Low serum CTRP3 levels are associated with nonalcoholic fatty liver disease in patients with type 2 diabetes mellitus

Decreased Serum CTRP3 level was associated with connective tissue diseases

Objective

Complement C1q tumor necrosis factor-related protein 3 (CTRP3) and 9 (CTRP9) are two of the most extensively studied adipokines, known for their diverse biological functions. However, it remains unclear whether serum levels of CTRP3 or CTRP9 are associated with connective tissue diseases (CTD).

Methods

Serum CTRP3 and CTRP9 levels were measured by enzyme-linked immune sorbent assay (ELISA) and analyzed in patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), primary Sjogren's syndrome (pSS), ankylosing spondylitis (AS), undifferentiated connective tissue disease (UCTD), as well as in healthy controls (HCs).

Results

Serum CTRP3 levels were all significantly lower in patients with RA, SLE, pSS and AS compared with HCs. However, there were no significant differences in serum CTRP9 levels between patients with RA, SLE, pSS, or AS and HCs. In pSS patients, CTRP3 showed a weak correlation with blood glucose, creatinine, and urine acid in pSS patients, while no correlations were observed between serum CTRP3 levels and clinical or laboratory indices in RA, SLE or AS patients. Stable associations between CTRP3 and RA, SLE, pSS and AS were evaluated using multivariate logistics regression analysis. Receiver operating characteristic (ROC) curves were plotted to evaluated CTRP3 as a marker for RA, SLE, pSS and AS, yielding area under curve (AUC) values of 0.691, 0.727, 0.658 and 0.694, respectively.

Conclusion

Decreased serum CTRP3 levels were associated with RA, SLE, pSS and AS.

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.

Global prevalence of non-alcoholic fatty liver disease in type 2 diabetes mellitus: an updated systematic review and meta-analysis

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease, with type 2 diabetes mellitus (T2DM) as a major predictor. Insulin resistance and chronic inflammation are key pathways in the pathogenesis of T2DM leading to NAFLD and vice versa, with the synergistic effect of NAFLD and T2DM increasing morbidity and mortality risks. This meta-analysis aims to quantify the prevalence of NAFLD and the prevalence of clinically significant and advanced fibrosis in people with T2DM.

METHODS

MEDLINE and Embase databases were searched from inception until 13 February 2023. The primary outcomes were the prevalence of NAFLD, non-alcoholic steatohepatitis (NASH) and fibrosis in people with T2DM. A generalised linear mixed model with Clopper-Pearson intervals was used for the analysis of proportions with sensitivity analysis conducted to explore heterogeneity between studies.

RESULTS

156 studies met the inclusion criteria, and a pooled analysis of 1 832 125 patients determined that the prevalence rates of NAFLD and NASH in T2DM were 65.04% (95% CI 61.79% to 68.15%, I2=99.90%) and 31.55% (95% CI 17.12% to 50.70%, I2=97.70%), respectively. 35.54% (95% CI 19.56% to 55.56%, I2=100.00%) of individuals with T2DM with NAFLD had clinically significant fibrosis (F2-F4), while 14.95% (95% CI 11.03% to 19.95%, I2=99.00%) had advanced fibrosis (F3-F4).

CONCLUSION

This study determined a high prevalence of NAFLD, NASH and fibrosis in people with T2DM. Increased efforts are required to prevent T2DM to combat the rising burden of NAFLD.

PROSPERO REGISTRATION NUMBER

CRD42022360251.

Circulating Levels of C1q/TNF-Related Protein 3 (CTRP3) and CTRP9 in Gestational Diabetes and Their Association with Insulin Resistance and Inflammatory Cytokines

Objective

Gestational diabetes mellitus (GDM) is closely related to obesity, adipose tissue, and adipokines. Adiponectin-homologous adipokines with anti-inflammatory properties, including C1q/TNF-related protein 3 (CTRP3) and CTRP9, regulate glucose and lipid metabolism, which was measured in pregnant women with GDM with the aim to assess their circulating levels and their relation with inflammatory cytokines and other biochemical data.

Methods

Serum levels of CTRP3, CTRP9, adiponectin, tumor necrosis factor (TNF)-α, and interleukin (IL)-6 were measured in 43 subjects with GDM and 42 healthy controls by enzyme-linked immunosorbent assay.

