Investigation of the relationship between betatrophin and certain key enzymes involved in carbohydrate and lipid metabolism in insulin-resistant mice.

OBJECTIVES: The present study sought to examine the relationship of betatrophin with certain key enzymes, namely lactate dehydrogenase-5 (LDH5), citrate synthase (CS), and acetyl-CoA carboxylase-1 (ACC1), in insulin-resistant mice. METHODS: Eight-week-old male C57BL6/J mice were used in this study (experimental group n=10 and control group n=10). S961 was administered using an osmotic pump to induce insulin resistance in the mice. The betatrophin, LDH5, CS, and ACC1 expression levels were determined from the livers of the mice using the real-time polymerase chain reaction (RT-PCR) method. Moreover, biochemical parameters such as the serum betatrophin, fasting glucose, insulin, triglyceride, total cholesterol, and high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol levels were analyzed. RESULTS: The betatrophin expression and serum betatrophin (p=0.000), fasting glucose, insulin, triglyceride (p≤0.001), and total cholesterol (p=0.013) levels were increased in the experimental group. In addition, the CS gene expression level was statistically significantly decreased in the experimental group (p=0.01). Although strong correlation was found between the expression and serum betatrophin and triglyceride levels, no correlation was found between the betatrophin gene expression and the LDH5, ACC1, and CS gene expression levels. CONCLUSIONS: The betatrophin level appears to play an important role in the regulation of triglyceride metabolism, while insulin resistance increases both the betatrophin gene expression and serum levels and decreases the CS expression level. The findings suggest that betatrophin may not regulate carbohydrate metabolism through CS and LDH5 or lipid metabolism directly through the ACC1 enzyme.

Adolescent obesity and ANGPTL8: correlations with high sensitivity C-reactive protein, leptin, and chemerin.

Angiopoietin-like proteins (ANGPTLs) mediate many metabolic functions. We had recently reported increased plasma levels of ANGPTL8 in obese adults of Arab ethnicity. However, data on ANGPTL8 levels in adolescent obesity is lacking. Arab population is characterized by a rapid transition, due to sudden wealth seen in the post-oil era, in lifestyle, food habits and extent of physical activity. We adopted a cross-sectional study on Arab adolescents from Kuwait to examine the role of ANGPTL8 in adolescent obesity. The study cohort included 452 adolescents, aged 11-14 years, recruited from Middle Schools across Kuwait. BMI-for-age growth charts were used to categorize adolescents as normal-weight, overweight, and obese. ELISA and bead-based multiplexing assays were used to measure plasma levels of ANGPTL8 and other inflammation and obesity-related biomarkers. Data analysis showed significant differences in the plasma levels of ANGPTL8 among the three subgroups, with a significant increase in overweight and obese children compared to normal-weight children. This observation persisted even when the analysis was stratified by sex. Multinomial logistic regression analysis illustrated that adolescents with higher levels of ANGPTL8 were 7 times more likely to become obese and twice as likely to be overweight. ANGPTL8 levels were correlated with those of hsCRP, leptin and chemerin. ANGPTL8 level had a reasonable prognostic power for obesity with an AUC of 0.703 (95%-CI=0.648-0.759). These observations relating to increased ANGPTL8 levels corresponding to increased BMI-for-age z-scores indicate that ANGPTL8, along with hsCRP, leptin and chemerin, could play a role in the early stages of obesity development in children. ANGPTL8 is a potential early marker for adolescent obesity and is associated with well-known obesity and inflammatory markers.

Evaluation of serum Angiopoietin-like protein 2 (ANGPTL-2), Angiopoietin-like protein 8 (ANGPTL-8), and high-sensitivity C-reactive protein (hs-CRP) levels in patients with gestational diabetes mellitus and normoglycemic pregnant women.

