.28, p = 0.0471). Regression analyses showed that only CRP (β = -0.16, standard error [SE]: 0.06, p = 0.0125) and sodium (β = 0.51, SE: 0.25, p = 0.0434) levels contributed significantly to the prediction of serum iron levels.

Conclusion

Underlying inflammation in T2D is associated with increased incidence of hypertension and reduced levels of serum iron, MCV and renal function. Although there was no apparent clinical anaemia or renal dysfunction in these patients, mitigating inflammation may be effective in circumventing the ultimate development of iron deficiency anaemia and chronic kidney disease in T2D.

Lipid Metabolic Disorders and Ovarian Hyperstimulation Syndrome: A Retrospective Analysis

OBJECTIVES

To evaluate the effect of dyslipidemia on the incidence of moderate and severe Ovarian hyperstimulation syndrome (OHSS) in the duration of assisted reproduction technique (ART).

METHODS

The study included 233 moderate and severe OHSS patients who received hospitalization after in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles to avoid severe complications. They were divided into dyslipidemia group and normal lipid metabolism group to evaluate whether dyslipidemia contributes to the development of severe OHSS. Subgroup analysis was set to avoid deviation including the freeze-all group and fresh embryo transfer (ET) group according to whether the eligible women chose fresh embryo transfer immediately after their IVF or ICSI cycles. The main outcome measures included the incidence of moderate OHSS and severe OHSS, total gonadotropin dose, number of oocytes retrieved, age and body mass index (BMI). In the ET groups, the rate of pregnancy is also included for analysis.

RESULTS

In the freeze-all group, lipid metabolism was ultimately identified as the factor affecting the morbidity of severe OHSS and the ones with dyslipidemia were more likely to develop to severe OHSS (P < 0.05), while the incidence of severe OHSS among the ET groups had no statistical significance (P > 0.05).

CONCLUSION

The findings of this study suggested that dyslipidemia might contribute to the development of OHSS, especially for those patients who chose the cryopreservation of all embryos. It is essential to consider the risk of OHSS in patients with dyslipidemia although they required cryopreservation of all embryos.

Pathophysiology of Type 2 Diabetes Mellitus

Type 2 Diabetes Mellitus (T2DM), one of the most common metabolic disorders, is caused by a combination of two primary factors: defective insulin secretion by pancreatic β-cells and the inability of insulin-sensitive tissues to respond appropriately to insulin. Because insulin release and activity are essential processes for glucose homeostasis, the molecular mechanisms involved in the synthesis and release of insulin, as well as in its detection are tightly regulated. Defects in any of the mechanisms involved in these processes can lead to a metabolic imbalance responsible for the development of the disease. This review analyzes the key aspects of T2DM, as well as the molecular mechanisms and pathways implicated in insulin metabolism leading to T2DM and insulin resistance. For that purpose, we summarize the data gathered up until now, focusing especially on insulin synthesis, insulin release, insulin sensing and on the downstream effects on individual insulin-sensitive organs. The review also covers the pathological conditions perpetuating T2DM such as nutritional factors, physical activity, gut dysbiosis and metabolic memory. Additionally, because T2DM is associated with accelerated atherosclerosis development, we review here some of the molecular mechanisms that link T2DM and insulin resistance (IR) as well as cardiovascular risk as one of the most important complications in T2DM.

Red Pepper (Capsicum annuum L.) Seed Extract Improves Glycemic Control by Inhibiting Hepatic Gluconeogenesis via Phosphorylation of FOXO1 and AMPK in Obese Diabetic db/db Mice

Obesity is a notable risk factor for developing type 2 diabetes, augmenting the concern of obese diabetes (ObD). Anti-obesity and antioxidant effects of red pepper seeds extract (RPSE) have increased our expectations that RPSE would also improve the pathological phenotypes of obese diabetes. Therefore, we hypothesized that RPSE would have an anti-diabetic effect in ObD mice. Animals were assigned either as follows: (1) db/+, (2) db/db control, (3) RPSE (200 mg/kg bw), or (4) a comparative control (metformin 150 mg/kg bw). RPSE was orally administered daily for 8 weeks. As a result, RPSE supplementation improved diabetic phenotypes, including fasting glucose, hemoglobin (HbA1c), and insulin levels. Pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6), and triglycerides were reduced in RPSE-treated mice. RPSE supplementation also diminished the rate-limiting enzymes of gluconeogenesis, including glucose 6-phosphatas (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK), in the liver. RPSE supplementation increased the phosphorylation of forkhead box protein O1 (FOXO1) and AMP-activated protein kinase (AMPK), which underlined the mechanism of the anti-diabetic effects of RPSE. Taken together, RPSE has the potential to improve glycemic control by repressing hepatic gluconeogenesis via the phosphorylation of FOXO1 and AMPK in ObD mice.

