Obese children aged 4-6 displayed decreased fasting and postprandial ghrelin levels in response to a test meal

Appetite-related Gut Hormone Responses to Feeding Across the Life Course

Appetite-related hormones are secreted from the gut, signaling the presence of nutrients. Such signaling allows for cross-talk between the gut and the appetite-control regions of the brain, influencing appetite and food intake. As nutritional requirements change throughout the life course, it is perhaps unsurprising that appetite and eating behavior are not constant. Changes in appetite-related gut hormones may underpin these alterations in appetite and eating. In this article, we review evidence of how the release of appetite-related gut hormones changes throughout the life course and how this impacts appetite and eating behaviour. We focus on hormones for which there is the strongest evidence of impact on appetite, food intake, and body weight: the anorexigenic glucagon like peptide-1, peptide tyrosine tyrosine, and cholecystokinin, and the orexigenic ghrelin. We consider hormone concentrations, particularly in response to feeding, from the very early days of life, through childhood and adolescence, where responses may reflect energy requirements to support growth and development. We discuss the period of adulthood and midlife, with a particular focus on sex differences and the effect of menstruation, pregnancy, and menopause, as well as the potential influence of appetite-related gut hormones on body composition and weight status. We then discuss recent advancements in our understanding of how unfavorable changes in appetite-related gut hormone responses to feeding in later life may contribute to undernutrition and a detrimental aging trajectory. Finally, we briefly highlight priorities for future research.

The impacts of COVID-19 on childhood obesity: prevalence, contributing factors, and implications for management

PURPOSE

This study aimed to identify changes in the prevalence of obesity and related diseases among children and adolescents during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

This study was conducted using data from the 2016-2021 Korean National Health and Nutrition Examination Survey and included 3,861 children and adolescents aged 10-18 years. The prevalence of obesity and related diseases was adjusted for age, sex, and income. We also analyzed the socioeconomic, nutritional, and physical activity items in the survey.

RESULTS

During the COVID-19 pandemic, there was a significant increase in the prevalence of obesity (p=0.02), central obesity (p=0.001), mean body mass index (BMI, p=0.03), and hemoglobin A1c (p=0.005) among children and adolescents aged 10-18 years. The intake of food and calories was significantly reduced in the normal-weight group (p=0.001 and <0.001) but not in the obese group. Incidences of skipping breakfast increased and eating out decreased, regardless of obesity status. However, the changes in health behaviors were not significant. The prevalence of central obesity and increased BMI showed a significant linear association between children and their parents, especially in the 10-12-year-old age group. A clear increase in the proportion of metabolically unhealthy children and adolescents was observed in the obese group, and the frequency of central obesity in parents also increased.

CONCLUSION

The number of metabolically unhealthy, obese children and adolescents increased during the COVID-19 pandemic. Age-specific strategies that consider growth, development, and genetic and social factors are required. Health strategies targeting the entire family are required to develop healthier habits.

Breakfast skipping and traits of cardiometabolic health: A mendelian randomization study

BACKGROUND

Breakfast skipping has been linked to poor cardiometabolic health in observational studies, but the causality remains unknown. Herein, we used Mendelian randomization (MR) approach to elucidate the potential causal effects of breakfast skipping on cardiometabolic traits.

METHODS

Genetic association estimates for breakfast skipping, cardiometabolic diseases, and cardiometabolic risk factors were extracted from the UK Biobank and several large genome-wide association studies. Two-sample MR analyses were performed primarily using the inverse variance weighted method, followed by sensitivity analysis to test the reliability of results.

RESULTS

MR results indicated no causal relationship between breakfast shipping with coronary heart disease (odds ratio [OR]: 1.079, 95 % confidence interval [CI]: 0.817-1.426; p = 0.591), stroke (OR: 0.877, 95 % CI: 0.680-1.131; p = 0.311), and type 2 diabetes mellitus (OR: 1.114, 95 % CI: 0.631-1.970; p = 0.709). However, genetically predicted breakfast skipping was significantly associated with increased body mass index (β: 0.250, standard error [SE]: 0.079; p = 0.001), waist-to-hip ratio (β: 0.177, SE: 0.076; p = 0.019), and low-density lipoprotein cholesterol (β: 0.260, SE: 0.115; p = 0.024). We found no evidence of association of genetic liability to breakfast skipping with blood pressure, glycemic traits, and other blood lipids. Sensitivity analysis supported the above results.

CONCLUSION

Our study suggested that breakfast skipping is causally linked to weight gain and higher serum low-density lipoprotein cholesterol, which may mediate the increased risk of cardiometabolic diseases reported in epidemiological studies.

