Cardiorespiratory fitness and adiposity in metabolically healthy overweight and obese youth

Cardiorespiratory Fitness and Physical Activity in Pediatric Diabetes: A Systemic Review and Meta-Analysis

Importance

It is unclear whether cardiorespiratory fitness (CRF) and physical activity are lower among youths with type 1 diabetes (T1D) and type 2 diabetes (T2D) compared with youths without diabetes.

Objective

To describe the magnitude, precision, and constancy of the differences in CRF and physical activity among youths with and without diabetes.

Data Sources

MEDLINE, Embase, CINAHL, and SPORTDiscus were searched from January 1, 2000, to May 1, 2022, for eligible studies.

Study Selection

Observational studies with measures of CRF and physical activity in children and adolescents aged 18 years or younger with T1D or T2D and a control group were included.

Data Extraction and Synthesis

Data extraction was completed by 2 independent reviewers. A random-effects meta-analysis model was used to estimate differences in main outcomes. The pooled effect estimate was measured as standardized mean differences (SMDs) with 95% CIs. The Preferred Reporting Items for Systematic Review and Meta-Analyses guideline was followed.

Main Outcomes and Measures

The main outcomes were objectively measured CRF obtained from a graded maximal exercise test and subjective or objective measures of physical activity. Subgroup analyses were performed for weight status and measurement type for outcome measures.

Results

Of 7857 unique citations retrieved, 9 studies (755 participants) with measures of CRF and 9 studies (1233 participants) with measures of physical activity for youths with T2D were included; for youths with T1D, 23 studies with measures of CRF (2082 participants) and 36 studies with measures of PA (12 196 participants) were included. Random-effects models revealed that directly measured CRF was lower in youths with T2D (SMD, -1.06; 95% CI, -1.57 to -0.56; I2 = 84%; 9 studies; 755 participants) and in youths with T1D (SMD, -0.39; 95% CI, -0.70 to -0.09; I2 = 89%; 22 studies; 2082 participants) compared with controls. Random-effects models revealed that daily physical activity was marginally lower in youths with T1D (SMD, -0.29; 95% CI, -0.46 to -0.11; I2 = 89%; 31 studies; 12 196 participants) but not different among youths with T2D (SMD, -0.56; 95% CI, -1.28 to 0.16; I2 = 91%; 9 studies; 1233 participants) compared with controls. When analyses were restricted to studies with objective measures, physical activity was significantly lower in youths with T2D (SMD, -0.71; 95% CI, -1.36 to -0.05; I2 = 23%; 3 studies; 332 participants) and T1D (SMD, -0.67; 95% CI, -1.17 to -0.17; I2 = 93%; 12 studies; 1357 participants) compared with controls.

Conclusions and Relevance

These findings suggest that deficits in CRF may be larger and more consistent in youths with T2D compared with youths with T1D, suggesting an increased risk for cardiovascular disease-related morbidity in adolescents with diabetes, particularly among those with T2D. The findings reinforce calls for novel interventions to empower youths living with diabetes to engage in regular physical activity and increase their CRF.

Associations among metabolic health, weight status, and various physical fitness components in Japanese adolescents: a cross-sectional study (NICE EVIDENCE study- Agano 3)

Aim was to examine associations among metabolic health, weight status, and various physical fitness (PF) components in 1744 Japanese adolescents aged 13-14. Anthropometric measurements and PF tests (20 m shuttle run test [20mSRT], handgrip strength/body mass [HG], standing long jump [SLJ], and sit ups [SU]) were administered. The bottom sex-specific quintile of PF indicated "low fit". Participants were classified as non-overweight (non-OW) or overweight/obese (OW) according to the International Obesity Task Force. Clustered metabolic risk was defined as the sum of Z scores for mean arterial pressure, non-high-density lipoprotein cholesterol, and HbA1c, divided by three, and ≥ 1 SD. Combination of weight status and scores for HG or SU were additively associated with clustered metabolic risk. Compared with the non-OW-moderate-high fit group, the OW-low HG group was 3.05 (95%CI: 1.88-4.97) times more likely to have clustered metabolic risk although risk was not significantly elevated in the OW-moderate-high HG group (1.52 [95%CI: 0.88-2.62]). A similar association was observed between OW and low SU scores but not between OW and low 20mSRT or SLJ scores. Adolescents with OW and moderate-high HG or SU scores had a lower prevalence of an unfavourable metabolic state than those with OW and low HG or SU results.

Differences in specific abdominal fat depots between metabolically healthy and unhealthy children with overweight/obesity: The role of cardiorespiratory fitness

OBJECTIVES

Fat depots localization has a critical role in the metabolic health status of adults. Nevertheless, whether that is also the case in children remains under-studied. Therefore, the aims of this study were: (i) to examine the differences between metabolically healthy (MHO) and unhealthy (MUO) overweight/obesity phenotypes on specific abdominal fat depots, and (ii) to further explore whether cardiorespiratory fitness plays a major role in the differences between metabolic phenotypes among children with overweight/obesity.

