The potential role of vitamin D in the link between obesity and asthma severity/control in children

Bibliometric Insights into Research Hotspots and Trends in Obesity and Asthma from 2013 to 2023

INTRODUCTION

Obesity and asthma are closely linked, but the current state of research on this topic and future research directions have yet to be comprehensively explored. This study aims to provide an up-to-date overview of the research landscape in the field of obesity and asthma.

METHODS

A bibliometric analysis was conducted using the Web of Science Core Collection database to identify papers published on obesity and asthma between 2013 and 2023. VOSviewer software was utilized for statistical analysis and visualization of collaborative networks, research trends, literature sources, citation analysis, co-citation analysis, and keyword analysis.

RESULTS

A total of 3,406 records from 1,010 journals authored by 17,347 researchers affiliated with 4,573 institutes across 117 countries and regions were retrieved. The number of publications and citations increased annually. The USA and China contributed the majority of records. Major nodes in the collaboration network map included Harvard Medical School, Johns Hopkins University, University of Newcastle, Karolinska Institution, University of Toronto, and Seoul National University. Prolific authors included Anne E. Dixon, Erick Forno, Lisa G. Wood, Deepa Rastogi, and Fernando Holguin. Research trends and hotspots focused on metabolism studies, Mendelian randomization, gut microbiome, inflammation response, gene, biomarker research, and comorbidities were identified as potential future research frontiers.

CONCLUSION

This study provides a comprehensive overview of the current research status and trends in the field of obesity and asthma. Our findings highlight the importance of understanding collaboration patterns, research hotspots, and emerging frontiers to guide future research in this area.

Associations between vitamin D, immunoglobulin E concentrations, and obesity

The prevalence of allergies and obesity has been increased in parallel. Low vitamin D [25(OH)D] levels have been linked to both higher body mass index (BMI) and allergies. Since the activation of the 25(OH)D receptor inhibits IgE production and 25(OH)D influences the IgE response specifically, we tested the hypothesis that circulating 25(OH)D concentrations are negatively related to circulating allergen-specific IgE concentrations distinctly in a large adult population-based study cohort. Moreover, we studied VDR gene expression in paired biopsies of abdominal subcutaneous (SAT) and visceral adipose tissue (VAT). We investigated whether magnetic resonance imaging-estimated visceral (VFM) and subcutaneous fat mass (SFM) are related to 25(OH)D levels. We found gender differences in circulating 25(OH)D and IgE concentrations. Participants with obesity showed lower 25(OH)D concentrations and higher IgE concentrations were detected in women only. Interestingly, participants with high levels of 25(OH)D are leaner and have improved glucose metabolism. In women, 25(OH)D correlate significant with VFM and SFM. VDR expression is significantly higher expressed in VAT and is positive associated with circulating 25(OH)D concentration. There was no association between serum IgE and 25(OH)D in the entire cohort. Based on these data, we could confirm that low levels of 25(OH)D are linked to higher BMI but could not prove our hypothesis because there is no relationship between 25(OH)D and IgE in adults. Women with higher BMI tend to have higher IgE levels what may have clinical relevance. The association between obesity and circulating 25(OH)D/IgE is not straightforward, and further knowledge is needed.

Vitamin D status in children and its association with glucose metabolism in northern China: a combination of a cross-sectional and retrospective study

OBJECTIVES

This study aimed to explore the vitamin D status of children in northern China and the association between vitamin D and glucose metabolism.

DESIGN

Cross-sectional study was conducted among child participants and retrospective study designs were conducted among adult participants.

SETTING AND PARTICIPANTS

Both studies were recruited from Harbin, 326 children were included in children's study, 8469 adults were included in adult study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Physical examination, lifestyle and dietary habit data were recorded in all the participants. Serum insulin, glucose, 25(OH)D₃ concentrations in children and serum glucose and lipids levels in adults were measured. Rickets history was also investigated in adults, which was used to define vitamin D deficiency in childhood. The associations were tested by linear regression and binary logistic regression.

RESULT

In the children's study, only 10.7% of participants were vitamin D sufficient (≥30 ng/mL). Inverse correlations between serum 25(OH)D₃ concentration and fasting insulin and homeostasis model assessment - insulin resistance (HOMA-IR) were found, and children with lower serum 25(OH)D₃ concentrations were likely to have insulin resistance (IR) (OR: 0.955, 95% CI: 0.917 to 0.995, p value: 0.027). In an adult study, rickets in childhood increased the risk of type 2 diabetes in male participants (OR=1.414, 95% CI=1.013 to 1.972; p value=0.042), but this result was not observed in female participants.

CONCLUSION

Our findings suggest that vitamin D deficiency is widespread in northern China. Vitamin D deficiency in childhood was associated with IR and increased the risk of type 2 diabetes in male adults.

