High density lipoproteins and type 2 diabetes: Emerging concepts in their relationship

Assessment of common risk factors of diabetes and chronic kidney disease: a Mendelian randomization study

Background

The increasing prevalence of diabetes and its significant impact on mortality and morbidity rates worldwide has led to a growing interest in understanding its common risk factors, particularly in relation to chronic kidney disease (CKD). This research article aims to investigate the shared risk factors between type 1 diabetes (T1D), type 2 diabetes (T2D), and CKD using a Mendelian randomization (MR) design.

Methods

The study utilized genome-wide association study (GWAS) datasets for T1D, T2D, and CKD from the FinnGen research project. GWAS summary statistics datasets for 118 exposure traits were obtained from the IEU OpenGWAS database. MR analyses were conducted to examine the causal relationships between exposure traits and each of the three outcomes. Multiple methods, including inverse-variance weighted, weighted median, and MR-Egger, were employed for the MR studies.

Results

Phenome-wide MR analyses revealed that eosinophil percentage exhibited a significant and suggestive causal association with T1D and CKD, respectively, suggesting its potential as a shared risk factor for T1D and CKD. For T2D, 34 traits demonstrated significant associations. Among these 34 traits, 14 were also significantly associated with CKD, indicating the presence of common risk factors between T2D and CKD, primarily related to obesity, height, blood lipids and sex hormone binding globulin, blood pressure, and walking pace.

Conclusion

This research has uncovered the eosinophil percentage as a potential common risk factor for both T1D and CKD, while also identifying several traits, such as obesity and blood lipids, as shared risk factors for T2D and CKD. This study contributes to the understanding of the common risk factors between diabetes and CKD, emphasizing the need for targeted interventions to reduce the risk of these diseases.

Dietary Iron Restriction Improves Muscle Function, Dyslipidemia, and Decreased Muscle Oxidative Stress in Streptozotocin-Induced Diabetic Rats

Diabetes mellitus is a chronic degenerative disease characterized by hyperglycemia and oxidative stress. Iron catalyzes free radical overproduction. High iron concentrations have previously been reported to promote an increase in oxidative stress; however, the effect of iron restriction in diabetes has not yet been explored, so we tested to see if iron restriction in diabetic rats reduces oxidative damage and improved muscle function. Wistar rats were assigned to 4 groups: Control; Diabetic; Diabetic rats with a high iron diet, and Diabetic with dietary iron restriction. After 8 weeks the rats were sacrificed, the muscles were extracted to prepare homogenates, and serum was obtained for biochemical measurements. Low iron diabetic rats showed an increase in the development of muscle strength in both muscles. Dietary iron restriction decreased triglyceride concentrations compared to the untreated diabetic rats and the levels of extremely low-density lipoproteins. Aggravation of lipid peroxidation was observed in the diabetic group with a high iron diet, while these levels remained low with iron restriction. Iron restriction improved muscle strength development and reduced fatigue times; this was related to better lipid profile control and decreased oxidant stress markers.

Deep Sea Water-Dissolved Organic Matter Intake Improves Hyperlipidemia and Inhibits Thrombus Formation and Vascular Inflammation in High-Fat Diet Hamsters

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease caused by oxidative stress, inflammation and lipid deposition within liver cells, and is subsequently contributing to cardiovascular diseases such as atherosclerosis. Deep sea water (DSW) is characterized by its clearance and abundant nutrients with antioxidant and anti-inflammatory activity to confer therapeutic potential. We aimed to explore the therapeutic capability of our prepared multi-filtration DSW-dissolved organic matter (DSW-DOM) on high-fat diet-induced hyperlipidemia and endothelial dysfunction in hamsters. A high-fat/high-cholesterol diet led to increased oxidative stress, including blood reactive oxygen species (ROS), plasma malondialdehyde (MDA) and hepatic CYP2E1 expression; an increased hyperlipidemic profile and SREBP 1-mediated fatty liver; promoted NFκB p65-mediated hepatic inflammation; triggered PARP-mediated hepatic apoptosis; and enhanced endothelial intercellular adhesion molecule-1 (ICAM-1) and von Willebrand factor (VWF)-mediated atherosclerosis associated with the depressed hepatic antioxidant Paraoxonase 1 (PON1) expression. The DSW-DOM-enriched 1295 fraction, with strong H2O2 scavenging activity, efficiently reduced several oxidative stress parameters, the lipid profile, inflammation, and apoptosis, possibly through the PON1-mediated antioxidant capability. Furthermore, DSW-DOM treatment significantly decreased the endothelial ICAM-1 and VWF expression, subsequently leading to the elongation of time to occlusion of FeCl3-induced arterial thrombosis and to the inhibition of FeCl3-induced fluorescent platelet adhesion to mesentery arterioles in the high-fat diet. Based on the above results, our data suggest that DSW-DOM intake via antioxidant defense mechanisms confers protective effects against high-fat diet-enhanced, oxidative stress-mediated hyperlipidemia, and endothelial dysfunction evoked atherosclerosis by downregulating oxidative injury, lipogenesis, inflammation and apoptosis.