METHODS

A total of 114 children with overweight/obesity (10.6 ± 1.1 years, 62 girls) were included. Children were classified as MHO (n = 68) or MUO. visceral (VAT), abdominal subcutaneous (ASAT), intermuscular abdominal (IMAAT), psoas, hepatic, pancreatic, and lumbar bone marrow adipose tissues were measured by magnetic resonance imaging. Cardiorespiratory fitness was assessed using the 20 m shuttle run test.

RESULTS

MHO children had lower VAT and ASAT contents and psoas fat fraction compared to MUO children (difference = 12.4%-25.8%, all p < 0.035). MUO-unfit had more VAT and ASAT content than those MUO-fit and MHO-fit (difference = 34.8%-45.3%, all p < 0.044). MUO-unfit shows also greater IMAAT fat fraction than those MUO-fit and MHO-fit peers (difference = 16.4%-13.9% respectively, all p ≤ 0.001). In addition, MHO-unfit presented higher IMAAT fat fraction than MHO-fit (difference = 13.4%, p < 0.001). MUO-unfit presented higher psoas fat fraction than MHO-fit (difference = 29.1%, p = 0.008).

CONCLUSIONS

VAT together with ASAT and psoas fat fraction, were lower in MHO than in MUO children. Further, we also observed that being fit, regardless of metabolic phenotype, has a protective role over the specific abdominal fat depots among children with overweight/obesity.

Associations of cardiorespiratory fitness and obesity parameters with blood pressure: fitness and fatness in youth Latin-American ethnic minority

Background: In spite of wide international evidence about cardiorespiratory fitness (CRF) and adiposity in association with cardiovascular disease, there is poor evidence about this relationship in schoolchildren of ethnic minorities.Aim: To examine the relationship between CRF and body composition on blood pressure (BP) in a sample of ethnic minority schoolchildren from three Latin-American countries.Material and methods: A descriptive cross sectional study of total n = 3866, mean age 12.5 (2.7) y [girls n = 1997, mean age 12.8 (2.8) y; boys n = 1869, mean age 12.2 (2.7) y] schoolchildren from three Latin-American countries (Colombia, Brazil, Chile). Main outcomes were CRF, body mass index (BMI), waist circumference, body fat percentage (%BF), and BP (systolic SB, diastolic BP, and mean arterial pressure (MAP).Results: In both sex, and after adjusting for covariates (age and ethnicity group), negative CRF by V˙O₂peak levels were associated with a higher body fatness parameters (BMI, WC, WHtR and %BF p<0.001), and blood pressure measures (systolic BP, diastolic BP, and MAP; p<0.001). A lower CRF (by V˙O₂peak) was associated with a higher BP in girls (systolic SB -0.15; -5.10 (0.30), diastolic BP -0.14; -4.43 (0.23), and MAP -0.15; -4.93 (0.26) at p<0.001), and boys (systolic SB -0.02; -0.85 (0.32), DB -0.07; -2.23 (0.23), and MAP-0.06; -1.89 (0.25 at p<0.001). There was a significant association between a 'high-CRF + low-%BF' with a lower systolic SB diff = - 9.6 [0.7], diastolic BP diff= - 11.0 [0.6]; and MAP level diff = - 10.6 [0.6] all p<0.001). There was a significant association between a 'high-CRF + low-BMI' with a lower systolic diff = - 10.3 [1.1], diastolic diff = - 11.2 [1.1], and MAP diff = - 10.9 [1.0] all p<0.001.Conclusion: A lower CRF is associated with a higher body fatness parameters, and higher BP levels in Latin-American ethnic schoolchildren.Abbreviators: %BF: Percentage of Body fat; BIA: Bioelectric impedance analysis; BMI: Body mass index; BP: Blood pressure; CRF: Cardiorespiratory fitness; CVD: Cardiovascular disease; LDL-cholesterol: SD: Standard deviation; WC: Waist circumference; WHtR: Waist-height to ratio; V˙O₂max: Maximal oxygen consumption; V˙O₂peak: Peak of oxygen consumption.

Temporal trends in the prevalence of metabolically healthy overweight and obesity in Korean youth: data from the Korea National Health and Nutrition Examination Survey 2011-2019

PURPOSE

Metabolically healthy overweight/obesity (MHO) and metabolically unhealthy overweight/obesity (MUO) are distinct clinical phenotypes classified by the presence of cardiometabolic risk factors in an individual. In the present study, we investigated temporal trends in the prevalence of MHO in Korean adolescents using nationally representative data.

METHODS

Data from the Korea National Health and Nutrition Examination Survey 2011-2019 were used in this study. A total of 5,667 adolescents (3,014 boys, 53.2%) aged 10-18 years was included in this study. MHO was defined as a body mass index ≥85th percentile for the corresponding age and sex and absence of any cardiometabolic risk factors.

RESULTS

The prevalence of overweight/obesity showed an increasing trend from 18.8% (boys 17.3% and girls 20.6%) in 2011 to 23.7% (boys 24.0% and girls 23.5%) in 2019 (p for trend=0.045). The overall prevalence of MHO during 2011-2019 was 39.2%, which was higher in girls than in boys (boys 33.5%, girls 46.2%, p<0.001), and the change in prevalence of MHO from 2011 to 2019 (from 34.8% to 35.7%) was not significant. Among MUO, the most prevalent cardiometabolic risk factor was dysglycemia (48.8%), followed by elevated blood pressure (41.5%), low high-density lipoprotein cholesterol (35.0%), and high triglycerides (29.7%).

