Adiponectin provides additional information to conventional cardiovascular risk factors for assessing the risk of atherosclerosis in both genders

AdipoRon and ADP355, adiponectin receptor agonists, in Metabolic-associated Fatty Liver Disease (MAFLD) and Nonalcoholic Steatohepatitis (NASH): A systematic review

Adiponectin replacement therapy holds the potential to benefit numerous human diseases, and ongoing research applies particular interest in how adiponectin acts against Metabolic-associated Fatty Liver Disease (MAFLD) and Nonalcoholic Steatohepatitis (NASH). However, the pharmacological limitations of the intact protein have prompted a focus on alternative options, specifically peptidic and small molecule agonists targeting the adiponectin receptor. AdipoRon is an extensively researched non-peptidic drug candidate in adiponectin replacement therapy. In turn, ADP355 is an adiponectin-based active short peptide. They have garnered significant attention due to their potential as substitutes for adiponectin. Researchers have studied AdipoRon's and ADP355's efficacy and therapeutic applications in various disease conditions. However, the effects of AdipoRon and ADP355 against NAFLD and NASH models advanced more, and no systematic review explored this area before. This systematic review was conceived to address the deficiency mentioned above and consider the lack of clinical evidence. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were utilized. To assess the risk of bias in systematic review, The Joanna Briggs Institute (JBI) Critical Appraisal Checklist was employed. Results from pre-clinical evidence show that AdipoRon and ADP355 represent promising effects in NAFLD and NASH-related models, including reducing hepatic steatosis, modulating inflammation, improving insulin sensitivity, enhancing mitochondrial function, and protecting against liver fibrosis. While AdipoRon and ADP355 exhibit promise in pre-clinical studies and experimental models, additional clinical trials are necessary to assess their effectiveness, safety, and potential translational therapeutic potential uses in NAFLD and NASH human cases.

Aortic stiffness and content of adipokines in the serum in persons of European and South Asian ethnic

Aim. To evaluate the cardiovascular risk (CVR) based on arterial stiffness and content of adipokines in young-aged persons of different ethnicity (European and South Asian). Materials and methods. 290 persons of European (Slavic) and South Asian (Korean) ethnicity aged from 19 to 49 years with and without arterial hypertension (AH) were examined. Clinical, anthropometric, laboratory examinations were performed, levels of resistin and adiponectin of blood were assessed. Total CVR was assessed by SCORE scale, patients under the age of 40 years were assessed by relative risk scale. Aortic stiffness was examined by non-invasive arteriography. Results. Patients of European ethnicity had higher blood pressure (BP), body mass index (BMI), waist circumference (WC), levels of resistin and adiponectin. Pulse wave velocity in the aorta (PWVA) did not differ significantly in ethnic groups. According to the SCORE scale in individuals of the European and South Asian races in general groups and groups with arterial hypertension a moderate absolute risk was determined, in individuals under 40 years of age a moderate relative risk was determined without a significant difference between the groups. However increased levels of PWVA (more than 10 m/s) were registered more often in Korean ethnicity (46.9% compared to Slavic ethnicity, 22.2%). Closer reliable correlations between the level of BP and BMI, WC, PWVA were revealed in Korean ethnicity. Ethnic differences in correlation of adipokines in blood and their dependence on anthropometric and hemodynamic characteristics were described. Conclusion. The assessment of CVR according to traditional scales does not always accurately represent its real level. New information was obtained on the features of adipokine metabolism and its connections with early manifestations of vascular remodeling in young-aged depending on the race. Taking into account ethnic differences, we recommend in-depth diagnostics of CVR in South Asians. The data can be useful for the design of personalized programs for the diagnostics and assessment of CVR.

Association between Plasma Adipocytokines Levels and Intracranial versus Extracranial Atherosclerotic among Chinese Patients with Stroke

BACKGROUND

To detect the levels of plasma Adipocytokines, TNF-α, IL-6 and PAI-1 in patients with intracranial and extracranial arteriosclerosis.

METHODS

From September 2015 to September 2017, 318 patients aged ≥60 years were enrolled. Overall, 192 patients were included in the case group (intracranial and extracranial arteriosclerosis group). The 196 outpatients who matched the case groupware selected as the control group. The levels of plasma APN, TNF-α, IL-6 and PAI-1 were measured and their inter- and intra-group comparisons were performed using t-test or analysis of variance. Multivariate logistic regression analysis was used to study the correlation between intracranial arteriosclerosis and extracranial arteriosclerosis.