Astragaloside IV inhibits excessive mesangial cell proliferation and renal fibrosis caused by diabetic nephropathy via modulation of the TGF-β1/Smad/miR-192 signaling pathway

Astragaloside IV (ASI) exhibits a wide variety of pharmacological effects in cardiovascular diseases, hepatitis and kidney disease and due to this, ASI has recently become an attractive research target. The present study aimed to determine the effect of ASI on renal fibrosis and the mechanisms underlying its therapeutic effects in diabetic nephropathy (DN). In vitro, ASI was added to rat mesangial cells (RMCs) and cultured with a high level of glucose (HG) to observe the effects exhibited on proliferation and fibrosis-related mRNA and protein expression. In vivo, a DN model was established using streptozotocin administration in rats, and renal injury was evaluated using renal histological examination. The expression levels of related mRNAs and proteins were analyzed using reverse transcription-quantitative PCR, western blot analysis and immunohistochemistry. ASI was demonstrated to downregulate miR-192 expression and inhibit excessive proliferation of RMCs, which was induced by HG, in a dose-dependent manner. Additionally, ASI exhibited a therapeutic effect on DN rats. ASI was also demonstrated to decrease the miR-192 expression and mRNA and protein expression of transforming growth factor-β1 (TGF-β1), Smad3, α-smooth muscle actin (α-SMA) and collagen type 1 (col1), and increase the mRNA and protein expression of Smad7 in vitro and in vivo. These results suggested that ASI exhibited a therapeutic effect on DN, possibly due to the inhibition of excessive mesangial proliferation and renal fibrosis via the TGF-β1/Smad/miR-192 signaling pathway.

Prevalence of dyslipidemia associated with complications in diabetic patients: a nationwide study in Thailand

Background

Dyslipidemia is an important modifiable risk factor for cardiovascular disease. It is diagnosed by the presence of an abnormal lipid profile, primarily with elevated levels of plasma cholesterol, triglyceride, or both, or reduced levels of high-density lipoprotein cholesterol. However, some studies have reported increased risk of ischemic stroke with elevated low-density lipoprotein cholesterol (LDL-C) levels and increased risk of cardiovascular mortality independent of LDL-C levels in type 2 diabetes mellitus (T2DM) patients.

Methods

In this cross-sectional study, data were included for Thai adults with diabetes from the Diabetes Mellitus/ Hypertension (DM/HT) study, 2010–2014 (data was collected by the Medical Research Network of the Consortium of Thai Medical Schools). The target population comprised T2DM patients who were treated at a hospital for more than 12 months. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated to determine factors associated with dyslipidemia.

Results

In total, 140,557 participants (average age, 60 years) were enrolled, with a dyslipidemia prevalence of 88.9% in the cohort. The factors associated with dyslipidemia included female sex (aOR: 1.47, 95% CI: 1.38–1.56); age < 50 years (aOR: 1.16, 95% CI: 1.10–1.22); waist circumference ≥ 90 cm in males and ≥ 80 cm in females (aOR: 1.23, 95% CI: 1.16–1.31); treatment at a primary care unit (aOR: 1.28, 95% CI: 1.23–1.33); and a history of unknown stroke (aOR: 1.10, 95% CI: 1.02–1.19), coronary revascularization (aOR: 0.85, 95% CI: 0.79–0.91), diabetic nephropathy (aOR: 1.06, 95% CI: 1.01–1.12), or renal insufficiency (aOR: 1.08, 95% CI: 1.02–1.13).

Conclusions

Dyslipidemia is prevalent among Thai T2DMpatients and is associated with gender; age; obesity; central obesity; treatment at a primary care unit; and a history of unknown stroke, coronary revascularization, diabetic nephropathy, and renal insufficiency. Our study results will help increase the awareness of healthcare providers regarding dyslipidemia in diabetic patients. To reduce cardiovascular risk, healthcare professionals should provide regular follow-up and proper advice and ensure primary prevention of vascular complications. Improved education and increased self-awareness regarding the need to change behaviors and regular intake of medication would help decrease dyslipidemia prevalence among diabetic patients.

Is Skin Tag Associated with Diabetic Macro and Microangiopathy?

INTRODUCTION

Although skin tag is associated with diabetes mellitus, no data in the literature show that the presence of skin tag is associated with diabetic macro and microangiopathy. The purpose of this study was to investigate the frequency of hypertension, dyslipidemia, obesity, macro and micro angiopathy in type 2 diabetic patients with and without skin tag.

MATERIAL AND METHODS

We evaluated 99 (40 female and 59 male) type 2 diabetic patients. All patients were evaluated for blood pressure, body mass index, lipids, HbA1c, macroangiopathy (peripheral vascular disease, cerebrovascular disease and coronary heart disease), microangiopathy (neuropathy, nephropathy, retinopathy) and skin tag.