OBJECTIVE: In the present study, we aimed to investigate the role of the fasting serum levels of Anjiopoetin 2 - like protein (ANGPTL2), Anjiopoetin 8-like protein (ANGPTL8), and high-sensitivity C-reactive protein (hs-CRP) in the etiopathogenesis of gestational diabetes mellitus (GDM), and analyze the relationships between insulin resistance parameters. MATERIAL AND METHOD: The 90 individuals admitted to Izmir Katip Celebi University Hospital Internal Medicine, Endocrinology and Obstetrics, and gynecology outpatient clinic were included in the study of similar ages and similar demographic characteristics. Forty-five women with diet-controlled GDM and 45 women with normoglycemic pregnancy were enrolled. ANGPTL-2, ANGPTL-8, hs-CRP, creatinine, ALT, GGT, lipid profile, HBA1c(%), and serum insülin, c-peptide levels were studied in the fasting serum samples of research groups. All individuals had 75-g OGTT testing. GDM screening was performed at 24-28 weeks' gestation. Exclusion criteria were as follows: Age <18 years or >40 years, pregestational diabetes (type 1 or 2), drug or alcohol abuse, thyroid dysfunction, Hepatitis B, and other infectious diseases (Herpes virus, Streptococcus B carriers, Chlamydia and Candida), Thalassemia carriers or other significant medical conditions, the use of any medication that interferes with lipid or glucose metabolism that would affect glucose regulation. RESULT: Forty-five women with GDM and for the control group, 45 women with normoglycemic pregnant women were identified. The mean gestational age was 30.7 (18-38) for GDM and 29.6 (24-39) for the control group. Serum ANGPTL-8 (GDM =19.5 ± 93 Control = 0.73 ± 3.78 p = <.001). There was a statistically significant difference between the case and control groups for serum ANGPTL-8 levels. Serum ANGPTL-2 (GDM =19.9 ± 23.1 Control = 26.0 ± 23.4 p = .105) and serum hs-CRP(GDM =106 ± 65.1 Control =98.2 ± 87.3 p = .768). There was no statistically significant difference between the case and control groups for serum ANGPTL-2 and hsCRP levels. Serum ANGPTL8 levels were positively correlated with FPG (r = 0.391, p = <.001), FPI (r = 0.212, p = .045), 1-h PPG (r = 0.514, p = <.001), 2-h PPG (r = 0.502, p = <.001), HOMA-IR) score (r = 0.310, p = .003), TG (r = 0.245, p = .020); they were not except for BMI, hs-CRP levels and ANGPTL2 levels. CONCLUSIONS: ANGPTL8 levels were significantly higher in GDM than in healthy control group. ANGPTL2 levels and hs-CRP levels were similar to the healthy control group. Elevated serum ANGPTL8 levels were correlated significantly with insulin resistance parameters, the main component of GDM pathophysiology. Our data showed that ANGPTL8 could be a new biomarker for diagnosing GDM.

Cardiorespiratory and metabolic fitness indicators in novice volleyball trainees: effect of 1-week antioxidant supplementation with N-acetyl-cysteine/zinc/vitamin C.

OBJECTIVES: This study aimed to determine the effect of 7-day dietary supplementation of N-acetylcysteine (NAC)/zinc/vitamin C on the time-to-exhaustion (TTE), the cardiorespiratory fitness (CRF) index, and metabolic indicators. METHODS: This study enrolled volleyball student trainees (n = 18 men) who took NAC/zinc/vitamin C (750 mg/5 mg/100 mg) for 7 days at Jouf University, Saudi Arabia. The CRF index and TTE were determined. Serum concentrations of metabolic regulators (insulin, betatrophin, and hepatocyte growth factor), biomarkers of cellular damage/hypoxia, and indicators of lipid and glycemic control were measured. RESULTS: Supplementation improved the TTE and CRF index, and lowered cytochrome c, C-reactive protein, hypoxia-inducible factor-1α (HIF-1α), total cholesterol, insulin, and glycated hemoglobin values. Before and after supplementation, the CRF index was negatively correlated with body mass index and positively correlated with the TTE. Before supplementation, the CRF index was positively correlated with betatrophin concentrations, and hepatocyte growth factor concentrations were positively correlated with betatrophin concentrations and negatively correlated with the homeostasis model assessment of insulin resistance index. After supplementation, the CRF index was negatively correlated with HIF-1α concentrations and metabolites. Additionally, the TTE was negatively correlated with HIF-1α, cytochrome c, and triacylglycerol concentrations. CONCLUSION: Supplementation of NAC/zinc/vitamin C improves metabolic and CRF performance.