CONCLUSION

We observed a high prevalence of MHO in Korean youth with overweight/obesity. Although the prevalence of overweight/obesity increased, the prevalence of MHO was stable during 2011-2019. A risk-stratified approach based on metabolic health status can help reducing the medical and socioeconomic costs associated with obesity treatment.

Effect of Diet and Exercise-Induced Weight Loss among Metabolically Healthy and Metabolically Unhealthy Obese Children and Adolescents

Objective: To study the effect of diet- and exercise-based lifestyle intervention on weight loss (WL) and cardiovascular risk among metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO) children and adolescents. Methods: The sample included 282 obese individuals (54% males, age (±SD) 12.9 (±2.3) years) who completed a 3- to 4-week WL camp program between 2017 and 2019. MUO was defined according to the consensus-based definition of pediatric MHO in 2018. Results: The intervention exhibited significantly benefits in improving body weight, body mass index, body fat ratio, waist circumference, systolic blood pressure (SBP), diastolic blood pressure (DBP), resting heart rate (RHR), triglycerides (TG), total cholesterol, and low-density lipoprotein−cholesterol levels in both MHO and MUO groups (for all comparisons, p < 0.01). However, the beneficial high-density lipoprotein−cholesterol (HDL-C) level (both p < 0.01) decreased evidently in both groups after intervention. In addition, percent changes in SBP (p < 0.001), DBP (p < 0.001), RHR (p = 0.025), fasting blood glucose (p = 0.011), and TG (p < 0.001) were more profound in MUO group than that in MHO group. Conclusion: Metabolical health is a mutable and transient state during childhood. Although both groups gained comparable WL benefits from diet- and exercise-based lifestyle intervention, the MUO group may benefit more than the MHO group. Strategies aiming at lowering blood pressure and preventing the decrease of HDL-C level should be considered for the precise treatment of childhood obesity in clinical practice, with the goal of improving metabolically healthy state.

Prepubertal Children With Metabolically Healthy Obesity or Overweight Are More Active Than Their Metabolically Unhealthy Peers Irrespective of Weight Status: GENOBOX Study

Background and Aim

The association of a metabolically healthy status with the practice of physical activity (PA) remains unclear. Sedentarism and low PA have been linked to increased cardiometabolic risk. The aim of this study was to evaluate the PA levels in metabolically healthy (MH) or unhealthy (MU) prepubertal children with or without overweight/obesity.

Methods

A total 275 children (144 boys) with 9 ± 2 years old were selected for the GENOBOX study. PA times and intensities were evaluated by accelerometry, and anthropometry, blood pressure, and blood biochemical markers were analyzed. Children were considered to have normal weight or obesity, and further classified as MH or MU upon fulfillment of the considered metabolic criteria.

Results

Classification resulted in 119 MH children (21% with overweight/obesity, referred to as MHO) and 156 MU children (47% with overweight/obesity, referred to as MUO). Regarding metabolic profile, MHO showed lower blood pressure levels, both systolic and diastolic and biochemical markers levels, such as glucose, Homeostatic Model Assessment of Insulin Resistance, triglycerides and higher HDL-c levels than MUO (P < 0.001). In addition, MHO children spent more time in PA of moderate intensity compared with MUO children. In relation to vigorous PA, MH normal weight (MHN) children showed higher levels than MUO children. Considering sex, boys spent more time engaged in moderate, vigorous, and moderate–vigorous (MV) PA than girls, and the number of boys in the MH group was also higher.

Conclusion

Prepubertal MHO children are less sedentary, more active, and have better metabolic profiles than their MUO peers. However, all children, especially girls, should increase their PA engagement, both in terms of time and intensity because PA appears to be beneficial for metabolic health status itself.

Irisin response to acute moderate intensity exercise and high intensity interval training in youth of different obesity statuses: A randomized crossover trial

Limited data exist regarding the impact of an acute bout of exercise with varying intensities on irisin levels in the youth of different obesity statuses. The objectives were to (1) compare an acute bout of moderate continuous intensity (MCI) exercise and an acute bout of high‐intensity interval training (HIIT) on irisin response in youth with different obesity statuses and, (2) investigate whether changes in irisin levels are correlated with exploratory outcomes. A randomized crossover design study was conducted on 25 youth aged 12–18 years old. Participants were classified as either healthy weight (BMI percentile <85; n = 14) or overweight/obese (BMI percentile ≥85; n = 11). Participants performed an MCI exercise session at 50% of heart rate reserve for 35 min and a HIIT exercise session for 35 min, with intervals every 5 min increasing from 50% heart rate reserve to 85–90% for 2 min. Irisin was measured using an enzyme‐linked immunoabsorbent assay from plasma sampling obtained throughout the exercise (at times 0, 7, 14, 21, 28, and 35 min). A time effect was observed throughout the HIIT session [F(1,5) = 6.478, p < 0.001]. Bonferonni post‐hoc analysis revealed significant differences in irisin levels post‐exercise (35 min) compared to times 7, 14, 21, and 28 min. Irisin increased during HIIT (81.0% ± 71.3; p = 0.012) in youth with a healthy weight. No differences were observed for youth living as overweight or with obesity. Overall, HIIT elicits a higher peak irisin response compared to MCI exercise training in youth.