RESULTS

Age, HbA1c and body mass index were 65.0 ± 14.2 years, 8.1 ± 2.0% and 30.5 ± 6.4 kg/m², respectively. The frequency of skin tags 53.5%, dyslipidemia 68.7%, hypertension 69.7%, obesity 39.4%, macroangiopathy 61.6% (peripheral vascular disease 12.1%, cerebrovascular disease 16.2%, and coronary heart disease 49.5%), microangiopathy 63.6% (neuropathy 21.2%, nephropathy 38.4%, retinopathy 38.4%) were detected. Higher body mass index (p = 0.04) and frequency of obesity (p = 0.03) were detected in patients with skin tag than without skin tag. Age (p = 0.8), gender (p = 0.6), HbA1c (p = 0.4) and the presence of dyslipidemia (p = 0.4), hypertension (p = 0.6), macroangiopathy (p = 0.2), and microangiopathy (p = 0.9) were not different in patients with and without skin tag.

CONCLUSION

We conclude that presence of skin tag is merely related to obesity and may not be strongly associated with macro- and microangiopathy in type 2 diabetic individuals. Further studies with large patient population are required to elucidate the association between the presence of skin tag and diabetic angiopathy.

Change in nonhigh-density lipoprotein cholesterol levels in adults with prediabetes

This study aimed to observe the change in nonhigh-density lipoprotein cholesterol (non-HDL-C) levels and analyzed its related factors in adults with prediabetes (impaired fasting glucose and/or impaired glucose tolerance).This case-controlled study included 56 adults with normal glucose tolerance (NGT) and 74 adults with prediabetes. The cases and controls were age and gender-matched. Anthropometric measurements including height, weight, waist circumference, and blood pressure were performed. All patients underwent an oral glucose tolerance test (OGTT) after 8 hours of fasting, and the levels of glucose, insulin, lipids, and uric acid were measured.The levels of non-HDL-C (3.63 ± 0.92 vs 3.27 ± 1.00 mmol/L) were significantly higher in prediabetic subjects than in NGT subjects (P < .05). Non-HDL-C positively correlated with HOMA-IR (r = 0.253, P = .004), triglyceride (r = 0.204, P = .020), and uric acid (r = 0.487, P = .000). After multivariate analysis, uric acid continued to be significantly associated with non-HDL-C (β = 0.006, P = .000).Non-HDL-C is elevated in adults with prediabetes. A relationship between non-HDL-C and uric acid was observed.

Characteristics of the Lipid Profile in Patients with Diabetes Mellitus and Chronic Kidney Disease

Background and aims Diabetes mellitus (DM) is one of the leading causes of end-stage chronic kidney disease (CKD). Patients with DM and CKD have a 10 or even 20 times higher cardiovascular risk (CVR) than the general population. Lipid metabolism disorders are more frequent in these patients, dyslipidemia being aggravated by the presence of hyperglycemia and insulin resistance. The main purpose of our study was to identify possible correlations between lipid profile parameters and altered renal function in patients with DM. We have also analyzed the correlations between lipid parameters, CKD, quality of glycemic control and CVR.

Material and method: The study was performed on 2732 patients with DM which received medical treatment and care at the Center for Diabetes Timisoara, for a 6-month period from March to October 2016, 1508 women (55.2%) and 1224 men (44.8%), mean age 63.7 ± 9.1 (33-78) years and mean diabetes duration 12.4 ± 6.8 (6-33) years. The study group included 312 patients (11.4%) with T1DM and 2420 patients (88.6%) with T2DM.

Results: The prevalence of CKD (GFR< 60 ml/min) was 12.5%. The levels of total cholesterol (TC), triglycerides (TG) and LDLc were significantly higher in the case of patients with DM and CKD (p<0.0001). Patients with CKD had twice the prevalence of ischemic heart disease and cerebrovascular disease when compared to patients without CKD. Peripheral artery disease was present in 16.9% of those with CKD and in 11% of those without CKD. Hypertension (HTN) was present in 91.8% of patients with CKD and in 67.1% of patients without CKD (GFR > 60 ml/min).

Conclusion: Analyzed data showed a strong correlation between CKD, dyslipidemia and CVR in patients with DM. Impaired renal function was strongly correlated with age, duration of DM and weight status of these patients.

Sex differences in the development of vascular and renal lesions in mice with a simultaneous deficiency of Apoe and the integrin chain Itga8

Background

Apoe-deficient (Apoe^−/−) mice develop progressive atherosclerotic lesions with age but no severe renal pathology in the absence of additional challenges. We recently described accelerated atherosclerosis as well as marked renal injury in Apoe^−/− mice deficient in the mesenchymal integrin chain Itga8 (Itga8^−/−). Here, we used this Apoe^−/−, Itga8^−/− mouse model to investigate the sex differences in the development of atherosclerosis and concomitant renal injury. We hypothesized that aging female mice are protected from vascular and renal damage in this mouse model.

