Adiponectin multimers, body weight and markers of cardiovascular risk in adolescence: Northern Ireland Young Hearts Project

Vascular Function and Distribution of Adiponectin Isomers during Puberty in Children and Adolescents with Obesity

INTRODUCTION

Youth with obesity have abnormal vascular function that relates to the anti-atherogenic adipose-derived hormone, adiponectin. The distribution of adiponectin isomers changes during normal puberty, but there are no data in relation to vascular function. We aimed to evaluate vascular function, adiponectin, and its isomers longitudinally in peri-pubertal youth with obesity and controls.

METHODS

The study is a cohort longitudinal study involving 30 children and adolescents with obesity (body mass index [BMI] z-score 2.31 ± 0.24; age 12.8 ± 3 years, 17 male participants) and 28 age-/sex-matched healthy controls (12.8 ± 3 years, 14 male participants). Vascular function (flow-mediated dilatation [FMD], glyceryl trinitrate-mediated dilatation [GTN]), total adiponectin and isomers, and laboratory and clinical variables were assessed at 0, 18, and 36 months.

RESULTS

FMD and GTN were stable during puberty in both groups, remaining consistently lower in obese children (p = 0.02, p < 0.001). The change in total (p = 0.02) and high-molecular weight (HMW) (p = 0.02) adiponectin differed between the groups: falling in controls by the end of puberty but not falling further during puberty in obesity. In obesity, impaired GTN was associated longitudinally with lower total (B = 7.85, p = 0.006) and HMW (B = 3.72, p = 0.03) adiponectin. In controls, more favourable GTN was longitudinally associated with a lower BMI z-score (B = -3.04, p = 0.027) and lower waist circumference (B = -0.35, p = 0.009).

CONCLUSIONS

Vascular dysfunction and lower levels of adiponectin are associated in children and adolescents with obesity during puberty and do not deteriorate further. Healthy children's better vascular function, within the normal range, is associated with a lower BMI z-score and waist circumference.

Durability of Changes in Biomarkers of Cardiometabolic Disease: 1-Year Family-Based Intervention in Children with Obesity

Background: The sustainability of health benefits in response to lifestyle-based interventions remains unclear in children with overweight and obesity, and cardiometabolic disease (CMD). We determined the changes in novel biomarkers of CMD in a 1-year family-based intervention (FBI) program, during 6-month active monitoring phase and at 12-month follow-up. Methods: Children with an age-adjusted body mass index (BMI) percentile ≥85 (N = 130; age 8-11 years) were recruited for a 1-year (6-month monitored and 6-month unmonitored) randomized controlled FBI program. Anthropometry and selected biomarkers of CMD were measured in 87 participants, randomly allocated to intervention (INT) and education-only (EDU) groups, at baseline, immediately after a 6-month active intervention or control period, and at 12-month unmonitored follow-up. Results: Samples from 87 participants (age 10.00 ± 0.11 years and Tanner stage ≤3) with obesity (BMI%ile = 97.45 ± 0.15) were available. Overall intervention effect (between groups), was observed for total (T) and high molecular weight (HMW) adiponectin, ratio of total to HMW adiponectin, fibrinogen, and interleukin (IL)-6 (P < 0.05 for all). However, between-group beneficial changes after adjusting for baseline levels were limited to BMI percentile, T and HMW adiponectin and their ratio, IL-6, and fibrinogen (P < 0.05 for all) mainly during the 6-month period of monitored intervention. Changes in traditional risk factors such as lipids and triglycerides were inconsistent. During the 6-month follow-up period, the changes in biomarkers leveled-off, except for T and HMW adiponectin, IL-6, and fibrinogen that continued to show benefits (P < 0.05) from the 6- to 12-month follow-up. Conclusions: The FBI program beneficially altered novel biomarkers of CMD during the monitored intervention phase in school-age children with obesity, but they mostly moved back toward baseline during the unmonitored follow-up phase. The changes in novel biomarkers of CMD appear to be more sensitive compared to the traditional risk factors. The study implies the need for refinements in lifestyle-based approaches in the preservation of cardiovascular health and calls for robust biomarkers to monitor the changes. The study was registered at ClinicalTrials.gov (NCT01146314).