Relationship between Serum Angiopoietin-like Proteins 3 and 8 and Atherogenic Lipid Biomarkers in Non-Diabetic Adults Depends on Gender and Obesity.

Hypertriglyceridemia is an independent risk factor for coronary artery disease. Lipoprotein lipase (LPL) plays an essential role in the metabolism of triglyceride-rich lipoproteins (TRLs). Angiopoietin-like proteins ANGPTL3 and ANGPTL8 are shown to be important regulators of LPL activity. Increased concentrations of these proteins may reflect cardiovascular risk, and the treatment of patients with dyslipidemia with ANGPTLs inhibitors may decrease this risk. We assessed the gender-specific relationships of serum ANGPTL3 and ANGPTL8 with atherogenic lipid biomarkers and obesity in non-diabetic adults. The study comprised 238 participants aged 25-74 [122 with triglycerides (TG) <150 mg/dL (<1.7 mmol/L) and 116 with hypertriglyceridemia]. Total cholesterol, HDL-cholesterol, LDL-cholesterol, TG, C-reactive protein (CRP), glycated hemoglobin, apolipoprotein B, small dense LDL-C (sd-LDL-C), ANGPTL3, and ANGPTL8 were measured. Non-HDL-cholesterol, remnant cholesterol (remnant-C) concentrations, and body mass index (BMI) were calculated. Results: Women and men did not differ in terms of age, CRP levels, the percentage of obese subjects, and concentrations of atherogenic lipid biomarkers, except higher TG in males and higher ANGPTL3 concentrations in females. Positive correlations of both ANGPTLs with TG, remnant-C, and sdLDL-C levels were found in females. In males, only ANGPTL3 correlated positively with atherogenic biomarkers, but there were no correlations with ANGPTL8. Concentrations of ANGPTL3 were higher in obese men, whereas ANGPTL8 levels were higher in obese women. In women alone, ANGPTL8 showed very good discrimination power to identify subjects with hypertriglyceridemia (AUC = 0.83). Contrary to this, ANGPTL3 was a better discriminator of hypertriglyceridemia (AUC = 0.78) in male subjects. Regression models, adjusted for age, sex, and BMI showed a weak but significant effect of ANGPTL8 to increase the risk of hypertriglyceridemia. Conclusions: In females, ANGPTL8 is more strongly associated with TRLs metabolism, whereas in males, ANGPTL3 plays a more important role. We suggest sex differences be taken into consideration when applying new therapies with angiopoietin-like proteins inhibitors in the treatment of dyslipidemia.

Role of ANGPTL8 in NAFLD Improvement after Bariatric Surgery in Experimental and Human Obesity.

Angiopoietin-like protein 8 (ANGPTL8) is an hepatokine altered in several metabolic conditions, such as obesity, type 2 diabetes, dyslipidemia and nonalcoholic fatty liver disease (NAFLD). We sought to explore whether ANGPTL8 is involved in NAFLD amelioration after bariatric surgery in experimental models and patients with severe obesity. Plasma ANGPTL8 was measured in 170 individuals before and 6 months after bariatric surgery. Hepatic ANGPTL8 expression was evaluated in liver biopsies of patients with severe obesity undergoing bariatric surgery with available liver pathology analysis (n = 75), as well as in male Wistar rats with diet-induced obesity subjected to sham operation, sleeve gastrectomy or Roux-en-Y gastric bypass (RYGB) (n = 65). The effect of ANGPTL8 on lipogenesis was assessed in human HepG2 hepatocytes under palmitate-induced lipotoxic conditions. Plasma concentrations and hepatic expression of ANGPTL8 were increased in patients with obesity-associated NAFLD in relation to the degree of hepatic steatosis. Sleeve gastrectomy and RYGB improved hepatosteatosis and reduced the hepatic ANGPTL8 expression in the preclinical model of NAFLD. Interestingly, ANGPTL8 inhibited steatosis and expression of lipogenic factors (PPARG2, SREBF1, MOGAT2 and DGAT1) in palmitate-treated human hepatocytes. Together, ANGPTL8 is involved in the resolution of NAFLD after bariatric surgery partially by the inhibition of lipogenesis in steatotic hepatocytes.

