Effects of aerobic training on serum omentin-1 and cardiometabolic risk factors in overweight and obese men

The effects of extracellular vesicles and their cargo on metabolism and its adaptation to physical exercise in insulin resistance and type 2 diabetes

Lifestyle modification represents the first-line strategy for the prevention and treatment of type 2 diabetes mellitus (T2DM), which is frequently associated with obesity and characterized by defective pancreatic insulin secretion and/or insulin resistance. Exercise training is an essential component of lifestyle modification and has been shown to ameliorate insulin resistance by reducing body fat mass and by enhancing skeletal muscle mitochondrial biogenesis and insulin-independent glucose uptake. Additionally, exercising stimulates the release of exerkines such as metabolites or cytokines, but also long non-coding RNA, microRNAs, cell-free DNA (cf-DNA), and extracellular vesicles (EVs), which contribute to inter-tissue communication. There is emerging evidence that EV number and content are altered in obesity and T2DM and may be involved in several metabolic processes, specifically either worsening or improving insulin resistance. This review summarizes the current knowledge on the metabolic effects of exercise training and on the potential role of humoral factors and EV as new biomarkers for early diagnosis and tailored treatment of T2DM.

Enhancing cardiometabolic health: unveiling the synergistic effects of high-intensity interval training with spirulina supplementation on selected adipokines, insulin resistance, and anthropometric indices in obese males

This study investigated the combined effects of 12 weeks of high-intensity interval training (HIIT) and spirulina supplementation on adipokine levels, insulin resistance, anthropometric indices, and cardiorespiratory fitness in 44 obese males (aged 25-40 years). The participants were randomly assigned to one of four groups: control (CG), supplement (SG), training (TG), or training plus supplement (TSG). The intervention involved daily administration of either spirulina or a placebo and HIIT three times a week for the training groups. Anthropometric indices, HOMA-IR, VO2peak, and circulating adipokines (asprosin and lipocalin2, omentin-1, irisin, and spexin) were measured before and after the 12-week intervention. Post-intervention analysis indicated differences between the CG and the three interventional groups for body weight, fat-free mass (FFM), percent body fat (%BF), HOMA-IR, and adipokine levels (p < 0.05). TG and SG participants had increased VO2peak (p < 0.05). Spirulina supplementation with HIIT increased VO2peak, omentin-1, irisin, and spexin, while causing decreases in lipocalin-2 and asprosin levels and improvements in body composition (weight, %fat), BMI, and HOMA-IR. Notably, the combination of spirulina and HIIT produced more significant changes in circulating adipokines and cardiometabolic health in obese males compared to either supplementation or HIIT alone (p < 0.05). These findings highlight the synergistic benefits of combining spirulina supplementation with HIIT, showcasing their potential in improving various health parameters and addressing obesity-related concerns in a comprehensive manner.

Effect of Exercise Training on Some Anti-Inflammatory Adipokines, High Sensitivity C-Reactive Protein, and Clinical Outcomes in Sedentary Adults With Metabolic Syndrome

OBJECTIVE

This study aimed to investigate the effects of aerobic interval training and resistance training on anti-inflammatory adipokines, high sensitivity C-reactive protein, and clinical outcomes in sedentary men with metabolic syndrome.

METHODS

A total of 33 sedentary men with metabolic syndrome (age: 46.2 ± 4.6 years; body mass index: 35.4 ± 1.9 kg.m2) were randomly assigned to one of 3 groups: aerobic interval training (n = 12), resistance training (n = 10), or control (n = 11). Participants in the exercise groups completed a 12-week training program, 3 sessions per week, while those in the control group maintained their sedentary lifestyle. The levels of high sensitivity C-reactive protein (hs-CRP), omentin-1, adiponectin, lipid profiles, blood pressure, glucose metabolism, body composition, and peak oxygen uptake (VO2peak) were measured at baseline and after the intervention.

RESULTS

Both aerobic interval training and resistance training significantly improved the levels of omentin-1 and adiponectin, as well as reduced inflammation, as indicated by a decrease in hs-CRP levels. Exercise training also led to significant improvements in lipid profiles, blood pressure, glucose metabolism, and body composition. Specifically, the aerobic interval training group had significantly greater increases in high-density lipoprotein cholesterol and VO2peak, as well as greater reductions in low-density lipoprotein cholesterol, triglycerides, and total cholesterol compared to the resistance training group.

CONCLUSION

Exercise training, particularly aerobic interval training and resistance training, can be an effective non-pharmacological intervention for managing inflammation and improving cardiovascular health in metabolic syndrome patients.

Effects of increasing light versus moderate-to-vigorous physical activity on cardiometabolic health in Chinese adults with obesity

Increasing daily physical activity (PA) is a practical way to decrease the risk of cardiometabolic diseases, while the studies on exercise intensity remain limited. The purpose of the present study was to compare the effects of increasing light PA (LPA) or moderate-to-vigorous PA (MVPA) for 12 weeks on cardiometabolic markers in Chinese adults with obesity. Fifty-three adults were randomly assigned to the 1) control group, 2) LPA group, and 3) MVPA group in free-living settings. The intervention effects on body composition, cardiorespiratory fitness, and cardiometabolic biomarkers were analysed using a generalized estimated equation model adjusted for baseline values and potential confounders. Compared with the control group, the MVPA group showed improvements in body composition, lipids, C-peptide, monocyte chemoattractant protein-1 (MCP-1), interleukin-8, leptin, and E-selectin. A favourable change in triglycerides and E-selectin were observed in the LPA group when compared to the control group. Lastly, improvements in waist circumference, C-reactive protein, and MCP-1 were observed in the MVPA group when compared to those in the LPA group. Although increasing both LPA and MVPA improved certain cardiometabolic biomarkers, the latter may have more benefits. These findings imply that MVPA may reduce cardiometabolic disease risk more effectively than LPA, especially in Chinese adults with obesity.

Aerobic Exercise Training Effects on Omentin-1, Insulin Resistance, and Lipid Profile Among Male Smokers

Background: Omentin-1 is a circulating adipokine that can serve as a biomarker for assessment of metabolic risk factors. We investigated the effect of eight weeks of aerobic exercise training on serum omentin-1, insulin resistance and lipid profile in nonsmokers and smokers. Methods: Nineteen male nonsmokers (aged 27.88 ± 2.47 years, and with BMI of 22.69 ± 1.77 kg.m-2) and twenty male smokers (aged 30.11 ± 1.96 years, and with BMI of 23.12 ± 1.91 kg.m-2) were randomly assigned into nonsmokers control group (C), nonsmokers exercise group (E), control smoker group (CS), and exercise smoker group (ES). Exercise groups participated in an eight-week aerobic exercise training program (three times a week, 20-35 min per session at 55%-70% of maximum heart rate). Serum omentin-1 and insulin values were determined by ELISA. The Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), glucose level and lipid profile were measured before and after the intervention. Pearson correlation test, Eta test, paired samples t-test, one and two-way analysis of variance (ANOVA) and post-hoc Tukey test were applied for data analysis (p < .05). Results: Aerobic exercise improved both serum omentin-1 and high lipoprotein cholesterol (HDL-C) in the exercise groups (P < .05). Also, exercise training reduced insulin, glucose, HOMA-IR, triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels (p < .05). Omentin-1 was significantly correlated with glucose, insulin, HOMA-IR, TG, TC, LDL-C and HDL-C in both nonsmokers and smokers. Conclusions: The findings suggest that aerobic exercise-induced changes in omentin-1 in the exercise-trained groups may be associated with the beneficial effects of exercise on reduced insulin resistance and lipid profile.

Impact of Two Types of Exercise Interventions on Leptin and Omentin Concentrations and Indicators of Lipid and Carbohydrate Metabolism in Males with Metabolic Syndrome

Leptin (LEP) and omentin (OMEN) are proteins whose concentrations change with the development of the metabolic syndrome (MetS). There are few intervention studies using various forms of physical activity in people with MetS that aim to determine the impact of physical exercise on the fluctuations of the presented hormones, and their results are contradictory. The present study aimed to examine the effect of two types of exercise intervention on LEP and OMEN concentrations and indicators of lipid and carbohydrate metabolism in males with MetS. The study included 62 males with MetS (age 36.6 ± 6.9 years, body mass 110.31 ± 17.37 kg), randomly allocated to EG1, the examined group with aerobic training (n = 21); EG2, the examined group with combined aerobic and resistance training (n = 21), both for 12 weeks, and the control group (CG) without interventions (n = 20). Anthropometric measurements, body composition (body fat [BF], android body fat [ANDR]), as well as a biochemical blood analysis (omentin [OMEN], leptin [LEP], quantitative insulin sensitivity check index [QUICKI], high-density lipoprotein cholesterol [HDL-C] and nonHDL-C) were performed at baseline, and at 6 and 12 weeks of interventions and after 4 weeks after ending intervention (follow-up). Intergroup and intragroup comparisons were performed. In the intervention groups EG1 and EG2, a decrease in BF was observed as well as an improvement in carbohydrate metabolism parameters. In the EG1 group, the level of ANDR was reduced. In EG2 a decrease in LEP concentration between measurements was confirmed. However, no significant changes were found in the concentration of OMEN in any groups. Combined aerobic and resistance exercises led to a higher reduction of LEP concentration than applying only aerobic training in males with MetS.