Diagnosis and Management of Endocrine Hypertension in Children and Adolescents

Hypertension in childhood and adolescence has increased in prevalence. Interest in the disease was raised after the 2017 clinical practice guidelines of the American Academy of Paediatrics on the definition and classification of paediatric hypertension. Among the secondary causes of paediatric hypertension, endocrine causes are relatively rare but important due to their unique treatment options. Excess of catecholamine, glucocorticoids and mineralocorticoids, congenital adrenal hyperplasia, hyperaldosteronism, hyperthyroidism and other rare syndromes with specific genetic defects are endocrine disorders leading to paediatric and adolescent hypertension. Adipose tissue is currently considered the major endocrine gland. Obesity-related hypertension constitutes a distinct clinical entity leading to an endocrine disorder. The dramatic increase in the rates of obesity during childhood has resulted in a rise in obesity-related hypertension among children, leading to increased cardiovascular risk and associated increased morbidity and mortality. This review presents an overview of pathophysiology and diagnosis of hypertension resulting from hormonal excess, as well as obesity-related hypertension during childhood and adolescence, with a special focus on management.

Association of Total and High Molecular Weight Adiponectin with Components of Metabolic Syndrome in Mexican Children

OBJECTIVE

Childhood obesity linked to metabolic alterations, tend to appear simultaneously with altered adipocytokines, suggesting a role in pathogenetic development. Low circulating level of total and high molecular weight (HMW) adiponectin have been associated with components of the metabolic syndrome (MetS) and could represent an independent risk factor with potential use as a biomarker. To examine the prevalence of MetS in Mexican school children and to investigate the association of total and HMW adiponectin levels with biochemical parameters related to MetS.

METHODS

The study included a population of boys and girls, from 8 to 11 years old. Anthropometric and biochemical parameters were evaluated according to weight and MetS status. A correlation analysis was fitted to establish an association between adiponectin concentrations and metabolic indicators.

RESULTS

One-hundred and fifty five children participated (59.4% females) from 8-11 years of age. The prevalence of MetS was of 10.3%. Impaired biochemical parameters, including total and HMW adiponectin, were associated with obesity. The adiponectin level was significantly lower in MetS than in non-MetS subjects (4.5 vs. 5.4 μg/mL). Total- but not HMW adiponectin concentration was negatively correlated with blood pressure, fasting insulin, fasting blood sugar and Homeostatic Model Assessment for Insulin Resistance.

CONCLUSION

In young children, the total adiponectin level is associated with impaired biochemical parameters of carbohydrate metabolism and could be an excellent early predictor of metabolic complications.

Adipocytokines and High Blood Pressure in Mexican Children

Given that adipocytokines may play an important role in the pathophysiology of high blood pressure (HBP) and because related reports in children are scarce and controversial, we evaluated the relationship of leptin, resistin, tumor necrosis factor-α, interleukin-6, adiponectin, and interferon-γ with HBP. Materials and Methods. A total of 129 (53.8%) girls and 111 (46.2%) boys, with average ages of 10.8 ± 0.9 and 10.6 ± 1.0 years, respectively, were enrolled in a cross-sectional study. HBP was defined by systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) between the 90th and 95th percentiles. A multivariate logistic regression backwards-stepwise analysis adjusted for body mass index, waist circumference, and triglyceride levels was performed to compute the association between adipocytokines and HBP. Results. Seventy-two (30.0%) participants showed HBP: 44 (61.1%) girls and 28 (38.9%) boys. Multivariate analysis showed that, irrespective of obesity, serum levels of adiponectin, but not those of other adipocytokines, are inversely associated with HBP (odds ratio 0.93; 95% CI 0.77 to 0.98, p = .04). Conclusions. Our results show that low serum adiponectin levels, but not those of other adipocytokines, are inversely associated with HBP; this association is independent of obesity.