Association of ANGPTL8 and Resistin With Diabetic Nephropathy in Type 2 Diabetes Mellitus.

Background: Previous studies showed altered angiopoietin-like protein-8 (ANGPTL-8) and resistin circulating levels in type 2 diabetes mellitus (T2DM). Whether or not the alteration in ANGPTL-8 and resistin level can be a predictive maker for increased diabetic nephropathy risk remains unclear. Aim: To Investigate the possible association of ANGPTL-8 and resistin with DN, and whether this association is affected by NAFLD status. Methods: A total of 278 T2DM patients were enrolled. Serum levels of ANGPTL8, resistin, BMI, blood pressure, duration of diabetes, glycosylated hemoglobin (HbA1c), fasting blood glucose (FPG), hypersensitive C-reactive protein (hs-CRP), lipid profile, liver, and kidney function tests were assessed. The relationship between DN with ANGPTL8 and resistin was analyzed in the unadjusted and multiple-adjusted regression models. Results: Serum levels of ANGPTL8 and resistin were significantly higher in DN compared with T2DM subjects without DN (respectively; P <0.001), especially in non-NAFLD populations. ANGPTL8 and resistin showed positive correlation with hs-CRP (respectively; P<0.01), and negative correlation with estimated GFR (eGFR) (respectively; P=<0.001) but no significant correlation to HOMA-IR(respectively; P>0.05). Analysis showed ANGPTL8 levels were positively associated with resistin but only in T2DM patients with DN(r=0.1867; P<0.05), and this significant correlation disappeared in T2DM patients without DN. After adjusting for confounding factors, both ANGPTL8(OR=2.095, 95%CI 1.253-3.502 P=0.005) and resistin (OR=2.499, 95%CI 1.484-4.208 P=0.001) were risk factors for DN. Data in non-NAFLD population increased the relationship between ANGPTL8 (OR=2.713, 95% CI 1.494-4.926 P=0.001), resistin (OR=4.248, 95% CI 2.260-7.987 P<0.001)and DN. The area under the curve (AUC) on receiver operating characteristic (ROC) analysis of the combination of ANGPTL8 and resistin was 0.703, and the specificity was 70.4%. These data were also increased in non-NAFLD population, as the AUC (95%CI) was 0.756, and the specificity was 91.2%. Conclusion: This study highlights a close association between ANGPTL8, resistin and DN, especially in non-NAFLD populations. These results suggest that ANGPTL-8 and resistin may be risk predictors of DN.

ANGPTL3 and ANGPTL8 in Thai subjects with hyperalphalipoproteinemia and severe hypertriglyceridemia.