[Features of Cardiovascular Risk Factors, Target Organ Damage in Patients with Diabetes Mellitus Type 2 and Arterial Hypertension]

AIM

to investigate relationship between arterial hypertension (AH) and risk factors / subclinical damage of target organs in patients with type 2 diabetes mellitus (DM2).

METHODS

We included into this clinical epidemiological study 528 patients with DM2 (30.5 % men, 69.5 % women; mean age 54.1±0.3 years; 80.3 % with AH, 19.7 % without AH), who answered questions of the ARIC study questionnaire related to risk factors. Also, we studied features of target organ damage and laboratory indicators.

RESULTS

In comparison with normotensives patients with AH more frequently had ischemic heart disease (12.7±1.6 % vs. 5.8±2.3 %, p<0.05), chronic heart failure (CHF) (30.9±2.2 % vs. 9.6±2.9 %, p<0.001), atherosclerosis of vessels of lower extremities (69.8±2.2 % vs. 53.8±4.9 %, p<0.01) and cerebral vessels (50.9±2.4 % vs. 28.8±4.4 %, p<0.001), history of stroke (5.0±1.1 % vs. 0 %, p<0.05), hypertonic angiopathy (14.5±1.8 % vs. 6.5±2.5 %, p<0.05), low level of high density lipoprotein (87.3±2.2 % vs. 74.5±6.4 %, p<0.05), electro- and echocardiographic signs of left ventricular hypertrophy (75.6±2.1 % vs. 45.4±5.1 %, p<0.001; 61.1±2.6 % vs. 24.4±4.7 %, p<0.001, respectively), lowering of left ventricular ejection fraction (12.5±1.7 % vs. 7.8±2.8 %, p<0.001), diastolic disfunction of the left ventricle (52.6±2.7 % vs. 23.2±4.7 %, p<0.001), atherosclerosis of the aorta (38.0±2.6 % vs. 20.7±4.5 %, p<0.01), lowering of the ankle-brachial index (left - 29.8±2.3 % vs. 14.9±3.5 %, p<0.01; right - 31.5±2.3 % vs. 9.9±3.0 %, p<0.001, respectively), increased intima-media thickness of the right carotid artery (84.6±5.0 % vs. 60.0±11.0 %, p<0.05).

CONCLUSION

In patients with type 2 diabetes and AH, in order to develop strategy of macro- and microvascular complications prevention, it is necessary to conduct early screening of risk factors and subclinical damage of target organs.

Dyslipidaemia in type 2 diabetes mellitus: bad for the heart

PURPOSE OF REVIEW

Type 2 diabetes mellitus (T2DM) is associated with increased coronary heart disease (CHD) morbidity and mortality. These patients are also more prone to heart failure, arrhythmias and sudden cardiac death. Furthermore, coronary interventions performed in such high-risk patients have worse outcomes. In this narrative review, we discuss the role of diabetic dyslipidaemia on the risk of CHD in patients with T2DM. The effects of hypolipidaemic, antihypertensive and antidiabetic drugs on lipid and glucose metabolism in T2DM are also considered.

RECENT FINDINGS

Among CHD risk factors, diabetic dyslipidaemia characterized by moderately elevated low-density lipoprotein (LDL) cholesterol, increased triglycerides and small, dense LDL particles as well as decreased high-density lipoprotein cholesterol levels may contribute to the increased CHD risk associated with T2DM. Hypolipidaemic, antihypertensive and antidiabetic drugs can affect lipid and glucose parameters thus potentially influencing CHD risk. Such drugs may improve not only the quantity, but also the quality of LDL as well as postprandial lipaemia.

SUMMARY

Current data highlight the importance of treating diabetic dyslipidaemia in order to minimize CHD risk. Both fasting and postprandial lipids are influenced by drugs in patients with T2DM; physicians should take this into consideration in clinical decision making.

Dyslipidaemia in the elderly: to treat or not to treat?

