Serum Leptin and Adiponectin Levels in Obese and Nonobese Asthmatic School Children in relation to Asthma Control

Role of adiponectin, resistin and monocyte chemo-attractant protein-1 in overweight/obese asthma phenotype in children

BACKGROUND

Asthma is a chronic inflammatory disorder of the airways with diverse overlapping pathologies and phenotypes contributing to a significant heterogeneity in clinical manifestations. Obesity may modify asthma risk, phenotype, and prognosis. A suggested mechanism linking obesity and asthma is through systemic inflammation. Adipokines secreted by adipose tissue were suggested to provide a link between obesity and asthma.

OBJECTIVE

To have an understanding for the contribution of adiponectin, resistin and MCP-1 to development of distinct asthma phenotype in overweight/obese children through assessment of their serum level and correlation to pulmonary function tests.

SUBJECTS AND METHODS

The study included 29 normal weight asthmatics, 23 overweight/obese asthmatic children and 30 controls. All cases were subjected to detailed history taking, thorough examination and pulmonary function tests. Serum adiponectin, resistin, MCP-1 and IgE were assessed to all recruited subjects.

RESULTS

Adiponectin level was significantly higher in overweight/obese asthmatics (24900 ± 1600 ng/ml) compared to normal weight asthmatics (21700 ± 1700 ng/ml) and control (23000 ± 3200 ng/ml), (p < 0.001 & 0.051 respectively). Normal weight asthmatics had significantly lower adiponectin level than control, (p = 0.039). A significant low level of MCP-1 in overweight/obese asthmatics (149.5 (20-545) ng/L) compared to control (175 (28 -1123.5) ng/L), p = 0.037. No significant difference was found regarding resistin. Normal weight asthmatics had significantly lower FEV₁% and FVC% compared to overweight/obese asthmatics (p = 0.036, 0.016 respectively). A significant positive correlation was found between (FEV1%, FVC) and BMI in normal weight asthmatics (P = 0.01, < 0.01 respectively) and a significant negative correlation between PEF and BMI (-0.42, p = 0.05) in obese/overweight asthmatics. Resistin/adiponectin ratio was not affected by sex, degree of asthma severity or level of asthma control in either normal weight or overweight/obese asthmatic.

CONCLUSION

This work could suggest that adiponectin may play a role in overweight/obese asthma phenotype where it is possible to have a dual action (pro & anti- inflammatory). It seems that resistin had no role in asthma pathogenesis.

Correlation between adiponectin level and obesity as a risk factor for allergy disease

Much research has focused on the connection between two inflammatory conditions, allergic reactions and obesity which has led to a focus on adiponectin, hormone with anti-inflammatory properties secreted by adipose tissue. The aim of this study was to determine the association of adiponectin with obesity, as a risk factor for the development of allergic condition in order to rationalize approach to its treatment. Research methods for inflammatory markers and biochemical parameters involve immunoassay technique. Statistical analysis was performed with Student’s t-test, Wilcoxon T-test and coefficient of correlation. The study included apparently healthy subjects and patients with allergy conditions with confirmed presence of specific IgE, classified into 2 groups according to their body mass index (BMI). The obtained data showed negative correlation (cor = – 0.6), between adiponectin levels and BMI values. Thus, decreased level of adiponectin is associated with increased BMI. The mean values of adiponectin in the studied population, with high statistical differen­ces between the groups (19.1 ± 1.5; 17.7 ± 0.9), (18.8± 1.1; 16.6 ± 1.0) demonstrated the relationship between low adiponectin level and development of obesity, and what, in turn, increasd risk of developing allergic conditions. The assumption was made that adiponectin may be used as a sensitive biochemical marker for early diagnostics of allergic reactions. Keywords: adiponectin, allergy reactions, obesity, specific IgE

The role of circulating miRNAs in leptin resistance in obese children

OBJECTIVES

Leptin resistance is one of the important causes of obesity in children. Besides known causes of leptin resistance like mutations in leptin and leptin receptor genes, overexpression of SOCS3 in arcuate nucleus is a potential cause of leptin resistance. We aimed to determine the effects of circulating miRNAs on leptin resistance in obese children by targeting SOCS3 pathway.

METHODS

miRNAs potentially targeting SOCS3 were determined by using online target prediction databases. Polymorphisms in miRNA target sequences were determined by using online genome browsers. miRNA expression levels of obese (n=35) and non-obese (n=30) children were determined by qPCR method, genotyping were performed by real-time PCR method and serum leptin, leptin receptor and SOCS3 levels were measured by ELISA method.

RESULTS

miRNA profiling have shown that serum miR-218-5p levels are significantly (p<0.05) increased in accordance with serum leptin levels in obese children.

CONCLUSIONS

In this study we used target prediction methods for evaluating potential miRNAs which may involve in development of leptin resistance. We have shown that miR-218-5p might be taking part in leptin resistance in obese children.

Diet: A Specific Part of the Western Lifestyle Pack in the Asthma Epidemic

The Western lifestyle is a complex concept that includes the diet as the main axis of different factors which contribute to a detrimental effect on health, lower life expectancy and low quality-of-life. This type of diet is characterized by being high in calories, mainly provided by saturated fats, and rich in sugars that can lead to changes in immune cells and their responsiveness, by different mechanisms that have yet to be totally clarified. Inflammatory processes are perpetuated through different pathways, in which adipose tissue is a major factor. High fat stores in overweight and obesity accumulate energy but the endocrine function is also producing and releasing different bioactive compounds, adipokines, known to be pro-inflammatory and which play an important role in the pathogenesis of asthma. This review therefore explores the latest evidence regarding the adverse effect of the Western diet on adipose tissue inflammation and its causative effect on the asthma epidemic.

