Serum CTRP3 Levels In Obese Children: A Potential Protective Adipokine Of Obesity, Insulin Sensitivity And Pancreatic β Cell Function

Low serum CTRP3 is related to more severe distal symmetric polyneuropathy in type 2 diabetes patients

BACKGROUND

Distal symmetric polyneuropathy (DSPN) is one of the most common chronic complications in patients with type 2 diabetes mellitus (T2DM). Our previous study found that serum C1q tumor necrosis factor-related protein 3 (CTRP3) levels were decreased in type 2 diabetic patients. Thus, this study was designed to reveal the relationship between low serum CTRP3 and the prevalence and severity of DSPN.

METHODS

A total of 178 cases of patients with T2DM were enrolled in the study. The subjects were divided into the DSPN group (n = 89) and the non-DSPN group (n = 89). Both anthropometric parameters and neurologic symptoms were recorded. Furthermore, neurologic signs, the neuropathy symptom score (NSS), and the neuropathy disability score (NDS) were assessed. Biochemical indexes, fasting insulin, and C peptide were measured. Serum CTRP3 concentrations were assayed using the ELISA method.

RESULTS

Serum CTRP3 levels decreased significantly in the DSPN group compared with the non-DSPN group (P < 0.05). CTRP3 was negatively associated with the number of positive signs, NSS score, and NDS score in patients with DSPN (all P < 0.05). Interestingly, the higher the NSS score or NDS score, the lower were the levels of serum CTRP3 (all P < 0.05). Moreover, patients with lower CTRP3 levels (< 7.58ng/ml) had a higher rate of neurologic signs (all P < 0.05). Binary logistic regression analysis showed that CTRP3 independently predicted the occurrence of DSPN (β = -0.316, P < 0.001). ROC curve analysis revealed that the best cut-off value of CTRP3 for the prediction of DSPN was 7.55ng/ml (sensitivity 78.7%, specificity 79.8%), the area under the curve (AUC) was 0.763 (95% CI 0.689-0.838, P < 0.001).

CONCLUSION

Low serum CTRP3 could be a predictor for the occurrence and progression of DSPN in Chinese patients with T2DM.

Mechanisms by which obesity regulates inflammation and anti-tumor immunity in cancer

Obesity is associated with an increased risk for 13 different cancers. The increased risk for cancer in obesity is mediated by obesity-associated changes in the immune system. Obesity has distinct effects on different types of inflammation that are tied to tumorigenesis. For example, obesity promotes chronic inflammation in adipose tissue that is tumor-promoting in peripheral tissues. Conversely, obesity inhibits acute inflammation that rejects tumors. Obesity therefore promotes cancer by differentially regulating chronic versus acute inflammation. Given that obesity is chronic, the initial inflammation in adipose tissue will lead to systemic inflammation that could induce compensatory anti-inflammatory reactions in peripheral tissues to suppress chronic inflammation. The overall effect of obesity in peripheral tissues is therefore dependent on the duration and severity of obesity. Adipose tissue is a complex tissue that is composed of many cell types in addition to adipocytes. Further, adipose tissue cellularity is different at different anatomical sites throughout the body. Consequently, the sensitivity of adipose tissue to obesity is dependent on the anatomical location of the adipose depot. For example, obesity induces more inflammation in visceral than subcutaneous adipose tissue. Based on these studies, the mechanisms by which obesity promotes tumorigenesis are multifactorial and immune cell type-specific. The objective of our paper is to discuss the cellular mechanisms by which obesity promotes tumorigenesis by regulating distinct types of inflammation in adipose tissue and the tumor microenvironment.

Serum adiponectin in Indian women with polycystic ovary syndrome

Poly Cystic Ovary Syndrome (PCOS) is mainly characterised by reproductive hormonal imbalance and increased androgen levels, ovulatory dysfunction and polycystic appearing ovaries on ultrasonography. The obesity is common factor to cause PCOS and this adipocytokines play an important role to cause obesity related disorders. Hence, the present study aimed to evaluate the role of adiponectin in women with PCOS compared them with healthy controls. This case control study included total eighty (80) subjects out of this fourty subjects with PCOS and remaining fourty (40) age and body mass index matched healthy controls. The fasting, post parandial blood sugars, glycated haemoglobin, lipid profile and adiponectin levels were measured and data was recorded. There was a significantly elevated levels of total cholesterol, triacylglycerol, very low density lipoprotein, low density lipoprotein (p = 0.0001**) and there were no significant levels of fasting and post parandial blood sugars, glycated haemoglobin levels were observed in women with PCOS than in controls. Additionally, we also observed significantly decreased levels of high density lipoprotein and adiponectin in women with PCOS when compared to healthy controls (p = 0.0001**). The adiponectin shown a positive correlation with age, high density lipoprotein and negative correlation with total cholesterol, triacylglycerol, very low density lipoprotein and low density lipoprotein (p = 0.0001**). The altered adiponectin levels in polycystic ovary syndrome appear to form an important link between obesity and the complications of PCOS.