Long-term effects of different exercise training modes on cytokines and adipokines in individuals with overweight/obesity and cardiometabolic diseases: A systematic review, meta-analysis, and meta-regression of randomized controlled trials

The present study aimed to investigate the evidence on the effects of different long-term training interventions (aerobic [AeT], resistance [RT], and combined [COMB]) and spontaneous physical activity (PA) in modifying cytokines and adipokines in individuals with overweight or obesity with or without cardiometabolic diseases while considering potential confounders. Although exercise interventions have become a potentially effective tool for preventing and treating metabolic diseases, the evidence provided by previous systematic reviews is inconclusive since several potential confounders have yet to be addressed. Therefore, we conducted a systematic literature search in Medline, Cochrane, and Embase databases from January 2000 to July 2022 and performed a meta-analysis. Inclusion criteria retrieved 106 full texts comprising 8,642 individuals with a range BMI of 25.1-43.8 kg m^-2 . We found that independently of the training mode, exercise had a beneficial effect on diminishing Adiponectin, C-reactive protein (CRP), IL-6, IL-18, IL-20, Leptin, sICAM, and TNF-α levels circulating levels. Furthermore, by subsequent analysis, we detected differential effects of AeT, RT, and COMB, with sex, age, body composition, and trial length acting as moderators. The comparison of training modes revealed a difference favoring COMB over AeT for regulating the increase in CRP with no differences in the remaining biomarkers. Meta-regression analysis revealed an effect of change in maximal oxygen uptake (VO_2max ) on CRP, IL-6, and TNF-α, while IL-10 was influenced by the change in body fat. The results suggest that all interventions, except PA, are effective in lessening this population's inflammatory status, provided that exercise results in an increase of VO_2max .

The impact of high intensity interval training on serum omentin-1 levels, lipid profile, and insulin resistance in obese men with type 2 diabetes mellitus

BACKGROUND: High-intensity interval training (HIIT) is an effective exercise method that could lead to favorable changes in obese and diabetic subjects. OBJECTIVE: To investigate the effects of HIIT on serum omentin-1 levels, lipid profile, and insulin resistance in diabetic obese men. METHODS: Fifty obese men suffering from T2DM with ages between 40 and 60 years were enrolled. Subjects were divided into two groups: the HIIT (n= 26) and control group (n= 24). The HIIT group subjects underwent 12 weeks (3 sessions per week) of HIIT program, while the control group subjects kept to their normal daily activities. Fasting blood glucose levels, serum omentin-1 levels, lipid profile, and insulin resistance were evaluated at baseline and after the experiment. RESULTS: HIIT resulted in significant improvements in the subjects’ body composition, serum omentin-1 levels, lipid profiles, fasting insulin, HOMA-IR (p< 0.05). Further, highly significant negative correlations were observed between serum omentin levels, on the one hand, and body mass index, body weight, and waist circumference, on the other. CONCLUSIONS: Twelve weeks of HIIT may be an effective training strategy to improve serum omentin-1 levels, body composition, lipid profile, and insulin sensitivity in diabetic obese men.

Association between sedentary behavior, physical activity, and cardiovascular disease-related outcomes in adults-A meta-analysis and systematic review

Background

Sedentary behavior (SB) and physical activity (PA) are modifiable risk factors for cardiovascular disease (CVD); however, previous research on the effects of PA and SB on CVD has been relatively homogeneous. Our study investigated the association between PA, SB, and CVD-related outcomes.

Methods

A comprehensive search strategy was conducted in the MEDLINE, Embase, Cochrane Library, and Web of Science databases from their inception to September 2022. We identified eligible studies according to PICOS: the populations comprised healthy adults, the interventions or exposures were PA or SB, the outcomes were CVD-related outcomes, and the study designs were randomized controlled trials (RCTs) and longitudinal studies (LS). Outcomes were pooled using fixed or random effects models, and the quality of individual studies was assessed by the Cochrane Risk of Bias Instrument and the Newcastle Ottawa Scale.

Results

A total of 148 RCTs and 36 LS were included, comprising a total of 75,075 participants. The study quality was rated as low to moderate. We found an increased hazard ratio (HR) for CVD in the population with SB (HR = 1.34; 95% confidence interval [CI]: 1.26 to 1.43; I² = 52.3%; P_{heterogeneity} < 0.001, random model) and a decreased HR for CVD in those who performed long-term PA (HR = 0.71; 95% CI: 0.66 to 0.77; I² = 78.0%, P_{heterogeneity} < 0.001, random model). Long-term PA improved the lipid profiles in healthy adults; participants in this group exhibited increased high-density lipoprotein (weighted mean difference [WMD] = 2.38; 95% CI: 1.00 to 3.76; I² = 84.7%; P_{heterogeneity} < 0.001, random model), decreased triglycerides (WMD = -7.27; 95% CI: -9.68 to -4.87; I² = 0%, P_{heterogeneity} = 0.670, fixed model), and lower total-cholesterol (WMD = -6.84; 95% CI: -9.15 to -4.52; I² = 38.4%, P_{heterogeneity} < 0.001, random model).

Conclusions

Long-term SB increases the risk of CVD in healthy adults, whereas PA reduces the risk of CVD and improves indicators associated with CVD. However, the ability of PA to improve blood lipids appeared to be limited. The detailed association of SB and PA on CVD needs to be further investigated in the future.

The effect of two types of diet on apoptosis indexes, lipid profile and histopathological outcome in acute kidney injury during exercise

Background

Exercise and some pre-AKI diets have been shown to improve injury, apoptosis, and lipid profile. In this study, the effect of two different diets along with exercise training on acute kidney injury (AKI) was investigated. 

Materials and methods

Laboratory rats were randomly divided into four groups of control, standard diet + exercise, exercise + calorie restriction (CR) and exercise + time restriction (TR). Each group was divided into two subgroups of AKI and no AKI. The animals received endurance training and diet regimens before AKI. Fasting blood glucose, serum creatinine, Bcl-2-associated X protein (Bax), B-cell lymphoma 2 (Bcl2) and histopathological outcome of renal tissue as well as serum lipid profile of animals were assessed 24 h after AKI. 

Results

The percentage of changes in renal Bcl2 and Bax after AKI in the group with previous exercise was lower than the group without previous exercise (p < 0.01). After induction of AKI, serum lipid profile changed in non-exercised rats (p < 0.001). Also, after injury, fasting blood glucose levels increased in non-exercised rats (p < 0.05). After injury, the start of both CR and TR diets during exercise caused less change in Bcl2 and Bax of non-exercised rats compared to exercised rats (p < 0.001). CR diet along with exercise improved lipid profile, and also CR diet along exercise decreased fasting blood glucose levels (p < 0.001). Also, both the CR and TR diets during exercise caused fewer changes in histopathological outcome after AKI.

Conclusion

Exercise alone decreased changes in apoptotic and histopathological indexes, fasting blood glucose, as well as lipid profile of rats after AKI. Reduction of apoptosis and improvement of histopathological outcome after AKI appeared more when CR and TR diets were commenced during exercise. The reduction of lipid profile changes was more pronounced in the group that received CR diet during exercise.

Effects of High-Intensity Interval Training on Selected Adipokines and Cardiometabolic Risk Markers in Normal-Weight and Overweight/Obese Young Males-A Pre-Post Test Trial

The study aimed to assess effects of high-intensity interval training (HIIT) on plasma adipokines and cardiometabolic markers in normal and excess weight youth. Eighteen healthy young males (18.2 ± 1.06 yrs.) were divided in normal-weight group (NWG; body mass index (BMI), 20.5 ± 1.51 kg/m2; n = 9) and excess-weight group (EWG; BMI, 30.8 ± 4.56 kg/m2; n = 9). Participants performed an eight-week HIIT program without caloric restriction. Body composition, plasma leptin, adiponectin, chemerin, omentin-1, lipids, C-reactive protein (CRP), and the homeostasis model assessment index for insulin resistance (HOMA-IR) were assessed before and after the HIIT program. The program resulted in significant increases in omentin levels (p < 0.01) in EWG (27%) and NWG (22%), but no changes in leptin, adiponectin, and chemerin in both groups. BMI (−1.62%; p = 0.015), body fat (−1.59%; p = 0.021), total cholesterol (−11.8%; p = 0.026), triglycerides (−21.3%; p = 0.023), and HOMA-IR (−31.5%; p = 0.043) decreased in EWG only. Repeated measures detected significant interaction “Time x Group” for body mass and BMI only. Eight-week HIIT program improved body composition, lipid profile, and insulin sensitivity in excess-weight individuals. It resulted in an increase in omentin levels in both normal- and excess-weight groups, but no changes in leptin, adiponectin, and chemerin. Body composition has not influenced the response of the four adipokines to HIIT.