Fibroblast Growth Factor 21, Adiponectin, and Irisin as Markers of Unfavorable Metabolic Features in 12-Year-Old Children

CONTEXT

Among cytokines, fibroblast growth factor 21 (FGF21), adiponectin (Adn), and irisin have been considered potential biomarkers for insulin sensitivity (IS).

OBJECTIVE

We evaluated whether serum FGF21, Adn, and irisin associate with markers of IS and serum lipids in 12-year-old children.

DESIGN PARTICIPANTS AND MAIN OUTCOME MEASURES

This cohort study included 192 12-year-old children (109 girls). Seventy-eight of them had been born appropriate for gestational age (AGA), 70 small for gestational age (SGA), and 44 from preeclamptic pregnancies (PREs) as AGA. Fasting serum FGF21, Adn, irisin, lipids, inflammatory markers, and IS markers were measured. Quantitative insulin sensitivity check index (QUICKI) was calculated.

RESULTS

The means of serum FGF21, high molecular weight (HMW) Adn, and irisin did not differ between the sexes or between the SGA, AGA, and PRE children. In the whole study population, FGF21 associated positively with irisin and uric acid and negatively with leptin and high-density lipoprotein cholesterol (HDL-C). HMW Adn associated positively with total Adn, HDL-C, leptin, and SHBG. Apart from FGF21, irisin associated positively with insulin, high-sensitivity C-reactive protein, γ-glutamyltransferase, and triglycerides, and negatively with QUICKI, SHBG, and IGF binding protein-1. In multivariate regression analyses, irisin predicted lower IS and HMW Adn predicted higher HDL-C body mass index-independently, whereas FGF21 had no independent contribution to IS or lipid variables.

CONCLUSION

In 12-year-old children, serum irisin was associated with markers reflecting reduced IS. HMW Adn predicted HDL-C, whereas FGF21 did not contribute to IS or lipid parameters in multivariate regression analyses.

Breast-feeding, Leptin:Adiponectin Ratio, and Metabolic Dysfunction in Adolescents with Obesity

OBJECTIVES

Increased adiposity increases leptin and decreases adiponectin concentrations, resulting in an increased leptin:adiponectin ratio (LAR). In adults, components of the metabolic syndrome and other cardiometabolic risk factors, what we classify here as "metabolic dysfunction," are associated with both a high LAR and a history of being breast-fed. The relation among breast-feeding, LAR, and degree of metabolic dysfunction in obese youth is unknown. The purpose of our pilot study was to explore this relation and estimate the effect size of the relations to determine the sample size needed to power future prospective studies.

METHODS

We obtained fasting levels of leptin, adiponectin, lipids, insulin, and glucose from obese youth (aged 8-17 years). Weight, height, waist circumference, blood pressure, and breast-feeding history also were assessed.

RESULTS

Of 96 participants, 78 were breast-fed as infants, 54% of whom were breast-fed for >6 months. Wide variation was observed in LARs among children who were and were not breast-fed (>100% coefficient of variation). Overall, prevalence of metabolic dysfunction in the cohort was 94% and was not proven to be associated with higher LAR.

CONCLUSIONS

In this cohort of obese youth, we found a high prevalence of breast-feeding, metabolic dysfunction, and wide variation in the LARs. Based on the effect size estimated, future studies would need to enroll >1500 patients or identify, stratify, and selectively enroll obese patients without metabolic dysfunction to accurately determine whether breast-feeding in infancy influences LARs or metabolic dysfunction among obese youth.

Understanding rural-urban differences in risk factors for breast cancer in an Indian population

PURPOSE

Although cancer registry data indicate that there are large differences in breast cancer (BC) rates between rural and urban regions of India, the reasons for these differences are not well understood.

METHODS

We conducted a hospital based case-control study (1,637 breast cancer cases; 1,515 visitor controls) in Mumbai, India, during the years 2009-2013. Extensive questionnaire data, anthropometry measurement and blood samples were collected on all participants. Using logistic regression models, we estimated risk based on odds ratio (OR) and 95 % confidence intervals (CI) for various reproductive and anthropometric measures, stratified by rural-urban status depending upon residence in first 20 years of life.

