Adipokines and Lipoproteins: Modulation by Antihyperglycemic and Hypolipidemic Agents

Role of Chemerin and Perivascular Adipose Tissue Characteristics on Cardiovascular Risk Assessment by Arterial Stiffness Markers in Patients with Morbid Obesity

BACKGROUND AND OBJECTIVE

The development of arterial stiffness (AS) in obesity is a multifactorial and complex process. The pleomorphic actions of adipokines and their local activity in perivascular adipose tissue (PVAT) are potential modulators of AS appearance and progression. We aimed to assess the correlations between two adipokines (chemerin, adiponectin), PVAT morphological changes (adipocyte size, blood vessel wall thickness) and AS parameters in the special subgroup of patients with morbid obesity.

MATERIAL AND METHODS

We enrolled 25 patients with morbid obesity and 25 non-obese patients, who were age- and gender-matched, untreated for cardiovascular risk factors, and admitted to hospital for laparoscopic surgical procedures (bariatric surgery for morbid obesity and non-inflammatory benign pathology surgery for non-obese patients). Before the surgical procedures, we evaluated demographic and anthropometric data and biochemical parameters including the studied adipokines. Arterial stiffness was evaluated using a Medexpert ArteriographTM TL2 device. In both groups, adipocyte size and vascular wall thickness as well as local adiponectin activity were analyzed in PVAT from intraoperative biopsies.

RESULTS

In our study, adiponectin (p = 0.0003), chemerin (p = 0.0001) and their ratio (p = 0.005) had statistically significant higher mean values in patients with morbid obesity compared to normal-weight patients. In patients with morbid obesity there were significant correlations between chemerin and AS parameters such as aortic pulse wave velocity (p = 0.006) and subendocardial viability index (p = 0.009). In the same group adipocyte size was significantly correlated with another AS parameter, namely, aortic systolic blood pressure (p = 0.030). In normal-weight patients, blood vessel wall thickness positively correlated with AS parameters such as brachial (p = 0.023) and aortic augmentation index (p = 0.023). An important finding was the negative adipoR1 and adipoR2 immunoexpression in PVAT adipocytes of patients with morbid obesity. Additionally, we found significant correlations between blood vessel wall thickness and blood fasting glucose (p < 0.05) in both groups.

CONCLUSIONS

Chemerin and adipocyte size could be predictive biomarkers for AS in patients with morbid obesity. Given the small number of patients included, our results need further validation.

Remnant cholesterol can identify individuals at higher risk of metabolic syndrome in the general population

Remnant cholesterol (RC) is a highly atherogenic lipid. Previous studies have shown that RC was closely associated with many metabolism-related diseases. However, the relationship of RC with metabolic syndrome (MetS) remains unclear. This study's objective is to investigate the relationship of RC with MetS. A total of 60,799 adults who received health assessments were included in this study. RC was calculated by subtracting the directly measured values for low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) from total cholesterol (TC) and divided into 5 groups according to its quintile. MetS diagnosis according to National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) definitions. Application of receiver operating characteristic (ROC) curve analysis and multivariate logistic regression to assess the association of RC with MetS. In RC quintile groups, the prevalence of MetS was 0.84, 1.10, 1.92, 3.87 and 37.71%, respectively. Multivariate logical regression analysis showed that RC and MetS maintained a stable independent positive correlation between both sexes. An interaction test further showed that the MetS risk associated with RC was significantly higher in women than in men. Moreover, ROC analysis results showed that RC had high accuracy in identifying MetS, especially among young and middle-aged men [(area under the curve: AUC) < 30 years: 0.9572, 30-39 years: 0.9306, 40-49 years: 0.9067]. The current study provided the first evidence of a positive association between RC and MetS, and that this correlation was stronger in women than in man, which may be due to the relative deficiency of estrogen in women.

Role of Chemerin in Cardiovascular Diseases

(1) Background: Obesity is closely connected to the pathophysiology of cardiovascular diseases (CVDs). Excess fat accumulation is associated with metabolic malfunctions that disrupt cardiovascular homeostasis by activating inflammatory processes that recruit immune cells to the site of injury and reduce nitric oxide levels, resulting in increased blood pressure, endothelial cell migration, proliferation, and apoptosis. Adipose tissue produces adipokines, such as chemerin, that may alter immune responses, lipid metabolism, vascular homeostasis, and angiogenesis. (2) Methods: We performed PubMed and MEDLINE searches for articles with English abstracts published between 1997 (when the first report on chemerin identification was published) and 2022. The search retrieved original peer-reviewed articles analyzed in the context of the role of chemerin in CVDs, explicitly focusing on the most recent findings published in the past five years. (3) Results: This review summarizes up-to-date findings related to mechanisms of chemerin action, its role in the development and progression of CVDs, and novel strategies for developing chemerin-targeting therapeutic agents for treating CVDs. (4) Conclusions: Extensive evidence points to chemerin's role in vascular inflammation, angiogenesis, and blood pressure modulation, which opens up exciting perspectives for developing chemerin-targeting therapeutic agents for the treatment of CVDs.

