Effects of a diet with or without physical activity on angiopoietin-like protein 8 concentrations in overweight/obese patients with newly diagnosed type 2 diabetes: a randomized controlled trial

Effectiveness of Calorie Restriction for Weight Loss in Type 2 Diabetes Mellitus: A Systematic Review

The effectiveness of calorie restriction (CR) for weight loss in type 2 diabetes mellitus (T2DM) has not been thoroughly studied. This review aims to evaluate CR's short- and long-term effectiveness for weight loss and its impact on cardiometabolic parameters in T2DM. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, Medline Complete, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Cochrane Library databases were searched to identify studies up to June 7, 2024. Furthermore, a reference search was conducted. Randomized controlled trials involving adults with T2DM examining CR and reporting weight changes were included. The revised Cochrane risk-of-bias tool was used to assess the study's quality. A narrative synthesis was used to analyze the findings. Eleven studies, with 1,554 participants, were included; all had a low risk of bias. The intervention group participants' mean baseline weight and Body Mass Index were 93.3 kg and 32.7 kg/m², respectively. Interventions used included total diet replacement (TDR) and very low- and low-calorie diets lasting 12 weeks to two years. CR with TDR resulted in >12% weight loss. Additionally, CR improved cardiometabolic parameters; glycated hemoglobin (HbA1c) decreased to ≤6.5%; diabetes remission was achieved in 19% to 83%; high-density lipoprotein significantly increased; and triglyceride, systolic, and diastolic blood pressure significantly decreased. In conclusion, CR effectively reduces weight and improves cardiometabolic markers in T2DM. However, large long-term studies addressing CR in T2DM are lacking, which challenges drawing firm conclusions. This highlights the need for further research to address this gap. This review is registered in the International Prospective Register of Systematic Reviews (PROSPERO) under the registration number CRD42024573505.

Effect of acute anaerobic performance on zinc alpha 2 glycoprotein, apelin and lipasin levels

The aim of this study was to investigate the effects of acute anaerobic exercise on serum levels of adipokines Zinc-α2-glycoprotein (ZAG), apelin, and lipasin. Eighteen male athletes who actively played soccer and trained at least four days a week, with a mean age of 19.11 ± 2.59 years, body weight of 70.61 ± 8.17 kg, height of 176.0 ± 7.71 cm, sport age of 7.22 ± 2.60 years and BMI of 22.76 ± 1.68 kg/m2 participated in the study. Athletes were subjected to the Running-Based Anaerobic Sprint Test (RAST) for anaerobic performance. Blood samples were collected from the athletes 4 times (at rest, 10 minutes, 60 minutes, and 24 hours after exercise). The results of the study showed that acute anaerobic exercise significantly increased ZAG levels (p < 0.05). However, no statistically significant difference was detected in apelin and lipasin levels (p > 0.05). In conclusion, the findings of this study indicate that acute anaerobic exercise is associated with an increase in ZAG levels, but not apelin or lipasin levels. The observations suggest that ZAG may have a specific response to anaerobic exercise, which provides valuable insight into its potential impact on energy metabolism.

Pedometer- and accelerometer- based physical activity interventions in Type 2 diabetes: A systematic review and meta-analysis

AIMS

Although accelerometer- and pedometer-based physical activity (PA) interventions can increase PA, there is no solid evidence for their benefits in patients with type 2 diabetes (T2DM). The aim of this systematic review and meta-analysis of randomized controlled clinical trials (RCTs) was to determine the effects of accelerometer- and pedometer-based PA interventions on hemoglobin A1c (HbA1c), fasting glucose, weight, BMI, blood pressure, lipids, and PA in adults with T2DM.

DATA SYNTHESIS

Records from MEDLINE/PubMed, EMBASE, LILACS, and Scopus were searched from inception through March 28th, 2022. RCTs of at least two weeks of duration evaluated the effectiveness of pedometers or accelerometers as motivating tools for increasing PA in T2DM patients. This study was registered with PROSPERO and followed the PRISMA reporting guide. Of the 7131 non-duplicated articles retrieved, 24 RCTs (1969 patients) were included. The mean baseline HbA1c of the experimental group of included studies varied from 6.3 ± 0.9 % to 9.0 ± 0.01 %. The accelerometer- and pedometer-based PA interventions resulted in a greater improvement in HbA1c (-0.22 %; 95%CI, -0.4 % to -0.05 %; I2 = 77 %) and triglycerides (-13.11 mg/dL; 95%CI, -25.21 to -1.02; I2 = 22 %) versus control participants. Pedometer ambulatory use as a motivating tool significantly increased PA by 2,131 steps/day (95 % CI, 1,348 to 2,914; I2 = 74 %) in T2DM patients.

