Adiposity trajectory and its associations with plasma adipokine levels in children and adolescents-A prospective cohort study

Leptin/adiponectin ratio as a prognostic factor for increased weight gain in girls with central precocious puberty

OBJECTIVE

To determine if the leptin, adiponectin, and leptin/adiponectin ratio (LAR) can predict weight gain at the end of GnRH analogs (GnRHa) treatment in girls with central precocious puberty (CPP).

MATERIAL AND METHODS

Study design: prospective cohort. Serum levels of leptin and adiponectin were determined at diagnosis of CPP. Anthropometry was performed at diagnosis of CPP and every six-months, until treatment with GnRHa was discontinued and they presented menarche. Patients were divided according to BMI<94 and BMI>95 percentile at diagnosis of CPP. The outcome was the increased in weight gain (e.g., from normal weight to overweight) at the end of follow-up. Statistical analysis: repeated measures ANOVA test and Student's t-test were used to compare groups. Logistic regression analysis was used to evaluate the association of leptin and adiponectin levels, as well as LAR values with increased weight gain.

RESULTS

Fifty-six CPP patients were studied, 18 had BMI >95 percentile and 38 BMI <94 percentile. Of the 18 patients who initially had BMI >95^th, two patients went from obesity to overweight, while among the 38 patients who started with BMI <94^th, 21 (55.2%) increased their weight gain at the end of follow-up. This last group had higher leptin levels (8.99 ± 0.6 vs 6.14 ± 0.8, p=0.005) and higher LAR values compared to those who remained in the same weight (1.3 ± 0.5 vs 0.96 ± 0.56, p=0.01). In the logistic regression analysis, it was found that higher leptin levels and higher LAR values were associated with increased weight gain (RR 1.31, 95%CI 1.03-1.66, RR 4.86, 95%CI 1.10-21.51, respectively), regardless of birth weight, pubertal stage, age, and bone/chronological age ratio.

CONCLUSIONS

In patients with CPP, leptin levels and higher LAR values appear to be associated with significantly greater weight gain during GhRHa treatment, particularly in girls starting with BMI < 94 percentile.

Is the Leptin/Adiponectin Ratio a Better Diagnostic Biomarker for Insulin Resistance than Leptin or Adiponectin Alone in Adolescents?

Background: Recently, the leptin/adiponectin (L/A) ratio has been suggested as a novel predictor of cardio-metabolic and other chronic diseases. Aim: To evaluate the ability of leptin (L), adiponectin (A), and the L/A ratio in identifying high risk of insulin resistance IR in adolescents, adjusted by cardiorespiratory fitness, adherence to the Mediterranean diet, and body fat percentage. Subjects and methods: This is a cross-sectional analysis with 529 adolescents aged 12−18 years-old. Blood samples were taken to analyze glucose, insulin, leptin, and adiponectin levels. IR (homeostasis model assessment of insulin resistance (HOMA-IR) was estimated from fasting serum insulin and glucose). Results: Adiponectin, leptin, and L/A ratio were accurate to predict IR among adolescents. The optimal L/A cut-off value to indicate risk of IR development was >0.35 in boys and >0.97 in girls. Logistic analyses showed that the suggested cut-off points for adiponectin (girls: OR: 2.87 (1.26−6.53); p = 0.012); leptin (boys: OR: 5.23 (1.16−7.14) p = 0.006; girls: OR: 2.99 (1.10−8.09) p = 0.031), and the L/A ratio (boys: OR: 8.38 (2.6−26.8) p < 0.001; girls: OR: 6.1 (2.1−17.0) p < 0.001), were significant predictors of IR, after adjustments for age, pubertal stage, adherence to the Mediterranean diet, cardiorespiratory fitness, and body fat percentage. Conclusion: Leptin and L/A ratio were associated with IR risk, after adjustments for confounders in both sexes and adiponectin in girls. The L/A ratio seems to have a higher diagnostic accuracy to identify IR risk than adiponectin or leptin, in both sexes.