Methods

Apoe^−/− mice were backcrossed with Itga8^−/− mice. Mice were kept on a normal diet. At the age of 12 months, the aortae and kidneys of male and female Apoe^−/−Itga8^+/+ mice or Apoe^−/−Itga8^−/− mice were studied. En face preparations of the aorta were stained with Sudan IV (lipid deposition) or von Kossa (calcification). In kidney tissue, immunostaining for collagen IV, CD3, F4/80, and PCNA and real-time PCR analyses for Il6, Vegfa, Col1a1 (collagen I), and Ssp1 (secreted phosphoprotein 1, synonym osteopontin) as well as ER stress markers were performed.

Results

When compared to male mice, Apoe^−/−Itga8^+/+ female mice had a lower body weight, equal serum cholesterol levels, and lower triglyceride levels. However, female mice had increased aortic lipid deposition and more aortic calcifications than males. Male Apoe^−/− mice with the additional deficiency of Itga8 developed increased serum urea, glomerulosclerosis, renal immune cell infiltration, and reduced glomerular cell proliferation. In females of the same genotype, these renal changes were less pronounced and were accompanied by lower expression of interleukin-6 and collagen I, while osteopontin expression was higher and markers of ER stress were not different.

Conclusions

In this model of atherosclerosis, the female sex is a risk factor to develop more severe atherosclerotic lesions, even though serum fat levels are higher in males. In contrast, female mice are protected from renal damage, which is accompanied by attenuated inflammation and matrix deposition. Thus, sex affects vascular and renal injury in a differential manner.

Electronic supplementary material

The online version of this article (doi:10.1186/s13293-017-0141-y) contains supplementary material, which is available to authorized users.

Common polymorphisms in antioxidant genes are associated with diabetic nephropathy in Type 2 diabetes patients

AIM

To investigate if antioxidative genes' polymorphisms influence the risk for Type 2 diabetes (T2D) complications.

MATERIALS & METHODS

In total, 181 T2D patients were genotyped for SOD2, CAT, GPX1, GSTP1, GSTM1*0, GSTT1*0, GCLC and GCLM.

RESULTS

After adjustment for duration of T2D, CAT rs1001179 and GSTP1 rs1138272 showed strongest association with risk for end-stage kidney failure (p = 0.005 and p = 0.049, respectively). In patients without end-stage kidney failure CAT rs1001179 influenced urea levels (p = 0.003), while GSTP1 rs1695 and GSTP1 haplotypes influenced the risk of moderately increased albuminuria (p = 0.024 and p = 0.014, respectively).

CONCLUSION

Common CAT and GSTP1 polymorphisms could be used to identify T2D patients at an increased risk for developing end-stage kidney failure.

Dyslipidemia, kidney disease, and cardiovascular disease in diabetic patients

This article reviews the relationship between dyslipidemia, chronic kidney disease, and cardiovascular diseases in patients with diabetes. Diabetes mellitus is associated with complications in the cardiovascular and renal system, and is increasing in prevalence worldwide. Modification of the multifactorial risk factors, in particular dyslipidemia, has been suggested to reduce the rates of diabetes-related complications. Dyslipidemia in diabetes is a condition that includes hypertriglyceridemia, low high-density lipoprotein levels, and increased small and dense low-density lipoprotein particles. This condition is associated with higher cardiovascular risk and mortality in diabetic patients. Current treatment guidelines focus on lowering the low-density lipoprotein cholesterol level; multiple trials have confirmed the cardiovascular benefits of treatment with statins. Chronic kidney disease also contributes to dyslipidemia, and dyslipidemia in turn is related to the occurrence and progression of diabetic nephropathy. Different patterns of dyslipidemia are associated with different stages of diabetic nephropathy. Some trials have shown that treatment with statins not only decreased the risk of cardiovascular events, but also delayed the progression of diabetic nephropathy. However, studies using statins as the sole treatment of hyperlipidemia in patients on dialysis have not shown benefits with respect to cardiovascular risk. Diabetic patients with nephropathy have a higher risk of cardiovascular events than those without nephropathy. The degree of albuminuria and the reduction in estimated glomerular filtration rate are also correlated with the risk of cardiovascular events. Treatment with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers to reduce albuminuria in diabetic patients has been shown to decrease the risk of cardiovascular morbidity and mortality.

Higher levels of small dense low-density lipoprotein (LDL) are associated with cardiac autonomic neuropathy in patients with type 2 diabetes

AIM

To investigate the relationship between small dense LDL cholesterol and cardiac autonomic neuropathy among patients with Type 2 diabetes.