Metabolically healthy obesity in children enrolled in the CANadian Pediatric Weight management Registry (CANPWR): An exploratory secondary analysis of baseline data

Our study purpose was to determine the prevalence of metabolically healthy obesity (MHO) and examine factors associated with MHO in children with obesity. This cross-sectional study was a secondary, exploratory analysis of data that included 2-17 years old with a body mass index (BMI) ≥85th percentile from the CANadian Pediatric Weight management Registry. Children were classified as having MHO or metabolically unhealthy obesity (MUO) using consensus-based criteria. Those with MHO had normal triglycerides, high-density lipoprotein cholesterol, blood pressure, and fasting glucose. Logistic regression was used to examine factors associated with MHO, which included calculating odds ratios (ORs) and 95% confidence intervals (CIs). In total, 945 children were included (mean age: 12.3 years; 51% female). The prevalence of MHO was 31% (n = 297), with lower levels across increasing age categories (2-5 years [n = 18; 43%], 6-11 years [n = 127; 35%], 12-17 years [n = 152; 28%]). Children with MHO were younger, weighed less, and had lower BMI z-scores than their peers with MUO (all p < 0.01). MHO status was positively associated with physical activity (OR: 1.18; 95% CI: 1.01-1.38), skim milk intake (OR: 1.10; 95% CI: 1.01-1.19), and fruit intake (OR: 1.12; 95% CI: 1.01-1.24) and negatively associated with BMI z-score (OR: 0.69; 95% CI: 0.60-0.79), total screen time in hours (OR: 0.79; 96% CI: 0.68-0.92), and intake of fruit flavoured drinks (OR: 0.91; 95% CI: 0.84-0.99). These findings may help guide clinical decision-making regarding obesity management by focusing on children with MUO who are at relatively high cardiometabolic risk.

The association between a metabolically healthy overweight/obesity phenotype and markers of inflammation among Chinese children and adolescents aged 10-18 years

OBJECTIVES

The association between metabolically healthy overweight/obesity (MHO) and inflammatory markers remains controversial. The aim of the present study was to describe the prevalence of different metabolic phenotypes and to examine the relationship of different metabolic phenotypes with inflammatory markers among Chinese children and adolescents.

METHODS

The study included 1,125 children and adolescents aged 10-18 years using a cross-sectional survey, and all subjects were classified into four groups based on a combination of BMI and metabolic status. In addition, the inflammatory markers we measured were high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6).

RESULTS

The prevalence of metabolically healthy with normal-weight (MHNW), MHO, metabolically unhealthy with normal-weight (MUNW), and metabolically unhealthy overweight/obesity (MUO) phenotypes was 38.76, 7.11, 38.67 and 15.47%, respectively. The results of logistic regression analysis showed that the MHO was associated with the z scores of hs-CRP in Chinese children and adolescents (OR=0.57, 95% CI: 0.39-0.83). Meanwhile, multivariate adjusted regression analysis showed that the relationship between hs-CRP and MHO among the overweight/obese was consistent with the results above, but among the normal-weight, only the highest quartile of TNF-α could increase the risk of MUNW (OR=1.65, 95% CI: 1.09-2.52).

CONCLUSIONS

MHO phenotypes were not common in Chinese children and adolescents. Individuals with MHO had a more beneficial hs-CRP profile than those with MUO.

Distinct whole-blood transcriptome profile of children with metabolic healthy overweight/obesity compared to metabolic unhealthy overweight/obesity

BACKGROUND

Youth populations with overweight/obesity (OW/OB) exhibit heterogeneity in cardiometabolic health phenotypes. The underlying mechanisms for those differences are still unclear. This study aimed to analyze the whole-blood transcriptome profile (RNA-seq) of children with metabolic healthy overweight/obesity (MHO) and metabolic unhealthy overweight/obesity (MUO) phenotypes.

METHODS

Twenty-seven children with OW/OB (10.1 ± 1.3 years, 59% boys) from the ActiveBrains project were included. MHO was defined as having none of the following criteria for metabolic syndrome: elevated fasting glucose, high serum triglycerides, low high-density lipoprotein-cholesterol, and high systolic or diastolic blood pressure, while MUO was defined as presenting one or more of these criteria. Inflammatory markers were additionally determined. Total blood RNA was analyzed by 5'-end RNA-sequencing.

RESULTS

Whole-blood transcriptome analysis revealed a distinct pattern of gene expression in children with MHO compared to MUO children. Thirty-two genes differentially expressed were linked to metabolism, mitochondrial, and immune functions.

CONCLUSIONS

The identified gene expression patterns related to metabolism, mitochondrial, and immune functions contribute to a better understanding of why a subset of the population remains metabolically healthy despite having overweight/obesity.

IMPACT

A distinct pattern of whole-blood transcriptome profile (RNA-seq) was identified in children with metabolic healthy overweight/obesity (MHO) compared to metabolic unhealthy overweight/obesity (MUO) phenotype. The most relevant genes in understanding the molecular basis underlying the MHO/MUO phenotypes in children could be: RREB1, FAM83E, SLC44A1, NRG1, TMC5, CYP3A5, TRIM11, and ADAMTSL2. The identified whole-blood transcriptome profile related to metabolism, mitochondrial, and immune functions contribute to a better understanding of why a subset of the population remains metabolically healthy despite having overweight/obesity.