RESULTS

Waist-to-hip ratio of ≥0.95 compared to ratio ≤0.84 was strongly associated with risk of BC in both rural and urban populations (ORurban = 4.10, 95 % CI 3.03-5.56; ORrural = 3.01, 95 % CI 1.85-4.90). First full-term pregnancy after the age of 25 compared to first full-term pregnancy below 20 years of age was associated with risk of BC in both urban and rural women (ORurban = 1.78, 95 % CI 1.32-2.41; ORrural = 2.24, 95 % CI 1.13-4.43). The prevalence of age at first full-term pregnancy was significantly lower in rural (mean age at first full-term pregnancy = 19.39 years) versus urban women (mean age at first full-term pregnancy = 22.62 years), whereas mean waist circumference was much higher in urban women (82.13 cm) compared to rural women (79.26 cm). We did not observe any association between breast feeding and risk of BC.

CONCLUSIONS

Differences in the prevalence of central adiposity and age at first full-term pregnancy between rural and urban women from India may explain some differences in breast cancer rates between these two populations.

Pathophysiology of hypertension in obese children: a systematic review

Hypertension is increasingly common in overweight and obese children. The mechanisms behind the development of hypertension in obesity are complex, and evidence is limited. In order to effectively treat obese children for hypertension, it is important to have a deeper understanding of the pathophysiology of hypertension in obese children. The present review summarizes the main factors associated with hypertension in obese children and discusses their potential role in its pathophysiology. Systematic searches were conducted in PubMed and EMBASE for articles published up to October 2014. In total, 60 relevant studies were included. The methodological quality of the included studies ranged from weak to strong. Several factors important in the development of hypertension in obese children have been suggested, including endocrine determinants, such as corticosteroids and adipokines, sympathetic nervous system activity, disturbed sodium homeostasis, as well as oxidative stress, inflammation and endothelial dysfunction. Understanding the pathophysiology of hypertension in overweight and obese children is important and could have implications for its screening and treatment. Based on solely cross-sectional observational studies, it is impossible to infer causality. Longitudinal studies of high methodological quality are needed to gain more insight into the complex mechanisms behind the development of hypertension in obese children.

Body composition parameters and adipokines levels in relation to bone mineral density in patients with malignant bone tumors after treatment

BACKGROUND

Recent data support the concept that adipokines, which are secreted by fat cells, are important modulators of bone metabolism. The aim of this study was to assess the relationships between body composition parameters, adipokines (leptin, adiponectin) and bone mineral density (BMD) in patients with malignant bone tumors after anticancer therapy.

PROCEDURE

The study included 35 patients (median age 14.8 years) with diagnosed malignant bone tumors treated according to obligatory protocols. Total fat mass, lean mass, bone mineral content (BMC) and BMD measurements were performed after treatment completion by dual energy-ray absorptiometry (DXA). Serum concentrations of leptin, leptin receptor and adiponectin were determined using immunoenzymatic assays. The control group consisted of 28 healthy children (median age 14.3 years).

RESULTS

Patients with bone tumor after chemotherapy had significantly higher fat mass (P < 0.01), increased ratio of fat mass/lean mass (P < 0.001), and a decrease (P < 0.001) in total body and lumbar spine BMD compared with controls. We observed higher serum leptin concentration (P < 0.01) and lower soluble leptin receptor (P < 0.001) and adiponectin (P = 0.01) in patients than in controls. The ratios of leptin/leptin receptor and leptin/adiponectin were about three-fold higher in patients compared with the control group (P = 0.001). We found a significant positive correlation between BMD and body composition and a negative correlation between BMD and adiponectin in the patients group.

CONCLUSIONS

Changes in body composition parameters coexisting with disturbed adipokine levels, especially higher levels of leptin and lower levels of adiponectin, might be associated with bone status in patients treated for malignant bone tumors.