Effects of regular physical exercise on skin blood flow and cardiovascular risk factors in overweight and obese subjects

Objective: it is well known that low omentin levels and reduced bioavailability of nitric oxide (NO) are outgrowth of obesity. Besides, in obese subjects, microvascular dysfunction can be an initial stage of cardiovascular diseases. This situation can be evaluated with skin laser–Doppler flowmetry (LDF).Methods: in this study we investigated the effects of 12 weeks moderate physical exercise on microvascular reactivity and plasma levels of omentin and NO in 25 overweight and obese subjects. Control group was composed of 28 sedentary participants who were neither obese nor overweight. Microvascular reactivity was handled by measurement of skin blood flow from the ring finger of the right hand with LDF, which is a non–invasive method for evaluation. With this method, it was aimed to examine the post–occlusive reactive hyperemia response of the patients. None of the participants in both groups have never followed a regular exercise schedule in their life span.Results: with regular exercise, there was a statistically significant decrease in glucose (p=0.008), cholesterol (p=0.05), and triglyceride (p=0.048) levels, while body mass index, high–density lipoprotein, and low–density lipoprotein levels did not change significantly in overweight/obese group. Also, the omentin level significantly increased (p=0.01), but NO level did not change significantly. Moreover, the amount of change in omentin and NO levels measured before and after the physical exercise were significantly correlated (r=0.57). Considering the microcirculation, rest flow (p=0.001) and peak flow value of LDF (p=0.001) increased after the physical exercise.Conclusion: our study shows that moderate physical exercise affects microvascular reactivity and plasma levels of omentin in overweight and obese subjects.

Omentin-1: A newly discovered warrior against metabolic related diseases

INTRODUCTION

: Chronic metabolism-related diseases are challenging clinical problems. Omentin-1 is mainly expressed in stromal vascular cells of adipose tissue and can also be expressed in airway goblet cells, mesothelial cells, and vascular cells. Omentin-1 has been found to exert important anti-inflammatory, antioxidative and anti-apoptotic roles and to regulate endothelial dysfunction. Moreover, omentin-1 also has protective effects against cancer, atherosclerosis, type 2 diabetes mellitus, and bone metabolic diseases. The current review will discuss the therapeutic potential of omentin-1.

AREAS COVERED

: This review summarizes the biological actions of omentin-1 and provides an overview of omentin-1 in metabolic-related diseases. The relevant literature was derived from a PubMed search spanning 1998-2021 using these search terms: omentin-1, atherosclerosis, diabetes mellitus, bone, cancer, inflammation, and oxidative stress.

EXPERT OPINION

: As a novel adipocytokine, omentin-1 is a promising therapeutic target in metabolic-related diseases. Preclinical animal studies have shown encouraging results. Moreover, circulating omentin-1 has excellent potential as a noninvasive biomarker. In the future, strategies for regulating omentin-1 need to be investigated further in clinical trials in a large cohort.

Relationships between serum omentin-1 concentration, body composition and physical activity levels in older women

This study aimed to investigate the relationships between omentin-1, body composition and physical activity (PA) levels in older women.Eighty-one older women (age = 64 ± 6years; body mass index = 24.2 ± 3.2 kg/m2; body fat percentage = 36.1 ± 5.7%) participated in this study. We divided the subjects into overweight/obesity and normal weight group. Body composition was measured by dual energy X-ray absorptiometry. Serum omentin-1 concentration was measured using enzyme linked immunosorbent assay. PA levels were obtained by using accelerometers. In addition, anthropometric and insulin resistance values were determined.Omentin-1 level in overweight/obesity group was significantly lower than in the normal weight group (P < .01). Analysis of all subjects showed that serum omentin-1 was negatively correlated with body weight, BMI (body mass index), waist circumference (WC), WHR (waist-to-hip ratio), percentage of body fat, total body fat mass (FM), fat-free mass (FFM) (r = -.571, -0.569, -0.546, -0.382, -0.394, -0.484, -0.524, all P < .01), respectively. We also found a negative correlation between moderate-to-vigorous physical activity (MVPA) and total body FM (r = -.233, P < .05). However, no significant correlation was found between omentin-1 and sedentary behavior and MVPA (both P > .05). Moreover, the relationship between omentin-1, body composition and PA was analyzed by using multiple linear stepwise regressions. The results showed that serum omentin-1 concentration was inversely correlated with total body FM (β = -0.334, P = .004) in multiple linear stepwise regression analysis.We found that total body FM was inversely related to serum omentin-1 concentration and PA levels, but there was no correlation between omentin-1 and PA levels. These results showed that PA may participate in the regulation of body composition, which may be also affected by serum omentin-1. However, the mechanism by which PA affects body composition may not be through omentin-1 and was more likely through other metabolic pathways.

Walking for hypertension

BACKGROUND

Increased physical activity has been recommended as an important lifestyle modification for the prevention and control of hypertension. Walking is a low-cost form of physical activity and one which most people can do. Studies testing the effect of walking on blood pressure have revealed inconsistent findings.

OBJECTIVES

To determine the effect of walking as a physical activity intervention on blood pressure and heart rate.

SEARCH METHODS

We searched the following databases up to March 2020: the Cochrane Hypertension Specialised Register, CENTRAL (2020, Issue 2), Ovid MEDLINE, Ovid Embase, CINAHL, PsycINFO, SPORTDiscus, PEDro, the WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also searched the following Chinese databases up to May 2020: Index to Taiwan Periodical Literature System; National Digital Library of Theses and Dissertation in Taiwan; China National Knowledge Infrastructure (CNKI) Journals, Theses & Dissertations; and Wanfang Medical Online. We contacted authors of relevant papers regarding further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

Randomised controlled trials of participants, aged 16 years and over, which evaluated the effects of a walking intervention compared to non-intervention control on blood pressure and heart rate were included.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Where data were not available in the published reports, we contacted authors. Pooled results for blood pressure and heart rate were presented as mean differences (MDs) between groups with 95% confidence intervals (CIs). We undertook subgroup analyses for age and sex. We undertook sensitivity analyses to assess the effect of sample size on our findings.

MAIN RESULTS

A total of 73 trials met our inclusion criteria. These 73 trials included 5763 participants and were undertaken in 22 countries. Participants were aged from 16 to 84 years and there were approximately 1.5 times as many females as males. The characteristics of walking interventions in the included studies were as follows: the majority of walking interventions was at home/community (n = 50) but supervised (n = 36 out of 47 reported the information of supervision); the average intervention length was 15 weeks, average walking time per week was 153 minutes and the majority of walking intensity was moderate. Many studies were at risk of selection bias and performance bias. Primary outcome We found moderate-certainty evidence suggesting that walking reduces systolic blood pressure (SBP) (MD -4.11 mmHg, 95% CI -5.22 to -3.01; 73 studies, n = 5060). We found moderate-certainty evidence suggesting that walking reduces SBP in participants aged 40 years and under (MD -4.41 mmHg, 95% CI -6.17 to -2.65; 14 studies, n = 491), and low-certainty evidence that walking reduces SBP in participants aged 41 to 60 years (MD -3.79 mmHg, 95% CI -5.64 to -1.94, P < 0.001; 35 studies, n = 1959), and those aged 60 years of over (MD -4.30 mmHg, 95% CI -6.17 to -2.44, 24 studies, n = 2610). We also found low certainty-evidence suggesting that walking reduces SBP in both females (MD -5.65 mmHg, 95% CI -7.89 to -3.41; 22 studies, n = 1149) and males (MD -4.64 mmHg, 95% CI -8.69 to -0.59; 6 studies, n = 203). Secondary outcomes We found low-certainty evidence suggesting that walking reduces diastolic blood pressure (DBP) (MD -1.79 mmHg, 95% CI -2.51 to -1.07; 69 studies, n = 4711) and heart rate (MD -2.76 beats per minute (bpm), 95% CI -4.57 to -0.95; 26 studies, n = 1747). We found moderate-certainty evidence suggesting that walking reduces DBP for participants aged 40 years and under (MD -3.01 mmHg, 95% CI -4.44 to -1.58; 14 studies, n = 491) and low-certainty evidence suggesting that walking reduces DBP for participants aged 41 to 60 years (MD -1.74 mmHg, 95% CI -2.95 to -0.52; 32 studies, n = 1730) and those aged 60 years and over (MD -1.33 mmHg, 95% CI -2.40 to -0.26; 23 studies, n = 2490). We found moderate-certainty evidence that suggests walking reduces DBP for males (MD -2.54 mmHg, 95% CI -4.84 to -0.24; 6 studies, n = 203) and low-certainty evidence that walking reduces DBP for females (MD -2.69 mmHg, 95% CI -4.16 to -1.23; 20 studies, n = 1000). Only 21 included studies reported adverse events. Of these 21 studies, 16 reported no adverse events, the remaining five studies reported eight adverse events, with knee injury being reported five times.

AUTHORS' CONCLUSIONS

Moderate-certainty evidence suggests that walking probably reduces SBP. Moderate- or low-certainty evidence suggests that walking may reduce SBP for all ages and both sexes. Low-certainty evidence suggests that walking may reduce DBP and heart rate. Moderate- and low-certainty evidence suggests walking may reduce DBP and heart rate for all ages and both sexes.