METHODS

A total of 175 patients who had not taken lipid-lowering agents previously were enrolled consecutively in this study. Small dense LDL cholesterol level was measured using polyacrylamide tube gel electrophoresis, which fractionates LDL cholesterol into seven components according to particle size and charge. We analysed the mean LDL cholesterol particle size and the proportion of small dense LDL cholesterol.

RESULTS

The mean (± sd) patient age was 56 (± 14) years, the mean (± sd) duration of diabetes was 10.3 (± 8.3) years, the mean (± sd) proportion of small dense LDL cholesterol was 21.3 (± 17.6)% and the mean (± sd) LDL cholesterol size was 26.33 (± 0.8) nm. Men with cardiac autonomic neuropathy had a longer duration of diabetes compared with those without cardiac autonomic neuropathy. Women with cardiac autonomic neuropathy had a larger waist circumference, higher plasma triglyceride levels, smaller mean (± sd) LDL cholesterol size [26.8 (± 4.3) nm vs 26.4 (± 6.9) nm; P < 0.01] and larger mean (± sd) proportion of small dense LDL cholesterol [10.1 (± 9.9)% vs 19.1 (± 16.8)%; P < 0.01] compared with those without cardiac autonomic neuropathy. After adjusting for other confounding risk factors, the triglyceride/ HDL cholesterol ratio (odds ratio = 1.698, 95% CI: 1.07-2.69; P = 0.025) and mean LDL cholesterol size (odds ratio = 0.873, 95% CI: 0.77-0.99; P = 0.038) remained as independent risk factors for cardiac autonomic neuropathy in women.

CONCLUSIONS

A more atherogenic lipid profile such as the triglyceride: HDL cholesterol ratio and a smaller mean LDL cholesterol particle size were related to the prevalence of cardiac autonomic neuropathy in women with Type 2 diabetes.

Markers of cardiovascular risk in postmenopausal women with type 2 diabetes are improved by the daily consumption of almonds or sunflower kernels: a feeding study

Dietary guidelines for the treatment of type 2 diabetes advocate the regular consumption of nuts and seeds. Key lipid abnormalities associated with diabetes include raised LDL-C, VLDL-C, and TAG concentrations and decreased concentrations of HDL-C. The fatty acid profiles of nuts and seeds differ and may potentially influence lipid outcomes in people with diabetes differently. To examine the effects of nut or seed consumption on lipid and lipoprotein markers of cardiovascular disease (CVD), we added almonds (AD) or sunflower kernels (SKD) to a recommended diet in a randomised crossover feeding study. Twenty-two postmenopausal women with type 2 diabetes consumed personalised diets, with the addition of 30 g/d of either almonds or sunflower kernels. All food was supplied for two periods of three weeks, separated by a four-week washout. There was a significant reduction in high-density lipoprotein cholesterol (HDL-C), triacylglycerol (TAG), and apolipoprotein (apo) A1 and B100 on the SKD compared to the AD. Total (TC) and low density lipoprotein cholesterol (LDL-C) decreased significantly on both diets from baseline, with no difference between diets. A diet with the addition of either almonds or sunflower kernels has clinically beneficial effects on lipid- and lipoprotein-mediated CVD risk.

Small fiber neuropathy is associated with the metabolic syndrome

BACKGROUND

The etiology of sensory neuropathies is often not found. We tested the hypothesis that the metabolic syndrome (MS) may be associated with painful neuropathy, in the absence of frank diabetes.

METHODS

Clinical and quantitative neuropathy assessments were performed on 10 neuropathy patients with MS, 20 with MS with type 2 diabetes (10 recent onset and 10 of >5 years in duration), and 10 healthy, age-matched subjects. Intraepidermal nerve fiber density (IENF) and mean dendrite length (MDL) were determined by quantitative immunofluorescence on skin biopsies using antibody to PGP 9.5.

RESULTS

In metabolic syndrome, MDL was reduced and correlated negatively with sensory symptoms, signs, HDL-C, and sural nerve amplitude. The strongest inverse metabolic correlate of the metabolic syndrome neuropathy was HDL-C, which also correlated negatively with sensory symptoms, signs, and sural nerve amplitudes. The strongest metabolic correlate of diabetic sensorimotor neuropathy was HbA1c, which was associated with reduced IENF in patients with >5 years in duration of disease as well as reduced peroneal nerve amplitudes.

CONCLUSIONS

These data indicate that metabolic features, including HDL-C in metabolic syndrome, are associated with small fiber neuropathy and that MDL is an early marker of sensory neuropathy in patients with MS. Reductions in IENF reflect a longer duration of diabetes, with hyperglycemia leading to a sensorimotor neuropathy. These findings support the possibility that there is a sensory neuropathy with reduced intraepidermal nerve fiber length, which cosegregates with features of metabolic syndrome.

