Association of ghrelin with cardiometabolic risk factors in Iranian adolescents: the CASPIAN-III study

Insulin resistance-related circulating predictive markers in the metabolic syndrome: a systematic review in the Iranian population

Background

Specific biomarkers for metabolic syndrome (MetS) may improve diagnostic specificity for clinical information. One of the main pathophysiological mechanisms of MetS is insulin resistance (IR). This systematic review aimed to summarize IR-related biomarkers that predict MetS and have been investigated in Iranian populations.

Methods

An electronic literature search was done using the PubMed and Scopus databases up to June 2022. The risk of bias was assessed for the selected articles using the instrument suggested by the Joanna Briggs Institute (JBI). This systematic review protocol was registered with PROSPERO (registration number CRD42022372415).

Results

Among the reviewed articles, 46 studies investigated the association between IR biomarkers and MetS in the Iranian population. The selected studies were published between 2009 and 2022, with the majority being conducted on adults and seven on children and adolescents. The adult treatment panel III (ATP III) was the most commonly used criteria to define MetS. At least four studies were conducted for each IR biomarker, with LDL-C being the most frequently evaluated biomarker. Some studies have assessed the diagnostic potency of markers using the area under the curve (AUC) with sensitivity, specificity, and an optimal cut-off value. Among the reported values, lipid ratios and the difference between non-HDL-C and LDL-C levels showed the highest AUCs (≥ 0.80) for predicting MetS.

Conclusions

Considering the findings of the reviewed studies, fasting insulin, HOMA-IR, leptin, HbA1c, and visfatin levels were positively associated with MetS, whereas adiponectin and ghrelin levels were negatively correlated with this syndrome. Among the investigated IR biomarkers, the association between adiponectin levels and components of MetS was well established.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01347-6.

Associations of low levels of air pollution with cardiometabolic outcomes and the role of diet quality in individuals with obesity

BACKGROUND

Exposure to air pollution is associated with adverse cardiometabolic health effects and increased mortality, even at low concentrations. Some of the biological mechanisms through which air pollution can affect cardiometabolic health overlap with health outcomes associated with diet quality and changes in diet.

OBJECTIVE

The objective of this study is to investigate associations of air pollutants at average concentrations below the World Health Organization, 2021 air quality guidelines with cardiometabolic outcomes. Furthermore, potential interaction between air pollutants and diet quality will be assessed.

METHODS

82 individuals with obesity participated in a combined weight loss and weight loss maintenance study for a total of 33 weeks. A secondary analysis was conducted incorporating air pollution measurements. Data were analysed with linear mixed-effects models.

RESULTS

A total of 17 significant associations were observed for single pollutants with 10 cardiometabolic outcomes, predominantly related to blood lipids, hormones, and glucose regulation. Diet quality, as measured by the Baltic Sea Diet score, did not appear to mediate the association of air pollution with cardiometabolic outcomes, however, diet quality was observed to significantly modify the association of PM2.5 with total cholesterol, and the associations of NO and O3 with ghrelin.

DISCUSSION

These findings suggest that exposure to ambient air pollutants, especially particulate matter, at levels below World Health Organization, 2021 air quality guidelines, were associated with changes in cardiometabolic risk factors. Diet may be a personal-level approach for individuals to modify the impact of exposure to air pollution on cardiometabolic health.

Valproate-Induced Metabolic Syndrome

Valproic acid (VPA) and its salts (sodium calcium magnesium and orotic) are psychotropic drugs that are widely used in neurology and psychiatry. The long-term use of VPA increases the risk of developing adverse drug reactions (ADRs), among which metabolic syndrome (MetS) plays a special role. MetS belongs to a cluster of metabolic conditions such as abdominal obesity, high blood pressure, high blood glucose, high serum triglycerides, and low serum high-density lipoprotein. Valproate-induced MetS (VPA-MetS) is a common ADR that needs an updated multidisciplinary approach to its prevention and diagnosis. In this review, we consider the results of studies of blood (serum and plasma) and the urinary biomarkers of VPA-MetS. These metabolic biomarkers may provide the key to the development of a new multidisciplinary personalized strategy for the prevention and diagnosis of VPA-MetS in patients with neurological diseases, psychiatric disorders, and addiction diseases.

Investigation of the association between cardio-metabolic risk factors, neurotrophins and gastric hormones among apparently healthy women: A cross-sectional analysis

Introduction: Although, some evidence has shown that obestatin, ghrelin, and neurotrophic factors can be involved in the development of cardio-metabolic risk factors, there are some contradictions in this regard. We aimed to investigate the association of serum neurotrophic factors and some gastric hormones with cardio-metabolic risk factors among apparently healthy women.