The effects of physical activity on adipokines in individuals with overweight/obesity across the lifespan: A narrative review

This narrative review summarizes current knowledge on the effects of physical activity (PA) on adipokine levels in individuals with overweight and obesity. Approximately 90 investigations including randomized control, cross-sectional and longitudinal studies that reported on the effects of a single session of PA (acute) or long-term PA (chronic) on adipokine levels in individuals with overweight/obesity were reviewed. The findings support the notion that there is consensus on the benefits of chronic exercise training-regardless of the mode (resistance vs. aerobic), intensity and cohort (healthy vs. diabetes)-on adipokine levels (such as tumour necrosis factor-alpha, interleukin-6, adiponectin, visfatin, omentin-1 and leptin). However, several confounding factors (frequency, intensity, time and type of exercise) can alter the magnitude of the effects of an acute exercise session. Available evidence suggests that PA, as a part of routine lifestyle behaviour, improves obesity complications by modulating adipokine levels. However, additional research is needed to help identify the most effective interventions to elicit the most beneficial changes in adipokine levels in individuals with overweight/obesity.

Effects of a One-week Vacation with Various Activity Programs on Metabolism and Adipokines

This study was conducted as part of a larger study of East Tyrolean health tourism, and investigates the effects of an active seven-day vacation on metabolic parameters and adipokines. Fifty-two healthy vacationers participated in two types of vacation activities (golf vs. Nordic walking or e-biking [nw&eb]). In the former group, 30 subjects played golf for a mean duration of 33.5 h per week; in the NW&EB group, 22 persons performed Nordic walking or e-biking for a mean duration of 14.2 h per week. Metabolic parameters and adipokines, such as leptin, adiponectin, GF-21, irisin, omentin-1, betatrophin, and resistin, were measured one day before and one day after the stay. After one week, only the NW&EB group experienced a significant decrease of 1.0 kg in body weight. Significant changes in HDL-C, FGF-21, irisin, and omentin-1 were seen in the golf group; and in triglycerides, HbA1c, leptin and adiponectin in the NW&EB group. No significant changes in betatrophin or resistin were registered in either group. A seven-day vacation with an activity program for several hours per week causes favorable changes in metabolic parameters and adipokines known to be involved in the pathophysiology of the metabolic syndrome. The changes differed in their magnitude and significance, depending on the type of activity.

Role of swimming on muscle PGC-1α, FNDC5 mRNA, and assessment of serum omentin, adropin, and irisin in high carbohydrate high fat (HCHF) diet induced obesity in rats

Background

Exercise benefits a variety of organ systems in mammals, and some of the best recognized effects of exercise on muscle are mediated by the transcriptional peroxisome proliferator-activated receptor gamma co-activator 1-α (PGC-1α). The regulatory effect of swimming on muscle PGC-1α, FNDC5 mRNA expression, and subsequently irisin levels is more controversial. This study aimed to investigate the role of swimming as an exercise on the expression of peroxisome proliferator-activated receptor-gamma coactivator1 alpha (PGC-1α) and Fibronectin type III domain containing 5 (FNDC5) mRNA in skeletal muscle and assessment of serum omentin, adropin, irisin, and PGC-1α levels in high carbohydrate high fat (HCHF) diet induced obesity in rats. Sixty male albino rats are randomly divided into 4 groups (15 rats/group). In the first group (control), rats are fed with standard diet. The 2nd group (cont + swim) is fed on standard diet and made swimming exercise. The 3rd group of rats is fed on HCHF, whereas in the 4th group (HCHF + swim) is also fed on HCHF diet and made swimming exercise for 20 weeks. Blood glucose, insulin, HOMA-IR, lipid profile, omentin, irisin, adropin, and PGC-1α were measured. Also, FNDC5 and PGC-1α are extracted and purified from muscle tissue samples measured by PCR test.

Results

Our results showed significant increase in glucose, insulin, insulin resistance, cholesterol, and triglycerides with significant decrease in omentin, irisin, adropin, PGC-1α, and HDL in HCHF group as compared to the control group. These results improved after exercise in all parameter in HCHF + swim group compare to HCHF group. Also, there was inverse correlation between omentin and fasting glucose and HOMA-IR in HCHF + swim group.

Conclusions

It concluded that swimming exercise improved all the above measured parameters in serum and tissues which might have been promising for the prevention of metabolic diseases.

The association between serum omentin level and bodyweight: A systematic review and meta-analysis of observational studies

BACKGROUND AND AIMS

A number of studies have examined the association between omentin and body weight, but the findings have been inconclusive. Here in, we systematically reviewed available observational studies to elucidate the overall relationship between omentin and body weight, by comparison of serum omentin level in overweight/obese and normal weight subjects.

METHODS

PubMed, Science direct, Scopus and ISI web of science databases were searched for all available literature until January 2020 for studies assessing the association between omentin and body weight. The Newcastle-Ottawa Quality Assessment Scale was used to assess the quality of each study.

RESULTS

A total of 27 articles met the inclusion criteria and were included in our systematic review and meta-analysis. There was a significant association between omentin serum level and body weight (Standard Mean Difference (SMD) -0.43; 95% CI, -0.70 to -0.15; P = 0.002; I² = 93.2%). In order to find the probable source of heterogeneity subgroup analysis based on the participants' age (adolescent, adult), gender (male, female, both gender), health status (healthy, unhealthy), geographical location (Asian, non-Asian countries), study quality (low, medium, high), study design (case-control, cross-sectional), participants' health status (healthy, unhealthy) and BMI (obese, overweight) was carried out.

CONCLUSION

According to what was discussed, we found that serum omentin level is significantly lower in overweight subjects but not obese ones. This finding should be interpreted cautiously because of significant heterogeneity among included studies.

ITLN1 modulates invasive potential and metabolic reprogramming of ovarian cancer cells in omental microenvironment

Advanced ovarian cancer usually spreads to the omentum. However, the omental cell-derived molecular determinants modulating its progression have not been thoroughly characterized. Here, we show that circulating ITLN1 has prognostic significance in patients with advanced ovarian cancer. Further studies demonstrate that ITLN1 suppresses lactotransferrin’s effect on ovarian cancer cell invasion potential and proliferation by decreasing MMP1 expression and inducing a metabolic shift in metastatic ovarian cancer cells. Additionally, ovarian cancer-bearing mice treated with ITLN1 demonstrate marked decrease in tumor growth rates. These data suggest that downregulation of mesothelial cell-derived ITLN1 in the omental tumor microenvironment facilitates ovarian cancer progression.

Advanced ovarian cancer usually spreads to the omentum. Here, the authors show that circulating intelectin-1 (ITLN1) has prognostic significance in patients with advanced ovarian cancer, and that mesothelial cell-derived ITLN1 in the omental tumor microenvironment suppresses ovarian cancer progression.

Link between omentin-1, obesity and insulin resistance in children: Findings from a longitudinal intervention study

OBJECTIVE

The adipokine omentin-1 has been suggested to be inversely associated with obesity and insulin resistance in humans. We studied the relationships between omentin-1, parameters of fat mass, insulin resistance, lipids and blood pressure in children with obesity in a longitudinal study.

METHODS

We analysed omentin-1 concentrations in 23 normal-weight children and in 82 children with obesity participating in a one-year lifestyle intervention. In the children with obesity, omentin-1, bioactive and conventional leptin, thyroid hormones (thyroid-stimulating hormone, free thyroxine 4, free triiodothyronine), body mass index, waist circumference, body fat based on skin-fold measurements and bioimpedance analyses, lipids, insulin resistance as homeostatic model assessment of insulin resistance (HOMA-IR) and blood pressure were determined at baseline and 1 year later. Furthermore, we measured omentin-1 concentrations 1 year after the end of the lifestyle intervention.

RESULTS

The omentin-1 concentrations were significantly (P = .008) lower in children with obesity compared to normal-weight children (296 ± 108 ng ml^-1 vs. 232 ± 99 ng ml^-1 ). Omentin-1 concentrations increased significantly (P < .001) in children with obesity and substantial weight loss (35 ± 55 ng ml^-1 ), while omentin-1 concentrations did not change significantly (P = .750) in children with obesity without weight loss (-5 ± 108 ng ml^-1 ) during the intervention. Substantial weight loss after the end of intervention led to a significant (P < .001) increase of omentin-1 concentrations (+64 ± 14 ng ml^-1 ). Omentin-1 was significantly and negatively associated with HOMA-IR both in cross-sectional (r = -.27, P = .006) and longitudinal analyses (r = -.33, P = .001). Omentin-1 concentrations were not related to pubertal stage, sex or thyroid hormones.

CONCLUSIONS

Our data do support the hypothesis that omentin-1 is reversibly decreased in obesity and is a link between obesity and insulin resistance.

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

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

Mechanistic Links Between Obesity, Diabetes, and Blood Pressure: Role of Perivascular Adipose Tissue

Obesity is increasingly prevalent and is associated with substantial cardiovascular risk. Adipose tissue distribution and morphology play a key role in determining the degree of adverse effects, and a key factor in the disease process appears to be the inflammatory cell population in adipose tissue. Healthy adipose tissue secretes a number of vasoactive adipokines and anti-inflammatory cytokines, and changes to this secretory profile will contribute to pathogenesis in obesity. In this review, we discuss the links between adipokine dysregulation and the development of hypertension and diabetes and explore the potential for manipulating adipose tissue morphology and its immune cell population to improve cardiovascular health in obesity.