INTRODUCTION

The elderly population (i.e. aged ≥ 65 years) is increasing worldwide. Ageing is associated with a higher incidence and prevalence of cardiovascular disease (CVD). Areas covered: The prevalence of CVD risk factors including type 2 diabetes mellitus, hypertension and dyslipidaemia also increases with advancing age, contributing to the higher absolute CVD risk observed in the elderly. The present narrative review comments on the associations of dyslipidaemia with CVD as well as the effects of lifestyle measures and lipid-lowering drugs on lipids and CVD risk with a special focus on the elderly population. Individual treatment goals and therapeutic options according to current guidelines are also reviewed. Finally, we discuss special characteristics of the elderly that may influence the efficacy and safety of drug therapy and should be considered before selection of hypolipidaemic pharmacotherapy. Expert commentary: There may be a greater CVD benefit in older patients following drug therapy compared with younger ones. Treatment goals and therapeutic options should be individualized according to current guidelines. Specific characteristics that may influence the efficacy and safety of drug therapy in the elderly should be considered in relation to dyslipidaemia treatment.

Serum paraoxonase 1 activity in patients with iron deficiency anemia

INTRODUCTION

In this study we aimed to detect paraoxonase 1 (PON-1) activity in iron deficiency anemia (IDA) and to compare it with healthy controls by observing the change after iron therapy.

MATERIAL AND METHODS

In this study, 50 adult patients with IDA and 40 healthy subjects were enrolled. All patients were analyzed at the beginning and after treatment according to laboratory assessments.

RESULTS

Mean paraoxonase and arylesterase activities in the iron deficiency anemia group were significantly lower than mean activities of the control group (102.4 ±19.2 U/l and 163.3 ±13.68 U/l, respectively and 157.3 ±26.4 U/l and 256.1 ±24.6 U/l, respectively; p = 0.0001 for both). Paraoxonase and arylesterase activities significantly increased after treatment for IDA (143.2 ±13.9 and 197.6 ±27.9 U/l, respectively, p = 0.0001). Mean activities after treatment with iron were significantly lower than mean activities in the control group (p = 0.002; p = 0.0001 respectively).

CONCLUSIONS

Paraoxonase and arylesterase activities in patients with IDA significantly increased after treatment with iron therapy. In adults IDA may also be one of the factors associated with increased risk of atherosclerosis.

Hyperlipidemia-induced hepatic and small intestine ER stress and decreased paraoxonase 1 expression and activity is associated with HDL dysfunction in Syrian hamsters

SCOPE

We aimed at investigating the mechanisms linking hyperlipidemia (HL) with dysfunctional HDL and its main antioxidant enzyme, paraoxonase1 (PON1). PON1 expression and activity was determined in the small intestine, liver, and sera of normal and HL hamsters and associated with the ER stress (ERS) and the development of aortic valve lesions.

METHODS AND RESULTS

Male Golden Syrian hamsters were fed standard chow (N) or standard diet with 3% cholesterol and 15% butter for 16 weeks. All hamsters on fat diet developed HL, 50% also hyperglycemia (HLHG) and a fourfold increased homeostasis model assessment of insuline resistance. PON1 expression was reduced in the small intestine and liver (N > HL > HLHG) along with the increased extent of ERS, oxidized lipids, and decreased expression of liver X receptors beta (LXRβ) in the small intestine, peroxisome proliferator-activated receptor-γ (PPARγ) in the liver, and of the glucose transporter 4 in the myocardium. Serum PON1 levels decreased along with the increase of oxidized LDL and lesion areas of the aortic valves (N > HL > HLHG).

CONCLUSION

The fat diet activates the ERS and oxidative stress, decreases LXRβ, PPARγ, and PON1 in the small intestine, liver, and sera of all HL animals, in parallel with the appearance of atherosclerotic lesions in the aortic valves.

Emerging risk biomarkers in cardiovascular diseases and disorders

Present review article highlights various cardiovascular risk prediction biomarkers by incorporating both traditional risk factors to be used as diagnostic markers and recent technologically generated diagnostic and therapeutic markers. This paper explains traditional biomarkers such as lipid profile, glucose, and hormone level and physiological biomarkers based on measurement of levels of important biomolecules such as serum ferritin, triglyceride to HDLp (high density lipoproteins) ratio, lipophorin-cholesterol ratio, lipid-lipophorin ratio, LDL cholesterol level, HDLp and apolipoprotein levels, lipophorins and LTPs ratio, sphingolipids, Omega-3 Index, and ST2 level. In addition, immunohistochemical, oxidative stress, inflammatory, anatomical, imaging, genetic, and therapeutic biomarkers have been explained in detail with their investigational specifications. Many of these biomarkers, alone or in combination, can play important role in prediction of risks, its types, and status of morbidity. As emerging risks are found to be affiliated with minor and microlevel factors and its diagnosis at an earlier stage could find CVD, hence, there is an urgent need of new more authentic, appropriate, and reliable diagnostic and therapeutic markers to confirm disease well in time to start the clinical aid to the patients. Present review aims to discuss new emerging biomarkers that could facilitate more authentic and fast diagnosis of CVDs, HF (heart failures), and various lipid abnormalities and disorders in the future.