CONCLUSIONS

Pedometers and accelerometers are associated with reductions in HbA1c and triglycerides when used as motivating tools. Larger and higher-quality studies are required to determine the full effects of PA as motivated by trackers in T2DM population.

Effects of exercise training on ANGPTL3/8 and ANGPTL4/8 and their associations with cardiometabolic traits

Angiopoietin-like protein (ANGPTL) complexes 3/8 and 4/8 are established inhibitors of LPL and novel therapeutic targets for dyslipidemia. However, the effects of regular exercise on ANGPTL3/8 and ANGPTL4/8 are unknown. We characterized ANGPTL3/8 and ANGPTL4/8 and their relationship with in vivo measurements of lipase activities and cardiometabolic traits before and after a 5-month endurance exercise training intervention in 642 adults from the HERITAGE (HEalth, RIsk factors, exercise Training And GEnetics) Family Study. At baseline, higher levels of both ANGPTL3/8 and ANGPTL4/8 were associated with a worse lipid, lipoprotein, and cardiometabolic profile, with only ANGPTL3/8 associated with postheparin LPL and HL activities. ANGPTL3/8 significantly decreased with exercise training, which corresponded with increases in LPL activity and decreases in HL activity, plasma triglycerides, apoB, visceral fat, and fasting insulin (all P < 5.1 × 10-4). Exercise-induced changes in ANGPTL4/8 were directly correlated to concomitant changes in total cholesterol, LDL-C, apoB, and HDL-triglycerides and inversely related to change in insulin sensitivity index (all P < 7.0 × 10-4). In conclusion, exercise-induced decreases in ANGPTL3/8 and ANGPTL4/8 were related to concomitant improvements in lipase activity, lipid profile, and cardiometabolic risk factors. These findings reveal the ANGPTL3-4-8 model as a potential molecular mechanism contributing to adaptations in lipid metabolism in response to exercise training.

Dynamic alteration of plasma levels of betatrophin in younger female onset obesity post acute moderate-intensity exercise training

Obesity is a global metabolic disease anchored by a lack of physical activity lipid disturbances. Hitherto, betatrophin is a potential liver-derived hormone that regulates lipid metabolism. A total of 26 selected onset obese individuals (BMI range ± 28-31) were enrolled in this study and given moderate-intensity exercise. Importantly, our data show that acute moderate-intensity interval exercise (MIIE) and acute moderate-intensity continue to exercise (MICE) for 40 min significantly decrease the plasma level of full-length betatrophin respectively (174.18 ± 48.19 ng/mL; 182.31 ± 52.69 ng/mL), compared to the placebo (283.97 ± 32.23 ng/mL) post 10 min and 6 h exercise treatment (p ≤ 0.05). The plasma level of betatrophin was significantly and negatively correlated with BMI (r = - 0.412, p = 0.037), fasting blood glucose (r = - 0.390, p = 0.049), and positively correlated with VO_2max (r = 0.456, p = 0.019). In addition, the linear and ordinal logistic regression analysis shows that betatrophin, is a potential predictor for BMI [estimate value = 0.995, p = 0.037 and OR (95 % CI) = 0.992 (0.0984-1.00), p = 0,048]. In summary, our data demonstrate that the circulating levels of betatrophin were decreased after acute moderate-intensity exercise training.

Betatrophin and Insulin Resistance

Betatrophin (angiopoietin-like protein 8 (ANGPTL8)) is a hormone that was recently discovered in the human liver. Multiple homologous sequences have been detected in mammalian liver, white adipose, and brown adipose tissues. Betatrophin is crucial for the development of type 2 diabetes (T2D), insulin resistance, and lipid metabolism. Similar to the intake of insulin, thyroid hormones, irisin, and calories, betatrophin expression in the organism is usually attributed to energy consumption or heat generation. It can mediate the activity of lipoprotein lipase (LPL), which is the key enzyme of lipoprotein lipolysis. Due to its association with metabolic markers and the roles of glucose and lipid, the physiological function of betatrophin in glucose homeostasis and lipid metabolism can be more comprehensively understood. Betatrophin was also shown to facilitate pancreatic β-cell proliferation in a mouse model of insulin resistance. There are also reports that demonstrate that betatrophin regulates triglycerides (TGs) in the liver. Therefore, the process of regulating the physiological function by betatrophin is complicated, and its exact biological significance remains elusive. This study provides a comprehensive review of the current research, and it discusses the possible physiological functions of betatrophin, and specifically the mechanism of betatrophin in regulating blood glucose and blood lipids.