Results

Serum levels of adiponectin and CTRP3 were lower in GDM subjects than in controls, whereas CTRP9, TNF-α, and IL-6 showed higher concentrations in subjects with GDM than in controls. In the subjects with GDM, there was a significant association of CTRP3 with homeostasis model assessment of insulin resistance (HOMA-IR), body mass index, and triglycerides, whereas CTRP9 is associated with TNF-α and HOMA-IR.

Conclusion

The differences in the assessed levels of CTRP3 and CTRP9 suggest a possible relation with the pathogenesis of GDM, in particular insulin resistance, which showed significant association with both adipokines.

CTRP3 ameliorates fructose-induced metabolic associated fatty liver disease via inhibition of xanthine oxidase-associated oxidative stress

OBJECTIVES

The incidence of metabolic associated fatty liver disease (MAFLD) induced by high fructose consumption is dramatically increasing in the world while lacking specifically therapeutic drugs. The present study aimed to investigate the effect of complement C1q/tumor necrosis factor-related protein-3 (CTRP3) on fructose-induced MAFLD and its potential mechanisms.

METHOD

The animal models with MAFLD were built with Sprague-Dawley (SD) rats drinking 10 % fructose solution for 12 weeks. Then, specific hepatic CTRP3 overexpression was conducted by a single caudal-vein injection of CTRP3-expressing adenoviruses. Rats were sacrificed two weeks later.

RESULTS

Drinking 10 % fructose solution for 12 weeks successfully built the rats models with MAFLD. Fructose feeding markedly decreased hepatic CTRP3 expression in rats. However, CTRP3 overexpression in liver alleviated hyperuricemia, dyslipidemia, liver function injury, intrahepatic triglyceride (TG) accumulation and histological changes of hepatic steatosis in rats fed with fructose. CTRP3 overexpression also inhibited hepatic XO activity in liver and improved subsequent oxidative stress, accompanied with downregulation of gene expression of sterol-regulatory element binding protein 1c (SERBP-1c) and fatty acid synthase (FAS).

CONCLUSION

CTRP3 attenuates MAFLD induced by fructose, which maybe partially attribute to rescued oxidative stress related with xanthine oxidase overactivity.

The Effects of Two Different Intensities of Combined Training on C1q/TNF-Related Protein 3 (CTRP3) and Insulin Resistance in Women with Non-alcoholic Fatty Liver Disease

Background: C1q/TNF-related protein (CTRP3) is a potent anti-inflammatory adipokine with activities, such as reduction of glucose level and inhibition of gluconeogenesis in the liver. However, the effect of exercise training on CTRP3 in patients with non-alcoholic fatty liver disease (NAFLD) remains unknown. Objectives: This study was done to investigate the effects of two different intensities of combined training on CTRP3 and insulin resistance in women with NAFLD and compare these two training patterns. Methods: Thirty-three women with NAFLD were randomly divided into three equal groups. Group 1 performed resistance training (RT), along with aerobic interval training (AIT) (2 - 5 intervals of four minutes, 70 - 75% HRmax), group 2 performed RT along with high-intensity interval training (HIIT) (8 - 13 intervals of one minute, 85 - 95% HRmax), and the control group did not participate in any training. The body composition measurements and blood sampling were carried out before and after 12 weeks of training. Data analysis was performed using repeated-measures ANOVA (α ≤ 0.05). Results: After 12 weeks, the CTRP3 level significantly increased in group 1 compared with the control group (P = 0.01) and group 2 (P < 0.001). The fasting glucose and fasting insulin levels significantly decreased in group 1 compared with the control group (P < 0.001 and P = 0.01, respectively). The insulin resistance index decreased in both group 1 and group 2; however, the difference was not significant compared with the control group (P > 0.05). Conclusions: Combined training (RT + AIT) in the present study increased the level of CTRP3; thus, it is likely that women with NAFLD can benefit from this program as a non-pharmacological adjunct treatment to prevent inflammation and progression of the disease.