RESULTS

The level of plasma APN in the intracranial and extracranial arteriosclerosis group was significantly lower than that in the control group (P=0.025). The plasma levels of PAI-1, TNF-α and IL-6 were obviously higher than those in the control group (P=0.003, P=0.008, P=0.043). In the intracranial arteriosclerosis group, the level of plasma APN in patients with arterial stenosis ≥70% was significantly lower than that in patients with stenosis 30%-69% (P=0.028).

CONCLUSION

Plasma APN, PAI-1, IL-6 and TNF-α levels can be used as monitoring indicators of intracranial and extracranial arteriosclerosis. Intracranial arteriosclerosis is significantly associated with the decrease of plasma APN level and the increase of plasma PAI- 1, IL-6 and TNF-α levels.

Multifaceted Physiological Roles of Adiponectin in Inflammation and Diseases

Adiponectin is the richest adipokine in human plasma, and it is mainly secreted from white adipose tissue. Adiponectin circulates in blood as high-molecular, middle-molecular, and low-molecular weight isoforms. Numerous studies have demonstrated its insulin-sensitizing, anti-atherogenic, and anti-inflammatory effects. Additionally, decreased serum levels of adiponectin is associated with chronic inflammation of metabolic disorders including Type 2 diabetes, obesity, and atherosclerosis. However, recent studies showed that adiponectin could have pro-inflammatory roles in patients with autoimmune diseases. In particular, its high serum level was positively associated with inflammation severity and pathological progression in rheumatoid arthritis, chronic kidney disease, and inflammatory bowel disease. Thus, adiponectin seems to have both pro-inflammatory and anti-inflammatory effects. This indirectly indicates that adiponectin has different physiological roles according to an isoform and effector tissue. Knowledge on the specific functions of isoforms would help develop potential anti-inflammatory therapeutics to target specific adiponectin isoforms against metabolic disorders and autoimmune diseases. This review summarizes the current roles of adiponectin in metabolic disorders and autoimmune diseases.

High molecular weight adiponectin inhibits vascular calcification in renal allograft recipients

BACKGROUND

Adiponectin (ADPN) prevents the development/recurrence of cardiovascular events via its anti-atherogenic effects. However, few long-term studies have examined the changes in serum ADPN levels and arterial calcification seen in renal allograft recipients.

SUBJECTS AND METHODS

The effects of the serum ADPN level on arterial calcification were examined in 51 Japanese renal allograft recipients. Abdominal aorta calcification was evaluated on computed tomography using the aortic calcification area index (ACAI). The change in the ACAI and serum high-molecular-weight (HMW)-ADPN fractions were studied over an 8-year period. The arterial expression of ADPN, ADPN receptors (AdipoR)1 and 2, and T-cadherin (cadherin-13) were also examined by immunohistochemistry.

RESULTS

The change in the ACAI were grouped into quartiles and compared with the alterations in the serum levels of each ADPN fraction over an 8-year period. The change in the ACAI was much lower in the patients with highly elevated HMW-ADPN levels.Multiple regression analysis demonstrated that an advanced age at transplant and a history of cardiovascular complications were associated with an increased change in the ACAI, while higher HMW-ADPN concentrations were associated with improvements in the ACAI. Serum HDL-C level was also identified as a positive factor to increase serum HMW-ADPN level.In immunohistochemical examinations, ADPN was detected on CD31-positive arterial endothelial cells from renal allograft biopsy samples. ADPN co-localized with T-cadherin and AdipoR1, but only partially co-localized with AdipoR2.

CONCLUSION

Both HMW-ADPN and HDL-C might inhibit the progression of vascular calcification by promoting ADPN binding to vascular endothelial cells via T-cadherin and AdipoR in Japanese renal allograft recipients.