Are Vitamin E Supplementation Beneficial for Female Gynaecology Health and Diseases?

Vitamin E is known as an essential vitamin, and many studies had demonstrated the importance of vitamin E throughout the reproductive process, such as miscarriage, premature birth, preeclampsia, and intrauterine growth restriction, which could be caused by a lack of vitamin E during pregnancy. Its potent antioxidant properties can counteract the oxidative stress induced by oxygen free radicals and imbalance of oxidative-antioxidant levels, hence it may play a role in maintaining the normal function of the female reproductive system. Despite the fact that vitamin E is acknowledged as the substance needed for reproduction, its beneficial effects on female fertility, gynaecological health, and diseases are still poorly understood and lacking. Therefore, the goal of this paper is to provide a summary of the known roles of vitamin E supplementation in women for gynaecological health and reproductive-related diseases, as well as its future perspective.

Novel molecular markers of cardiovascular disease risk in type 2 diabetes mellitus

Diabetes represents the leading risk factor for the development of cardiovascular disease (CVD). Chronic hyperglycemia and/or acute post-prandial changes in blood glucose determine an increase in reactive oxygen species (ROS), which play a fundamental role in endothelial dysfunction and in the nuclear transport of pro-atherogenic transcription factors that activate the "inflammasome". In addition, the glycemic alteration favors the formation and stabilization of atherosclerotic plaque through the mechanism of non-enzymatic glycation of different molecules, with the establishment of the so-called "advanced glycosylation end products" (AGE). Laboratory information provided by the level of biomarkers could make a quantitative and qualitative contribution to the clinical process of screening, prediction, prevention, diagnosis, prognosis and monitoring of cardiovascular (CV) risk linked to diabetes. This review describes the importance of specific biomarkers, with particular focus on novel ones, for stratifying and management of diabetes CV risk.

Metabolic effects of antidiabetic drugs on adipocytes and adipokine expression

Several classes of antidiabetic agents have been developed that achieve their hypoglycemic outcomes via various molecular mechanisms. Adipose tissue is a major metabolic and energy-storing tissue and plays an important role in many metabolic pathways, including insulin signaling and insulin sensitivity. Adipose tissue monitors and regulates whole body homeostasis via production and release of potent proteins, such as adipokine and adiponectin, into the circulation. Therefore, any agent that can modulate adipocyte metabolism can, in turn, affect metabolic and glucose homeostatic pathways. Antidiabetic drugs are not only recognized primarily as hypoglycemic agents but may also alter adipose tissue itself, as well as adipocyte-derived adipokine expression and secretion. In the current review, we present the major evidence concerning routinely used antidiabetic agents on adipocyte metabolism and adipokine expression.

Associations of lipid parameters with insulin resistance and diabetes: A population-based study

OBJECTIVE

A dramatic gap exists between the clinical practice and guidelines for the dyslipidemia control in patients with diabetes. It is still uncertain which routinely available lipid measure is more applicable in estimation of insulin sensitivity and blood glucose control. The present study aims to investigate associations of routine lipid profiles with insulin resistance and diabetes, respectively.

METHODS

We conducted a population-based study in 9764 Chinese participants. The homeostasis model assessment of insulin resistance was calculated to estimate insulin sensitivity. Diabetes was diagnosed according to the 1999 World Health Organization diagnostic criteria.

RESULTS

Participants with insulin resistance or diabetes presented with significantly higher triglycerides (TG), Non-high-density lipoprotein cholesterol (Non-HDL-C), Non-HDL-C/HDL-C, TG/HDL-C and lower HDL-C when compared with control subjects (all P < 0.0001). Such lipid measures were significantly correlated with fasting insulin, fasting plasma glucose (FPG), oral glucose tolerance test (OGTT) 2 h glucose and Hemoglobin A1c (HbA1c) in Pearson's correlation analysis and multivariate linear regression analysis (all P < 0.0001). In logistic regression analysis, subjects were more likely to have prevalent insulin resistance and diabetes with the elevated quartiles of TG, Non-HDL-C, Non-HDL-C/HDL-C and TG/HDL-C (all P < 0.05). TG/HDL-C ratio, compare with other lipid parameters, have shown the strongest correlation with increased odds of insulin resistance and diabetes.