New Insights Into Implications of CTRP3 in Obesity, Metabolic Dysfunction, and Cardiovascular Diseases: Potential of Therapeutic Interventions

Adipose tissue, as the largest endocrine organ, secretes many biologically active molecules circulating in the bloodstream, collectively termed adipocytokines, which not only regulate the metabolism but also play a role in pathophysiological processes. C1q tumor necrosis factor (TNF)-related protein 3 (CTRP3) is a member of C1q tumor necrosis factor-related proteins (CTRPs), which is a paralog of adiponectin. CTRP3 has a wide range of effects on glucose/lipid metabolism, inflammation, and contributes to cardiovascular protection. In this review, we comprehensively discussed the latest research on CTRP3 in obesity, diabetes, metabolic syndrome, and cardiovascular diseases.

Increased mRNA Expression of CTRP3 and CTRP9 in Adipose Tissue from Obese Women: Is it Linked to Obesity-Related Parameters and mRNA Expression of Inflammatory Cytokines?

Background

Obesity, a medical condition with impaired adipokine secretion and function, has a detrimental effect on insulin and glucose metabolism. CTRP3 and CTRP9 are adipokines with possible roles in energy homeostasis regulation. We sought to compare CTRP3, CTRP9, and inflammatory gene expression in subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) from obese women who underwent bariatric surgery and non-obese women as controls.

Methods

For this study, the investigators recruited 20 morbidly obese women (BMI> 35) who qualified for bariatric surgery and 20 normal-weight women (BMI< 25) who underwent elective surgeries. Real-time PCR was performed to investigate mRNA expression of CTRP3, CTRP9, and the inflammatory genes IL1-β, IL-6, MCP-1, and TNF-α in SAT and VAT from both obese patients and controls.

Results

We observed that CTRP3 mRNA levels were significantly greater in VAT from obese patients than from controls (P< 0.0003). Also, patient group had higher levels of CTRP9 that control group (P< 0.0026). Inflammatory cytokines were markedly increased in SAT of obese patients compared to controls (P< 0.05). In addition, our results revealed a positive correlation of CTRP9 with HOMA-IR and waist circumference in VAT and CTRP3 with IL-1β, MCP-1, and TNF-α in SAT.

Conclusion

Both CTRP3 and CTRP9 expression were significantly higher in VAT from obese patients than from controls, and CTRP3 expression positively correlated with inflammatory parameters. Our findings indicate that CTRP3 and CTRP9 might be important in regulating glucose metabolism and obesity-related conditions such as inflammation.

Serum levels of C1q/TNF-related protein-3 in inflammatory bowel disease patients and its inverse association with inflammatory cytokines and insulin resistance

Ulcerative colitis (UC) and Crohn's disease (CD) are two major forms of inflammatory bowel disease (IBD), which is an inflammatory disease. Studies have shown that adipose tissue and inflammation play important roles in the pathogenesis of IBD. C1q/TNF-related protein-3 (CTRP3) is a newly discovered adipokine playing a substantial role during inflammatory process, and for the first time in the present study, serum levels of this adipokine were measured in the UC and CD patients. This case-control study included 70 control, 50 UC, and 50 CD patients who were diagnosed by standard criteria. Serum levels of adiponectin, IL-6, TNF-α, TGF-β, and CTRP3 were evaluated using ELISA kits. Serum levels of IL-6, TNF-α, and TGF-β elevated in the UC and CD patients compared with the controls while adiponectin and CTRP3 diminished in the patient's groups compared with the control. Furthermore, decrease in CTRP3 serum levels was associated with the risk of UC and CD diseases. Moreover, CTRP3 indicated negative correlation with BMI, FBS, insulin, homeostasis model assessment of insulin resistance, IL-6, TNF-α, and TGF-β and also a positive correlation with adiponectin in both the UC and CD patients. For the first time, the present study demonstrated lower levels of CTRP3 in the UC and CD patients. Decreased serum levels of CTRP3 and its inverse relationship with inflammatory cytokines and TGF-β levels suggested a possible role for CTRP3 in the pathogenesis of UC and CD diseases.

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.

Serum levels of CTRP3 in diabetic nephropathy and its relationship with insulin resistance and kidney function

Background

C1q TNF related protein 3 (CTRP3) is an adipokine secreted from adipose tissue. Previous studies have suggested that CTRP3 improves insulin sensitivity and reduces inflammation. Human studies have evaluated circulating levels of this adipokine in patients with diabetes mellitus (DM), diabetic retinopathy, metabolic syndrome, and coronary artery diseases. However, circulating levels of this adipokine in patients with diabetic nephropathy have not been evaluated. The present study aimed to assess serum levels of CTRP3 in patients with type 2 diabetes mellitus (T2DM) and diabetic nephropathy (T2DM-NP) and its relationship with metabolic and inflammatory markers.