Adiponectin Intervention to Regulate Betatrophin Expression, Attenuate Insulin Resistance and Enhance Glucose Metabolism in Mice and Its Response to Exercise

Aims: Adiponectin stimulates mitochondrial biogenesis through peroxisome proliferator-activated receptor-coactivator1α (PGC-1α), a major regulator of mitochondrial biogenesis, and its effect on the genesis of insulin resistance is organ-specific. Expressed predominantly in fat and liver tissues, betatrophin is primarily involved in lipid metabolism, and could be a putative therapeutic target in metabolic syndrome and T2D. We hypothesized that the adiponectin pathway may regulate the production and/or secretion of betatrophin in liver. We aimed to determine whether exercise and adiponectin affect betatrophin to improve insulin resistance in mice. Methods: To investigate this hypothesis, we used wild-type C57BL/6 mice subjected to a high-fat diet, an exercise regimen, and i.p. injection of recombinant mouse adiponectin (Acrp30), and adiponectin knockout (Adipoq−/−) mice (C57BL/6 background) subjected to i.p. injection of Acrp30. Results: In Adipoq–/– mice, betatrophin levels in the plasma and liver were upregulated. In mice, plasma and liver betatrophin levels were significantly upregulated following a high-fat diet. Exercise and i.p. Acrp30 downregulated betatrophin levels and increased adiponectin mRNA and protein expression in the plasma and liver. The trend of change in PGC-1α and betatrophin levels in the liver was consistent. Conclusions/interpretation: Exercise reverses pathogenic changes in adiponectin and betatrophin levels in insulin-resistant mice. Exercise increased adiponectin levels and reduced betatrophin levels. Furthermore, exercise reduced betatrophin levels via adiponectin, which modulated the LKB1/AMPK/PGC-1α signaling axis but was not solely dependent on it for exerting its effects.

Effect of physical activity in a weight loss program on circulating total ANGPTL8 concentrations in northern Americans with obesity: A prospective randomized controlled trial

BACKGROUND AND AIMS

The primary goals of this study were to clarify 1) the effect of weight loss by lifestyle intervention on circulating total angiopoietin-like protein 8 (ANGPTL8), and 2) the role of physical activity on serum total ANGPTL8 in northern Americans with obesity but without diabetes.

METHODS AND RESULTS

A total of 130 subjects with body mass index (BMI) ≧ 35 kg/m² but without diabetes were recruited, and 121 subjects completed a weight loss program for data analysis. Abdominal adipose tissue was determined by non-contrast computed tomography (CT). Serum total ANGPTL8 was higher in the group with obesity than in the lean control group. Serum total ANGPTL8 was positively correlated with waist circumference (WC), BMI, fasting insulin, HOMA-IR, HOMA-B, QUICKI, hs-CRP, IL-6, and leptin. Serum total ANGPTL8 did not significantly differ between the two intervention groups at baseline, and it was significantly lower after weight loss, with comparable changes with diet only and diet plus physical activity.

CONCLUSION

Among northern Americans with obesity but without diabetes, a lifestyle modification resulted in significant reduction of circulating total ANGPTL8 concentrations in a 6-month weight-loss period. Although addition of physical activity resulted in greater total and liver fat loss, it did not promote further significant decline of serum total ANGPTL8 beyond diet alone.

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.

The addition of exercise to a weight loss diet on inflammatory markers: a systematic review and Meta-analysis of controlled clinical trials

This systematic review and meta-analysis of controlled clinical trials was performed to evaluate the effects of weight-loss diets plus exercise compared with weight-loss diets alone on inflammatory biomarkers in adults. PubMed, Scopus, EMBASE, Web of Science (ISI), and Google Scholar were searched up to April 2021. Overall effects were derived using a random effects model. The overall quality of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Twenty-nine trials were included in this systematic review and meta-analysis. The meta-analysis showed no significant difference in serum high sensitivity C-reactive protein (hs-CRP) [weighted mean difference (WMD) = -0.004 mg/l, 95% CI: -0.140, 0.132, P = 0.954], interleukin-6 (IL-6) (WMD = -0.039 pg/ml, 95% CI: -0.233 to 0.156, P = 0.696), and tumor necrosis factor-α (TNF-α) (WMD = 0.405 ng/ml, 95% CI: -1.036 to 0.226, P = 0.209) after adding exercise to a weight-loss diet compared with a weight-loss diet alone. Subgroup analysis revealed that exercise plus a weight-loss diet significantly reduced TNF-α in studies greater than 16 weeks in duration (WMD = -0.742 ng/ml, 95% CI: -1.384 to -0.1, P = 0.024). This systematic review and meta-analysis indicate that exercise in addition to a weight-loss diet does not have a significant effect on further reducing inflammatory markers compared to a weight loss diet alone.