The Circulating CTRP13 in Type 2 Diabetes and Non-Alcoholic Fatty Liver Patients

Numerous studies have shown that C1q/TNF-related proteins (CTRPs) are involved in the pathophysiology of metabolic disorders, such as Non-alcoholic fatty liver disease (NAFLD) and Type 2 Diabetes (T2DM). There is a little information concerning CTRP13 in the context of NAFLD and T2DM. We evaluated the plasma levels of CTRP13 in healthy control and patients with NAFLD, T2DM and NAFLD+T2DM, and also correlations between CTRP13 plasma levels and clinical and subclinical features. Circulating CTRP13 was examined in 88 male (20 healthy control, 22 T2DM patients, 22 NAFLD patients and 22 NAFLD+T2DM patients). CTRP13 and adiponectin plasma levels were measured by ELISA method. CTRP13 serum levels were higher in the control group than the other groups (all p <0.001). CTRP13 had significant negative correlation with unfavorable anthropometric and metabolic factors including BMI, visceral fat, Insulin, HOMA-IR, TG, AST, ALT and ɣ-GT and have a positive correlation with plasma concentration of adiponectin. CTRP13 had a significant inverse correlation with cIMT (r = -0.345) and liver stiffness (LS) (r = -0.372) (both, p <0.001). Also, the multiple stepwise linear regression has shown that visceral fat is a significant predictor of CTRP13 serum levels (p <0.001). Multiple stepwise linear regression with LS as the dependent variable showed that ALT (p < 0.001) and SBP (p = 0.010) were two predictor factors for LS. Strikingly, multiple stepwise linear regression showed that CTRP13 (p = 0.006) and SBP (p = 0.007) were two independent predictors for cIMT. Lower CTRP13 in patients with T2DM, NAFLD and NAFLD + T2DM was associated with increased risk of the diseases. CTRP13 have negative associations with unfavorable metabolic factors and also is a negative predictor of cIMT. Our results suggested that CTRP13 could be an associated factor with NAFLD in patients with and without T2DM.

Adiponectin Fractions Influence the Development of Posttransplant Diabetes Mellitus and Cardiovascular Disease in Japanese Renal Transplant Recipients

Background

A few studies have investigated the role of adiponectin fraction for cardiovascular disease (CVD) in RTx recipients.

Subjects and Methods

We studied 57 adult subjects (39 males, 18 females; 10 cadaveric donors) with at least three years of allograft survival (median 251 months). We examined clinical backgrounds such as treated drugs, blood pressure (BP, mmHg), body mass index (BMI), and blood chemistry including cholesterol (total, LDL-C, HDL-C), glucose, glycated hemoglobin (HbA1c), and serum high and low-molecular-weight (HMW/LMW) ADPN fractions with regard to the associations of the visceral and subcutaneous fat areas on CT scan. We also analyzed the associations of CVD and post-transplant diabetes (PTDM) with ADPN fractions and the fat areas.

Results

The visceral fat area was inversely correlated with serum HMW and LMW ADPN levels and HMW ADPN ratio (r = -0.400, p = 0.002 and r = -0.296, p = 0.025 and r = -0.444, p<0.001, respectively). Furthermore, the visceral fat area was positively with the LMW ADPN ratio (r = 0.467, p<0.001), but no significant correlation was noted between the subcutaneous fat area and the ADPN ratio. On multiple regression analysis, eGFR and the visceral fat area were significant reducing factors of HMW ADPN levels, and the alteration of eGFR was identified as an increasing factor of HMW ADPN levels. Patients with CVD had larger visceral fat area (p = 0.004), lower HMW ADPN ratio (p = 0.022) and higher LMW ADPN ratio (p = 0.049). In addition, the higher HMW ADPN ratio and statin treatment were identified as reducing factors of the development of CVD, but the LDL-C level was an aggravating factor. Moreover, the higher LMW ADPN ratio and the visceral fat area were aggravating factors of PTDM.

Conclusion

Even in Japanese renal transplant recipients, visceral fat area and ADPN fractions were significant factors for the development of both CVD and PTDM.

Circulating adiponectin and carotid intima-media thickness: A systematic review and meta-analysis

BACKGROUND

Adiponectin (APN) is an adipokine with insulin-sensitizing, anti-inflammatory, and vasculoprotective properties. Hypoadiponectinemia has been linked with disease states, such as obesity, type 2 diabetes, and cardiovascular disease. Carotid intima-media thickness (cIMT) is a strong and independent predictor of both coronary and cerebrovascular events, and has been used as a surrogate marker of subclinical atherosclerosis. The aim of this report is to systematically review the evidence on the relationship between APN and cIMT in a wide range of individuals.

MATERIALS AND METHODS

Medline, Embase, Biosis, Scopus, Web of Science, and Pubmed were searched for published studies and conference abstracts. The "sign test" and "vote count" methods were used to estimate the direction and significance of the relationship between APN and cIMT. The quality of the eligible studies was evaluated using an adapted version of the New Castle Ottawa quality assessment scale.