BACKGROUND: The role of ANGPTL3 and ANGPTL8 in lipid regulation in patients with very high levels of HDL-cholesterol and triglyceride is unknown. OBJECTIVE: We examined plasma levels of ANGPTL3 and ANGPTL8 in subjects with hyperalphalipoproteinemia (HALP) and in those with severe hypertriglyceridemia (HTG). METHODS: Plasma ANGPTL3 and ANGPTL8 levels were measured by ELISA in 320 subjects, consisting of HALP subjects with HDL-cholesterol ≥100 mg/dl (n=90) and healthy controls (n=90) and subjects with triglyceride ≥886 mg/dl (n=89) and control subjects (n=51). RESULTS: The mean plasma ANGPTL3 level was significantly higher in the HALP group compared to that of the controls (297 ± 112 ng/mL vs. 230 ± 100 ng/mL, p<0.001). Similarly, the mean plasma ANGPTL8 level was also higher in the HALP group (30 ± 11 ng/mL vs. 20 ± 8 ng/mL, p<0.001). Both ANGPTL3 and ANGPTL8 levels positively correlated with HDL-cholesterol levels. In the severe HTG group, plasma ANGPTL3 level was significantly higher than those in the control group (223 ± 105 ng/mL vs. 151 ± 60 ng/mL, p<0.001), but not ANGPTL8 (23 ± 20 ng/mL vs. 31 ± 23 ng/mL in controls, p=0.028). Only ANGPTL3, but not ANGPTL8, levels positively correlated with triglyceride levels. CONCLUSION: Plasma level of ANGPTL3 was increased in both HALP and severe HTG whereas an increase in plasma level of ANGPTL8 was found only in HALP, and not in severe HTG, suggesting that both ANGPTL3 and ANGPTL8 might play distinct roles in lipid regulation on these two extremes of dyslipidemia.

Circulating ANGPTL8 levels and risk of kidney function decline: Results from the 4C Study.

BACKGROUND: ANGPTL8, an important regulator of lipid metabolism, was recently proven to have additional intracellular and receptor-mediated functions. This study aimed to investigate circulating levels of ANGPTL8 and its potential association with the risk of kidney function decline in a cohort study. METHODS: We analysed 2,311 participants aged 40 years old and older from the China Cardiometabolic Disease and Cancer Cohort (4C) Study. Kidney function decline was defined as an estimated glomerular filtration rate (eGFR) less than 60 mL per minute per 1.73 m2 of body surface area, a decrease in eGFR of ≥ 30% from baseline, chronic kidney disease (CKD)-related hospitalization or death, or end-stage renal disease. The association between baseline ANGPTL8 levels and kidney function decline was assessed using multivariable-adjusted Cox proportional hazards models, and inverse possibility of treatment weight (IPTW) was utilized to prevent overfitting. RESULTS: There were 136 (5.9%) cases of kidney function decline over a median of 3.8 years of follow-up. We found that serum ANGPTL8 levels at baseline were elevated in individuals with kidney function decline compared to those without kidney function decline during follow-up (718.42 ± 378.17 vs. 522.04 ± 283.07 pg/mL, p < 0.001). Compared with the first quartile, multivariable-adjusted hazard ratio (95% confidence intervals [CIs]) for kidney function decline was 2.59 (95% CI, 1.41-4.77) for the fourth ANGPTL8 quartile. Furthermore, compared with patients in the first ANGPTL8 quartile, those in the fourth ANGPTL8 quartile were more likely to report a higher stage of CKD (relative risk: 1.33; 95% CI, 1.01-1.74). The conclusions of the regression analyses were not altered in the IPTW models. Multivariable-adjusted restricted cubic spline analyses suggested a linear relationship of ANGPTL8 with kidney function decline (p for nonlinear trend = 0.66, p for linear trend < 0.001). CONCLUSIONS: Participants with higher circulating ANGPTL8 levels were at increased risk for kidney function decline, highlighting the importance of future studies addressing the pathophysiological role of ANGPTL8 in CKD.

Associations Between Betatrophin with Irisin and Metabolic Factors: Effects of Two Exercise Trainings in Diabetic Rats.