Methods: In the present study, 90 apparently healthy women were recruited by a convenient sampling method from the nutrition counseling clinic in Tabriz, Iran. All participants need dietary counseling for weight loss and were recruited before receiving any dietary interventions. Anthropometric, biochemical, physical activity, and blood pressure (BP) measurements, as well as dietary assessment, were done in all participants.

Results: Women who were in the highest tertile of serum obestatin levels (OR=0.118, 95% CI:0.035-0.396) had a significantly lower risk for development of hypertriglyceridemia compared to the reference group (P_trend < 0.001). Participants in the highest tertile of serum ghrelin had a significant lower risk of hypertriglyceridemia, hyperglycemia, low HDL-C, and MetS (P_trend < 0.05). Women who were in the higher tertile of serum NGF levels had a significantly lower risk for development of hypertriglyceridemia after adjustment for potential confounding variables (OR=0.091, 95% CI: 0.023-0.361 and OR=0.193, 95% CI: 0.057-0.649 respectively).

Conclusion: In the current study serum levels of obestatin, NGF, and ghrelin were associated with some cardio-metabolic risk factors such as hypertriglyceridemia and MetS. It seems that these factors are associated with metabolic regulation. However, further studies are needed to substantiate this claim.

The interaction between dietary inflammatory index and 6 P21 rs2010963 gene variants in metabolic syndrome

BACKGROUND

The Vascular endothelial growth factor (VEGF) regulates endothelial cell proliferation, migration and angiogenesis, promotes vascular and capillary permeability and also is involved in inflammation. VEGF gene has been suggested to play an important role in the pathogenesis of metabolic syndrome. The aim of this study was to investigate the association between inflammatory potential of a diet and + 405 VEGF C/G (rs2010963) polymorphism and metabolic components in patients with metabolic syndrome.

METHODS

One hundred fifty patients with metabolic syndrome and fifty healthy individuals were enrolled. A semi-quantitative food-frequency questionnaire (FFQ) was used for dietary assessments and dietary inflammatory index (DII) calculation. Biochemical assays including fasting serum glucose (FSG), serum insulin, matrix metalloproteinase-3 (MMP-3), liver enzymes and lipid profile were measured. Polymerase chain reaction-restriction fragments length polymorphism (PCR-RFLP) method was used for the determination of gene polymorphism.

RESULTS

In the current study, patients with metabolic syndrome had higher serum low density lipoprotein (LDL) and lower high density lipoprotein (HDL) concentrations compared with healthy subjects. Patients with lower DII quartiles and lower inflammatory potential of the diet had lower waist to hip ratio (WHR) and lower diastolic blood pressure (DBP) compared with patients in higher DII quartiles (P < 0.05). Moreover, patients and healthy subjects in second quartile of DII had significantly higher aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations compared with subjects in the first quartile; also healthy subjects in third quartile had significantly higher triglyceride (TG) and total cholesterol (TC) concentrations compared with subjects in second quartile (P < 0.05). Among different genotypes of 6 P21 rs2010963 gene variants in patients with metabolic syndrome, CC genotype indicated the highest DII compared with other genotypes (P < 0.05).

CONCLUSION

The current study revealed the association between DII and metabolic risk factors of metabolic syndrome.

LEVEL OF EVIDENCE

Level III, case-control analytic study.

The Association Between Salivary Ghrelin Levels with Anthropometric Measures in Underweight, Normal, Overweight and Obese Healthy Adult Males

OBJECTIVES

The study aimed to measure salivary ghrelin levels in healthy adult males and investigate their association with age, weight, height, total as well as regional body fat and muscle mass. The study also aimed to investigate the relative contribution of body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) in predicting salivary ghrelin levels in the studied groups.

METHODS

A sample of young adult males was divided into underweight, normal weight, overweight, and obese groups, according to their BMI. Standardised methods were used to measure height, WC and HC. Total body fat, visceral fat, subcutaneous fat, total and regional muscle mass were assessed by bioelectrical impedance technique utilising Karada scan. Salivary ghrelin concentrations were assessed using enzyme-linked immunosorbent assay.

RESULTS

A total of 90 adult males were included in the analysis (underweight n=9, normal weight n=41, overweight n=22, and obese n=18). One-way ANOVA test revealed significant differences among the groups in all of the variables except height and salivary ghrelin levels. Multiple linear regression revealed a significant association between salivary ghrelin levels with total fat, subcutaneous fat, visceral fat and muscle mass in the obese group. The analysis also revealed that BMI, WC, HC, WHR and WHtR were reliable predictors for salivary ghrelin levels in the obese group but not in other groups.

CONCLUSIONS

Anthropometric measures can be used as predictors for salivary ghrelin levels in healthy obese adults. However, they are poor predictors for salivary ghrelin levels in healthy lean, normal and overweight adults.