RESULTS

Fifty-five articles fulfilled the inclusion criteria, comprised of only cross-sectional studies, including healthy subjects, general population, and individuals with metabolic, inflammatory, or other chronic diseases. Most associations between APN and cIMT followed a negative direction in the healthier and general populations, and also in cohorts with metabolic disorders and other chronic diseases, but not in those with inflammatory diseases (sign test). These associations were generally found to be weak or non-significant among all cohort groups studied (vote count).

CONCLUSION

Our results are suggestive but not conclusive for an inverse association between APN levels and cIMT in diseased and non-diseased populations.

Inflammation Activation Contributes to Adipokine Imbalance in Patients with Acute Coronary Syndrome

Inflammation can be activated as a defensive response by the attack of acute coronary syndrome (ACS) for ischemic tissue injury. The aim of the present study was to investigate the impact of ACS-activated inflammation on adipokine imbalance and the effects of statins on the crosstalk between inflammation and adipokine imbalance during ACS. In this study, 586 subjects were categorized into: (1) control group; (2) SA (stable angina) group; and (3) ACS group. Circulating levels of hs-CRP, adiponectin and resistin were measured by ELISA. Furthermore, forty C57BL/6 mice were randomized into: sham, AMI, low-statin (atorvastatin, 2 mg/kg/day) and high-statin (atorvastatin, 20 mg/kg/day) group. After 3 weeks, AMI models were established by surgical coronary artery ligation. Circulating levels and adipose expressions of adiponectin and resistin were assessed in animals. Besides, we investigate the effects of atorvastatin on ox-LDL-induced adipokine imbalance in vitro. As a result, we found that ACS patients had higher hs-CRP and resistin levels and lower adiponectin levels. Our correlation analysis demonstrated hs-CRP concentrations were positively correlated with resistin but negatively with adiponectin levels in humans. Our animal findings indicated higher circulating hs-CRP and resistin levels and lower adiponectin levels in AMI mice. Atorvastatin pre-treatment dose-dependently decreased hs-CRP and resistin levels but increased adiponectin levels in mice. The consistent findings were observed about the adipose expressions of resistin and adiponectin in mice. In study in vitro, ox-LDL increased cellular resistin expressions and otherwise for adiponectin expressions, which dose-dependently reversed by the addition of atorvastatin. Therefore, our study indicates that the ACS attack activates inflammation leading to adipokine imbalance that can be ameliorated by anti-inflammation of atorvastatin.

Low Impact of Traditional Risk Factors on Carotid Intima-Media Thickness: The ELSA-Brasil Cohort

OBJECTIVE

There is little information about how much traditional cardiovascular risk factors explain common carotid artery intima-media thickness (CCA-IMT) variance. We aimed to study to which extent CCA-IMT values are determined by traditional risk factors and which commonly used measurements of blood pressure, glucose metabolism, lipid profile, and adiposity contribute the most to this determination in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) cohort baseline.

APPROACH AND RESULTS

We analyzed 9792 individuals with complete data and CCA-IMT measurements. We built multiple linear regression models using mean left and right CCA-IMT as the dependent variable. All models were stratified by sex. We also analyzed individuals stratified by 10-year coronary heart disease risk and, in separate, those with no traditional risk factors. Main models' R(2) varied between 0.141 and 0.373. The major part of the explained variance in CCA-IMT was because of age and race. Indicators of blood pressure, lipid profile, and adiposity that most frequently composed the best models were pulse pressure, low-density lipoprotein/high-density lipoprotein ratio, and neck circumference. The association between neck circumference and CCA-IMT persisted significant even after further adjustment for vessel sizes and body mass index. Indicators of glucose metabolism had smaller contribution.

CONCLUSIONS

We found that >60% of CCA-IMT were not explained by demographic and traditional cardiovascular risk factors, which highlights the need to study novel risk factors. Pulse pressure, low-density lipoprotein/high-density lipoprotein ratio, and neck circumference were the most consistent contributors.

Oxidative damage markers are significantly associated with the carotid artery intima-media thickness after controlling for conventional risk factors of atherosclerosis in men

Background

This study aimed to assess the association between oxidative damage markers and carotid artery intima-media thickness (CIMT) after controlling for conventional risk factors of atherosclerosis in multiple logistic regression models.