A metabolic profiling strategy for biomarker screening by GC-MS combined with multivariate resolution method and Monte Carlo

A GC-MS based metabolic profiling method via a multivariate resolution method and Monte Carlo PLS-DA is proposed for screening potential biomarkers, and applied to Type 2 diabetes mellitus. The metabolic profiles of plasma samples from healthy control and Type 2 diabetes mellitus patient groups were obtained by GC-MS, and 25 compounds considered as endogenous metabolites excluding glucose were identified. With the help of a multivariate resolution method, qualitative and quantitative results of the metabolic profiles were extracted for subsequent multivariate statistical analysis. In order to select potential biomarkers, responsible for the classification of the two groups, Monte Carlo PLS-DA was introduced. The distribution of the regression coefficients of PLS-DA models corresponding to the metabolites was obtained. The levels of metabolites with all positive coefficients were considered as decreased from healthy controls to patients, and all negative coefficients were considered as increased. Univariate t-test was employed to check for metabolites whose levels changed significantly. Metabolites identified as potential biomarkers of Type 2 diabetes mellitus were ten in total, namely lactate, alanine, α-hydroxyisobutyric acid, phosphate, serine, pyroglutamic acid, palmitic acid, stearic acid, 1-monopalmitin and cholesterol. Finally, canonical correlation analysis was used to explore the correlation between the selected ten metabolites and blood glucose, which was considered to be a routine parameter reflecting the disease state. The results showed that the ten selected metabolites correlated well with blood glucose (r = 0.81, p = 0.03), and may be considered as possible biomarkers of Type 2 diabetes mellitus. The results demonstrated that the proposed method may be a useful tool to discover potential biomarkers of diseases.

Prevalence of microalbuminuria and its risk factors in type 2 diabetic patients

A cross-sectional study was performed from November 2005 to July 2007 to determine the prevalence of microalbuminuria and its risk factors among type 2 diabetic patients.. Two hundred and eighty-eight type 2 diabetic patients (141 males and 147 females) referred to Yazd diabetes research center were randomly recruited for the study. Microalbuminuria was detected by measuring the albumin to creatinine ratio in the early morning urine. Microalbuminuria was diagnosed if this ratio was between 30 and 300 mg/g on two occasions during three months. Prevalence of microalbuminuria was 14.2%. Chi-square analysis revealed that microalbuminuria was correlated with the diastolic blood pressure (P = 0.003) and the duration of diabetes (P = 0.000). No statistically significant correlation was found between microalbuminuria and age, sex, body mass index, levels of fasting blood sugar, glycosylated hemoglobin (HbA1c), serum triglyceride, and serum cholesterol, or systolic blood pressure. For 240 patients for whom the duration of diabetes was known from the answers in their questionnaires, logistic regression was used for analysis. Results showed that two variables including the duration of diabetes and Diastolic Blood Pressure (DBP) play a role in this model and the following Logic association was obtained: g; (x) = -9.233 +/- 0.079 DBP +/- 0.114 duration according to this model, both DBP and duration of diabetes were directly correlated with microalbuminuria. Determination of the urine albumin to creatinine ratio is an easy method for screening of microalbuminuria that is suggested for all diabetic patients, especially diabetic patients with hypertension and long-term diabetes.

Differential dyslipidemia associated with albuminuria in type 2 diabetic patients in Taiwan

BACKGROUND

This study evaluated the lipid abnormalities associated with different stages of albuminuria in type 2 diabetic patients.

METHODS AND RESULTS

A total of 549 patients (245 men and 304 women) with mean age of 63.4 were studied. Normoalbuminuria (n=251), microalbuminuria (n=242) and macroalbuminuria (n=56) were defined as albumin-to-creatinine ratio of < 30, 30-299 and > or = 300 microg/mg, respectively. Lipid parameters included total cholesterol, triglyceride (TG), high- and low-density lipoprotein (LDL) cholesterol, apolipoproteins A1 and B (ApoB), and lipoprotein(a) [Lp(a)]. Results showed that ApoB differed significantly (p<0.05) between normoalbuminuria and microalbuminuria/macroalbuminuria and Ln[Lp(a)] differed between normoalbuminuria/microalbuminuria and macroalbuminuria. Ln(TG) increased progressively with increasing albuminuria. In multivariate logistic regression analyses, only ApoB showed significant odds ratio (95% confidence interval) for microalbuminuria: 1.013 (1.004-1.022); and both ln(TG) and ln[Lp(a)] were significant for macroalbuminuria [respective odds ratios: 1.995 (1.010-3.938) and 1.708 (1.200-2.430)].

