Waist circumference to height ratio predicts inflammatory risk in children

Systems biology approach identifies key genes and related pathways in childhood obesity

BACKGROUND

Childhood obesity is triggered by a complex interplay of environmental, genetic, and epigenetic factors; however, the molecular mechanisms behind this disease are not completely elucidated. Thus, the aim of this study was to investigate molecular mechanisms involved in childhood obesity by implementing a systems biology approach.

METHODS

Experimentally validated and computationally predicted genes related to childhood obesity were downloaded from DisGeNET database. A protein-protein interaction (PPI) network was constructed using the STRING database and analyzed at Cytoscape web-tool. Hub-bottleneck genes and functional clusters were identified through CytoHubba and MCODE plugins, respectively. Functional enrichment analyses were performed based on Gene Ontology terms and KEGG Pathways.

RESULTS

The DisGeNET search retrieved 191 childhood obesity-related genes. The resulting PPI network contained 12 hub-bottleneck genes (INS, LEP, STAT3, POMC, ALB, TNF, BDNF, CAT, GCG, PPARG, VEGFA, and ADIPOQ) and 4 functional clusters, with cluster 1 showing the highest interaction score. Genes at this cluster were enriched at inflammation, carbohydrate, and lipid metabolism pathways. With exception of POMC, all hub-bottleneck genes were found in cluster 1, which contains highly connected genes that possibly play key roles in obesity-related pathways.

CONCLUSIONS

Our systems biology approach revealed a set of highly interconnected genes associated with childhood obesity, providing comprehensive information regarding genetic and molecular factors involved in the pathogenesis of this disease.

Abdominal Obesity Is Associated with an Increased Risk of All-Cause Mortality in Males but Not in Females with HFpEF

Background. Association between abdominal obesity and development of heart failure (HF) with preserved ejection fraction (HFpEF) between the sexes is not completely understood. Objectives. This study evaluated the association between abdominal obesity and the risk of all-cause mortality in patients with HFpEF while performing a gender outcome comparison. Methods. A post hoc analysis was undertaken from the American cohort of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT). The primary outcome (all-cause mortality) and the secondary outcomes (cardiovascular mortality, hospitalization for HF, stroke, and MI) were evaluated via Cox proportional hazards models to compare the hazard ratios (HRs) between sexes in HFpEF patients. Abdominal obesity was defined as a waist circumference of ≥102 cm in men and ≥88 cm in women. Results. A total of 3320 HFpEF patients (1620 men [48.80%] and 1700 women [51.20%]) were included in the analysis. The mean follow-up period was $3.4\pm 1.7$ years, with 503 patients dying during that time. After multivariable adjustment, abdominal obesity was significantly associated with an increased risk of all-cause mortality in males (adjusted HR: 1.32; 95% confidence interval [CI]: 1.02 to 1.71; $p=0.038$ ). Abdominal obesity was associated with hospitalization for HF in both male (adjusted HR: 1.39; 95% CI: 1.01 to 1.93; $p=0.045$ ) and female patients (adjusted HR: 1.15; 95% CI: 1.18 to 3.28; $p=0.010$ ). Conclusions. Abdominal obesity is associated with increased risks of all-cause mortality in the male but not the female HFpEF population and is associated with increased risks of hospitalization for HF in both sexes.

Evaluation of Cardiovascular Risk by Waist-to-Height Ratio in School-Age Children

Background: Childhood overweight and obesity are among the major public health problems worldwide. In Mexico, it has been reported in 2018 that 35.6% of children between 5 and 11 years old were overweight or obese. Central obesity is associated with the development of different complications, such as cardiovascular diseases (CVDs). An important tool used to evaluate obesity is the waist-to-height ratio (WHtR), and values higher than 0.5 suggest the existence of cardiovascular risk (CVR). The aim of this study was to evaluate CVR by the WHtR in school-age children from Yucatan, Mexico. Methods: This study included a sample of school-age children between the ages of 10 and 13 years from public schools in Yucatan, Mexico. Anthropometric parameters such as body weight, height, body mass index z-score (zBMI), waist circumference, WHtR, and CVR were evaluated. Results: A total of 2559 children with a median age of 12.1 ± 0.57 years old were evaluated. The classification by height z score showed that 26.8% were of short height, 73.1% were of normal height, and 0.1% were of tall height. The prevalence of body weight excess determined by zBMI was 48%. The prevalence of normal weight was 44%, and the prevalence of body weight deficiencies was 8%. The CVR determined by WHtR was 47.5%. In the population with obesity, 63.3% had an increased risk of CVDs and 30.7% had a very high risk. Moreover, it was observed that 13.2% of the population with normal weight had an increased risk of CVDs. Conclusion: One out of two child 10 to 13 years of age is overweight or obese as defined with zBMI in Mexico. According to WHtR, almost half of this population is at increased CVR, while near two-third of child with obesity are at high or very high CVR.

