Adipokines and vascular risk in type 2 diabetes mellitus

Effect of Curcumin on Glycemic Control in Patients with Type 2 Diabetes: A Systematic Review of Randomized Clinical Trials

Type 2 diabetes mellitus (T2DM) is a chronic metabolic condition, which carries considerable morbidity and mortality. There is growing evidence that curcumin could modulate glucose homeostasis and improve vascular risk in patients with T2DM. The aim of this systematic review was to study the effect of curcumin on glycemic indices in patients with diabetes. A comprehensive search was conducted in PubMed, Scopus, Embase, and Google Scholar up to March 5, 2020, to identify randomized control trials investigating the effect of curcumin supplementation on glycemic indices including fasting blood glucose (FBS), hemoglobin A1c (HbA1C), and the homeostatic model assessment for insulin resistance (HOMA-IR). Eleven articles comprising 1131 individuals with T2DM were included in the study. Treatment with curcumin significantly reduced the level of FBS and HbA1c in 8 and 7 studies, respectively. HOMA-IR was evaluated in five studies, and this was reduced significantly by curcumin supplementation in three of those studies. Patients who took curcumin supplementation over longer periods (≥12 weeks) showed a significant reduction in glycemic indices. The current systematic review showed that curcumin can improve glycemic control in patients with T2DM. However, further studies are required to determine the optimum conditions for these effects of curcumin, particularly regarding readouts of insulin resistance.

Inflammatory Markers in Cardiovascular Disease; Lessons Learned and Future Perspectives

BACKGROUND

Cardiovascular disease (CVD) still remains the leading cause of morbidity and mortality worldwide. It is now established that inflammation plays a crucial role in atherosclerosis and atherothrombosis, and thus, it is closely linked to cardiovascular disease.

OBJECTIVE

The aim of the present review is to summarize and critically appraise the most relevant evidence regarding the potential use of inflammatory markers in the field of CVD.

METHODS

We conducted a comprehensive research of the relevant literature, searching MEDLINE from its inception until November 2018, primarily for meta-analyses, randomized controlled trials and observational studies.

RESULTS

Established markers of inflammation, mainly C-reactive protein, have yielded significant results both for primary and secondary prevention of CVD. Newer markers, such as lipoprotein-associated phospholipase A2, lectin-like oxidized low-density lipoprotein receptor-1, cytokines, myeloperoxidase, cell adhesion molecules, matrix metalloproteinases, and the CD40/CD40 ligand system, have been largely evaluated in human studies, enrolling both individuals from the general population and patients with established CVD. Some markers have yielded conflicting results; however, others are now recognized not only as promising biomarkers of CVD, but also as potential therapeutic targets, establishing the role of anti-inflammatory and pleiotropic drugs in CVD.

CONCLUSION

There is significant evidence regarding the role of consolidated and novel inflammatory markers in the field of diagnosis and prognosis of CVD. However, multimarker model assessment, validation of cut-off values and cost-effectiveness analyses are required in order for those markers to be integrated into daily clinical practice.

Associations between Adiponectin Gene Variability, Proinflammatory and Angiogenetic Markers: Implications for Microvascular Disease Development in Type 2 Diabetes Mellitus?

BACKGROUND

Adiponectin gene (ADIPOQ) variability may affect the risk for type 2 diabetes mellitus (T2DM) but it remains unclear whether it is involved in microvascular complications.

OBJECTIVE

To explore the impact of ADIPOQ variability on markers of inflammation and angiogenesis in T2DM.

METHODS

Overall, 220 consecutive T2DM patients from our outpatient diabetic clinic were genotyped for G276T (rs1501299) and T45G (rs2241766) single nucleotide polymorphisms of ADIPOQ gene. Serum levels of interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), vascular endothelial growth factor (VEGF) were measured by enzyme-linked immunosorbent assay and high sensitivity Creactive protein (hsCRP) by immunonephelometry.

RESULTS

Homozygosity for the G allele on rs2241766 was associated with significantly lower serum VEGF and ICAM-1 levels compared with other genotype groups, but had no effect on IL-6. Genetic variability on rs1501299 was not associated with either VEGF or ICAM-1 levels, but T homozygotes for rs1501299 had significantly lower IL-6 concentrations compared with G carriers. Furthermore, the presence of the G allele on rs2241766 was associated with significantly lower HbA1c, whereas no associations were observed for both body mass index and hsCRP with either rs2241766 or rs1501299.

CONCLUSION

Genetic variability on adiponectin gene was associated with serum levels of inflammatory and angiogenetic markers. Further research is required to elucidate the role of adiponectin in the development and/or progression of microvascular disease in T2DM patients.

Biomarkers and Gene Polymorphisms in Members of Long- and Short-lived Families: A Longevity Study

BACKGROUND

The influence of biomarkers in human lifespan has been investigated but with no clear results yet.

MATERIALS AND METHODS

Lipids, Uric Acid (UA), Adiponectin (ADIPOQ), Insulin-like Growth Factor (IGF-1), cholesteryl ester transfer protein (CETP) and angiotensin-converting enzyme (ACE) proteins, as well as CETP, ADIPOQ, insulin-like growth factor binding protein-3 (IGFBP3) and ACE-gene polymorphisms were evaluated in 149 Greek individuals. The Long-Lived Families (LON) (n=84) comprised of 3 generations: long-lived aged ≥90 years (P), offspring (FL1) and their grandchildren (FL2), while the Short-Lived Families (EAD) (n=65) where both parents died <75 years, comprised of 2 generations: middle-aged (FD1) and children (FD2).