The associations between some biological markers, obesity, and cardiovascular risk in Slovenian children and adolescents

INTRODUCTION

The occurrence of cardiovascular diseases and metabolic disorders steadily increases with the body mass index (BMI). Since the latter is not the best and earliest indicator of obesity and cardiovascular risk, the aim of the study was to evaluate some potential biological markers that would allow us to detect children and adolescents at higher risk at an early stage.

METHODS

A sample of 330 children and adolescents were included in the study and divided into four groups: obese patients with hypertension, normal-weight patients with hypertension, patients with mildly elevated lipids and a control group of healthy children and adolescents. Some clinical parameters (age, body weight, body height, BMI, waist circumference, hip circumference, blood pressure), biochemical parameters (glucose, total cholesterol, triglycerides, HDL, LDL, apolipoprotein A1, homocysteine) and biological markers of obesity (ghrelin, adiponectin, leptin) were evaluated.

RESULTS

Ghrelin and adiponectin were found to have a strong negative statistically significant correlation with BMI in all three observed groups (p < 0.001), but not in the control group (p = 0.053 and p = 0.316, respectively). In addition, leptin had a strong positive statistically significant correlation with BMI in all four groups (p < 0.001 for the research groups, p = 0.009 for the controls). In the group of obese patients with hypertension, statistically significant differences in all three markers of obesity were found in comparison to the control group (p < 0.001 for all markers). In the group of patients with mildly elevated lipids, ghrelin and leptin were significantly different (p = 0.002 and p < 0.001, respectively). In the group of normal-weight hypertensive patients, only values of ghrelin were different compared to the control group (p = 0.001).

CONCLUSION

In the research groups, significant differences were found in clinical, biochemical and biological parameters compared to the control group. The observed biological markers of obesity are useful early markers for identifying groups of patients that are at cardiovascular risk.

Serum concentrations of cholecystokinin, peptide YY, ghrelin and high sensitive C-reactive protein in association with metabolic syndrome ingredients in obese individuals

Objective

Metabolic syndrome (MetS) is a metabolic condition with high prevalence worldwide. This study aims to examine the relationship between serum concentrations of gastrointestinal hormones such as cholecystokinin (CCK), ghrelin, peptide YY (PYY), and high sensitive C-reactive protein (hs-CRP) and the ingredients of MetS in obese population.

Subjects and Methods

This case-control study included 40 obese subjects (20 with MetS and 20 BMI and age-matched control individuals). The age range of the participants was 20-50 years and the participants' anthropometric characteristics were measured. Serum lipids and the concentrations of oxidized low density lipoprotein (Ox-LDL), insulin, hs-CRP, CCK, PYY, and ghrelin were assessed with commercial ELISA kits.

Results

Serum levels of hs-CRP, total cholesterol (TC) and triglycerides (TG) in patients with MetS were significantly higher while CCK and insulin concentrations were higher in obese non- MetS group (P <0.05). PYY had a negative association with waist circumference (WC) and high density lipoprotein cholesterol (HDL-C) and ghrelin had a positive association with systolic blood pressure (SBP) and TC in obese control group (P < 0.05). In obese patients with MetS, hs-CRP had a strong positive association with TG.

Conclusion

The current study revealed the possible role of hs-CRP and several GI- hormones in the pathogenesis of obesity-associated diseases and MetS. Additional works are needed to elucidate the possible underlying mechanisms and clarify several controversies in this issue.

Only serum pepsinogen I and pepsinogen I/II ratio are specific and sensitive biomarkers for screening of gastric cancer

Purpose We aimed to determine optimal cut-off points of plasma levels of ghrelin and serum levels of pepsinogen I, II, and their ratio for screening of gastric cancer (GC). Methods Blood samples were taken from 41 patients with confirmed gastric cancer along with 82 patients without malignancy. Serum levels of pepsinogen I and II, plus plasma levels of acylated ghrelin were measured using commercial ELISA kits. Results The case group had significant lower plasma levels of ghrelin, pepsinogen I, and pepsinogen I/II ratio in comparison to the control group (P<0.001). In the control group, there was significant higher serum pepsinogen I (P=0.028) and pepsinogen II (P=0.003) and lower pepsinogen I/II ratio (P=0.020) in males versus females; significantly higher serum pepsinogen II (P=0.047) and lower pepsinogen I/II ratio (P=0.030) in overweight compared to normal weight patients; and significantly lower pepsinogen I/II ratio (P=0.030) in smokers versus non-smoker. In the case group, there was only significantly lower pepsinogen I (P=0.006) in males versus females, and significantly lower plasma ghrelin (P=0.017) in overweight compared to normal weight patients. The characteristic curve analysis indicated that pepsinogen I at a cut-off of 70.95 μg/L and pepsinogen I/II ratio at cut-off of 2.99, had good sensitivity and specificity. Conclusions Just serums levels of pepsinogen I and the ratio of pepsinogen I/II can be used as biomarker to screen GC.