Prevalence and Clinical Characteristics of Children and Adolescents with Metabolically Healthy Obesity: Role of Insulin Sensitivity

Obesity represents a major risk factor for metabolic disorders, but some individuals, "metabolically healthy" (MHO), show less clinical evidence of these complications, in contrast to "metabolically unhealthy" (MUO) individuals. The aim of this cross-sectional study is to assess the prevalence of the MHO phenotype in a cohort of 246 overweight/obese Italian children and adolescents, and to evaluate their characteristics and the role of insulin resistance. Homeostasis model assessment-insulin resistance (HOMA-IR), insulin sensitivity index (ISI), insulinogenic index (IGI) and disposition index (DI) were all calculated from the Oral Glucose Tolerance Test (OGTT). MHO was defined by either: (1) HOMA-IR < 2.5 (MHO-IRes), or (2) absence of the criteria for metabolic syndrome (MHO-MetS). The MHO prevalence, according to MHO-MetS or MHO-IRes criteria, was 37.4% and 15.8%, respectively. ISI was the strongest predictor of the MHO phenotype, independently associated with both MHO-IRes and MHO-MetS. The MHO-MetS group was further subdivided into insulin sensitive or insulin resistant on the basis of HOMA-IR (either < or ≥ 2.5). Insulin sensitive MHO-MetS patients had a better metabolic profile compared to both insulin resistant MHO-MetS and MUO-MetS individuals. These data underscore the relevance of insulin sensitivity to identifying, among young individuals with overweight/obesity, the ones who have a more favorable metabolic phenotype.

Influences of Cardiovascular Fitness and Body Fatness on the Risk of Metabolic Syndrome: A Systematic Review and Meta-Analysis

OBJECTIVE

The purpose of this meta-analysis was to investigate the associations between combined cardiovascular fitness, obesity, and the risk of metabolic syndrome.

DATA SOURCES

The MEDLINE and EMBASE databases were used to select relevant studies that included the relative risk (RRs) of metabolic syndrome based on the combined effects of cardiovascular fitness and obesity from January 1990 to July 2019.

STUDY INCLUSION AND EXCLUSION CRITERIA

The inclusion criteria were providing the RRs for the associations between combined cardiovascular fitness and obesity and the risk of metabolic syndrome. The exclusion criteria were review studies, duplicated studies, and no RRs reported for those associations.

DATA EXTRACTION

All selected studies categorized levels of cardiovascular fitness (high cardiovascular fitness vs low cardiovascular fitness) and obesity (normal vs obesity) and directly extracted the RRs for the risk of metabolic syndrome from these data. All selected studies were cross-sectional studies.

DATA SYNTHESIS

All RRs and 95% CIs from the selected studies were computed to find the associations between combined cardiovascular fitness and obesity and the risk of metabolic syndrome.

RESULTS

A total of 8 studies were selected for this meta-analysis. Low cardiovascular fitness was associated with 3. Fifty-nine times increased metabolic syndrome risk regardless of obesity (3.59, 95% CI: 3.07-4.20; P = .00). And obesity was associated with 1.62 times increased metabolic syndrome risk regardless of cardiovascular fitness level (1.62, 95% CI: 1.32-1.98; P = .00). Lastly, the risk of metabolic syndrome decreased by 77% with high cardiovascular fitness regardless of obesity (0.23, 95% CI: 0.12-0.43; P = .00).

CONCLUSIONS

The combined effects of cardiovascular fitness and obesity are important factors when determining metabolic syndrome risk. The minimum level of cardiovascular fitness is 8.39 metabolic equivalent (METs) for adults to lower the risk of metabolic syndrome. Enhanced cardiovascular fitness and maintaining normal weight should be recommended for individuals to reduce the risk of metabolic syndrome.

Higher Cardiorespiratory Fitness Levels May Attenuate the Detrimental Association between Weight Status, Metabolic Phenotype and C-Reactive Protein in Adolescents-A Multi-Cohort Study

Results from several studies show that only obese, unfit subjects, but not obese, fit subjects, are at higher mortality risk than are normal-weight fit subjects. The aim of the study was two-fold: (1) to examine the differences in C-reactive protein levels across different metabolic phenotypes (healthy and unhealthy) of weight status and (2) ascertain whether high levels of cardiorespiratory fitness (CRF) attenuate the association of C-reactive protein and metabolic phenotypes of weight status. This was a pooled study, which included data from three cross-sectional projects (1706 youth (921 girls) aged 12-18 years). We used a Shuttle run test to assess CRF. Adolescents were classified into six metabolic phenotypes (healthy and unhealthy) of weight status (non-overweight, overweight and obese), based on age- and sex-specific cutoff points for triglycerides, systolic blood pressure, HDL-cholesterol, glucose and body mass index. High-sensitivity assays were used to obtain the C-reactive protein as inflammatory biomarker. After adjustment for potential confounders (age, sex, pubertal stage and country), the analysis of covariance (ANCOVA) shows that C-reactive protein is directly associated with metabolic phenotypes of weight status. Subjects with obesity, regardless of their metabolic profile, had higher levels of C-reactive protein Z-score. In addition, (after adjustments for potential confounders) a two-way ANCOVA showed that high levels of CRF attenuated the associations of C-reactive protein levels in metabolic healthy non-overweight and in adolescents with obesity. In conclusion, higher CRF levels may attenuate the detrimental association between obesity and C-reactive protein independently of metabolic phenotype. Findings from this study are important for prevention, clinical practice on issues associated with adiposity and metabolic disorders.