RESULTS

Serum CETP and IGF-1 levels were lower, whereas AdipoQ concentrations were higher in P compared with FL1 and FL2 members (CETP: p = 0.03 for both comparisons; IGF-1 p < 0.001 for both comparisons and ADIPOQ: p = 0.001 and p = 0.004, respectively). Furthermore, serum triglycerides, UA and glucose concentrations were higher in FD1 compared with FD2 subjects (p=0.001, 0.02 and ≤0.001, respectively). In FD2 and FL2, CETP levels were lower in individuals with B2B2 compared with B1B1 genotype (p=0.007). Additionally, ACE concentrations were higher in individuals with DD compared with II genotype in both Families (p=0.001). After adjustment for age and gender, CETP levels were lower in P and FL2 individuals with B2B2 compared with the B1B1 genotype (p=0.004 and 0.007, respectively).

CONCLUSION

Increase serum TGs, UA and GL concentrations were higher in the middle-aged individuals compared with their children in families independently of their lifespan. The serum adiponectin concentration was the highest in the oldest old individuals implying beneficial influence on lifespan. Independently of family's lifespan history, the youngest individuals with CETPB2B2 genotype, compared with individuals with CETPB1B1 genotypes, had lower serum CETP concentrations. The knowledge of the unfavourable gene(s)influencing human lifespan may be helpful in encouraging individuals to follow healthier lifestyle habits and better control their high-risk biomarkers.

Leptin, cardiovascular diseases and type 2 diabetes mellitus

Leptin, an adipokine that is implicated in the control of food intake via appetite suppression, may also stimulate oxidative stress, inflammation, thrombosis, arterial stiffness, angiogenesis and atherogenesis. These leptin-induced effects may predispose to the development of cardiovascular diseases. In the present review we discuss the evidence linking leptin levels with the presence, severity and/or prognosis of both coronary artery disease and non-cardiac vascular diseases such as stroke, carotid artery disease, peripheral artery disease (PAD) and abdominal aortic aneurysms (AAA) as well as with chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). Leptin levels have been positively associated with the presence, severity, extent and lesion complexity of coronary atherosclerosis as well as with the presence, severity and poor clinical outcomes of both ischemic and hemorrhagic strokes. But conflicting results also exist. Furthermore, leptin was reported to independently predict common carotid intima-media thickness and carotid plaque instability. A link between hyperleptinemia and PAD has been reported, whereas limited data were available on the potential association between leptin and AAA. Elevated leptin concentrations have also been related to CKD incidence and progression as well as with insulin resistance, T2DM, micro- and macrovascular diabetic complications. Statins and antidiabetic drugs (including sitagliptin, metformin, pioglitazone, liraglutide and empagliflozin) may affect leptin levels. Further research is needed to establish the potential use (if any) of leptin as a therapeutic target in these diseases.

Adiponectin as an Independent Predictor of Left Ventricular Hypertrophy in Nondiabetic Patients With Hypertension

We evaluated novel and traditional biomarkers as well as hemodynamic parameters associated with the development of left ventricular hypertrophy (LVH) in nondiabetic patients with hypertension. Nondiabetic patients with hypertension (n = 86) were evaluated for lipids, glucose, insulin, homeostasis model assessment-insulin resistance (HOMA-IR), adiponectin, aldosterone, renin, matrix metalloproteinase 2, and endothelin. Arterial elasticity was evaluated using pulse wave contour. The LVH parameters were assessed echographically. Adiponectin was significantly and inversely associated with left ventricular mass (LVM; P = .032). The aldosterone–renin ratio (ARR) was significantly, positively associated with LVM ( P = .031). Fasting insulin as well as HOMA-IR was significantly, positively associated with LVM ( P = .036 and P = .025, respectively). In multiple linear regression analysis, adiponectin and ARR remained a significant predictor of LVM. The present study found that adiponectin and ARR are important independent determinants of LVH in nondiabetic patients with hypertension.

Effects of chitosan on plasma lipids and lipoproteins: a 4-month prospective pilot study

Chitosan can favorably modulate plasma lipids, but the available data are not conclusive. We evaluated the effect of chitosan on plasma lipids and lipoproteins in 28 patients with plasma triglyceride levels >150 mg/dL (mean age: 63 ± 12 years), not taking other lipid-lowering agents. All patients received a chitosan derived from fungal mycelium (Xantonet, Bromatech, Italy) at a fixed dose of 125 mg/d in addition to their current medications for 4 months. Polyacrylamide gel electrophoresis was used to measure low-density lipoprotein (LDL) subclasses. After treatment, total cholesterol reduced by 8%, LDL cholesterol by 2%, and triglycerides by 19%, with a concomitant 14% increase in high-density lipoprotein cholesterol. We also found a beneficial effect of chitosan on LDL subclasses, with a significant increase in LDL-2 particles (from 37 ± 8% to 47 ± 8%, P = .0001) and a decrease (although not significant) in atherogenic small, dense LDL. Whether these findings may affect cardiovascular risk remains to be established in future studies.