Circulating complement-1q tumor necrosis factor-α-related protein isoform 5 levels are low in type 2 diabetes patients and reduced by dapagliflozin

CTRP7 Is a Biomarker Related to Insulin Resistance and Oxidative Stress: Cross-Sectional and Intervention Studies In Vivo and In Vitro

Objective

CTRP7 is a cytokine that is known to be associated with obesity. However, its relationship with insulin resistance (IR) and metabolic diseases remains unknown. The aim of this study is to investigate the relationship between CTRP7 and IR under in vivo and in vitro conditions.

Methods

CTRP7 expression in mice and hepatocytes was determined using RT-qPCR and western blotting. Circulating CTRP7 concentrations were measured with an ELISA kit. EHC, OGTT, lipid-infusion, physical activity, and cold-stimulation experiments were performed in humans and mice. SOD, GSH, and MDA were measured by commercial kits. ROS levels were detected using dichlorofluorescein diacetate.

Results

The expression levels of CTRP7 protein in the liver and fat of ob/ob and db/db mice were higher than that of WT mice. Individuals with IGT, T2DM, and obesity had higher circulating CTRP7 levels. CTRP7 levels were associated with HOMA-IR, obesity, and other metabolic parameters. During OGTT, serum CTRP7 levels gradually decreased, while CTRP7 levels significantly increased during EHC in response to hyperinsulinemia in healthy individuals without IR. In addition, lipid infusion-induced IR further increased serum CTRP7 levels in healthy adults. Physical activity increased serum CTRP7 levels in healthy individuals and CTRP7 protein expression in iWAT and skeletal muscle in mice. Under in vitro conditions, the expression of the CTRP7 protein was inhibited in a glucose concentration-dependent manner but was promoted by FFAs and insulin stimulation in hepatocytes. Furthermore, CTRP7 overexpression facilitated oxidative stress and suppressed the phosphorylation of insulin signaling molecules in hepatocytes.

Conclusions

Our evidence shows that CTRP7 could be a useful biomarker and potential treatment target in IR and metabolic disorders.

Circulating C1q/TNF-related protein-12 levels are associated with the severity of coronary artery disease

BACKGROUND

Coronary artery disease (CAD) is the world's largest cause of death. The association of CAD with inflammation is well established. Recently, it has been confirmed that the C1q/TNF-related protein 12 (CTRP12) has a great anti-inflammatory effect. However, few data are available regarding the serum CTRP12 concentration levels in CAD patients.

OBJECTIVE

The study was performed to evaluate the correlation between the serum levels of CTRP12 and the CAD severity regarding to the number of affected vessels.

METHODS

About 200 suspected CAD patients and 50 healthy ones as a control, were evaluated based on case-control study. According to the results of angiography, patients were divided into CAD+ (n = 150) with any major coronary artery stenosis ≥50% and CAD- (n = 50) with <50% stenosis of the arteries. The CAD+patients were categorized into one- (1VD), two- (2VD) and three-vessel disease (3VD) based on the number of stenotic vessels. In the current study, different parameters such as CTRP12, tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), total oxidant status (TOS), total antioxidant capacity (TAC), and malondialdehyde (MDA) levels were evaluated, and also lipid profiles, hs-CRP and demographic factors were investigated as well.

RESULTS

Data revealed that CTRP12 and TAC levels in CAD + group were significantly lower than control subjects (P < 0.05). CTRP12 levels were found to be significantly lower in the 3VD compared with 1VD and 2VD subgroups (p < 0.01 and p < 0.05, respectively).

CONCLUSION

Our results confirmed that serum CTRP12 level is inversely associated with CAD severity. Therefore, it may be used as a prediction marker for CAD.

The circulating levels of CTRP1 and CTRP5 are associated with obesity indices and carotid intima-media thickness (cIMT) value in patients with type 2 diabetes: a preliminary study

BACKGROUND

There is growing evidence that the C1qTNF-related protein (CTRP) family has a crucial role in the pathophysiology of metabolic disorders such as type 2 diabetes (T2D) and obesity. We sought to identify the association of CTRP1 and CTRP5 circulating levels with various obesity parameters such as visceral adipose tissue (VAT) thickness, visceral adiposity index (VAI), and with carotid intima-media thickness (cIMT) in patients with T2D and controls.

METHODS

This preliminary study consisted of men with T2D (n = 42) and men without T2D (n = 42). The measurement of cIMT and VAT thickness was performed using an Accuvix XQ ultrasound. Circulating levels of CTRP1, CTRP5, and adiponectin were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

CTRP-1 and CTRP1/CTRP5 ratio were markedly higher in patients with T2D compared to controls (p < 0001 and p = 0004 respectively). Interestingly, binominal logistic regression revealed that a higher circulating level of CTRP1 was associated with the presence of T2D (odds ratio [OR]: 1.009 [95% CI: 1.004-1.015]; P = .001). CTRP1 circulating levels were correlated with WHR, VAT, and HOMA-IR in the whole population study. Also, we observed that the ratio of CTRP1 to CTRP5 in plasma (β = 0.648, P = 0.005) and CTRP5 circulating levels (β = 0.444, P = 0.049) are independently associated with cIMT value.

CONCLUSIONS

Our results indicated that CTRP1 and CTRP5 concentrations were correlated with atherosclerosis in men with T2D and these adipokines might have a causal role for cardiometabolic risk in T2D.However, more studies in large sample sizes are required to clarify the role of CTRPs in T2D pathogenesis.