Adipose Tissue-Derived Signatures for Obesity and Type 2 Diabetes: Adipokines, Batokines and MicroRNAs

: Obesity is one of the main risk factors for type 2 diabetes mellitus (T2DM). It is closely related to metabolic disturbances in the adipose tissue that primarily functions as a fat reservoir. For this reason, adipose tissue is considered as the primary site for initiation and aggravation of obesity and T2DM. As a key endocrine organ, the adipose tissue communicates with other organs, such as the brain, liver, muscle, and pancreas, for the maintenance of energy homeostasis. Two different types of adipose tissues-the white adipose tissue (WAT) and brown adipose tissue (BAT)-secrete bioactive peptides and proteins, known as "adipokines" and "batokines," respectively. Some of them have beneficial anti-inflammatory effects, while others have harmful inflammatory effects. Recently, "exosomal microRNAs (miRNAs)" were identified as novel adipokines, as adipose tissue-derived exosomal miRNAs can affect other organs. In the present review, we discuss the role of adipose-derived secretory factors-adipokines, batokines, and exosomal miRNA-in obesity and T2DM. It will provide new insights into the pathophysiological mechanisms involved in disturbances of adipose-derived factors and will support the development of adipose-derived factors as potential therapeutic targets for obesity and T2DM.

Myokine/Adipokine Response to "Aerobic" Exercise: Is It Just a Matter of Exercise Load?

Purpose

Exercise health benefits are partly mediated by exertional changes in several myokines/adipokines. This study aimed to compare the acute response of some of these biomarkers to aerobic exercise performed at the intensity corresponding to the maximum fat oxidation rate (FATmax) or the “anaerobic” threshold (AT).

Methods

Following a cross-over, counterbalanced design, 14 healthy untrained men (23 ± 1 years) performed a 45-min exercise bout at their FATmax or AT intensity (been previously determined through incremental exercise tests). The concentration of interleukin (IL)-15, follistatin, myostatin, fibroblast-growth factor (FGF)-21, irisin, resistin, and omentin was measured at baseline and 0, 1, 3, 24, 48, and 72 h post-exercise.

Results

AT exercise was performed at a higher intensity (85 ± 8 vs. 52 ± 14% of maximal oxygen uptake [VO_{2 max}], p < 0.001) and induced a higher energy expenditure (p < 0.001) than FATmax, whereas a greater fat oxidation was observed in the latter (p < 0.001). A higher peak response of FGF-21 (+90%, p < 0.01) and follistatin (+49%, p < 0.05) was found after AT-exercise, as well as a trend toward a higher peak level of omentin (+13%, p = 0.071) and a greater decrease in resistin (−16%, p = 0.073).

Conclusion

Increasing exercise load (from FATmax to AT) results in a higher response of FGF-21, follistatin and omentin to aerobic exercise, with the subsequent potential cardiometabolic benefits. No effects were, however, observed on the remainder of biomarkers. Future research should address if manipulating other exercise variables (e.g., type, frequency) can promote a higher myokine/adipokine response.

Exercise and Omentin: Their Role in the Crosstalk Between Muscle and Adipose Tissues in Type 2 Diabetes Mellitus Rat Models

This study aims to analyze the effects of resisted, aerobic, and combined exercises on omentin levels in visceral adipose tissue and muscle of rats with experimental diabetes to verify whether these adipokines are related to the glucose pathway and inflammation process in this model. Male Wistar rats received a high-fat diet for 4 weeks and a low dose of streptozotocin (35 mg/kg) to induce experimental diabetes. After inducing diabetes, the animals were divided into 4 experimental groups (n = 10): diabetic control (C); resistance training (RT); aerobic training (AT); and combined training (CT). The groups were exercised for 12 weeks, 3 times/week, where: RT means the stair climbing protocol until exhaustion; AT is the 30 min/day reaching 20 m/min protocol, and CT is the combination of RT and AT. The AT group showed reduced retroperitoneal and mesenteric adipose tissue and abdominal fat deposits. Our study also showed a possible control of blood glucose, as well as decreased Interleukin 6 (IL-6) and C-reactive protein, increased circulating adiponectin and increased omentin in visceral adipose tissue. In addition, the AT group affected the glucose pathway by stimulating phosphorylation of Akt in muscle tissue. Omentin also showed a strong positive correlation with adiponectin and a moderate negative correlation with IL-6. Thus, our findings indicated that omentin in type 2 diabetes is changed by AT. Furthermore, increased omentin levels had a close association with the glucose pathway by stimulating phosphorylation of Akt in muscle tissue and with IL-6 in serum, suggesting that omentin is likely to have anti-inflammatory and protective action in experimental diabetes.

Serum omentin-1 levels in type 2 diabetic obese women in relation to glycemic control, insulin resistance and metabolic parameters

Background

Omentin-1 a new anti-inflammatory adipokine has been identified as a major visceral (omental) secretory adipokine which plays important roles in glucose homeostasis, lipid metabolism, insulin resistance and diabetes. The aim of our study was to evaluate serum omentin-1 levels in type 2 diabetic obese females and assess its relation with glycemic control, insulin resistance and metabolic parameters.

Methods

The study included 60 obese type 2 diabetic females and 30 healthy female subjects formed the control group. They subjected to full clinical examination, weight, height, waist and hip circumference. Fasting (blood glucose, insulin, lipid profile, omentin-1) and HbA1c were measured. BMI and HOMA-IR were calculated. Our data analyzed and expressed in terms of mean ± SD. Pearson correlation performed to study the correlation of serum omentin-1 in relation to glycemic control, insulin resistance and metabolic parameters in the studied groups.

Results

We found significant decrease in serum omentin-1 levels in cases with mean ± SD (16.5 ± 2.6 pg/ml) compared to controls (25.3 ± 1.0 pg/ml) (P < 0.001). We also found strong significant negative correlations between serum omentin-1 and (BMI, fasting insulin, HOMA-IR) (r = −0.909, −0.853, −0.511) respectively (P < 0.001) and systolic blood pressure (r = −0.274, p = 0.031). The best cut off point of serum omentin-1 was 22.2 pg/ml to differentiate cases from controls using ROC curve analysis.

Conclusion

Our study has shown significant low levels of serum omentin-1 in obese type 2 diabetic females in comparison to healthy subjects. Omentin-1 inversely related to obesity, insulin resistance and SBP. No significant associations with glycemic control and fasting lipids. Serum omentin-1 can be used as a biomarker for obesity related metabolic disorders.

Usefulness of Serum Omentin-1 Levels for the Prediction of Adverse Cardiac Events in Patients with Hypertrophic Cardiomyopathy

OBJECTIVE

To investigate the association between serum omentin-1 levels and adverse cardiac events in patients with hypertrophic cardiomyopathy (HCM).

SUBJECTS AND METHODS

This prospective, observational study included 87 patients with HCM and 50 age- and sex-matched control subjects. Serum omentin-1 and brain natriuretic peptide (BNP) levels were measured in all subjects, using enzyme-linked immunosorbent assay and electrochemiluminescence, respectively. Patients with HCM were divided into 2 groups according to their omentin levels, i.e., low: ≤291 ng/mL (n = 48) and high: > 291 ng/mL (n = 39). Cardiac mortality, hospitalization due to heart failure, and implantable cardioverter-defibrillator (ICD) implantation were considered adverse cardiac events. Statistical analysis included uni- and multivariant logistic regression, receiver-operating characteristic (ROC) analysis, and the Kaplan-Meier method.

RESULTS

Serum omentin-1 levels were significantly lower in the obstructive (253.9 ± 41.3 ng/mL) and nonobstructive (301.9 ± 39.8 ng/mL) HCM groups than in the control group (767.1 ± 56.4 ng/mL), p < 0.001, respectively. The BNP levels were higher in the obstructive and nonobstructive HCM groups than in the control group (269.5 ± 220, 241.0 ± 227, and 24.0 ± 18.9 pg/mL, respectively, p < 0.001). The Kaplan-Meier analysis indicated that patients with low omentin-1 levels showed a significantly higher (48.2%) 2-year cumulative incidence of overall adverse cardiac events than those with high omentin-1 levels (16.2%) (log-rank test, p  =  0.001). In the multivariate logistic regression analysis, omentin-1, interventricular septum (IVS) thickness, and male gender were independent predictors of adverse cardiac events in the follow-up.

CONCLUSION

Omentin-1 levels were lower in patients with HCM than in the control group, and this was associated with worse cardiac outcomes.

Independent and opposite associations of serum levels of omentin-1 and adiponectin with increases of glycaemia and incident type 2 diabetes in an older population: KORA F4/FF4 study

OBJECTIVE

Cross-sectional studies found that higher levels of the novel adipokine omentin-1 were associated with higher adiponectin and lower levels of risk factors for type 2 diabetes, but its relevance for incident type 2 diabetes is currently not understood. Therefore this study investigated whether serum omentin-1 was associated with changes in glycaemia and incident type 2 diabetes independently of adiponectin.