BACKGROUND: Irisin and betatrophin are involved in insulin resistance. We investigated the effects of aerobic and resistance exercise (AE/RE) and de-training (cessation of the training after the AE/RE) on betatrophin, irisin and some metabolic factors in rats. METHODS: Wistar rats were assigned into six groups: non-diabetic rats (C), non-diabetic rats that performed AE/RE, diabetic rats (Dia), and diabetic rats that performed AE/RE (Dia+AE and Dia+RE). Diabetes was induced by high-fat diet/streptozotocin model. The rats de-trained for four weeks after the 12-week exercise training. Blood samples were analyzed by enzyme-linked immunosorbent assay (ELISA) method and statistical analyses were performed using repeated measures and 1-way analysis of variance (ANOVA). RESULTS: The 12-week ET improved homeostasis model assessment of IR (HOMA-IR), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC) and triglycerides (TG) in the trained diabetic groups (p<0.05). ET reduced betatrophin level in the Dia+RE but not in the Dia+AE group. Positive correlations between betatrophin and body weight (r=0.547; p<0.01), and HOMA-IR (r=0.461; p<0.05) but a negative correlation with LDL-C and TC (r=-0.684, r=-0.669; both p<0.01) were observed, whereas no significant correlation was found between betatrophin and HDL-C and TG (r=-0.225, r=-0.360; both p>0.05). Betatrophin was correlated with irisin in the healthy rats but not the diabetic rats (p<0.01). CONCLUSIONS: It seems that RE has greater efficiency than AE in reducing betatrophin level and irisin resistance. However, de-training caused most of the improvements resulting from RE to be lost, but not the improvements resulting from AE.

Circulating angiopoietin-like proteins in metabolic-associated fatty liver disease: a systematic review and meta-analysis.

BACKGROUND: Angiopoietin-like proteins (ANGPTLs) are closely related to insulin resistance and lipid metabolism, and may be a key in metabolic syndrome. Non-alcoholic fatty liver disease (NAFLD) (newly named metabolic-associated fatty liver disease (MAFLD)) is based on metabolic dysfunction. There may be some correlation between ANGPTLs and MAFLD, but the specific correlation is unclear. This study aims to explore the predictive role of ANGPTLs in MAFLD and its progression. METHODS: Seven databases (PubMed, EMBASE, Cochrane Library, CNKI, WANFANG, CBM and Clinicaltrials.gov ) were searched with free terms and MeSH terms. The random-effects model was used to pool the data, and Standardized Mean Difference (SMD) and 95% confidence intervals (CI) were taken as the overall outcome. No language restrictions existed in the article selection. RevMan 5.3, Stata 16 and MetaXL software were applied to analyse the data and the GRADE system was utilized to assess the certainty of evidence. RESULTS: After reviewing 823 related articles, 13 studies (854 cases and 610 controls) met the inclusion criteria, and contributed to this meta-analysis. The results showed that circulating ANGPTL8 level was significantly elevated in the MAFLD group than in the healthy control group (SMD = 0.97 pg/mL, 95%CI: 0.77, 1.18). Conversely, there was no significant difference in the ANGPTL4 (SMD = 0.11 ng/mL, 95%CI: - 0.32, 0.54) and ANGPTL3 (SMD = - 0.95 ng/mL, 95%CI: - 4.38, 2.48) between the two groups. Subgroup analysis showed that: 1) the MAFLD group had significantly higher ANGPTL8 levels than the healthy control group in Asian and other races; 2) the ANGPTL8 levels in Body Mass Index (BMI) > 25 kg/m2 patients with MAFLD were higher than those in the healthy control group; 3) the higher ANGPTL8 levels were observed in moderate to severe MAFLD group than the healthy control group. Meta-regression demonstrated that BMI might effectively explain the high heterogeneity. No significant publication bias existed (P > 0.05). The certainty of evidence was assessed as very low by the GRADE system. CONCLUSIONS: The ANGPTLs may be related to MAFLD. The increased ANGPTL8 level may be positively correlated with different situations of MAFLD, which may act as a potential indicator to monitor the development trends.

Serum and urine ANGPTL8 expression levels are associated with hyperlipidemia and proteinuria in primary nephrotic syndrome.