CONCLUSIONS

A differential dyslipidemia is observed for microalbuminuria and macroalbuminuria. Apo(B) and Lp(a) increase at the stages of microalbuminuria and macroalbuminuria, respectively. However, TG increases significantly throughout the three stages of albuminuria.

Regulation of Na+/H+ exchanger 1 allosteric balance by its localization in cholesterol- and caveolin-rich membrane microdomains

The Na+/H+ exchanger 1, which plays an essential role in intracellular pH regulation in most tissues, is also known to be a key actor in both proliferative and apoptotic processes. Its activation by H+ is best described by the Monod-Wyman-Changeux model: the dimeric NHE-1 oscillates between a low and a high affinity conformation, the balance between the two forms being defined by the allosteric constant L(0). In this study, influence of cholesterol- and caveolin-rich microdomains on NHE-1 activity was examined by using cholesterol depleting agents, including methyl-beta-cyclodextrin (MBCD). These agents activated NHE-1 by modulating its L(0) parameter, which was reverted by cholesterol repletion. This activation was associated with NHE-1 relocation outside microdomains, and was distinct from NHE-1 mitogenic and hormonal stimulation; indeed MBCD and serum treatments were additive, and serum alone did not change NHE-1 localization. Besides, MBCD activated a serum-insensitive, constitutively active mutated NHE-1 ((625)KDKEEEIRK(635) into KNKQQQIRK). Finally, the membrane-dependent NHE-1 regulation occurred independently of Mitogen Activated Protein Kinases, especially Extracellular Regulated Kinase activation, although this kinase was activated by MBCD. In conclusion, localization of NHE-1 in membrane cholesterol- and caveolin-rich microdomains constitutes a novel physiological negative regulator of NHE-1 activity.

Cardiovascular disease risk in youth with diabetes mellitus

In the United States, cardiovascular disease is the leading cause of mortality in adults with diabetes over age 30 years. Studies in persons without diabetes have shown that atherosclerosis, a central factor in cardiovascular disease, begins in childhood and the presence of cardiovascular disease risk factors in youth lead to increased cardiovascular disease risk in adults. Therefore, youth with diabetes are at increased risk for developing cardiovascular disease as adults and there is a role for risk factor screening and addressing modifiable factors to lower cardiovascular disease risk starting in childhood. This paper reviews the literature on traditional cardiovascular disease risk factors in youth with diabetes including hyperglycemia, hypertension, dyslipidemia, smoking, obesity and family history of cardiovascular disease with an emphasis on type 1 diabetes as well as current American Diabetes Association guidelines for screening and treatment of modifiable risk factors. Current roles of inflammatory markers and measures of subclinical vascular changes such as arterial stiffness are also discussed.

Elevated levels of remnant lipoproteins are associated with plasma platelet microparticles in patients with type-2 diabetes mellitus without obstructive coronary artery disease

AIMS

Platelets participate in the pathogenesis of arterial thrombosis and it has been demonstrated that enhanced platelet activation occurs in patients with diabetes mellitus (DM). Dyslipidaemia is a common feature of diabetes. We investigated the association between certain lipid fractions and plasma platelet-derived microparticle (PMP) levels in patients with type-2 DM.

METHODS AND RESULTS

We measured fasting serum levels of remnant-like lipoprotein particles-cholesterol (RLP-cholesterol) and assessed in vivo platelet activation by quantifying the number of PMP in the plasma detected as CD42b-positive microparticles by flow cytometry in Japanese type-2 DM patients without obstructive coronary artery disease who were more slender when compared with Western diabetic patients. The levels of total cholesterol, triglycerides, RLP-cholesterol, and plasma glucose were significantly higher in patients with type-2 DM (n = 105) than in non-diabetic patients (n = 92). The plasma levels of PMP were elevated significantly in type-2 DM patients when compared with non-diabetic control subjects [7.41(5.39-10.50) x 10(6) vs. 3.44(2.43-4.41)x10(6), P < 0.001]. We found that RLP-cholesterol levels were the best predictor of PMP in multivariable linear regression analyses (beta = 0.375, P < 0.001). Lipid-lowering medication with bezafibrate successfully reduced levels of both RLP-cholesterol and PMP in patients with type-2 DM (P < 0.05).

CONCLUSIONS

RLP-cholesterol and platelet microparticles are both elevated in type-2 DM patients when compared with controls. RLP-cholesterol is the primary and only predictor of platelet microparticles in the multivariable analysis, which include several standard atherosclerosis risk factors. This suggested that reducing elevated RLP-cholesterol with lipid-lowering therapy may be an effective strategy to prevent thrombogenic vascular complications in type-2 DM.

