CHEMERIN AND FACTORS RELATED TO CARDIOVASCULAR RISK IN CHILDREN AND ADOLESCENTS: A SYSTEMATIC REVIEW

Impacts of Chemerin Levels and Antioxidant Capacity on the Severity of Cardiovascular Autonomic Neuropathy in Patients with Type 2 Diabetes and Prediabetes

Existing evidence supports an association between chemerin levels and cardiovascular risk, while reduced thiol levels are linked to diabetes mellitus. It is hypothesized that chemerin may contribute to autonomic dysfunction and cardiovascular risk in type 2 diabetes mellitus (T2DM), potentially mediated by the antioxidant capacity of patients with well-controlled T2DM and prediabetes. Comprehensive cardiovascular autonomic testing and biomarker assessments were conducted for all participants. The severity of cardiovascular autonomic neuropathy (CAN) was evaluated using the composite autonomic scoring scale (CASS). A mediation model was employed to explore the potential relationships among chemerin levels, antioxidant capacity (indicated by thiol levels), and CAN severity (indicated by CASS values). A total of 184 participants were enrolled in this study, comprising 143 individuals with T2DM and 40 individuals with prediabetes. The findings reveal a significant negative association between thiols levels (r = -0.38, p < 0.0001) and the CASS values, while a positive association is observed between chemerin levels (r = 0.47, p < 0.0001) and the CASS values. Linear regression analysis identified chemerin and thiols as independent variables significantly associated with CASS values. Subsequent mediation analysis elucidated that thiols levels act as mediators in the relationship between elevated chemerin levels and an increased CASS value. This study shows that poor cardiovascular function, higher chemerin levels, and reduced antioxidant capacity coexist in individuals with T2DM and prediabetes. Mediation analysis suggests a pathophysiological link between high chemerin levels and low antioxidant capacity, adversely impacting CAN severity.

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.

Chemerin in atherosclerosis

Atherosclerosis (AS), a chronic arterial disease, is characterized by endothelial dysfunction, inflammatory reactions and lipid accumulation in parallel with aberrant angiogenesis and vascular smooth muscle cell (VSMC) proliferation. Adipose tissue has been suggested to have an integral influence on metabolism and endocrine secretion, while there have been increasing concerns about the possible involvement of adipokines in cardiovascular diseases, including AS. Here, we focused on chemerin, an adipokine highly expressed in adipose tissue, with strong evidence of an association with inflammation, endothelial dysfunction, metabolic disorder, aberrant angiogenesis, VSMC proliferation and calcification. In this review, we discuss chemerin and its receptors in the pathogenesis of AS. However, the existing data assign various, even contradictory, roles to chemerin in atherosclerosis, such as inhibiting vascular calcification and impairing endothelial function. Current studies focusing on its anti- and pro-atherogenic effects have pinpointed its distinct role in specific cell types and contexts in the pathogenesis of atherosclerosis. Therefore, the gaps in current knowledge regarding the specific role played by chemerin in the etiology of AS require additional future studies. It seems reasonable to suggest that targeted chemerin therapy can be developed as an innovative approach for treating AS.

Higher Lipopolysaccharide Binding Protein and Chemerin Concentrations Were Associated with Metabolic Syndrome Features in Pediatric Subjects with Abdominal Obesity during a Lifestyle Intervention

Background: Elevated circulating plasma levels of both lipopolysaccharide-binding protein (LBP) and chemerin are reported in patients with obesity, but few studies are available on lifestyle intervention programs. We investigated the association of both LBP and chemerin plasma levels with metabolic syndrome (MetS) outcomes in a lifestyle intervention in children and adolescents with abdominal obesity Methods: Twenty-nine patients enrolled in a randomized controlled trial were selected. The lifestyle intervention with a 2-month intensive phase and a subsequent 10-month follow-up consisted of a moderate calorie-restricted diet, recommendations to increase physical activity levels, and nutritional education. Results: Weight loss was accompanied by a significant reduction in MetS prevalence (−43%; p = 0.009). Chemerin (p = 0.029) and LBP (p = 0.033) plasma levels were significantly reduced at 2 months and 12 months, respectively. At the end of intervention, MetS components were associated with both LBP (p = 0.017) and chemerin (p < 0.001) plasma levels. Conclusions: We describe for the first time a reduction in both LBP and chemerin plasma levels and its association with MetS risk factors after a lifestyle intervention program in children and adolescents with abdominal obesity. Therefore, LBP and chemerin plasma levels could be used as biomarkers for the progression of cardiovascular risk in pediatric populations.

Serum Calprotectin and Chemerin Concentrations as Markers of Low-Grade Inflammation in Prepubertal Children with Obesity

In adults, obesity is associated with chronic low-grade inflammation, which may cause long-term adverse health consequences. We evaluated whether obesity in prepubertal children also generates this kind of inflammation and whether calprotectin and chemerin may be useful markers for early detection of such inflammation in this group of children. The study population included 83 children aged 2 to 10 years; 62 with obesity and without components of metabolic syndrome and 21 healthy controls with normal body weight. White blood cell (WBC) count, concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), calprotectin, and chemerin were determined in peripheral blood. Our study showed that in the group with obesity, serum concentrations of calprotectin and chemerin, as well as CRP were significantly higher as compared with the controls. We found a significant positive correlation between serum chemerin concentrations and BMI z-score (r = 0.33, p < 0.01) in children with obesity. Chemerin concentration was also positively correlated with CRP level (r = 0.36, p < 0.01) in the whole group of children. These findings suggest that obesity may generate chronic low-grade inflammation as early as in the prepubertal period which can be indicated by significantly higher serum concentrations of calprotectin and chemerin. Calprotectin and especially chemerin seem to be promising indicators of this type of inflammation in children with obesity, but the correlation between these markers requires further research.

Serum Chemerin Levels Correlate With Determinants of Metabolic Syndrome in Obese Children and Adolescents

Objectives

This study aimed to investigate serum chemerin concentrations in obese children and adolescents and to investigate the associations of chemerin with body mass index (BMI), lipid levels, and insulin sensitivity.

Methods

Forty-eight obese and 40 nonobese Chinese children and adolescents were included in the study. BMI and levels of chemerin, lipids, glucose, and insulin were measured following an overnight fast. The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and BMI standard deviation score (BMI-SDS) were determined for all participants.

Results

Serum chemerin levels were found to be significantly higher in obese children and adolescents than in control group members (94.83 ± 5.99 ng/mL vs 56.43 ± 4.16 ng/mL, P < .001). There were significant correlations between chemerin and age, BMI, BMI-SDS, total triglyceride (TG) levels, insulin levels, and HOMA-IR. After controlling for age, we found that chemerin levels were also significantly correlated with BMI-SDS (r =+ 0.284, P = .008) and HOMA-IR (r =+ 0.241, P = .034). In a stepwise multiple regression analysis, we observed only BMI-SDS to be an important determinant of chemerin level.

Conclusions

In our sample of Chinese children and adolescents, chemerin levels were significantly higher in the obese group than in the control group. Chemerin levels were positively correlated with BMI-SDS and HOMA-IR and negatively correlated with age. We thus believe that further study is necessary to investigate the risk of metabolic abnormalities in young obese children and adolescents.