Associations Between Betatrophin with Irisin and Metabolic Factors: Effects of Exercise Training 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.

The effect of 4-week endurance training on serum levels of irisin and betatrophin in streptozotocin- induced diabetic rats

Betatrophin known as pancreatic β-cell proliferation marker is secreted as a result of the muscle irisin's expression induced by exercise. The present study aimed to investigate the effect of endurance training on serum levels of irisin and betatrophin in diabetic rats. Twenty-four Wistar rats were randomly divided into three groups of (1) healthy control group (H-CG), (2) diabetic control group (D-CG), and diabetic group submitted to endurance training (D-ETG). The D-ETG performed endurance exercise (4 week/5 days) on the rodent treadmill. For data analysis we used one-way ANOVA, Scheffe test and Pearson correlation coefficient. Irisin (p = .04) and betatrophin (p = .005) levels were significantly decreased in the D-CG. Endurance exercise only increased serum levels of irisin significantly (p = .03). There was a significant correlation was shown between serum betatrophin and beta-cell function (p = .03). It appears that a specific exercise training can increase irisin hormone, with possible impact on betatrophin expression in diabetic individuals.

Circulating betatrophin/ANGPTL8 levels correlate with body fat distribution in individuals with normal glucose tolerance but not those with glucose disorders

BACKGROUND

The relationship between betatrophin/ANGPTL8 and obesity has been investigated using body mass index (BMI); however, since BMI reflects overall adiposity rather than body fat distribution, it remains unclear whether fat deposition in different areas of the body affects betatrophin expression. Here, we investigated the correlation between circulating betatrophin levels and body fat distribution in patients with different glucose tolerance.

METHODS

We performed a cross-sectional study in 128 participants with impaired glucose tolerance (IGT; n = 64) or normal glucose tolerance (NGT; n = 64). Circulating betatrophin levels were detected by enzyme-linked immunosorbent assay (ELISA). Body fat distribution (subcutaneous, visceral, and limb fat) was measured by magnetic resonance imaging (MRI) and a body fat meter.

RESULTS

After controlling for age, sex, and BMI, betatrophin was correlated positively with visceral adipose tissue-to-subcutaneous adipose tissue ratio (VAT/SAT ratio; r = 0.339, p = 0.009) and negatively with body fat ratio (BFR; r = - 0.275, p = 0.035), left lower limb fat ratio (LLR; r = - 0.330, p = 0.011), and right lower limb fat ratio (RLR; r = - 0.288, p = 0.027) in the NGT group, with these correlations remaining after controlling for triglycerides. VAT/SAT ratio (standardized β = 0.419, p = 0.001) was independently associated with serum betatrophin levels; however, betatrophin was not associated with body fat distribution variables in the IGT group.

CONCLUSIONS

Circulating betatrophin levels correlated positively with VAT/SAT ratio and negatively with lower limb fat, but not with subcutaneous or upper limb fat, in individuals with normal glucose tolerance. Thus, betatrophin may be a potential biomarker for body fat distribution in individuals without glucose disorders.

Loss of Glycine N-Methyltransferase Associates with Angiopoietin-Like Protein 8 Expression in High Fat-Diet-Fed Mice

Imbalance of lipid metabolism is a main cause of metabolic syndrome leading to life-threatening metabolic diseases. Angiopoietin-like protein 8 (Angptl8) was recently identified as a liver and adipose tissue-released hormone that is one of the molecules involved in triglyceride metabolism. However, the regulatory mechanism of Angptl8 is largely unknown. A high fat diet (HFD)-fed mouse model, which showed high cholesterol, high triglyceride, and high insulin in the blood, revealed the upregulation of hepatic and plasma Angptl8 and the downregulation of hepatic glycine N-methyltransferase (GNMT). The inverse correlation of hepatic Angptl8 and GNMT expression in the livers of HFD-fed mice was also confirmed in a publicly available microarray dataset. The mechanistic study using primary hepatocytes showed that the Angptl8 expression could be induced by insulin treatment in a dose- and time-dependent manner. Inhibition of PI3K/Akt pathway by the specific inhibitors or the dominant-negative Akt blocked the insulin-induced Angptl8 expression. Moreover, knockout of GNMT promoted the Akt activation as well as the Angptl8 expression. These results suggested that GNMT might be involved in insulin-induced Angptl8 expression in HFD-mediated metabolic syndrome.