Clinical Diagnostic Values of C1q/TNF-Related Protein-3 for Polycystic Ovary Syndrome Women with Insulin Resistance

Polycystic ovary syndrome (PCOS) is the most common disease caused by complex endocrine and metabolic abnormalities in women. Insulin resistance is considered an important pathophysiological factor in the pathogenesis of PCOS. Here we investigated the clinical values of C1q/TNF-related protein-3 (CTRP3) as predictive factor for insulin resistance. Our study included 200 patients with PCOS, among which 108 had insulin resistance. Serum CTRP3 levels were measured using enzyme-linked immunosorbent assay. Predictive values of CTRP3 for insulin resistance was analyzed using receiver operating characteristic (ROC) analysis. Correlations of CTRP3 to insulin levels, obesity measurements and blood lipid levels were determined using Spearman's correlation analysis. Our data suggested that PCOS patients with insulin resistance had a higher obesity, lower high-density lipoprotein cholesterol, higher total cholesterol, higher insulin levels and lower CTRP3 levels. CTRP3 had a high sensitivity (72.22%) and specificity (72.83%). CTRP3 significantly correlated to insulin levels, body mass index, waist-to-hip ratio, high-density lipoprotein, and total cholesterol levels. The predictive value of CTRP3 in PCOS patients with insulin resistance was supported by our data. Our findings suggest that CTRP3 is involved in the pathogenesis and insulin resistance of PCOS, which indicates its value as an indicator for the PCOS diagnosis.

Low Complement C1q/TNF-related Protein-13 Levels are Associated with Childhood Obesity But not Binge Eating Disorder

Objective

C1q/tumor necrosis factor-related proteins (CTRPs) are recently described members of the adipokine family. CTRP-13, a new member of this family, has been shown to increase insulin sensitivity and had an anorexigenic effect on food intake in experimental studies. The aim was to investigate serum CTRP-13 levels in children with obesity, and its relationship with other adipokines, metabolic parameters, or binge eating disorder (BED).

Methods

A cross-sectional study was conducted with 105 pubertal children attending a single center. Clinical (metabolic syndrome, BED) and biochemical (glucose, insulin, lipids, leptin, adiponectin, CTRP-13 levels) parameters were assessed.

Results

Sixty children with obesity [24 males (40%); median age 14.7 (13.0-16.4) years] and 45 healthy controls [15 males (33.3%); median age 15.2 (14.1-16.5) years] were included. Serum adiponectin and CTRP-13 levels were significantly lower in children with obesity than controls (7.1 vs 20.1 μg/mL, p<0.001; 64.7 vs 103.8 ng/mL, p<0.001, respectively). CTRP-13 levels correlated negatively with body mass index (Spearman rho=-0.230, p=0.018) and positively with high-density lipoprotein-cholesterol levels (Spearman rho=0.218, p=0.026). There was no significant difference in serum CTRP-13 concentrations in terms of the presence of metabolic syndrome or BED.

Conclusion

Childhood obesity seems to be causing dysregulation in adipokine production and function, including the down-regulation of CTRP-13. The positive correlation between CTRP-13 and HDL-C levels suggested a possible effect of this adipokine on lipid metabolism. Thus CTRP-13 may be a novel biomarker for dyslipidemia in childhood obesity.