Methods and Findings

Fifty-one case male participants (CIMT ≥ 0.9 mm) were enrolled during their visits to Korean Genomic Rural Cohort Study of Wonju centers between May 1 and August 31, 2011, along with 51 control participants (CIMT < 0.9 mm) selected using frequency matching by age group. The levels of oxidative damage markers, 8-hydroxy-2′-deoxyquuanosine (8-OHdG), malondialdehyde (MDA), and 8-iso-prostaglandin F2α (Isoprostane), were measured. Conditional logistic regression models were used to evaluate relative relationships between the oxidative damage markers and the risk of high CIMT.

Results

The markers of oxidative lipid (Isoprostane and MDA) and DNA (8-OHdG) damage were associated with CIMT after controlling for the conventional risk factors, including age, low density lipoprotein, body mass index, smoking history, alcohol consumption, and metabolic syndrome (ORs [95% CI] for Isoprostane: 3^rd tertile, 8.47 [2.59-27.67]; for MDA: 3^rd tertile, 8.47 [2.59-27.67]; for 8-OHdG: 3^rd tertile, 5.58 [1.79-17.33]). When all the oxidative damage markers were incorporated in the same logistic regression model, only Isoprostanewas significantly related to CIMT (OR [95% CI]: 4.22 [1.31-13.53] in 2^nd tertile and 14.21 [3.34-60.56] in 3^rd tertile).

Conclusions

In this nested case-control study, the oxidative damage markers of lipid and DNA were associated with CIMT even after controlling for the conventional risk factors of cardiovascular diseases.

Central alarin ameliorated insulin resistance of adipocytes in type 2 diabetic rats

Alarin, a regulatory peptide, belongs to the galanin family and plays the same regulatory roles as galanin in orexigenic activity and energy metabolism. Our previous studies had found that galanin might facilitate insulin sensitivity via activation of its central receptors. To date, little is known about whether central alarin may exert similar effects on insulin sensitivity. In order to investigate this, alarin and its specific antagonist, alarin 6-25Cys, were administered into the cerebral ventricles of type 2 diabetic rats (T2DR) to evaluate the changes in insulin resistance. The results indicated that central treatment with alarin significantly increased the body weight of animals, the 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose uptake, the plasma adiponectin levels, the glucose infusion rates in hyperinsulinemic-euglycemic clamp tests, the vesicle-associated membrane protein 2 as well as glucose transporter 4 (GLUT4 (SLC2A4)) protein and mRNA levels, and the ratios of GLUT4 contents in plasma membranes to total cell membranes in adipocytes, but reduced blood glucose and plasma retinol-binding protein 4 levels. These effects of alarin may be inhibited by pretreatment with alarin 6-25Cys. The above-mentioned results suggest that the central alarin projective system may facilitate insulin sensitivity and glucose uptake via the increase in GLUT4 content and GLUT4 translocation from intracellular pools to plasma membranes in T2DR.

Pioglitazone improves the cardio-ankle vascular index in patients with type 2 diabetes mellitus treated with metformin

BACKGROUND

Type 2 diabetes is known to be associated with elevated cardiovascular mortality. Pioglitazone improves blood pressure (BP) and pulse wave velocity (PWV), which is an arterial stiffness parameter. Arterial stiffness is closely associated with cardiovascular disease. However, PWV is correlated with BP. The cardio-ankle vascular index (CAVI) reflects arterial stiffness independent of BP. Pioglitazone improves PWV but reduces blood pressure. The aim of this study was to re-evaluate the effect of pioglitazone on arterial stiffness with CAVI.

METHODS

Sixty patients with type 2 diabetes mellitus and already on 500 mg/day of metformin received add-on therapy of pioglitazone 15 mg/day or glimepiride 1 mg/day for 6 months, during which time changes in their metabolic parameters and CAVI were observed.

RESULTS

After 6 months of treatment, both pioglitazone (n=30) and glimepiride (n=30) improved fasting blood glucose and glycated hemoglobin. The changes in fasting blood glucose and glycated hemoglobin between the two groups were greater in the pioglitazone group. Systolic and diastolic BP was decreased in both groups, with no significant between-group differences. Only pioglitazone increased serum adiponectin levels, and the change in adiponectin between the pioglitazone and glimepiride groups was significantly different. CAVI was decreased significantly by pioglitazone but remained unchanged after treatment with glimepiride. The change in CAVI between the two groups was significantly different.

CONCLUSION

These results suggest that pioglitazone improves CAVI, a BP-independent arterial stiffness parameter, in patients with type 2 diabetes mellitus treated with metformin.