BACKGROUND: This study aimed to investigate the expression characteristics of ANGPTL8 in patients with primary nephrotic syndrome and its possible correlation with hyperlipidemia and proteinuria. METHODS: ANGPTL8 levels were determined using an enzyme-linked immunosorbent assay in 133 subjects with PNS and 60 healthy controls. RESULTS: Compared with healthy controls, subjects with primary nephrotic syndrome had higher levels of serum and urine ANGPTL8 (P < 0.001). In primary nephrotic syndrome patients, serum ANGPTL8 was positively correlated with cholesterol (r = 0.209, P < 0.05) and triglycerides (r = 0.412, P < 0.001), while there was no correlation with 24 hUTP. Urine ANGPTL8 was positively correlated with high-density lipoprotein cholesterol (r = 0.181, P < 0.05) and was significantly negatively correlated with creatinine (r = - 0.323, P < 0.001), eGFR (r = - 0, P < 0.001) and 24 hUTP (r = - 0.268, P = 0.002). Interestingly, the urine ANGPTL8 concentrations in membranous nephropathy and mesangial proliferative glomerulonephritis pathological types were different. CONCLUSIONS: Serum and urine ANGPTL8 levels in primary nephrotic syndrome patients were correlated with blood lipid levels and proteinuria, respectively, suggesting that ANGPTL8 may play a role in the development of primary nephrotic syndrome hyperlipidemia and proteinuria.

Down-regulation of betatrophin enhances insulin sensitivity in type 2 diabetes mellitus through activation of the GSK-3ß/PGC-1α signaling pathway.

OBJECTIVE: The incidence of type 2 diabetes mellitus (T2DM) among children and adolescents has been rising. Accumulating evidences have noted the significant role of betatrophin in the regulation of lipid metabolism and glucose homeostasis. In our study, we tried to figure out the underlying mechanism of betatrophin in insulin resistance (IR) in type 2 diabetes mellitus (T2DM). METHODS: First, fasting serum betatrophin, fasting blood glucose (FBG), insulin, total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) were detected in T2DM children. The homeostasis model assessment of insulin resistance (HOMA-IR), Gutt insulin sensitivity index (ISIG) and Matsuda insulin sensitivity index (ISIM) were calculated. A T2DM-IR mouse model was induced by high-fat diet, with the expression of GSK-3ß and PGC-1α detected. Besides, HepG2 cells were induced by a high concentration of insulin to establish an IR cell model (HepG2-IR). The cell viability, glucose consumption, liver glycogen content, inflammation, and fluorescence level of GSK-3ß and PGC-1α were analyzed. RESULTS: Betatrophin was highly expressed in serum of T2DM children and was positively correlated with FBG, insulin, TC, TG, LDL-C and HOMA-IR, while negatively correlated with ISIG and ISIM. Betatrophin and GSK-3ß in the liver tissues of T2DM-IR mice were increased, while the PGC-1α expression was decreased. Betatrophin expression was negatively correlated with PGC-1α and positively correlated with GSK-3ß. Silencing of betatrophin enhanced insulin sensitivity through the activation of GSK-3ß/PGC-1α signaling pathway. In vitro experiments also found that silencing of betatrophin promoted glucose consumption and glycogen synthesis while inhibited inflammation. CONCLUSION: Our findings concluded that silencing of betatrophin could enhance insulin sensitivity and improve histopathological morphology through the activation of GSK-3ß/PGC-1α signaling pathway.

Angiopoietin-Like Protein 8/Leptin Crosstalk Influences Cardiac Mass in Youths With Cardiometabolic Risk: The BCAMS Study.

Objectives: The link between excess adiposity and left ventricular hypertrophy is multifaceted with sparse data among youths. Given that adipokines/hepatokines may influence lipid metabolism in myocardium, we aimed to investigate the relation of the novel hepatokine angiopoietin-like protein 8 (ANGPTL8) and other adipokines with cardiac structure in a cohort of youths and explore to what extent these adipokines/hepatokines affect cardiac structure through lipids. Methods: A total of 551 participants (aged 15-28 years) from the Beijing Child and Adolescent Metabolic Syndrome Study (BCAMS) cohort underwent echocardiographic measurements plus a blood draw assayed for five adipokines/hepatokines including adiponectin, leptin, retinol binding protein 4, fibroblast growth protein 21 and ANGPTL8. Results: Both ANGPTL8 (ß = -0.68 g/m2.7 per z-score, P= 0.015) and leptin (ß = -1.04 g/m2.7 per z-score, P= 0.036) were significantly inversely associated with left ventricular mass index (LVMI) independent of classical risk factors. Total cholesterol and low-density lipoprotein cholesterol significantly mediated the ANGPTL8-LVMI association (proportion: 19.0% and 17.1%, respectively), while the mediation effect of triglyceride on the ANGPTL8-LVMI relationship was strongly moderated by leptin levels, significantly accounting for 20% of the total effect among participants with higher leptin levels. Other adipokines/hepatokines showed no significant association with LVMI after adjustment for body mass index. Conclusions: Our findings suggest ANGPTL8, particularly interacting with leptin, might have a protective role in cardiac remodeling among youths with risk for metabolic syndrome. Our results offer insights into the pathogenesis of the cardiomyopathy and the potential importance of tissue-tissue crosstalk in these effects.