Reference Gene Validation for RT-qPCR in PBMCs from Asthmatic Patients with or without Obesity

Obesity is known to impair the efficacy of glucocorticoid medications for asthma control. Glucocorticoid-induced gene expression studies may be useful to discriminate those obese asthmatic patients who present a poor response to glucocorticoids. The expression of genes of interest is normalized with respect to reference genes (RGs). Ideally, RGs have a stable expression in different samples and are not affected by experimental conditions. The objective of this work was to analyze suitable RGs to study the role of glucocorticoid-induced genes in obese asthmatic patients in further research. The gene expression of eight potential RGs (GUSB, B2M, POLR2A, PPIA, ACTB, GAPDH, HPRT1, and TBP) was assessed with reverse transcription-quantitative polymerase chain reaction in peripheral blood mononuclear cells (PBMCs) from asthmatic, obese asthmatic, and healthy individuals. Their stability was analyzed using four different algorithms-BestKeeper, ΔCt, geNorm, and NormFinder. geNorm analysis recommended the use of a minimum of three genes for normalization. Moreover, intergroup variation due to the treatment was calculated by NormFinder, which found that B2M was the gene that was least affected by different treatments. Comprehensive rankings indicated GUSB and HPRT1 as the best RGs for qPCR in PBMCs from healthy and asthmatic subjects, while B2M and PPIA were the best for obese asthmatic subjects. Finally, our results demonstrated that B2M and HPRT1 were the most stable RGs among all groups, whereas ACTB, TBP, and GAPDH were the worst shared ones.

Metabolomics in asthma: A platform for discovery

Asthma, characterized by airway hyperresponsiveness, inflammation and remodeling, is a chronic airway disease with complex etiology. Severe asthma is characterized by frequent exacerbations and poor therapeutic response to conventional asthma therapy. A clear understanding of cellular and molecular mechanisms of asthma is critical for the discovery of novel targets for optimal therapeutic control of asthma. Metabolomics is emerging as a powerful tool to elucidate novel disease mechanisms in a variety of diseases. In this review, we summarize the current status of knowledge in asthma metabolomics at systemic and cellular levels. The findings demonstrate that various metabolic pathways, related to energy metabolism, macromolecular biosynthesis and redox signaling, are differentially modulated in asthma. Airway smooth muscle cell plays pivotal roles in asthma by contributing to airway hyperreactivity, inflammatory mediator release and remodeling. We posit that metabolomic profiling of airway structural cells, including airway smooth muscle cells, will shed light on molecular mechanisms of asthma and airway hyperresponsiveness and help identify novel therapeutic targets.

Dilemmas in Vitamin D Management in Children and Adolescents

The importance of vitamin D and its role in several biological processes has been a topic of interest in recent years. Vitamin D is an essential nutrient that is needed for metabolic bone health and for maintaining bone calcium homeostasis. It is primarily synthesized in the skin on exposure to sunlight. Of late, vitamin D deficiency has been associated with conditions such as obesity, poor control of asthma and other autoimmune diseases, which has led to questions about its potential role in causation and management of these conditions. Given the increase in data about this topic, providers may often have questions about whom to screen and what to tell patients. In this article, we address screening guidelines for vitamin D in children and adolescents, management of vitamin D deficiency, and current literature on the role of vitamin D in conditions such as obesity, asthma, and type 1 diabetes mellitus. [Pediatr Ann. 2019;48(8):e298-e303.].

Children with Obesity and Asthma: Which Are the Best Options for Their Management?

Obesity and asthma are complex disorders related to gene-environment interactions and various lifestyle factors. At present, they represent two of the most significant paediatric health problems worldwide, particularly in industrialized nations. The aim of this narrative review is to evaluate possible therapeutic strategies to manage asthma in children with overweight/obesity. PubMed was used to search for all of the studies published from January 2008 to June 2018 using the following key words: “asthma” and “overweight” or “obesity” or “obese” and “children” or “paediatric”. The literature review showed that growing evidence underlines the existence of an “obese asthma” phenotype characterised by difficult-to-control asthma with additional symptoms, worse control, more frequent and severe exacerbations, reduced response to inhaled corticosteroids, and lower quality of life than other phenotypes. Currently, therapeutic strategies centred on prevention are suggested and the development of resources to assist families with weight loss strategies seems useful for effective weight control and optimal asthma management. Studies on vitamin D supplementation and further knowledge are needed to better define the best therapeutic options to manage asthma in children with overweight/obesity and to reduce the onset and severity of this chronic respiratory disease through the design of a multifactorial intervention.

The role of vitamin D in obstructive sleep apnoea syndrome

Obstructive sleep apnoea syndrome (OSAS) is a common disorder of multifactorial pathogenesis and is associated with obesity, diabetes and cardiovascular disease. Vitamin D is a fat-soluble vitamin with an important function in calcium absorption and homeostasis, which is also implicated in several nonskeletal conditions. The prevalence of vitamin D deficiency is increasing worldwide and is associated with similar metabolic disturbances to OSAS. Moreover, recent data suggest that in OSAS patients serum levels of vitamin D are lower compared with non-apnoeic subjects. However, the mechanisms linking vitamin D deficiency and OSAS are not completely understood and several hypotheses have been advanced. To date, a limited number of studies have assessed the association between lower serum concentrations of vitamin D and OSAS, and have reported inconsistent results. Similarly, contradictory results have been produced by studies which evaluated the effect of continuous positive airway pressure treatment on serum vitamin D levels. The aim of this review is to summarise current knowledge on the association between OSAS and vitamin D levels.