Association Between a Comprehensive Movement Assessment and Metabolically Healthy Overweight Obese Adults

Physical activity (PA) and sedentary behavior are associated with metabolic health in overweight and obese individuals. However, the role of comprehensive health-related movement guidelines on PA, recreational screen time, and sleep among Metabolically Healthy Overweight-Obese (MHO) individuals is unknown. We investigated differences in comprehensive movement assessment scores between adults classified as MHO or Non-MHO. The sample included 513 adults (46.2% male), aged 19 to 85 years, body mass index (BMI) ≥ 25, from cycle 2005–2006 of the National Health and Nutrition Examination Survey. Comprehensive movement assessment outcomes were defined as meeting modified 24-Hour Movement Guidelines criteria, with thresholds adapted for adults. 13.8% of participants were MHO (normal serum glucose, triglycerides, HDL-cholesterol, and systolic and diastolic blood pressure). Only 1.4% of MHO participants met all guidelines. MHO and Non-MHO participants had similar comprehensive movement assessment scores (MHO: 18.3% vs. Non-MHO: 10.9%; p = 0.072). MHO individuals had less continuous recreational screen time than Non-MHO individuals (1.8 ± 1.4 hrs/day vs. 2.5 ± 1.6 hrs/day; p < 0.001). Meeting the recreational screen time recommendation was the only variable associated with the MHO phenotype (OR:4.84 95%CI: 2.33–10.07). This association remained after adjusting for age, sex, ethnicity, education, and BMI (OR: 3.53 95%CI: 1.72–7.24). Our results suggest the importance of limiting recreational screen time in adults to optimize cardiometabolic risk profile in individuals living with overweight or obesity. Using movement guidelines with a screen time component to assess the risk associated with health outcomes in adults appears to provide a better assessment.

Cardiovascular Risk Factors Associated With the Metabolically Healthy Obese (MHO) Phenotype Compared to the Metabolically Unhealthy Obese (MUO) Phenotype in Children

Background: In pediatric age the prevalence of obesity is high. Obese children who do not have other risk factors than excess weight have been defined as "metabolically healthy obese" (MHO). Aim: The aim of this study is to evaluate, in a population of obese children, the prevalence of the MHO and "metabolically unhealthy obese" (MUO) phenotype. Furthermore, we evaluated the distribution of Uric Acid, HOMA index and Waist-Height ratio (W-Hr) in the MHO and MUO sub-groups and the impact of these non-traditional risk factors on the probability to be MUO. Methods: In 1201 obese children and adolescents [54% males, age (±SD) 11.9 (±3.0) years] weight, height, waist circumference, systolic (SBP) and diastolic (DBP) blood pressure, pubertal status, glucose, insulin, HDL cholesterol, triglycerides and Uric Acid serum values were assessed. MUO phenotype was defined as the presence of at least one of the following risk factors: SBP or DBP ≥ 90th percentile, glycaemia ≥ 100 mg/dl, HDL cholesterol <40 mg/dl, triglycerides ≥100 mg/dl (children <10 years) or ≥130 mg/dl (children ≥10 years). A multivariate logistic regression analysis was used to estimate the association between MUO phenotype and non-traditional cardiovascular risk factors. Results: The prevalence of the MUO status was high (61%). MUO subjects were more often male, older and pubertal (p < 0.001). The levels of the three non-traditional risk factors were significantly higher in MUO children compared to MHO children (p < 0.001) and all of them were independent predictors of the fact of being MUO [OR 1.41 (95% CI 1.24-1.69); 1.15 (95% CI 1.06-1.23) and 1.03 (95% CI1.01-1.05) for Uric Acid, HOMA index and W-Hr, respectively]. About 15% of MHO subjects had serum Uric Acid, HOMA index and W-Hr values within the highest quartile of the study population. Conclusion: The prevalence of MUO subjects in a large pediatric population is high and serum Uric Acid, HOMA index and W-Hr values are independent predictors of the probability of being MUO. A non-negligible percentage of subjects MHO has high values of all three non-traditional risk factors.

Adherence to the Mediterranean diet in metabolically healthy and unhealthy overweight and obese European adolescents: the HELENA study

PURPOSE

To examine the adherence to the Mediterranean dietary pattern (MDP) in metabolically healthy overweight or obese (MHO) and metabolically unhealthy obese (MUO) European adolescents.