Several Circulating Biomarkers for PCOS Diagnosis.

AIMS: Irisin, Betatrophin and Zinc-α2-glycoprotein (ZAG) have been shown to be associated with insulin resistance (IR) and polycystic ovary syndrome (PCOS), respectively. The purpose of this study is to explore the potential accuracy of this combination of three cytokines in screening PCOS. METHODS: 186 individuals were recruited for this study. Circulating Irisin, Betatrophin and ZAG concentrations were measured by enzyme-linked immunosorbent assay. The association between these serum biomarkers and PCOS was assessed by logistic regression analysis. Receiver operating curve (ROC) analysis was performed to evaluate the diagnostic value of these biomarkers for PCOS women. RESULTS: In women with PCOS, serum Irisin and Betatrophin levels were markedly elevated compared to those in healthy controls (p<0.01), while ZAG levels were lower (p<0.01). PCOS women with IR (M-value<6.28) had lower circulating ZAG concentrations, and higher circulating Irisin and Betatrophin levels relative to PCOS women without IR (M-value ≥ 6.28). ROC curve analyses showed that the AUC for Irisin, ZAG and Betatrophin for predicting PCOS were 0.77, 0.83 and 0.85, respectively. In a joint ROC curves analysis of these serum markers and other parameters, the results showed that the AUC was 0.93, and the sensitivity and specificity were 82.1 % and 92.3 %, respectively. CONCLUSIONS: When compared to using single cytokine, the analysis of Irisin, ZAG and Betatrophin elevates the accuracy in diagnosing PCOS.

Angiopoietin-like 8 (ANGPTL8) as a potential predictor of NAFLD in paediatric patients with Prader-Willi Syndrome.

PURPOSE: Angiopoietin-like 8 (ANGPTL8) is a liver- and adipose tissue-produced protein that predicts non-alcoholic fatty liver disease (NAFLD) and altered metabolic homeostasis in the general population as well as in persons with common and genetic obesity, including the Prader-Willi syndrome (PWS). However, its metabolic correlate in paediatric patients with respect to PWS is unknown. METHODS: This cross-sectional study investigated circulating ANGPTL8 and adipocytokines levels in 28 PWS and 28 age-, sex- and BMI-matched children and adolescents (age, 7.0-17.8y) in relation to NAFLD and metabolic homeostasis assessed by OGTT, paediatric metabolic index (PMI) and fatty liver index (FLI), liver ultrasonography (US), as well as dual-energy X-ray absorptiometry (DEXA) for analysis of fat (FM) and fat-free mass (FFM). RESULTS: At the set level of significance, PWS children showed lower values of FFM (p < 0.01) but healthier insulin profiles (p < 0.01) and PMI values (p < 0.05) than matched controls. By US, the prevalence of NAFLD was similar between groups but less severe in PWS than controls. Analysis of ANGPTL8 levels showed no difference between groups, yet only in PWS ANGPTL8 levels were associated with ALT levels, FLI values and NAFLD. In stepwise multivariable regression analysis on merged data, ANGPTL8 levels were independently predicted by BMI SDS, leptin levels and NAFLD. CONCLUSION: ANGPTL8 levels are similar in PWS and controls and, overall, they are directly associated with the presence and severity of NAFLD in patients with PWS.