Association between the Habitual Snack Consumption at School and the Prevalence of Overweight in Adolescent Students in Tasikmalaya, Indonesia

Background: Worldwide, More than 340 million children and adolescents have overweight problems, and snacking habits are likely contributing factors. However, little is known about habitual snack consumption in school, especially regarding snack types that may lead to overweight.  Purpose: Our study aims to analyse the association between habitual snack consumption and the prevalence of overweight in junior high school students. Methods: An observational study with a cross-sectional design was conducted in Tasikmalaya, West Java, Indonesia, involving 397 participants from five public junior high schools. The habitual snack consumption included the consumption habits of various types of snacks (sweet-fried snacks, salty-fried snacks, sweet-non-fried snacks, salty-non-fried snacks, fruits, and sugar-sweetened beverages) measured by a food frequency questionnaire (FFQ) and categorised into rarely and often. The overweight status was determined based on the BMI-for-age z-score (BAZ) and categorised into not-overweight and overweight. We analysed the data using a logistic regression test.  Results: The habits of often consuming sweet-fried snacks (p<0.001; aOR=5.448; 95% CI=2.303–12.886), salty-fried snacks (p=0.040; aOR=3.662; 95%CI=1.063-12.621), and sugar-sweetened beverages (p=0.026; aOR= 3.100; 95%CI=1.143-8.407) were risk factors associated with overweight. Conclusion: The habit of often consuming sweet-fried snacks was a risk factor for being overweight with the greatest odds. Therefore, education on healthy snacks could be included in school learning materials to prevent overweight in adolescent students.  

Breakfast Skipping among a Multi-Ethnic Population of Young Men and Relationship with Sociodemographic Determinants and Weight Status

Breakfast skipping is linked with obesity incidence. This study was conducted to assess the prevalence of breakfast skipping among a multi-ethnic population of young men residing in Saudi Arabia and its relationship with sociodemographic determinants and weight status. A total of 3600 young men aged 20 to 35 years and living in Riyadh, Saudi Arabia, were involved in this cross-sectional study. Sociodemographic determinants and breakfast-consumption frequency were collected from subjects by personal interviews. This study defines breakfast skipping as skipping breakfast at least one day per week. Weight and height were measured following standardized methods. The prevalence of breakfast skipping was observed among 52.8% of the study subjects. Nationality was a predictor of breakfast skipping, with the lowest and highest rates of breakfast skipping reported among young men from Bangladesh (14.0%) and Saudi Arabia (86.5%), respectively. Weight status was another predictor of breakfast skipping, as the mean body mass index for breakfast skippers (25.4 kg/m2) was significantly (p-value < 0.001) higher than that for breakfast consumers (24.8 kg/m2). Overweight/obese subjects have a significantly higher rate of breakfast skipping (56.9%) than underweight/normal weight subjects (48.9%). In conclusion, breakfast skipping prevalence is relatively high among young men residing in Saudi Arabia. The findings confirm a relationship between breakfast skipping and sociodemographic determinants and weight status.

Breakfast Skipping in a Multi-Ethnic Population of Middle-Aged Men and Relationship With Sociodemographic Variables and Weight Status

Background

Breakfast eating is regarded to be necessary for maintaining a healthy body weight. On the other hand, breakfast skipping has been linked with obesity incidence. This study was carried out to determine the prevalence of breakfast skipping among a multi-ethnic group of middle-aged men living in Saudi Arabia and the association between breakfast skipping and sociodemographic variables and weight status.

Methods

This cross-sectional study included 1,800 middle-aged men aged 36–59 years. Participants' sociodemographic information and frequency of breakfast eating were obtained through personal interviews. The body mass index was determined after measuring body weight and height using standardized methods.

Results

The prevalence of breakfast skipping was 42.1% of the study participants. Nationality was a predictor of breakfast skipping. Bangladeshi participants (N = 100) have the lowest rate of breakfast skipping (9.0%), whilst Saudi participants (N = 161) have the highest rate (73.3%). Weight status was another predictor of breakfast skipping as breakfast skippers had a significantly higher average body mass index (27.1 ± 3.8) than breakfast consumers (26.2 ± 3.5). Overweight/obese participants have a significantly higher breakfast skipping rate (44.9%) than participants with underweight/normal weight (36.6%).

Conclusion

The rate of breakfast skipping is relatively high among middle-aged men living in Saudi Arabia. The data support a link between breakfast skipping and sociodemographic variables and weight status.

The Insight into Insulin-Like Growth Factors and Insulin-Like Growth-Factor-Binding Proteins and Metabolic Profile in Pediatric Obesity

Insulin-like growth factors (IGFs) and insulin-like growth-factor-binding proteins (IGFBPs) regulate cell proliferation and differentiation and may be of importance in obesity development. The aim of the study was to analyze the expression of chosen IGF-axis genes and the concentration of their protein products in 28 obese children (OB) and 34 healthy control (HC), and their correlation with essential parameters associated with childhood obesity. The gene expression of IGFBP7 was higher, and the expression of IGF2 and IGFBP1 genes was lower in the OB. The expression of IGFBP6 tended to be lower in OB. IGFBP4 concentration was significantly higher, and IGFBP3 tended to be higher in the OB compared to the HC, while IGFBP1, IGFBP2, and IGFBP6 were significantly lower, and IGFBP7 tended to be lower in OB. We found numerous correlations between IGFs and IGFBP concentration and obesity metabolic parameters. IGFBP6 correlated positively with apelin, cholecystokinin, glucagone-like peptide-1, and leptin receptor. These peptides were also significantly lower in obese children in our study. The biological role of decreased levels of IGFBP6 in obese children needs further investigation.