Due to multiple confounding factors, vitamin D deficiency is common among sleep apnoea patients; thus, screening should be performed when clinically indicatedhttp://ow.ly/L3ow30krmol

The effect of obesity, weight gain, and weight loss on asthma inception and control

PURPOSE OF REVIEW

There is ample and growing evidence that obesity increases the risk of asthma and morbidity from asthma. Here, we review recent clinical evidence supporting a causal link between obesity and asthma, and the mechanisms that may lead to 'obese asthma'.

RECENT FINDINGS

Although in some children obesity and asthma simply co-occur, those with 'obese asthma' have increased asthma severity, lower quality of life, and reduced medication response. Underlying mechanistic pathways may include anatomical changes of the airways such as obstruction and dysanapsis, systemic inflammation, production of adipokines, impaired glucose-insulin metabolism, altered nutrient levels, genetic and epigenetic changes, and alterations in the airway and/or gut microbiome. A few small studies have shown that weight loss interventions may lead to improvements in asthma outcomes, but thus far research on therapeutic interventions for these children has been limited.

SUMMARY

Obesity increases the risk of asthma - and worsens asthma severity or control - via multiple mechanisms. 'Obese asthma' is a complex, multifactorial phenotype in children. Obesity and its complications must be managed as part of the treatment of asthma in obese children.

[Effect of obesity on treatment outcome of asthma predictive index-positive infants and young children with wheezing]

OBJECTIVE

To study the effect of obesity on the treatment outcome of asthma predictive index (API)-positive infants and young children with wheezing.

METHODS

A total of 208 API-positive infants and young children with wheezing were enrolled. According to the Kaup index, the patients were divided into an obese group (n=93) and a non-obese group (n=115). The patients were given multimodality therapy in an acute episode of wheezing and aerosol inhalation of inhaled corticosteroid (ICS) budesonide suspension in the remission stage. The dose of ICS was adjusted according to clinical control. The patients were treated for 6 months, and were followed up at 2 weeks after treatment and once per month afterwards.

RESULTS

At 2 weeks and 1 month after treatment, the obese group had significantly lower remission rates of clinical symptoms than the non-obese group (35.5%/75.3% vs 53.0%/87.8%; P<0.05). Compared with the non-obese group, the obese group had significantly higher incidence rates of wheezing at 3 and 6 months after treatment and a significantly higher proportion of patients who visited the emergency service or were hospitalized due to wheezing within 6 months (P<0.05).

CONCLUSIONS

Obesity can inhibit the response to ICS treatment in API-positive infants and young children with wheezing.

Vitamin D and bronchopulmonary dysplasia in preterm infants

OBJECTIVE

Vitamin D deficiency is associated with asthma and reactive airway disease in childhood but its potential contribution to bronchopulmonary dysplasia (BPD) in preterm infants is unknown. Preterm infants have lower levels of 25-hydroxyvitamin D (25(OH)D) at birth and are at risk for nutritional deficiencies after birth. The objective of the study was to evaluate the association of 25(OH)D concentrations at birth and at 36 weeks' corrected gestational age with BPD in preterm infants born before 29 completed weeks of gestation.

STUDY DESIGN

We collected umbilical cord blood samples from 44 preterm infants (gestational age <29 weeks) delivered at Brigham and Women's Hospital in Boston. In addition, with parental consent we collected venous samples at 36 weeks' corrected age from 20 preterm infants born before 29 weeks' gestation (including 6 infants with previously collected cord blood). Samples were frozen at -80 °C until subsequent measurement of 25(OH)D levels by chemiluminescence. We used multivariable logistic models to adjust for gestational age and considered other confounding variables, including maternal race, age, mode of delivery and infant sex.

RESULTS

Among 44 infants, 41 (93.2%) survived and 3 (6.8%) died before 36 weeks' corrected age. Median 25(OH)D levels at birth were 30.4 ng ml(-1) in preterm infants who subsequently died or developed BPD and 33.8 ng ml(-1) in infants who survived without BPD (P=0.6). Median 25(OH)D levels at corrected age of 36 weeks were 59.0 ng ml(-1) among survivors without BPD and 64.2 ng ml(-1) among survivors with BPD (P=0.9). Neither cord blood nor 36 weeks' corrected 25(OH)D levels were associated with odds of death or BPD (adjusted odds ratio (OR) 1.00, 95% confidence interval (CI): 0.73 to 1.37; and OR 0.93, 95% CI: 0.61 to 1.43, respectively).

CONCLUSIONS

Among this population of extremely preterm infants neither cord blood nor the 36 weeks' corrected age 25(OH)D levels were associated with development of BPD. Notably, at the current level of supplementation, all extremely preterm infants in our cohort had achieved 25(OH)D levels >30 ng ml(-1) by 36 weeks' corrected age, which is thought to represent sufficiency in adult and pediatric populations.