Methods

This cross-sectional study was performed on 55 controls, 54 patients with T2DM, and 55 patients with T2DM-NP. Serum levels of CTRP3, adiponectin, TNF-α, and IL-6 were measured by ELISA technique.

Results

Serum levels of CTRP3 were significantly lower in patients with T2DM (257.61 ± 69.79 ng/mL, p < 0.001) and T2DM-NP (222.03 ± 51.99 ng/mL, p < 0.001) compared to controls (328.17 ± 80.73 ng/mL), and those with T2DM-NP compared to T2DM group. CTRP3 was independently associated with HOMA-IR (r = -0.327, p < 0.05) and adiponectin (r = 0.436, p < 0.01) in T2DM group. In T2DM-NP patients, CTRP3 independently was associated with eGFR (r = 0.428, p < 0.01) and HOMA-IR (r = -0.436, p < 0.01). Furthermore, CTRP3 revealed a ability to differentiate T2DM-NP patients from controls (area under curve (95% confidence interval): 0.881 (0.820–0.943) and p < 0.001).

Conclusion

Decreased serum levels of CTRP3 in patients with T2DM and diabetic nephropathy and its association with pathologic mechanism in these patients suggested a possible role for CTRP3 in pathogenesis of diabetic nephropathy; nevertheless, further studies are required in this regard.

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

PURPOSE

CTRP3 is a novel peptide that has recently emerged as an important regulatory adipokine of obesity and related metabolic disease. Little is known about its role in children. The current study aimed to investigate the potential role of CTRP3 in obese children and explore its relationships with insulin sensitivity, pancreatic β cell function, and obesity-related markers.

PATIENTS AND METHODS

We studied the levels of serum CTRP3 in 48 obese and 36 normal weight pre-puberty children. The levels of blood pressure, lipids, glucose, and insulin were measured, and the values of HOMA-IR, HOMA-β and insulinogenic index were calculated. The correlations of these measurements with CTRP3 levels were analyzed.

RESULTS

In this study, we found that CTRP3 serum levels significantly decreased in obese children compared to controls, and insulin resistant obese subjects have lower CTRP3 levels in contrast with the non-insulin resistant obese subjects. Moreover, serum CTRP3 concentrations significantly decreased, while glucose and insulin concentrations significantly increased after a 3 hrs oral glucose tolerance test in obese children. Furthermore, Serum CTRP3 levels correlated negatively and significantly with BMI, triglycerides, systolic blood pressure, fasting insulin, glucose, HOMA-IR, HOMA-β and insulinogenic index in obese children.

CONCLUSION

In summary, serum CTRP3 levels significantly decreased in obese children, and negatively correlated with insulin resistance and pancreatic β cell function indicators. Therefore, CTRP3 may play a protective role in the glucose homeostasis and tightly related to β cell function as well as obesity-related markers in obese children.

The sex specific effect of alcohol consumption on circulating levels of CTRP3

The goal of this project was to establish the effect of alcohol consumption on the circulating levels of the adipose tissue derived protein C1q TNF Related Protein 3 (CTRP3). Adipose tissue secretes several adipokines, such as adiponectin and leptin, which exert a multitude of biological effects important for human health. However, adipose tissue is extremely sensitive to alcohol consumption, leading not only to disrupted fat storage, but also to disruptions in adipokine production. Changes to adipokine secretion could have widespread biological effects and potentially contribute to alcohol-induced ailments, such as alcoholic fatty liver disease (ALD). CTRP3 has been previously demonstrated to attenuate fatty liver disease, and suppression of CTRP3 with alcohol consumption could contribute to development of and progression to alcoholic fatty liver disease. To examine the effect of ethanol consumption on circulating adipokine levels, male and female mice were fed an ethanol containing diet (Lieber-DeCarli 5% (v/v) ethanol diet) for 10-days followed by a single gavage of 5 g/kg ethanol (the NIAAA model), or for 6-weeks with no binge added (chronic model). In female mice, adiponectin levels increased ~2-fold in both models of ethanol feeding, but in male mice increased adiponectin levels were only observed after chronic ethanol feeding. On the other hand, in female mice, circulating CTRP3 levels decreased by ~75% and ~50% in the NIAAA and chronic model, respectively, with no changes observed in the male mice in either feeding model. Leptin levels were unchanged with ethanol feeding regardless of model or sex of mice. Lastly, chronic ethanol feeding led to a significant increase in mortality (~50%) in female mice, with no difference in relative ethanol consumption. These findings indicate that ethanol consumption can dysregulate adipokine secretion, but that the effects vary by sex of animal, method of ethanol consumption, and adipokine examined. These findings also indicate that female mice are more sensitive to the chronic effects of ethanol than male mice. Notably, this is the first study to document the effects of ethanol consumption on the circulating levels of CTRP3. Understanding the impact of excessive alcohol consumption on adipokine production and secretion could identify novel mechanisms of alcohol-induced human disease. However, the mechanism responsible for the increased sensitivity remains elusive.