Dynamic relationships between body fat and circulating adipokine levels from adolescence to young adulthood: The Santiago Longitudinal Study

BACKGROUND AND AIMS

Adipose tissue secretes adipokines such as adiponectin and leptin, playing important roles in energy metabolism. The longitudinal associations between such adipokines and body fat accumulation have not been established, especially during adolescence and young adulthood and in diverse populations. The study aims to assess the longitudinal association between body fat measured with dual X-ray absorptiometry and plasma adipokines from adolescence to young adulthood.

METHODS AND RESULTS

Among Hispanic/Latino participants (N = 537) aged 16.8 (SD: 0.3) years of the Santiago Longitudinal Study, we implemented structural equation modeling to estimate the sex-specific associations between adiposity (body fat percent (BF%) and proportion of trunk fat (PTF)) and adipokines (adiponectin and leptin levels) during adolescence (16 y) and these values after 6 years of follow-up (22 y). In addition, we further investigated whether the associations differed by baseline insulin resistance (IR) status. We found evidence for associations between 16 y BF% and 22 y leptin levels (β (SE): 0.58 (0.06) for females; 0.53 (0.05) for males), between 16 y PTF and 22 y adiponectin levels (β (SE): -0.31 (0.06) for females; -0.18 (0.06) for males) and between 16 y adiponectin levels and 22 y BF% (β (SE): 0.12 (0.04) for both females and males).

CONCLUSION

We observed dynamic relationships between adiposity and adipokines levels from late adolescence to young adulthood in a Hispanic/Latino population further demonstrating the importance of this period of the life course in the development of obesity.

The impacts of exercise on pediatric obesity

Over the last few decades, the rates of pediatric obesity have more than doubled regardless of sociodemographic categorization, and despite these rates plateauing in recent years there continues to be an increase in the severity of obesity in children and adolescents. This review will discuss the pediatric obesity mediated cardiovascular disease (CVD) risk factors such as attenuated levels of satiety and energy metabolism hormones, insulin resistance, vascular endothelial dysfunction, and arterial stiffness. Additionally, early intervention to combat pediatric obesity is critical as obesity has been suggested to track into adulthood, and these obese children and adolescents are at an increased risk of early mortality. Current suggested strategies to combat pediatric obesity are modifying diet, limiting sedentary behavior, and increasing physical activity. The effects of exercise intervention on metabolic hormones such as leptin and adiponectin, insulin sensitivity/resistance, and body fat in obese children and adolescents will be discussed along with the exercise modality, intensity, and duration. Specifically, this review will focus on the differential effects of aerobic exercise, resistance training, and combined exercise on the cardiovascular risks in pediatric obesity. This review outlines the evidence that exercise intervention is a beneficial therapeutic strategy to reduce the risk factors for CVD and the ideal exercise prescription to combat pediatric obesity should contain both muscle strengthening and aerobic components with an emphasis on fat mass reduction and long-term adherence.

Fetal and Infancy Growth Pattern, Cord and Early Childhood Plasma Leptin, and Development of Autism Spectrum Disorder in the Boston Birth Cohort

Leptin is a proinflammatory cytokine that plays an important role in energy homeostasis. Emerging evidence suggests that leptin levels are altered in children with autism spectrum disorder (ASD); however, this has not been studied prospectively. Rapid growth during infancy and early childhood has been implicated in ASD, but the evidence is inconsistent. As leptin is involved in growth and is a potential risk factor for ASD, we explored the associations between (a) cord, early childhood leptin and ASD; and (b) birth weight for gestational age, early childhood weight gain, and ASD. We also assessed the mediating role of leptin in the relationship between weight gain during infancy and ASD. This study was conducted in a sample of 822 subjects from the Boston Birth Cohort. ASD was defined from diagnostic codes in electronic medical records. Extremely rapid weight gain during infancy was associated with a greater ASD risk and this persisted after adjusting for potential confounders (aOR: 3.11; 95% CI: 1.37, 7.07). Similarly, children that had higher plasma leptin levels, prior to ASD diagnosis, had an increased ASD risk in both unadjusted and adjusted models (aOR: 7.87; 95% CI: 2.06, 30.04). Further, early childhood leptin indirectly mediated the relationship between rapid weight gain and ASD. No associations were found between birth weight for gestational age, cord leptin and risk of ASD. Our findings provide a basis to further explore whether the combination of early life growth pattern and a biomarker such as leptin can predict ASD earlier. Autism Res 2018, 11: 1416-1431. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Is early life growth and a biomarker leptin related to ASD risk? To answer this question, we followed 822 children from birth and found that those who gained weight very quickly in infancy, had higher leptin levels in early childhood, had a greater chance of later ASD diagnosis. More research is needed to see if infant's weight gain pattern along with a biomarker (such as leptin) can be used to identify children with ASD sooner.