DESIGN AND METHODS

The study was based on participants aged 62-81 years from the population-based Cooperative Health Research in the Region of Augsburg (KORA) F4/FF4 cohort. Associations of baseline serum levels of omentin-1 and adiponectin with changes in glycaemia were assessed in 471 non-diabetic participants, and associations between both adipokines and incident type 2 diabetes were assessed in 76 cases and 430 non-cases (follow-up time 6.5 years). Multivariable linear and logistic regression models were adjusted for multiple potential confounders.

RESULTS

Higher serum levels of omentin-1 were associated with increases in fasting glucose, 2-h glucose and HbA1c (all P < 0.001) and with incident type 2 diabetes (adjusted odds ratio (OR) (95% CI): 1.40 (1.03; 1.90) per s.d. of log₂-transformed omentin-1; P = 0.032). These associations were independent from adiponectin levels, which showed associations with changes in glycaemia and risk of type 2 diabetes in the opposite direction. We found no statistically significant interactions of omentin-1 with adiponectin or sex in the association with incident type 2 diabetes (all P > 0.1).

CONCLUSIONS

Systemic levels of omentin-1 were positively associated with increases in glycaemia and incident type 2 diabetes in this older population. These associations were independent of potential confounders including adiponectin.

Exercise Improves Insulin Sensitivity in the Absence of Changes in Cytokines

PURPOSE

The benefits of aerobic exercise training on insulin sensitivity in subjects with metabolic syndrome (MetS) are, at least in part, associated with changes in cytokines. Recent studies identified novel cytokines (e.g., fractalkine, omentin, and osteopontin) that are strongly involved in glucose homeostasis and therefore potentially contribute in the exercise-induced changes in insulin sensitivity. Therefore, we aim to examine changes in skeletal muscle RNA expression and plasma levels of novel cytokines after exercise training and correlate these changes to the exercise-induced changes in insulin sensitivity.

METHODS

Women with metabolic syndrome (MetS, n = 11) and healthy women (n = 10) participated in a 6-month aerobic exercise training intervention (three times a week, 45 min per session at 65%-85% of individual heart rate reserve). Before and after training, we examined insulin sensitivity (M value during hyperinsulinemic euglycemic clamp) and circulating blood levels of cytokines (venous blood sample; leptin, adiponectin, omentin, fraktalkin, and osteopontin). The skeletal muscle RNA expression of these cytokines (muscle biopsy) was examined in two subgroups (MetS, n = 6; healthy women, n = 6).

RESULTS

At baseline, plasma levels of omentin (85.8 ± 26.2 ng·mL) and adiponectin (5.0 ± 1.7 μg·mL) levels were significantly higher in controls compared with MetS (51.1 ± 27.1; 3.6 ± 1.1 respectively), and leptin levels were lower in controls (18.7 ± 11.5 vs 53.0 ± 23.5 ng·mL). M value was significantly higher in controls (8.1 ± 1.9 mg·kg·min) than in MetS (4.0 ± 1.7). Exercise training significantly improved M values in both groups (P < 0.01). Exercise training did not alter plasma and skeletal muscle RNA expression levels of cytokines, but no correlation was observed between changes in cytokine level/RNA expression and M values (P > 0.05).

CONCLUSION

Although exercise training successfully improves insulin sensitivity in MetS and healthy women, we found no change in plasma and mRNA expression levels of novel cytokines.

Role of Omentin, Vaspin, Cardiotrophin-1, TWEAK and NOV/CCN3 in Obesity and Diabetes Development

Adipose tissue releases bioactive mediators called adipokines. This review focuses on the effects of omentin, vaspin, cardiotrophin-1, Tumor necrosis factor-like Weak Inducer of Apoptosis (TWEAK) and nephroblastoma overexpressed (NOV/CCN3) on obesity and diabetes. Omentin is produced by the stromal-vascular fraction of visceral adipose tissue. Obesity reduces omentin serum concentrations and adipose tissue secretion in adults and adolescents. This adipokine regulates insulin sensitivity, but its clinical relevance has to be confirmed. Vaspin is produced by visceral and subcutaneous adipose tissues. Vaspin levels are higher in obese subjects, as well as in subjects showing insulin resistance or type 2 diabetes. Cardiotrophin-1 is an adipokine with a similar structure as cytokines from interleukin-6 family. There is some controversy regarding the regulation of cardiotrophin-1 levels in obese -subjects, but gene expression levels of cardiotrophin-1 are down-regulated in white adipose tissue from diet-induced obese mice. It also shows anti-obesity and hypoglycemic properties. TWEAK is a potential regulator of the low-grade chronic inflammation characteristic of obesity. TWEAK levels seem not to be directly related to adiposity, and metabolic factors play a critical role in its regulation. Finally, a strong correlation has been found between plasma NOV/CCN3 concentration and fat mass. This adipokine improves insulin actions.

The Effect of 12 Weeks Aerobic, Resistance, and Combined Exercises on Omentin-1 Levels and Insulin Resistance among Type 2 Diabetic Middle-Aged Women

BACKGROUND

Recent studies have shown that omentin-1 derived from adipokines can affect physiological regulations and some metabolic dis-eases such as type 2 diabetes mellitus (T2DM).

METHODS

The purpose of this study was to examine the impact of 12 weeks of aerobic (cycle ergometer), resistance, and combined exercises on omentin-1 level, glucose and insulin resistance indices in overweight middle age women with T2DM. In this study, 60 overweight middle age diabetic women were selected using simple random sampling and they were assigned to three groups of aerobic exercise (n=12), resistant exercise (n=12) and combined exercise (n=13), and one control group (n=15). Exercises were done in a three times per week sessions for a total of 12 weeks. Blood samples were collected before each exercise session and 24 hours after of the last session.

RESULTS

Present study showed that fasting blood sugar decreased significantly in all intervention groups, while homeostasis model assessment of insulin resistance (HOMA-IR) decreased only in the aerobic and combined exercises groups. Furthermore, there was a significant increase in the omentin-1 level only in the combined exercise group.

CONCLUSION

Compared to aerobic and resistance exercises, 12 weeks of combined exercise was more efficient in improving HOMA-IR and increasing serum omentin-1 among women with T2DM.

Plasma Omentin-1 Level as a Predictor of Good Coronary Collateral Circulation

Aims: Coronary collateral circulation (CCC) is crucial during an acute ischemic attack. Evidences showed that omentin-1 exhibited remarkable antiatherogenic effects and ischemia-induced revascularization. The aim of this study was to investigate the relationship between plasma omentin-1 levels and CCC in patients with ≥ 90% angiography-proven coronary occlusion.

Methods: 142 patients with ≥ 90% luminal diameter stenosis in at least one major epicardial coronary artery were recruited. Among them, 79 patients with Rentrop 0–1 grade were classified into the poor CCC group and 63 patients with Rentrop 2–3 grade were included into the good CCC group. The association between plasma omentin-1 levels and CCC status was assessed.

Results: Plasma omentin-1 level was significantly higher in patients with good CCC than those with poor CCC (566.57 ± 26.90 vs. 492.38 ± 19.70 ng/mL, p = 0.024). Besides, omentin-1 was positively correlated with total cholesterol (TC), high-density lipoprotein, and gensini score but inversely with hyperlipidemia and body mass index (all p values < 0.05). Multivariate regression analysis indicated that omentin-1 [odds ratio (OR) = 1.002, 95% confidence interval (CI): 1.000 – 1.004, p = 0.041)], TC, the number of the diseased vessels, a higher frequency of left circumflex artery and right coronary artery, chronic total occlusion, and gensini score remained as the independent predictors of good CCC.

Conclusion: Higher plasma omentin-1 level was associated with better CCC development. Our findings suggest that omentin-1 may be an alternative marker for adequate CCC in patients with ≥ 90% coronary occlusion.

SERUM OMENTIN-1 LEVELS AND ENDOTHELIAL DYSFUNCTION IN OBESITY

Introduction

Our aim was to investigate the relationship between serum omentin-1 levels and endothelial dysfunction in obese patients.

Material and Methods

We evaluated 50 obese patients, and age/gender matched 45 healthy non-obese subjects as controls. Oral glucose tolerance test, lipid parameters, uric acid levels, homeostatic model assessment-insulin resistance (HOMA-IR) index, serum omentin-1 levels and flow mediated dilatation (FMD) % were measured in all subjects. Body compositions were analyzed with bioelectrical impedance method using a Tanita Body Composition Analyzer and ViScan.

Results

Serum omentin-1 levels were found significantly lower in obese population compared to the control subjects. FMD response was significantly decreased in obese population. There was a significant positive correlation between serum omentin-1 levels and FMD response (r=0.359, p<0.001). Serum omentin-1 levels were negatively correlated with body mass index (BMI), waist circumference, total fat percentage, visceral fat, fasting insulin and HOMA-IR index.

Conclusion

Lower serum omentin-1 levels and decreased FMD response may be an early marker of endothelial dysfunction in obese patients.