METHODS

In this cross-sectional study, 137 overweight/obese adolescents aged 12-17 years old from the HELENA study were included. Height, weight, waist circumference and skinfold thickness were measured and body mass index and body fat percent were calculated. Systolic and diastolic blood pressure, glucose, HDL cholesterol, triglycerides and cardiorespiratory fitness (20 m shuttle run test) were measured. MHO and MUO phenotypes were categorized following the Jolliffe and Janssen criteria. Two non-consecutive 24 h recalls were used for dietary intake assessment and the adherence to the MDP was calculated using the Mediterranean dietary pattern score (MDP score) (range 0-9).

RESULTS

A total of 45 (22 girls) adolescents (32.8%) were categorized as MHO. The adherence to the MDP was significantly higher in MHO than in MUO adolescents regardless of age, sex, body fat percentage, energy intake and center (MDP score: 4.6 ± 1.6 vs. 3.9 ± 1.5, p = 0.036), but this difference became non-significant after further adjustment for cardiorespiratory fitness. Participants who had a low adherence to the MDP (MDP score ≤ 4) had a higher likelihood of having MUO phenotype regardless of sex, age, energy intake, center and body fat percentage (OR 2.2; 95% CI 1.01-4.81, p = 0.048).

CONCLUSIONS

Adherence to the MDP might be beneficial to maintain metabolic health in overweight/obese adolescents, yet cardiorespiratory fitness seems to play a key role on the metabolic phenotype.

Fasting insulin resistance affects the prevalence of metabolically healthy obesity in Brazilian adolescents

AIM

We aimed to assess the influence of fasting insulin resistance on metabolically healthy obesity (MHO) prevalence in adolescents and to identify associated factors.

METHODS

This retrospective, registry-based, cross-sectional study included 418 (51.9% girls) 10- to 18-year-old adolescents with obesity from a tertiary outpatient clinic in Sao Paulo, Brazil, between 2009 and 2013. The prevalence of MHO was estimated according to two definitions: (i) no cardiometabolic risk factors (CMRF) by the International Diabetes Federation parameters and (ii) no CMRF and homeostatic model assessment for insulin resistance <3.16. Adjusted prevalence ratios and 95% confidence intervals (CI) evaluated the association of gender, age, pubertal stages, skin colour and degree of obesity with MHO.

RESULTS

Metabolically healthy obesity prevalence was lower in definition II than definition I (12.7%; 95% CI 9.1-16.3% versus 43.1%; 95% CI 38.0-48.2%, respectively). Adjusted results showed negative association between severe obesity and MHO by both definitions (p ≤ 0.01). Male and later pubertal stages were also less likely to have MHO, but neither remained significant in definition II.

CONCLUSION

Metabolically healthy obesity prevalence decreased when insulin resistance was part of the definition. Detecting pre-clinical insulin resistance may improve the management of treatment-seeking adolescents, especially when they present no CMRF.

Health-related physical fitness and weight status in 13- to 15-year-old Latino adolescents. A pooled analysis

OBJECTIVE

The aim of this study was to investigate the relation between health-related physical fitness and weight status in 13- to 15-year-old Latino adolescents.

METHOD

The final sample consisted of 73,561 adolescents aged 13-15 years (35,175 girls) from Chile (n=48,771) and Colombia (n=24,790). Cardiorespiratory and musculoskeletal fitness were measured using 20-m shuttle run (relative peak oxygen uptake - VO_2peak) and standing broad jump test (lower body explosive strength), respectively. The International Obesity Task Force definition was used to define weight status (i.e., underweight, normal weight, overweight, and obese).

RESULTS

The present study found an inverted J-shape relationship between body mass index, cardiorespiratory fitness, and musculoskeletal fitness in both genders and all age groups (p<0.01). Results also suggest that underweight adolescents, and not just overweight and obese adolescents, have lower odds of having a healthy cardiorespiratory fitness (based on new international criterion-referenced standards) profile when compared with their normal weight peers, except in girls aged 14 (p=0.268) and 15 years (p=0.280).

CONCLUSIONS

The present results indicate low cardiorespiratory fitness and musculoskeletal fitness levels in underweight, overweight, and obese adolescents when compared with their normal weight peers. The findings appear to suggest that exercise programs should to decrease fat mass in overweight/obese adolescents and increase muscle mass in underweight adolescents.

Effectiveness of a multi-faceted intervention among elementary school children

Childhood obesity has been shown to be closely related to future obesity and comorbidities. As its prevalence and impact has increased significantly worldwide, researchers have focused on prevention and intervention. This study assessed a multifaceted intervention for elementary school children.A retrospective data collection with a cohort analysis was employed. A 16-week school-based intervention with nutritional intervention, physical activity, and behavioral education was designed and conducted by a multidisciplinary team for 1860 children aged 6 to 13 years. Basic information, anthropometrics, and physical fitness (PF) were recorded before and after the intervention. The differences compared with a reference group, and compared between subgroups, were analyzed.Significant favorable changes in body weight and composition were found. Children's height, weight, and muscle weight increased, whereas BMI, BMI z-score (zBMI), waist circumference, hip circumference, waist-hip ratio, waist-height ratio, body fat percentage, and visceral fat area decreased. Sit-ups and 800-m run time significantly improved. Girls exhibited a greater reduction in body weight outcomes; boys improved more in body composition and PF. Students with higher zBMI had a greater reduction in all anthropometrics; students with lower zBMI showed greater PF improvement, except for the 800-m run.The intervention improved weight measures, body composition, and PF. Subgroup differences suggested the need for sex- and weight-specific interventions.