Oxidative DNA damage and subclinical hypothyroidism in children with obesity

Background

Obesity-related oxidation stress plays a key role in obesity complications; however, its relation to thyroid status is an area for further research. The study aimed to assess thyroid function in obese children and its relation to oxidative deoxyribonucleic acid (DNA) damage.

Results

Fifty obese and 40 normal weight children were included. Anthropometric measurement, lipid profile, thyroid function, anti-thyroglobulin antibody, thyroid peroxidase antibody, and 8-hydroxydeoxyguanosine serum level as marker of oxidative DNA damage were measured. Thirty-six percent of children with obesity have subclinical hypothyroidism. Central obesity but not oxidative DNA damage and lipid profile was significantly associated with subclinical hypothyroidism. Waist circumference > 97th centile increases the risk for subclinical hypothyroidism (odd ratio 10.82; confidence interval 95% 2.75–42.409; p-value<0.001).

Conclusion

Central obesity represents a risk factor for subclinical hypothyroidism in obese children. Oxidation DNA damage did not show significant association with subclinical hypothyroidism.

Performance of Waist-To-Height Ratio, Waist Circumference, and Body Mass Index in Discriminating Cardio-Metabolic Risk Factors in a Sample of School-Aged Mexican Children

The most common tools used to screen for abdominal obesity are waist circumference (WC) and waist-to-height ratio (WHtR); the latter may represent a more suitable tool for the general non-professional population. The objective of this study was to evaluate the association of WHtR, WC, and body mass index with lipidic and non-lipidic cardio-metabolic risk factors and the prediction capability of each adiposity indicator in a sample of school-aged Mexican children. Overall, 125 children aged 6 to 12 years were analyzed. Anthropometric, biochemical, and dietary parameters were assessed. Receiving operating characteristic (ROC) analysis and univariate and multivariate linear and logistic regression analyses were performed. All the three adiposity indicators showed significant areas under the ROC curve (AURC) greater than 0.68 for high low-density lipoprotein cholesterol (LDL-c), triglycerides, and atherogenic index of plasma, and low high-density lipoprotein cholesterol (HDL-c). A significant increased risk of having LDL-c ≥ 3.4 mmol/L was observed among children with WHtR ≥ 0.5 as compared to those with WHtR < 0.5 (odds ratio, OR: 2.82; 95% confidence interval, CI: 0.75–7.68; p = 0.003). Fasting plasma glucose was not associated with any of the adiposity parameters. WHtR performed similarly to WC and z-BMI in predicting lipidic cardio-metabolic risk factors; however, a WHtR ≥ 0.5 was superior in detecting an increased risk of elevated LDL-c.

The chemokine system and its role in obesity

The chemokine system is a complex arrangement of molecules that attract leukocytes to the site of injury or inflammation. This chemotactic behavior gives the system the name "Chemokine." The intricate and redundant nature of the chemokine system has made it a subject of ongoing scientific investigation. Obesity is characterized as low-grade systemic or chronic inflammation that is responsible for the release of cytokines, adipokines, and chemokines. Excessive tissue fat expansion triggers the release of chemokines, which in turn attract various leukocytes and activate the resident immune surveillance system, eventually leading to worsening of obesity and other related comorbidities. To date, 50 chemokines and 20 chemokine receptors that belong to the G-protein-coupled receptor family have been discovered, and over the past two decades, the physiological and pathological roles of many of these chemokines and their receptors have been elucidated. The objective of this review is to present an update on the link between chemokines and obesity under the light of recent knowledge.