Effect of High-Intensity Interval Training on Plasma Omentin-1 Concentration in Overweight/Obese and Normal-Weight Youth

OBJECTIVES

Omentin-1 is a recently discovered adipokine, mainly produced by visceral adipose tissue, which is thought to improve insulin sensitivity. The study aimed to assess the association of plasma omentin-1 with cardiometabolic traits and physical performance and to test its response to high-intensity interval training (HIIT) in obese and normal-weight subjects.

METHODS

Nine overweight/obese (OG) and 9 normal-weight (NWG) young men performed an 8-week HIIT program. Body composition, physical performance, homeostasis model assessment index for insulin resistance (HOMA-IR) as well as plasma omentin-1and lipid levels were assessed before and after the HIIT program.

RESULTS

Baseline plasma omentin-1 was lower in OG than NWG men (359 ± 138 vs. 470 ± 114 ng/ml; p = 0.052). Plasma omentin-1 was related to body fat (r = -0.57; p = 0.03) and LDL-cholesterol (r = -0.49; p = 0.04). There was a trend towards significant association of omentin-1 with BMI (r = -0.47; p = 0.06) and VO2max (r = 0.41; p = 0.09). However, no association was observed with HOMA-IR. Following the HIIT program, omentin-1 concentrations have significantly (p < 0.01) increased in OG (359 ± 138 to 455 ± 126 ng/ml) and NWG men (470 ± 114 to 572 ± 115 ng/ml). In parallel, the cardiometabolic profile has improved with a significant decrease of HOMA-IR in OG.

CONCLUSIONS

HIIT resulted in a plasma omentin-1 increase and an improvement with regard to cardiometabolic traits in the OG men, which may contribute to modulate insulin sensitivity.

Association of Serum Omentin-1 Concentrations with the Presence of Atrial Fibrillation

BACKGROUND Omentin-1 is one of the adipokines associated with obesity, diabetes, and coronary heart disease development. We determined to investigate whether serum omentin-1 concentrations were correlated with the presence of atrial fibrillation (AF). MATERIAL AND METHODS Serum omentin-1 concentrations were examined in a cross-sectional population that included 220 patients with AF (70 with paroxysmal AF, 78 with persistent AF, and 72 with permanent AF) and 115 healthy controls. RESULTS Reduced serum omentin-1 concentrations were found in AF patients compared to the controls. In addition, patients with permanent AF had lower serum omentin-1 concentrations compared to patients with persistent AF and patients with paroxysmal AF. Significantly decreased serum omentin-1 concentrations were observed in persistent AF patients compared to paroxysmal AF patients. Spearman correlation analysis suggested that serum omentin-1 concentrations were negatively correlated with left atrial diameter in AF patients. CONCLUSIONS Serum omentin-1 concentrations were correlated with the presence of AF and atrial remolding.

The response of circulating omentin-1 concentration to 16-week exercise training in male children with obesity

OBJECTIVES

The purpose of the present study was to investigate the effects of the 16-week exercise training program on serum omentin-1 in relation to change in insulin resistance in obese male children.

METHODS

Thirty-two obese male children, aged 9-12 years, were randomly assigned into Exercise Group (ExG; n = 16) and Control Group (CG; n = 16). ExG participated in a 16-week exercise training program which combined various forms of aerobic activities and resistance training. Body composition, body mass index (BMI), waist circumference (WC), fasting glucose and insulin, homeostasis model assessment estimate of insulin resistance (HOMA2-IR), blood lipids and serum omentin-1 were assessed before and after 16 weeks of training.

RESULTS

Exercise training significantly decreased body mass (7.5%), BMI (7.6%), WC (4.3%), body fat % (15%), fasting insulin (18.5%), total cholesterol (TC) (5.4%), low-density lipoprotein cholesterol (LDL-C) (17%) and triglyceride (TG) (7.4%) compared to CG. Between-groups comparison showed a considerable exercise-induced upregulation in omentin-1 (ES = 89; P < 0.05) levels. Furthermore, in ExG serum omentin-1 levels were significantly increased from 24.5 ± 8.4 to 35.9 ± 9.3 ng/ml (45%; P < 0.001) after the training program, which was accompanied with significantly decreased fasting insulin (P < 0.001). The changes in omentin-1 concentrations correlated with the changes in BMI (r = -0.67, P < 0.001), WC (r = -0.62, P = 0.002), body fat % (r = -0.50, P = 0.004), insulin (r = -0.65, P = 0.001), HOMA2-IR (r = -0.60, P = 0.004), TC (r = -0.53, P = 0.004) and LDL-C (r = -0.51, P = 0.004) in ExG. BMI (β = -0.50, P = 0.009) and fasting insulin (β = -0.54, P = 0.006) changes were found to be independent predictors of omentin-1 increment in multiple regression analysis.

CONCLUSION

Exercise training resulted in a significant increase in serum omentin-1 concentrations in children with obesity. The findings suggest that exercise-induced changes in omentin-1 may be associated with the beneficial effects of exercise on reduced insulin and weight lost.

Detraining-induced alterations in adipokines and cardiometabolic risk factors after nonlinear periodized resistance and aerobic interval training in obese men

This study compared the effects of nonlinear resistance training (NRT), aerobic interval training (AIT), and detraining on adipokines and cardiometabolic risk factors in middle-aged obese men. Thirty-three obese men were randomly allocated to NRT (n = 12), AIT (n = 10), and control (CON, n = 11) groups. Subjects in experimental groups performed exercise protocols 3 days per week for 12 weeks followed by a 4-week detraining period. The NRT involved 55 min of weight training with flexible periodization. The AIT consisted of running on a treadmill (4 × 4-min intervals at 90% of maximal heart rate, with each interval separated by 3 min at 65%). Peak oxygen consumption increased significantly after training compared with CON (P < 0.01), but it increased more in the AIT group than in the NRT group (P = 0.004). After detraining, peak oxygen consumption decreased significantly in both training groups (P < 0.001); however, the value in the AIT group was still higher than that in the CON group (P = 0.003). No significant changes were observed in serum levels of omentin-1 and interleukin (IL)-18 after training (P > 0.05), but omentin-1 decreased significantly in both training groups and IL-18 increased significantly in the NRT group after detraining (P < 0.05). High-density lipoprotein cholesterol (HDL-C) increased significantly after training in the AIT group compared with the CON group (P < 0.05) and returned to the pre-training level after detraining. Conversely, apelin-13 increased significantly in response to training, compared with baseline (P < 0.05), and remained unchanged after detraining. Both training regimens had similar effects on most markers; however, AIT seems to have stronger anti-coronary disease effects (as indicated by HDL-C and peak oxygen consumption) than NRT.

Omentin-1 plasma levels and cholesterol metabolism in obese patients with diabetes mellitus type 1: impact of weight reduction

Background:

Omentin-1 is an anti-inflammatory adipokine produced preferentially by visceral adipose tissue. Plasma levels of omentin-1 are decreased in obesity and other insulin-resistant states. Insulin resistance contributes to the changes of cholesterol synthesis and absorption as well. The aim of this study was to characterise omentin-1 plasma levels in obese patients with diabetes mellitus type 1 during weight reduction, and to elucidate the relationship between cholesterol metabolism and omentin-1.

Methods:

Plasma levels of omentin-1 were measured in obese type 1 diabetics (n=14, body mass index >30 kg m⁻², age 29–62 years) by enzyme-linked immunosorbent assay (BioVendor). Gas chromatography with flame ionisation detector (Fisons Plc.,) was used to measure squalene and non-cholesterol sterols—markers of cholesterol synthesis and absorption (phase I). Measurements were repeated after 1 month (phase II; 1 week of fasting in the hospital setting and 3 weeks on a diet containing 150 g saccharides per day) and after 1 year (phase III) on a diet with 225 g saccharides per day.

Results:

Omentin-1 plasma levels were stable during phases I and II, but significantly increased (P<0.001) during phase III. Omentin-1 plasma dynamics were significantly associated with plasma levels of high-density lipoprotein (P=0.005) and triacylglycerols (P=0.01), as well as with lathosterol (P=0.03).

Conclusion:

Omentin-1 plasma levels significantly increased during the weight reduction programme. Omentin-1 plasma dynamics suggest a close relationship with cholesterol metabolism.

Serum Omentin Levels in Adolescent Girls With Anorexia Nervosa and Obesity

It is believed that omentin is secreted by stromal cells of adipose tissue and modulates insulin sensitivity. Data from a few studies have shown lower serum omentin in obese children and higher in anorexia nervosa. However, to date, there is lack of research on serum omentin concentrations in adolescent patients in a wide range of body mass index (BMI) and insulin resistance. In this cross-sectional study omentin-1 serum concentrations were evaluated using commercially available ELISA kit in 47 Polish girls with restrictive anorexia nervosa (AN), 50 with simple obesity (OB) and 39 healthy controls (C). The mean serum omentin-1 concentration in girls with AN was statistically significantly higher than that of C and OB girls. Statistically significant (P<0.0001) negative correlations between the serum concentrations of omentin-1 and body weight (r=−0.73), BMI (r=−0.75), standard deviation score for body mass index (BMI-SDS) (r=−0.75), insulin (r=−0.81) and HOMA-IR index (r=−0.82) were seen in the entire examined population. We conclude, that omentin-1 is the nutritional marker reflecting body weight and insulin resistance. Our findings support the hypothesized role of omentin in maintenance of body weight and regulation of appetite and suggest the adaptation of its secretion to body weight and glucose metabolism.