Adolescent cohorts assessing growth, cardiovascular and cognitive outcomes in low and middle-income countries

Introduction

Life-course studies are needed to explore how exposures during adolescence, particularly puberty, contribute to later cardiovascular risk and cognitive health in low and middle-income countries (LMIC), where 90% of the world’s young people live. The extent of any existing cohorts investigating these outcomes in LMIC has not previously been described.

Methods

We performed a systematic literature review to identify population cohort studies of adolescents in LMIC that assessed anthropometry and any of cardiovascular risk (blood pressure, physical activity, plasma glucose/lipid profile and substance misuse), puberty (age at menarche, Tanner staging, or other form of pubertal staging) or cognitive outcomes. Studies that recruited participants on the basis of a pre-existing condition or involved less than 500 young people were excluded.

Findings

1829 studies were identified, and 24 cohorts fulfilled inclusion criteria based in Asia (10), Africa (6) and South / Central America (8). 14 (58%) of cohorts identified were based in one of four countries; India, Brazil, Vietnam or Ethiopia. Only 2 cohorts included a comprehensive cardiovascular assessment, tanner pubertal staging, and cognitive outcomes.

Conclusion

Improved utilisation of existing datasets and additional cohort studies of adolescents in LMIC that collect contemporaneous measures of growth, cognition, cardiovascular risk and pubertal development are needed to better understand how this period of the life course influences future non-communicable disease morbidity and cognitive outcomes.

Association between Leptin, Adiponectin, and Leptin/Adiponectin Ratio with Clustered Metabolic Risk Factors in Portuguese Adolescents: The LabMed Physical Activity Study

Introduction: Circulating leptin and adiponectin levels have been associated with impaired vascular function, insulin resistance, and acute cardiovascular evens. This study aimed to evaluate the associations of leptin, adiponectin, and the leptin/adiponectin (L/A) ratio with a clustering of metabolic risk factors (MRF) in adolescents aged 12-18 years. Methods: This is a cross-sectional analysis with 529 Portuguese adolescents aged 12-18 years. Blood samples were taken to analyze total cholesterol (TC) and high-density lipoprotein (HDL) cholesterol (HDL-c), triglycerides glucose, insulin, leptin, and adiponectin levels. A continuous variable of clustered MRF score (sum of Z-scores of body fat percentage, systolic blood pressure, ratio TC/HDL, triglycerides, homeostatic model assessment insulin resistance, and cardiorespiratory fitness*[-1]) was computed. Results: Regression analyses showed that adiponectin was a significant and negative predictor of MRF score (boys: β = -0.199; p < 0.001; girls: β = -0.200; p < 0.001); whereas leptin was a significant positive predictor of MRF score (boys: β = 0.553; p < 0.001; girls: β = 0.399; p < 0.001). The L/A ratio was also a significant positive predictor of MRF score in both sexes (boys: β = 0.593; p < 0.001; girls: β = 0.461; p < 0.001), after adjustments for age, pubertal stage, adherence to the Mediterranean diet, and socioeconomic status. In addition, adiponectin, leptin, and L/A ratio were accurate to predict MRF among adolescents, but L/A ratio showed the highest area under receiver operating characteristic curve. Conclusion: Leptin, adiponectin, and L/A ratio are associated with the clustering of MRF in adolescents after adjustments for age, sex, pubertal stage, adherence to the Mediterranean diet, and socioeconomic status. L/A ratio was more strongly associated with MRF score than adiponectin or leptin.

Leptin and Leptin-to-Adiponectin Ratio Predict Adiposity Gain in Nonobese Children over a Six-Year Period

BACKGROUND

Previous longitudinal studies have shown inconsistent results regarding the influence of adipokines on changes in weight and body fat. We aimed to determine the predictive value of serum leptin, adiponectin, and their ratio on subsequent changes in obesity measures in children.