Obesity and childhood asthma in male schoolchildren in Saudi Arabia: Is there a role for leptin, interleukin-4, interleukin-5, and interleukin-21?

BACKGROUND

Adiposity is associated with high serum levels of adipokines and chemokines which are possibly implicated in a co-existence of obesity and asthma.

OBJECTIVES

Elucidate the possible roles of leptin, interleukin (IL)-4, IL-5 and IL-21 in linking obesity with childhood asthma.

DESIGN

Cross-sectional, analytical.

SETTING

Population of schoolchildren in a small Saudi city.

SUBJECTS AND METHODS

The study included a representative sample of Saudi schoolchildren grouped as obese asthmatics, non-obese asthmatics, or obese nonasthmatics, with nonobese nonasthmatics as a control group. An asthma control test was done for the asthmatic groups.

MAIN OUTCOME MEASURES

Serum levels of leptin, IL-4, IL-5, and IL-21.

SAMPLE SIZE

345 male schoolchildren with a mean (SD) age of 13.0 (2.3) years.

RESULTS

Median serum leptin concentrations in obese asthmatics were significantly higher than in nonobese asthmatics ( P<.001). Uncontrolled asthmatics also had significantly higher leptin levels than controlled asthmatic children ( P<.002). Leptin levels were weakly but significantly correlated with the cytokines IL-4, IL-5, and IL-21.

CONCLUSIONS

Leptin may contribute to a link between obesity and childhood asthma. Differences in IL-21 levels between nonobese and obese asthmatics suggest that the co-existence of asthma and obesity increased IL-21 levels. Leptin plus some proinflammatory cytokines especially IL-21 may be potential predictors for asthma control in children.

LIMITATIONS

Blood sampling at different stages of asthma might influence cytokine expression.

CONFLICT OF INTEREST

None.

Metabolomics reveals an entanglement of fasting leptin concentrations with fatty acid oxidation and gluconeogenesis in healthy children

Background

Leptin and adiponectin communicate with organ systems in order to regulate energetic and metabolic homeostasis. Their different points of action have been well characterized; however, no study has investigated their interrelationship with the metabolism at the molecular level in vivo.

Objective

To examine the associations of leptin and adiponectin with the metabolic profile reflecting the intercellular and interorgan communication as well as activated metabolic pathways.

Patients/Methods

We measured plasma concentrations of leptin, adiponectin, and insulin along with concentrations of 196 metabolites in 400 healthy, fasting 8-years old German children who participated in the German Ulm Birth Cohort Study (UBCS). Using multiple linear mixed models, we evaluated the associations between hormones and metabolites.

Results

Leptin levels increased exponentially with increasing BMI. Leptin was furthermore strongly associated with alanine and aspartate (Bonferroni corrected P[P_BF] = 5.7×10⁻⁸ and 1.7×10⁻⁶, respectively), and negatively associated to the sum of the non-esterified fatty acids (NEFA) and the sum of the long-chain acylcarnitines C12–C18 (P_BF = 0.009 and 0.0001, respectively). Insulin showed a similar association pattern, although the associations were less strong than for leptin. Adiponectin was neither related to BMI nor to any metabolite.

Conclusion

Although children were presumably metabolically similar, we found strong associations of insulin and leptin with the metabolite profile. High alanine concentrations and the lower concentrations of NEFA in children with high fasting leptin concentrations might arise from an increased gluconeogenesis and from the disinhibiting effect of leptin on the carnitine-palmitoyltransferase-1, respectively. As insulin had the same trend towards these associations, both hormones seem to be related to processes that provide the body with energy in fasting state.

Obesity related skin disorders

Obesity is a serious global problem. In recent years, it has been an increase in patients with obesity. In a review of literature presents data on the effect of obesity on the skin. It is responsible for the development of a number of dermatological diseases, including acantosis nigricans, akrohordony, follicular hyperkeratosis, infectious diseases of the skin. Against the background of obesity worsens psoriasis. The connection between obesity and atopic dermatitis.

Leptin Resistance: A Possible Interface Between Obesity and Pulmonary-Related Disorders

CONTEXT

Under normal physiological conditions, leptin regulates body weight by creating a balance between food intake and energy expenditure. However, in obesity, serum leptin levels increase and become defective to retain energy balance.

EVIDENCE ACQUISITION

Elevated serum leptin levels are regarded as an established marker of obesity. It is also reported that obese asthmatic patients have maximum serum leptin levels compared to other groups such as non-obese asthmatics, and normal obese and non obese subjects without asthma. In addition to having an appetite suppressing effect, leptin also regulates certain acute-phase protein expressions including α-1 antitrypsin (A1AT) in the liver.

RESULTS

A1AT is a protease inhibitor that counterbalances the activity of the neutrophil elastase (NE) enzyme. A1AT reductions in obese-leptin resistant subjects lead to increased NE activity. The overactivity of NE degrades lung tissue proteins, which may lead to pulmonary disorders including asthma.

CONCLUSIONS

On the basis of prior studies, it could be hypothesized that, in obese asthmatic patients, the highest degree of leptin failure/resistance might lead to the creation of an imbalance between NE and its inhibitor A1AT. To ascertain this, large scale prospective studies are warranted to assess the comparative serum leptin and A1AT levels and NE activity in asthmatic non-obese and obese patients, simultaneously. Such studies might help to devise novel interventional therapies for the treatment of pulmonary-related problems including asthma, chronic obstructive pulmonary disorder (COPD), and other lung defects in susceptible obese subjects in the future.