Serum omentin-1 levels as a possible risk factor of mortality in patients with diabetes on haemodialysis

AIM

The main cause of mortality in haemodialysis (HD) patients is cardiovascular disease. Serum omentin-1 level was found to be associated with cardio-metabolic disorders. The aim of this study was to examine the role of omentin-1 as a predictor of mortality in a group of diabetes positive HD patients.

METHODS

A total of 120 prevalent HD patients were included in the study from December 2012 to May 2014. Patients were divided into two groups according to the presence or absence of diabetes. Venous blood samples were taken at months 0 and 18 following an overnight fast (prior to a midweek HD session). Serum omentin-1 level was assessed by enzyme-linked immunosorbent assay.

RESULTS

A total of 84 HD patients were analysed at the end of an 18-month follow-up. Omentin-1 levels of HD patients with diabetes were found to be lower than of HD patients without diabetes (9.1±5.8 ng/mL vs. 11.4±4.1 ng/mL, respectively; P=0.015) at the end of follow-up. Omentin-1 levels of survived patients with diabetes were found to be higher than of nonsurvived patients with diabetes (16.5±10.1 ng/mL vs. 12.9±5.3 ng/mL, respectively; P=0.045). During follow-up, 36 patients (30%) died, of whom 25 had diabetes (34%).

CONCLUSIONS

Serum omentin-1 levels were significantly lower in HD patients with diabetes. A decrease in omentin-1 levels could be an independent mortality risk factor in this patient group. Further investigation in a greater number of patients is needed.

The impact of acute aerobic exercise on chitinase 3-like protein 1 and intelectin-1 expression in obesity

Chitinase 3-like 1 (CHI3L1) and intelectin 1 (ITLN-1) recognize microbial N-acetylglucosamine polymer and galactofuranosyl carbohydrates, respectively. Both lectins are highly abundant in plasma and seem to play pro- and anti-inflammatory roles, respectively, in obesity and inflammatory-related illnesses. The aim of this study was to examine whether plasma levels of these lectins in obese subjects are useful for monitoring inflammatory conditions immediately influenced by acute aerobic exercise. Plasma interleukin-6, a pro-inflammatory cytokine, was also examined. Twenty-two (11 obese and 11 normal-weight) healthy subjects, ages 18-30 years, were recruited to perform a 30 min bout of acute aerobic exercise at 75% VO2max. We confirmed higher baseline levels of plasma CHI3L1, but lower ITLN-1, in obese subjects than in normal-weight subjects. The baseline levels of CHI3L1 were negatively correlated with cardiorespiratory fitness (relative VO2max). However, when controlled for BMI, the relationship between baseline level of CHI3L1 and relative VO2max was no longer observed. While acute aerobic exercise elicited an elevation in these parameters, we found a lower ITLN-1 response in obese subjects compared to normal-weight subjects. Our study clearly indicates that acute aerobic exercise elicits a pro-inflammatory response (e.g. CHI3L1) with a lower anti-inflammatory effect (e.g. ITLN-1) in obese individuals. Furthermore, these lectins could be predictors of outcome of exercise interventions in obesity-associated inflammation.

Adiponectin may mediate the association between omentin, circulating lipids and insulin sensitivity: results from the KORA F4 study

OBJECTIVE

Reduced circulating omentin levels have been reported in obesity and type 2 diabetes, but data were mostly derived from univariate analyses in small study samples. This study aimed to investigate the relationship between omentin, abnormal glucose tolerance and related metabolic factors in a large population-based cross-sectional study.

DESIGN AND METHODS

Serum omentin was measured by ELISA in 1092 participants of the German KORA F4 survey (2006-2008). Associations between omentin serum levels, glucose tolerance (assessed with an oral glucose tolerance test) and diabetes-related factors were estimated using logistic and linear regression models respectively.

RESULTS

Serum levels of omentin were not related to categories of glucose tolerance. However, serum omentin was positively associated with whole-body insulin sensitivity index (ISI (composite)) and HDL cholesterol and showed inverse associations with 2-h post-load glucose, fasting insulin, homeostasis model assessment-estimated insulin resistance, BMI and triglycerides (all P≤0.03 after adjustment for age, sex and lifestyle factors). Further adjustment for BMI and/or serum lipids attenuated the associations with parameters of glucose metabolism, whereas adjustment for serum adiponectin virtually abolished all aforementioned associations. In contrast, adjustment for omentin had no effect on the positive association between adiponectin levels and ISI (composite).

CONCLUSIONS

The data from this large population-based cohort show that circulating omentin levels are associated with insulin sensitivity. Our observations further suggest that omentin acts via upregulation of adiponectin, which in turn affects lipid metabolism and thereby also indirectly enhances insulin sensitivity, but mechanistic studies are required to corroborate this hypothesis.

Does 8 weeks of strenuous bicycle exercise improve diabetes-related inflammatory cytokines and free fatty acids in type 2 diabetes patients and individuals at high-risk of metabolic syndrome?

In the present study, the effects of 8 weeks of low volume high intensity interval training (HIIT) was investigated on circulating diabetes-related cytokines and free fatty acids (FFA) in adults with type 2 diabetes (T2D) and matched controls (CON).

METHODS

Participants exercised for 8 weeks (3 weekly sessions: 10 × 60 sec HIIT) on a cycle ergometer supervised by medical staff. Prior to the intervention and after the last HIIT session, venous blood samples were collected.

RESULTS

Circulating omentin-1 concentrations increased significantly in both the CON-group (p = 0.003) and in the T2D-group (p = 0.002). Pentraxin-3 (p = 0.010) and IL-1ra (p = 0.031) levels increased significantly in the CON-group. Plasma FFA in the T2D-group was significantly reduced after 60 min (p = 0.011). Post HIIT area under curve of circulating FFAs was reduced by -17.73 ± 6.99% (p = 0.041) in the T2D-group.

CONCLUSION

We observed only modest exercise-induced improvements of multiple diabetes-related cytokines. Circulating levels of FFAs were significantly lowered in the T2D-group.

Omentin changes following bariatric surgery and predictive links with biomarkers for risk of cardiovascular disease

BACKGROUND

Although no receptor has yet been identified, changes in circulating levels of the adipokine designated as Omentin have been demonstrated in obesity and related comorbidities such as cardiovascular disease, insulin resistance, metabolic syndrome and chronic inflammation.

METHODS

Changes in Omentin levels at 1 and 5 days and 6 and 12 months in response to biliopancreatic diversion with duodenal switch bariatric surgery were evaluated, specifically to investigate if changes preceded gain of insulin sensitivity.

RESULTS

Pre-operative plasma Omentin was not different between men (n = 18) vs women (n = 48), or diabetic status but correlated with body mass index (BMI). Altogether, Omentin increased as early as 24-h post-surgery, with changes maintained up to 1-year. Fifty-nine percent of subjects increased Omentin >10% by 24-H following surgery (OmentinINC p < 0.0001), while 18% of subjects decreased (OmentinDEC p < 0.0001), with changes maintained throughout one-year. These two groups had comparable age, sex distribution, diabetes, BMI, waist circumference and fat mass, however OmentinDEC had elevated levels of cardiovascular risk markers; homocysteine (p = 0.019), NT-proBNP (p = 0.006) and total bilirubin (p = 0.0001) while red blood cell (RBC) count was lower (p = 0.0005) over the one-year period. Omentin levels at 1-DAY also correlated with immune parameters (white blood cell count, % neutrophil, % monocytes, % lymphocytes).

CONCLUSION

OmentinDEC at 1 day following surgery may be a marker of cardiovascular "at-risk" group before weight loss or insulin sensitivity restoration.

Omentin-1 levels are reduced by pharmacologic doses of leptin, but remain unaffected by energy deprivation and display no day-night variation

Objective

To study the day-night variation of omentin-1 levels and assess whether leptin, and/or short-and long-term energy deprivation alter circulating omentin-1 levels via cytokines.

Design and Methods

Omentin-1 levels were measured hourly in serum samples from six healthy men to evaluate for day-night variation. To study effects of acute energy deprivation and of leptin administration, eight healthy subjects were studied in the fasting state for 72 hours with administration of either placebo or metreleptin in physiological replacement doses. We evaluated the effect of leptin in pharmacological doses on serum omentin-1 and cytokine levels, as well as on omentin-1 levels in ex vivo omental adipose tissue, in fifteen healthy volunteers. To study the effect of chronic energy deprivation and weight loss on omentin-1 levels we followed eighteen obese subjects for 12 months who underwent bariatric surgery.

Results

There is no day-night variation in omentin-1 levels. Short-term and chronic energy deprivation as well as ex vivo leptin administration and physiological replacement doses of leptin do not alter omentin-1 levels, whereas pharmacologic doses of metreleptin reduce omentin-1 levels whereas levels of TNF-α receptor II and IL-6 tend to increase.

Conclusions

Omentin-1 levels are reduced by pharmacological doses of metreleptin independent of effects on cytokine levels.