METHODS

Two hundred forty-six obese and 532 nonobese children aged 6-11 years were remeasured for BMI and waist circumference after 6.4 ± 0.2 years. Z-score of BMI was used to standardize for age and sex. Obesity was defined using the international BMI cutoffs. Waist-to-height ratio (WHtR) was calculated to define central obesity using a boundary value of 0.5. Fasting serum leptin and adiponectin levels were measured at baseline.

RESULTS

Newly identified obese children had significantly higher levels of leptin and leptin-to-adiponectin ratio than nonobese children. There were lower adiponectin levels in boys with persistent obesity versus those with transient obesity. After adjusting for age, Tanner stage, and corresponding adiposity measures at baseline, leptin levels and leptin-to-adiponectin ratio were positively associated with BMI Z-score gain in girls and WHtR gain in boys. An inverse association between leptin and BMI Z-score gain was detected in boys. Stratified analyses revealed significant associations only in the nonobese and prepubertal group. There were no significant associations between adiponectin and changes in obesity measures.

CONCLUSIONS

High leptin levels and leptin-to-adiponectin ratio are sex-specific predictors of obesity measures gain in nonobese and prepubertal children. Body composition measurement is necessary to assess fat mass growth and distribution during childhood and adolescence.

Exercise, adipokines and pediatric obesity: a meta-analysis of randomized controlled trials

BACKGROUND/OBJECTIVE

Adipokines are involved in the etiology of diabetes, insulin resistance, and the development of atherosclerosis and other latent-onset complications. The objective of this meta-analysis was to determine the effectiveness of exercise interventions on adipokines in pediatric obesity.

SUBJECTS/METHODS

A computerized search was made using three databases. The analysis was restricted to studies that examined the effect of exercise interventions on adipokines (adiponectin, leptin, resistin and visfatin) in pediatric obesity (6-18 years old). Fourteen randomized controlled trials (347 youths) were included. Weighted mean difference (WMD) and 95% confidence intervals were calculated.

RESULTS

Exercise was associated with a significant increase in adiponectin (WMD=0.882 μg ml-1, 95% CI, 0.271-1.493) but did not alter leptin and resistin level. Likewise, exercise intensity and change in body fat; as well as total exercise program duration, duration of the sessions, and change in body fat all significantly influenced the effect of exercise on adiponectin and leptin, respectively.

CONCLUSIONS

Exercise seems to increase adiponectin levels in childhood obesity. Our results also suggested that exercise on its own, without the concomitant presence of changes in body composition levels, does not affect leptin levels.

Neuroendocrine Inflammatory Responses in Overweight/Obese Infants

Childhood obesity is related to a cascade of neuroendocrine inflammatory changes. However, there remains a gap in the current literature regarding the possible occurrence of these changes in overweight/obese infants. The objective of this study was to evaluate adipokines, cortisol, brain-derived neurotrophic factor (BDNF) and redox status in overweight/obese infants versus normal-weight peers. A cross-sectional study was conducted with 50 infants (25 in the overweight/obese group and 25 in the normal-weight group) between 6 and 24 months. Plasma levels of leptin, adiponectin, resistin, soluble tumor necrosis factor (TNF) receptors, chemokines, BDNF, serum cortisol and redox status were measured. Unpaired Student's t-test was used to analyze the results and a probability of p<0.05 was acceptable for rejection of the null hypothesis. The Pearson correlation was used to verify the association between the biomarkers analyzed in each group. Plasma levels of leptin (p = 0.0001), adiponectin (p = 0.0007) and BDNF (p = 0.003), and serum cortisol (p = 0.048) were significantly higher in overweight/obese infants than normal-weight infants. In contrast, the concentration of thiobarbituric acid reactive substances (TBARS) (p = 0.004), and catalase (p = 0.045) and superoxide dismutase activity (p = 0.02) were lower in overweight/obese infants than normal-weight peers. All the results together indicate neuroendocrine inflammatory response changes in overweight/obese infants between 6 and 24 months. Although there is already an environment that predisposes for a subsequent pro-inflammatory response, neuroendocrine secretion changes that permit the control of the inflammatory process in this age interval can be observed.