Association of metabolic syndrome components with circulating levels of cytokine clusters in young women

BACKGROUND

The purpose of this study was to investigate the relationship between circulating zinc α 2-glycoprotein (ZAG), irisin, betatrophin and adiponectin concentrations and metabolic syndrome (MetS) components and to analyze the effects of blood glucose and insulin on these cytokine concentrations in vivo.

METHODS

A total of 196 young women, including 78 healthy women and 118 women with MetS components, were recruited for this cross-sectional study. An oral glucose tolerance test and euglycemic-hyperinsulinemic clamp (EHC) were performed in healthy subjects and women with MetS components. An ELISA kit was used to measure serum ZAG, irisin, betatrophin, and adiponectin levels, and their relationship with the MetS components was analyzed.

RESULTS

In women with MetS components, circulating irisin and betatrophin levels were significantly higher than those in the healthy women ((207 (150-248) vs 178 (147-228); P < 0.05) for irisin; (0.51 (0.38-0.63) vs 0.38 (0.23-0.52); P < 0.001) for betatrophin), but circulating ZAG and adiponectin levels were significantly lower (39.8 (26.4-50.4) vs (46.7 (40.6-63.0); P < 0.001) for ZAG; (36.5 (22.0-47.6) vs 41.2 (35.7-54.7); P < 0.01) for adiponectin). FBG, WC, and triglyceride were significantly correlated with the circulating levels of these four cytokines (P < 0.001 or <0.05). All four cytokines were associated with MetS and its components. In response to increasing insulin levels, circulating ZAG concentrations were markedly increased in both healthy subjects and women with MetS components during the EHC. However, serum irisin, betatrophin, and adiponectin levels in both healthy subjects and women with MetS components were significantly reduced compared with baseline.

CONCLUSION

Serum ZAG, irisin, betatrophin and adiponectin were associated with MetS and might be biomarkers for screening MetS components.

Correlation of serum C1q-tumour necrosis factor-related protein 5 levels with metabolic parameters and carotid intima-media thickness in newly diagnosed type 2 diabetes mellitus patients

PURPOSE

Recent studies have shown that cytokines secreted from adipose tissues play a role in the pathogenesis of type 2 diabetes mellitus (T2DM). CTRP5 (C1q-TNF-related protein 5) is a novel adipokine that has been shown to be associated with glucose and lipid metabolism. Varying levels of CTRP5 have been reported in individuals with diabetes, obesity and coronary artery disease. The aim of this study was to examine serum levels of CTRP5 and to show the relationship with cardiometabolic parameters in T2DM patients.

METHOD

The study included 40 T2DM patients and 40 age- and sex-matched healthy control subjects. All the study participants were evaluated with respect to BMI, waist circumference, lipid profile, insulin resistance (HOMA-IR), serum CTRP5 levels, carotid intima-media thickness, and hs-CRP.

RESULTS

No statistically significant differences were found between the control group and the diabetic group in terms of age, sex, or BMI. Serum CTRP5 levels (T2DM = 94.55 ± 28.70 ng/ml, control = 76.02 ± 27.22 ng/ml, P = 0.004*) were significantly higher in the group of newly diagnosed diabetic patients. A positive correlation was found between CTRP5 and the cardiometabolic parameters of carotid intima-media thickness (CIMT), hs-CRP, HOMA-IR and BMI. Regression analysis results showed that CTRP5 levels were independently correlated with insulin resistance estimated by HOMA-IR.

CONCLUSION

Serum CTRP5 levels were correlated with cardiometabolic parameters and could therefore be a promising indicator of metabolic status and a possible biomarker of insulin resistance. However, the contradictory results reported in different studies indicate the need for further research to assess the significance of CTRP5 for diagnosis and monitoring of treatment efficacy.

Circulating levels of C1q/TNF-α-related protein 6 (CTRP6) in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders affecting females of reproductive age. It has been associated with cardiometabolic disorders including diabetes mellitus and cardiovascular disorders, and increases the risk of developing fecundity pathologies including recurrent pregnancy loss (RPL) and infertility. C1q/tumor necrosis factor-α-related protein-6 (CTRP6) is a novel adipokine involved in glucose and lipid metabolism, host inflammation, and organogenesis. In the present study, we aimed to determine the association of serum CTRP6 levels with some components of metabolic syndrome in PCOS patients (infertile PCOS [inf-PCOS] and PCOS-RPL). This case-control study included 120 PCOS patients (60 inf-PCOS and 60 PCOS-RPL) and 60 healthy controls. Serum high-sensitivity C-reactive protein (hs-CRP) and homocysteine were measured using commercial kits, while adiponectin and CTRP6 levels were assessed using ELISA technique. Inf-PCOS and PCOS-RPL individuals had higher levels of serum CTRP6 than controls (546.15 ± 125.02 ng/ml and 534.04 ± 144.19 ng/ml vs. 440.16 ± 159.24 ng/ml; both p < .001). Moreover, serum adiponectin levels were significantly reduced, while fasting insulin, homeostasis model assessment of insulin resistance, free testosterone, and hs-CRP levels were significantly elevated in PCOS group, when compared with controls. Furthermore, serum CTRP6 positively associated with body mass index in all subjects. It showed an inverse correlation with adiponectin in PCOS group and subgroups. However, it had a direct association with hs-CRP in PCOS group and inf-PCOS subgroup, but not PCOS-RPL subgroup. These findings unravel a probable role of CTRP6 in PCOS pathogenesis, which poses a possibility to be a good diagnostic target. However, further investigation is needed.