Relationship between insulin resistance, metabolic syndrome components and serum uric acid

BACKGROUND

Metabolic syndrome is cluster of abnormality related with increasing cardiovascular events. Hyperuricemia is level of uric acid more than 7 mg/dL for men. Some research have reported relation between metabolic syndrome mediated by insulin resistance with increasing of serum uric acid level.

OBJECTIVE

Assess relationship between insulin resistance and metabolic syndrome components with the level of serum uric acid.

METHOD

Observational study with cross sectional approach conducted on 102 outpatient subjects at Dr. RSUP Wahidin Sudirohusodo (RSWS) hospital and Hasanuddin University Hospital in the period of July-September 2018.

RESULTS

Subjects with IR were found to be significantly higher for having MetS (88.23% vs. 11.77% p = 0,000). In subjects with IR, the average serum uric acid level was higher compared to non-IR subjects, but this difference was not significant (6.63 vs 6.42 mg/dL; P = 0.325). In subjects with MetS, the average serum uric acid level was higher compared to subjects with non-MetS but this difference was not significant (6.62 vs. 6.28 mg/dL; P = 0.556). No significant relationship was found between IR and MetS with serum uric acid level.

CONCLUSION

Insulin resistance is related to the incidence of MetS and in both of these circumstances an independent tendency is found to increase uric acid levels. The role of insulin resistance in the relationship between metabolic syndrome and uric acid levels was not proven in this study.

Dietary diversity score is associated with cardiovascular risk factors and serum adiponectin concentrations in patients with metabolic syndrome

Background

Metabolic syndrome is associated with cardio-metabolic risk factors and lipid abnormalities. Previous studies evaluated the dietary habits and nutrient intakes among patients with metabolic syndrome; however the association between metabolic risk factors and adiponectin with dietary diversity score (DDS) in patients with metabolic syndrome has not been evaluated yet. Therefore the aim of the current study was to evaluate these relationships among patients with metabolic syndrome.

Methods

One hundred sixty patients with metabolic syndrome were recruited in the study. The anthropometric parameters including weight, height, waist circumference and hip circumference were measured. Serum adiponectin concentration was measured by enzyme- linked immunosorbent assay method (ELISA). Lipid profile and fasting serum glucose concentrations (FSG) were also measured with enzymatic colorimetric methods. Blood pressure was also measured and DDS was calculated using the data obtained from food frequency questionnaire (FFQ).

Results

Subjects in lower DDS categorizes had significantly lower energy and fiber intake; whereas mean protein intake of subjects in the highest quartile was significantly higher than second quartile. Higher prevalence of obesity was also observed in the top quartiles (P < 0.001). Subjects in the lower quartiles had higher serum triglyceride concentrations and systolic blood pressure (SBP) values and lower serum adiponectin concentrations compared with subjects in higher DDS categorizes (P < 0.05). The prevalence of metabolic syndrome components among patients in lower DDS quartiles was significantly higher (P < 0.05).

Conclusion

Our study found a lower serum triglyceride and SBP and higher serum adiponectin concentrations in top quartiles of DDS. The findings clarify the possible preventive role of higher dietary diversity score against metabolic syndrome. However, for further confirming the findings, more studies are warranted.

Gender-Specific Association of Desacylated Ghrelin with Subclinical Atherosclerosis in the Metabolic Syndrome

OBJECTIVE

Ghrelin, a gastric hormone with pleiotropic effects modulates vascular function and may influence atherosclerosis. Plasma ghrelin is reduced in the metabolic syndrome (MS), which is also characterized by early atherosclerosis. Ghrelin circulates in acylated (AG) and desacylated (DAG) forms. Their relative impact and that of gender on subclinical atherosclerosis in MS is unknown.

AIM OF THE STUDY

To investigate potential associations of total, AG and DAG with carotid atherosclerosis and with gender in the MS.

METHODS

Plasma total ghrelin, AG, DAG and carotid artery IMT (cIMT) were measured in 46 MS patients (NCEP-ATP III criteria, 22M/24F).

RESULTS

Compared with males, females had higher (p <0.05) total and DAG. In the association analysis, age and plasma glucose were positively (p <0.05) correlated with cIMT in all MS patients. The positive (p <0.05) association between cIMT and age was also confirmed in males, while that between cIMT and glucose was significant in women. In contrast, neither total ghrelin nor AG and DAG were associated with cIMT in all MS patients nor in the male subgroup. In females, a negative (p <0.05) association between carotid artery IMT, DAG and glucose was detected, but not between cIMT, total ghrelin and AG. In multivariate modeling, DAG remained negatively (p <0.05) associated with cIMT after adjusting for plasma glucose and cardiovascular risk factors.

CONCLUSIONS

These data indicate a negative independent association between DAG and cIMT in middle-aged women with the MS and suggest a gender-specific modulatory function of DAG in the development of atherosclerosis.