Transgenic overexpression of CTRP3 prevents alcohol-induced hepatic triglyceride accumulation

This study tested the ability of a novel adipose tissue derived cytokine, C1q TNF-related protein-3 (CTRP3), to prevent alcohol-induced hepatic lipid accumulation, or alcoholic fatty liver disease (ALD). Previous work has demonstrated that CTRP3 is effective at preventing high-fat diet-induced fatty liver; however, the potential of CTRP3 to inhibit ALD has not been explored. To test the potential protective effects of CTRP3, transgenic mice overexpressing CTRP3 (Tg) or wild-type littermates (WT) were subjected to one of two different models of ALD. In the first model, known as the NIAAA model, mice were fed control or alcohol-containing liquid diets (5% vol/vol) for 10 days followed by a single gavage of ethanol (5 g/kg). In the second model, the chronic model, mice were fed control or alcohol-containing diets for 6 wk with no gavage. This study found that CTRP3 reduced triglyceride accumulation in the chronic model of alcohol consumption by ~50%, whereas no reduction was observed in the NIAAA model. Further analysis of isolated primary hepatocytes from WT and Tg mice demonstrated that CTRP3 increased oxygen consumption in the presence of fatty acids, indicating that CTRP3 increases hepatic fatty acid utilization. In conclusion, this study indicates that CTRP3 attenuates hepatic triglyceride accumulation in response to long-term chronic, but not short-term, alcohol consumption.

The adipokine C1q TNF related protein 3 (CTRP3) is elevated in the breast milk of obese mothers

Background

C1q TNF related protein 3 (CTRP3) is a relatively novel hormonal factor primarily derived from adipose tissue and has anti-diabetic properties. To determine if CTRP3 could play a role in early childhood development, the purpose of this study was to establish the presence of CTRP3 in breast milk (BM) and to determine whether CTRP3 levels were correlated with pregravid obesity status of the mother.

Methods

Breast milk was collected from breast-feeding mothers who had a pregravid body mass index (BMI) classification of normal weight (BMI 18-25 kg/m², n = 23) or obese (BMI > 30 kg/m², n = 14). Immunoprecipitation followed by immunoblot analysis confirmed the presence of CTRP3 in BM. The concentration of CTRP3 in BM samples was determined by ELISA. Additional bioactive components were also measured by commercially available assays: ghrelin, insulin, leptin, adiponectin, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and glucose. Bioactive components in normal weight and obese mothers were compared using unpaired t-test (parametric) and Mann-Whitney U-test (non-parametric), as appropriate.

Results

The primary findings of this study are that the adipokine CTRP3 is present in BM and CTRP3 levels are increased with pregravid obesity. Additionally, this study independently confirmed previous work that BM from obese mothers has a higher concentration of insulin and leptin. Further, no differences were observed in BM between obese and normal weight mothers in ghrelin, adiponectin, IL-6, TNF-α, or glucose levels.

Conclusion

This study identified a novel factor in BM, CTRP3, and showed that BM CTRP3 levels higher in obese mothers. Because of the purported insulin sensitizing effect of CTRP3, it is possible that the elevated levels of CTRP3 in the BM of obese mothers may offset negative effects of elevated leptin and insulin levels in the BM of obese mothers. Future studies will need to be conducted to determine the relevance of CTRP3 in BM and to examine the presence of other adipose tissue-derived hormonal factors.