Effects of microbiome changes on endocrine ghrelin signaling - A systematic review

The 28-amino acid peptide hormone ghrelin plays a unique role in the gut-brain axis: It is mainly produced peripherally in gastric X/A-like cells but stimulates food intake centrally via hypothalamic nuclei; thus, providing orexigenic communication between the gut and central food intake-regulatory centers. Another component of the gut-brain axis that gained increasing interest in recent years due to its ability to influence central signaling via metabolites is the gut microbiome. Interestingly, there is increasing evidence that changes in the microbiome are related to alterations in ghrelin expression, secretion, activation and signaling. Since ghrelin is supposedly implicated in the pathogenesis of obesity, changes in the microbiome were hypothesized to improve obesity via modulation of ghrelin abundance and receptor interaction. To shed more light on the association between the microbiome and ghrelin a systematic search of Medline, EMBASE and Web of science using the search term combination "microbiome AND ghrelin" was performed. As a result of the search, 42 publications were included into this systematic review, of which 30 publications reported preclinical and 12 manuscripts presented clinical data. In addition to a critical analysis of the present data, gaps in knowledge were highlighted in order to foster further research.

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.

Skipping breakfast is associated with overweight and obesity: A systematic review and meta-analysis

OBJECTIVE

In recent years, many original studies have shown that skipping breakfast has been associated with overweight and obesity; however, the results of different studies are inconsistent. Therefore, we conducted a systematic review and meta-analysis of observational studies to synthesize the associations between skipping breakfast and the risk of overweight/ obesity.

METHODS

We did a systematic search using Pubmed, and Ovid searched up to August 2019. Observational studies (cohort studies and cross-sectional studies) reporting adjusted Odds Ratio or Risk Ratio estimates for the association between breakfast skipping and overweight/obesity (including abdominal obesity). Summary odds ratio (or Risk Ratio) and 95% confidence intervals calculated with a random-effects model.

RESULTS

45 observational studies (36 cross-sectional studies and 9 cohort studies) were included in this meta-analysis. In cross-sectional studies, The ORs of low frequency breakfast intake per week versus high frequency were 1.48 (95% CI 1.40-1.57; I²=54.0%; P=0.002) for overweight/obesity, 1.31 (95% CI 1.17-1.47; I²=43.0%; P=0.15) for abdominal obesity. In cohort studies, The RR of low-frequency breakfast intake per week versus high frequency was 1.44 (95% CI 1.25-1.66; I²=61%; P=0.009) for overweight/obesity.

CONCLUSIONS

This meta-analysis confirmed that skipping breakfast is associated with overweight/obesity, and skipping breakfast increases the risk of overweight/obesity. The results of cohort studies and cross-sectional studies are consistent. There is no significant difference in these results among different ages, gender, regions, and economic conditions.

Pharmacological Modulation of Ghrelin to Induce Weight Loss: Successes and Challenges

PURPOSE OF REVIEW

Obesity is affecting over 600 million adults worldwide and has numerous negative effects on health. Since ghrelin positively regulates food intake and body weight, targeting its signaling to induce weight loss under conditions of obesity seems promising. Thus, the present work reviews and discusses different possibilities to alter ghrelin signaling.

RECENT FINDINGS

Ghrelin signaling can be altered by RNA Spiegelmers, GHSR/Fc, ghrelin-O-acyltransferase inhibitors as well as antagonists, and inverse agonists of the ghrelin receptor. PF-05190457 is the first inverse agonist of the ghrelin receptor tested in humans shown to inhibit growth hormone secretion, gastric emptying, and reduce postprandial glucose levels. Effects on body weight were not examined. Although various highly promising agents targeting ghrelin signaling exist, so far, they were mostly only tested in vitro or in animal models. Further research in humans is thus needed to further assess the effects of ghrelin antagonism on body weight especially under conditions of obesity.

Saliva and serum ghrelin and obestatin in iron deficiency anemia patients

Background

Serum ghrelin level is also associated with iron deficiency anemia (IDA), but no study has yet been published on the obestatin level in patients with IDA, even though both hormones are a single gene product. Therefore, the purpose of this investigation was to determine whether there is a link between IDA and these two hormones among other hematological parameters in patients with IDA.

Methods

To measure ghrelin and obestatin, human saliva and serum were collected from 30 women with IDA and 30 control women with repeated collection of samples over a period of 1 week and 1 month. Saliva and serum ghrelin levels were measured by enzyme-linked immunosorbent assay.

Results

Saliva and serum ghrelin and obestatin levels were significantly lower in the IDA group compared with controls; these levels increased slightly above baseline with iron treatment, but remained below the control values. Serum hemoglobin (Hb), ferritin and hematocrit (Hct) levels significantly increased with iron treatment, while total iron-binding capacity (TIBC) decreased compared to baseline concentrations.

Conclusions

The findings suggest that IDA might be linked to imbalance of circulating (serum) and non-circulating (saliva) ghrelin and obestatin levels. Using saliva in place of serum for monitoring the two hormones should minimize inconvenience and patient discomfort.