Kidney disease and cardiovascular disease: implications of dyslipidemia

Cardiovascular complications are common inpatients with kidney disease. Regulating the lipid levels in these patients is important so that the risks of kidney and cardiovascular complications can be minimized. Lipid regulation decreases the incidence of coronary vascular events and other vascular complications in patients with kidney disease; however, whether lipid regulation slows progression of kidney disease is not yet known. Additional studies of the implications of dyslipidemia in patients with kidney disease are needed.

Differential postprandial lipoprotein responses in type 2 diabetic men with and without clinical evidence of a former myocardial infarction

Postprandial lipemia plays an important role in the development of coronary heart disease through an elevation of triglyceride-rich lipoproteins. In type 2 diabetic male subjects, our aim was to compare postprandial lipemia in a high-risk population with former myocardial infarction (MI) with that of a lower risk population free of clinically detectable heart disease. 32 male type 2 diabetic subjects were included in the study. We matched 17 cases with a verified history of MI with 15 controls according to age, BMI, HbA1c, diabetes duration, smoking, and treatment of diabetes. Ongoing metformin, insulin, or lipid lowering pharmacological treatment were exclusion criteria. After a maximal exercise tolerance test and echocardiography, the subjects underwent a hyperinsulinemic, euglycemic clamp and a vitamin A fat loading test. Plasma triglyceride levels in the case group were significantly higher after 360 minutes (4.6 +/- 3.1 vs. 2.8 +/- 1.8 mmol/l, p = 0.04) and 480 minutes (3.6 +/- 2.2 vs. 2.4 +/- 2.4 mmol/l, p = 0.03), as was the incremental Area Under the Curve (iAUC) for the whole period (560 +/- 452 vs. 297 +/- 214 mmol x 480 min./l; p = 0.048). In addition, the retinyl palmitate responses in the chylomicron-fraction from the case group were significantly higher (iAUC 311,502 +/- 194,933 vs. 187,004 +/- 102,928 ng x 480 min./ml; p = 0.035). Type 2 diabetic males with prior MI had higher postprandial triglyceride-rich lipoprotein responses than those without MI, indicating that high responses may be a marker for a high-risk population.

Obesity, glucose intolerance and diabetes and their links to cardiovascular disease. Implications for laboratory medicine

This article provides an overview of the role of metabolite toxicity, low-grade inflammation and disturbed cellular signaling in obesity, glucose intolerance and diabetes. It also highlights links between this continuum of deteriorating glucose tolerance and atherosclerosis. Obesity, diabetes mellitus, and cardiovascular disease are all related to diet and to the level of physical activity. They have reached epidemic proportions worldwide. Glucose intolerance and diabetes increase the risk of atherosclerotic events. Moreover, obesity, and glucose intolerance or diabetes, are components of the metabolic syndrome, which also imparts an increased cardiovascular risk. There is increasing recognition that common mechanisms contribute to diabetes and cardiovascular disease. Following increased calorie intake and/or decreased physical activity, fuel metabolism generates excess of 'toxic' metabolites, particularly glucose and fatty acids. Homeostasis is affected by the endocrine output from the adipose tissue. Reactive oxygen species are generated, creating oxidative stress, which exerts major effects on signaling pathways, further affecting cellular metabolism and triggering low-grade inflammatory reaction. This perspective on the diabetic syndrome has been reflected in the approach to its treatment, which integrates maintenance of glycemic control with primary and secondary cardiovascular prevention. Laboratory medicine should support diabetes care with an integrated package of tests which, in addition to glycemic control, enable assessment and monitoring of the risk of microvascular complications as well as cardiovascular disease.

The BBZDR/Wor Rat Model for Investigating the Complications of Type 2 Diabetes Mellitus

Congenic and inbred strains of rats offer researchers invaluable insight into the etiopathogenesis of diabetes and associated complications. The inbred Bio-Breeding Zucker diabetic rat (BBZDR)/Wor rat strain is a relatively new and emerging model of type 2 diabetes. This strain was created by classical breeding methods used to introgress the defective leptin receptor gene (Lepr(fa)) from insulin-resistant Zucker fatty rats into the inbred BBDR/Wor strain background. The diabetic male BBZDR/Wor rat is homozygous for the fatty mutation and shares the genetic background of the original BB strain. Although lean littermates are phenotypically normal, obese juvenile BBZDR/Wor rats are hyperlipidemic and hyperleptinemic, become insulin resistant, and ultimately develop hyperglycemia. Furthermore, the BBZDR/Wor rat is immune competent and does not develop autoimmunity. Similar to patients with clinical diabetes, the BBZDR/Wor rat develops complications associated with hyperglycemia. The BBZDR/Wor rat is a model system that fully encompasses the ability to study the complications that affect human type 2 diabetic patients. In this review, recent work that has evaluated type 2 diabetic complications in BBZDR/Wor rats is discussed, including the authors' preliminary unpublished studies on cardiovascular disease.