Anti-Inflammatory Effects of C1q/Tumor Necrosis Factor-Related Protein 3 (CTRP3) in Endothelial Cells

The C1q/TNF-related protein 3 (CTRP3) represents a pleiotropic adipokine reciprocally associated with obesity and type 2 diabetes mellitus and exhibits anti-inflammatory properties in relation to lipopolysaccharides (LPS)-mediated effects in adipocytes, as well as monocytes/macrophages. Here, we focused on the influence of CTRP3 on LPS-mediated effects in endothelial cells in order to expand the understanding of a possible anti-inflammatory function of CTRP3 in a setting of endotoxemia. An organ- and tissue-specific expression analysis by real-time PCR revealed a considerable Ctrp3 expression in various adipose tissue compartments; however, higher levels were detected in the aorta and in abundantly perfused tissues (bone marrow and the thyroid gland). We observed a robust Ctrp3 expression in primary endothelial cells and a transient upregulation in murine endothelial (MyEND) cells by LPS (50 ng/mL). In MyEND cells, CTRP3 inhibited the LPS-induced expression of interleukin (Il)-6 and the tumor necrosis factor (Tnf)-α, and suppressed the LPS-dependent expression of the major endothelial adhesion molecules Vcam-1 and Icam-1. The LPS-induced adhesion of monocytic cells to an endothelial monolayer was antagonized by CTRP3. In C57BL/6J mice with an LPS-induced systemic inflammation, exogenous CTRP3 did not affect circulating levels of TNF-α, ICAM-1, and VCAM-1. In conclusion, we characterized CTRP3 beyond its function as an adipokine in a setting of vascular inflammation. CTRP3 inhibited LPS-induced endothelial expression of adhesion molecules and monocyte cell adhesion, indicating an important vascular anti-inflammatory role for CTRP3 in endotoxemia.

Downregulation of CTRP-3 by Weight Loss In Vivo and by Bile Acids and Incretins in Adipocytes In Vitro

The adipokine CTRP-3 (C1q/TNF-related protein-3) exerts anti-inflammatory and anti-diabetic effects. Its regulation in obesity and during weight loss is unknown. Serum and adipose tissue (AT) samples were obtained from patients (n = 179) undergoing bariatric surgery (BS). Moreover, patients (n = 131) participating in a low-calorie diet (LCD) program were studied. CTRP 3 levels were quantified by ELISA and mRNA expression was analyzed in AT and in 3T3-L1 adipocytes treated with bile acids and incretins. There was a persistent downregulation of CTRP-3 serum levels during weight loss. CTRP-3 expression was higher in subcutaneous than in visceral AT and serum levels of CTRP-3 were positively related to AT expression levels. A rapid decrease of circulating CTRP-3 was observed immediately upon BS, suggesting weight loss-independent regulatory mechanisms. Adipocytes CTRP-3 expression was inhibited by primary bile acid species and GLP 1. Adipocyte-specific CTRP-3 deficiency increased bile acid receptor expression. Circulating CTRP-3 levels are downregulated during weight loss, with a considerable decline occurring immediately upon BS. Mechanisms dependent and independent of weight loss cause the post-surgical decline of CTRP-3. The data strongly argue for regulatory interrelations of CTRP-3 with bile acids and incretin system.

Circulating Adipokine Levels in Nonobese Women With Polycystic Ovary Syndrome and in Nonobese Control Women: A Systematic Review and Meta-Analysis

Levels of circulating adipokines in nonobese polycystic ovary syndrome (PCOS) patients have been reported in many studies. However, the results are inconsistent. The aim of this meta-analysis is to assess whether the levels of circulating adipokines are changed in nonobese PCOS relative to nonobese healthy controls. To identify eligible studies, a literature research was performed in the PubMed, Embase, and Web of Science databases without restricting by region, journal, or language. A total of 81 studies met the eligibility criteria. The meta-analysis showed that the circulating level of adiponectin (standardized mean difference [SMD]: -0.95; 95% CI: -1.36 to -0.53) was significantly decreased in nonobese PCOS patients. In contrast, the circulating levels of chemerin (SMD: 1.13; 95% CI: 0.08 to 2.18), leptin (SMD: 0.47; 95% CI: 0.13 to 0.81), resistin (SMD: 0.45; 95% CI: 0.03 to 0.88), and visfatin (SMD: 1.38; 95% CI: 0.68 to 2.09) were significantly increased in nonobese PCOS patients. There were no significant changes in the circulating levels of apelin (SMD: 0.32; 95% CI: -1.34 to 1.99), irisin (SMD: 1.01; 95% CI: -0.68 to 2.70), omentin (SMD: -0.37; 95% CI: -1.05 to 0.31), or vaspin (SMD: 0.09; 95% CI: -0.14 to 0.32). Thus, scientific evidence suggests that the circulating adipokine levels are altered in nonobese PCOS patients compared to nonobese healthy controls. Therefore, independent of the degree of obesity, dysregulated circulating adipokine levels might play important roles in the occurrence and development of PCOS.