Association of serum adiponectin with asthma and pulmonary function in the Japanese population

Conflicting findings have been reported regarding the role of adiponectin in asthma. The aim of this study was to evaluate the association of adiponectin with pulmonary functions and asthma in the Japanese population. First, among a general population that participated in a previous study (group 1), we selected 329 subjects after excluding those with asthma, chronic obstructive pulmonary disease, and a smoking history and examined the associations of the serum total adiponectin levels with pulmonary functions. In a second cohort (group 2) consisting of 61 asthmatic patients and 175 control non-asthmatic subjects, we examined the associations between asthma and the levels of total, high (HMW), middle (MMW) and low (LMW) molecular weight adiponectin isoforms as well as the ratio of each isoform to total adiponectin level. Although the total adiponectin levels were not significantly different between the asthmatic and control subjects in group 2, the levels were significantly and positively associated with the forced expiratory volume in 1 s after adjustments for confounding factors (P < 0.05) in women in group 1. In group 2, the LMW adiponectin level was significantly higher and the MMW/total adiponectin ratio was significantly lower among the asthmatic subjects than among the control subjects after adjustments for confounding factors in both sexes (P < 0.05). The present study showed that a low total adiponectin level may lead to airway narrowing compatible with asthmatic airways in women, and higher LMW adiponectin levels and lower MMW/total adiponectin ratio are significantly associated with current asthma in both sexes.

Association of serum vaspin and adiponectin levels with renal function in patients with or without type 2 diabetes mellitus

Vaspin and adiponectin are two adipocytokines with antidiabetic effects. Some studies reported that levels of adiponectin and vaspin were correlated with decreased glomerular filtration rate (FGR) and increased albuminuria. We therefore evaluated the vaspin and adiponectin levels in renal insufficiency (RI) patients with or without T2DM. Serum vaspin, adiponectin levels were measured in 416 subjects with or without T2DM. Analysis was made between groups divided by these subjects presence or absence of RI. We found that serum adiponectin level was significantly higher in nondiabetic patients with RI than in nondiabetic subjects without RI; however, there were no statistical differences between the diabetic patients with RI and without RI. In all the subjects, the serum adiponectin level was also higher in 50 individuals with RI than that in 366 subjects without RI. The serum vaspin levels showed no significant differences between the diabetic patients or nondiabetics subjects with RI and without RI. Contrary to adiponectin, the serum vaspin level was lower in 169 patients with T2DM than in 247 individuals without T2DM. Our data suggested that both of T2DM and renal insufficiency were correlated with the serum level of adiponectin. However, the serum vaspin levels showed no significant difference between the individuals with renal insufficiency and without renal insufficiency.

Adiponectin, Leptin, and Resistin in Asthma: Basic Mechanisms through Population Studies

Adipokines, factors produced by adipose tissue, may be proinflammatory (such as leptin and resistin) or anti-inflammatory (such as adiponectin). Effects of these adipokines on the lungs have the potential to evoke or exacerbate asthma. This review summarizes basic mechanistic data through population-based and clinical studies addressing the potential role of adipokines in asthma. Augmenting circulating concentrations of adiponectin attenuates allergic airway inflammation and airway hyperresponsiveness in mice. Murine data is supported by human data that suggest that low serum adiponectin is associated with greater risk for asthma among women and peripubertal girls. Further, higher serum total adiponectin may be associated with lower clinical asthma severity among children and women with asthma. In contrast, exogenous administration of leptin results in augmented allergic airway hyperresponsiveness in mice. Alveolar macrophages obtained from obese asthmatics are uniquely sensitive to leptin in terms of their potential to augment inflammation. Consistent with this basic mechanistic data, epidemiologic studies demonstrate that higher serum leptin is associated with greater asthma prevalence and/or severity and that these associations may be stronger among women, postpubertal girls, and prepubertal boys. The role of adipokines in asthma is still evolving, and it is not currently known whether modulation of adipokines may be helpful in asthma prevention or treatment.