CONCLUSION

Our study suggests a discordant association of lipid parameters with blood glucose level and TG/HDL-C is a better marker for evaluating insulin resistance and diabetes in Chinese population when compared with other routine lipid measures.

Correlation of Leptin, Adiponectin, and Resistin Levels in Different Types of Lipodystrophy in HIV/AIDS Patients

BACKGROUND

Leptin, adiponectin, and resistin may play an important role in the development of lipodystrophy (LD) in HIV/AIDS patients. The aim of this study was to correlate levels of leptin, adiponectin, and resistin between HIV/AIDS patients with LD and without lipodystrophy (non-LD), as well as between subgroups of LD [lipoatrophy (LA), lipohypertrophy (LH), and mixed fat redistribution (MFR)] and non-LD patients.

METHODS

Cross-sectional study of 66 HIV/AIDS patients. Serum levels of leptin, adiponectin, and resistin were measured. The associations between adipocytokine levels and metabolic variables were estimated by Spearman correlation. Analysis of covariance with bootstrapping method was used to examine the relationship between adiponectin and leptin and lipodystrophy categories.

RESULTS

The LD was observed in 29 (44%) patients, while 15 (52%) of them had LA, 4 (14%) had LH, and 10 (34%) patients had MFR. No significant differences regarding leptin, adiponectin, and resistin levels, between LD and non-LD patients, were observed. LH patients had significantly higher levels of leptin and adiponectin in comparison with non-LD patients (P = 0.039, P = 0.011, respectively). Within the LD group, LA patients had significantly lower levels of leptin (LA vs. LH, P = 0.020; LA vs. MFR, P = 0.027), while LH patients had significantly higher levels of adiponectin (LH vs. LA, P = 0.027; LH vs. MFR, P = 0.028). Correlation of adiponectin with LD remains significant in the LH subgroup after adjustment for age, body mass index, cystatin-C, plasminogen activator inhibitor-1 (PAI-1), and interferon gamma (IFN-γ) (P = 0.001).

CONCLUSIONS

Adiponectin and leptin levels differ significantly between LH patients and non-LD patients, as well as between the LD subgroups. Adiponectin may be a more useful marker of LD in HIV/AIDS patients.

Annexin A6 regulates adipocyte lipid storage and adiponectin release

Lipid storage and adipokine secretion are critical features of adipocytes. Annexin A6 (AnxA6) is a lipid-binding protein regulating secretory pathways and its role in adiponectin release was examined. The siRNA-mediated AnxA6 knock-down in 3T3-L1 preadipocytes impaired proliferation, and differentiation of AnxA6-depleted cells to mature adipocytes was associated with higher soluble adiponectin and increased triglyceride storage. The latter was partly attributed to reduced lipolysis. Accordingly, AnxA6 overexpression in 3T3-L1 adipocytes lowered cellular triglycerides and adiponectin secretion. Indeed, serum adiponectin was increased in AnxA6 deficient mice. Expression analysis identified AnxA6 protein to be more abundant in intra-abdominal compared to subcutaneous adipose tissues of mice and men. AnxA6 protein levels increased in white adipose tissues of obese mice and here, levels were highest in subcutaneous fat. AnxA6 protein in adipocytes was upregulated by oxidative stress which might trigger AnxA6 induction in adipose tissues and contribute to impaired fat storage and adiponectin release.

Age at Immigration and Kidney Function among Self-Identified Healthy Africans in the United States

Kidney disease disparately affects those of African descent. Age trends have generally been established for kidney function in the overall US population, but the contribution of age at the time of immigration for African immigrants is unknown. To examine the independent and joint effects of age and age at the time of immigration, and kidney function. Estimated glomerular filtration rate (eGFR) was calculated for 93 African immigrants (60 % male; mean age = 33.5). Hierarchical regression and post hoc analyses revealed a significant age × age at the time of immigration interaction after accounting for traditional risk factors among those who immigrated at age ≤21. Younger age at the time of immigration to the US may exacerbate an inverse relationship between age and kidney function in a self-identified healthy African immigrant sample. Investigation of biopsychosocial factors associated with kidney health among African immigrants is warranted.