Body Composition and Cardiorespiratory Fitness Between Metabolically Healthy Versus Metabolically Unhealthy Obese Black and White Adolescents

PURPOSE

We compared body composition and cardiorespiratory fitness (CRF) between metabolically healthy overweight/obese (MHO) versus metabolically unhealthy overweight/obese (MUO) adolescents in 189 black and white adolescents (BMI ≥ 85th percentile, 12-18 years of age).

METHODS

Participants were defined as MHO or MUO if their insulin-stimulated glucose disposal, measured by a 3-hour hyperinsulinemic-euglycemic clamp, was in the upper quartile or in the lower three quartiles. Total fat was measured by dual-energy X-ray absorptiometry, and visceral adiposity and liver fat were measured by magnetic resonance imaging and proton magnetic resonance spectroscopy, respectively. CRF was measured by a graded maximal treadmill test.

RESULTS

Black MHO adolescents had lower (p < .05) 2-hour oral glucose tolerance test glucose, triglycerides, very-low-density lipoprotein cholesterol, and higher high-density lipoprotein cholesterol, with a lower prevalence of impaired fasting glucose and impaired glucose tolerance compared with black MUO adolescents. White MHO adolescents had lower (p < .05) triglycerides and very-low-density lipoprotein cholesterol, with a lower prevalence of impaired fasting glucose compared with white MUO adolescents. Independent of race, CRF was higher in MHO versus MUO adolescents. After accounting for gender, Tanner stage, and BMI, there were no differences in total fat (kg, %) between MHO versus MUO in both races. MHO adolescents had significantly lower trunk fat, waist circumference, and visceral fat compared with MUO adolescents in both races. In whites, MHO adolescents had lower (p = .055) liver fat compared with MUO adolescents.

CONCLUSIONS

Independent of race, the MHO phenotype is characterized by high CRF, lower waist circumference and visceral fat, and lower rates of dysglycemia in youth.

Lifestyle Habits, Dietary Factors, and the Metabolically Unhealthy Obese Phenotype in Youth

OBJECTIVE

To determine whether lifestyle habits and dietary factors at age 8-10 years predict the development of metabolically unhealthy obesity 2 years later among children who were previously metabolically healthy obese.

STUDY DESIGN

The QUebec Adipose and Lifestyle InvesTigation in Youth cohort comprises 630 youth with a parental history of obesity. Metabolically healthy obesity and metabolically unhealthy obesity were defined using cut-offs for the components of pediatric metabolic syndrome. Dietary factors, physical activity, fitness, sedentary behavior, screen time, and sleep duration were measured. Multivariable logistic regressions were used to examine associations.

RESULTS

At baseline, 48 participants with metabolically healthy obesity were identified; 2 years later, 19 became metabolically unhealthy obese and 29 remained metabolically healthy obese. Every additional daily portion of fruits and vegetables decreased the risk of converting to metabolically unhealthy obesity by 39% (OR 0.61, 95% CI 0.40-0.94). Cumulating more hours of screen time and diets high in saturated fat and sugar-sweetened beverages and low in protein were associated with a tendency to develop metabolically unhealthy obesity.

CONCLUSIONS

Fruit and vegetable intake and possibly screen time, saturated fat, sugar-sweetened beverages, and protein intake may be important targets for the prevention of cardiometabolic complications in obese children.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03356262.

Children With Metabolically Healthy Obesity: A Review

Children with "metabolically healthy obesity" (MHO) are a distinct subgroup of youth with obesity, who are less prone to the clustering of cardiometabolic risk factors. Although this phenotype, frequently defined by the absence of metabolic syndrome components or insulin resistance, was first described during the early 1980s, a consensus-based definition of pediatric MHO was introduced only recently, in 2018. The purpose of this review was to concisely summarize current knowledge regarding the MHO phenomenon in youth. The prevalence of MHO in children varies from 3 to 87%, depending on the definition used and the parameters evaluated, as well as the ethnicity and the pubertal status of the sample. The most consistent predictors of MHO in youth include younger age, lower body mass index, lower waist circumference, and lower body fat measurements. Various hypotheses have been proposed to elucidate the underlying factors maintaining the favorable MHO phenotype. While preserved insulin sensitivity and lack of inflammation were previously considered to be the main etiological factors, the most recent findings have implicated adipokine levels, the number of inflammatory immune cells in the adipose tissue, and the reduction of visceral adiposity due to adipose tissue expandability. Physical activity and genetic factors also contribute to the MHO phenotype. Obesity constitutes a continuum-increased risk for cardiometabolic complications, which is less evident in children with MHO. However, some findings have highlighted the emergence of hepatic steatosis, increased carotid intima-media thickness and inflammatory biomarkers in the MHO group compared to peers without obesity. Screening should be directed at those more likely to develop clustering of cardiometabolic risk factors. Lifestyle modifications should include behavioral changes focusing on sleep duration, screen time, diet, physical activity, and tobacco smoke exposure. Weight loss has also been associated with the improvement of insulin sensitivity and inflammation. Further investigative efforts are needed in order to elucidate the mechanisms which protect against the clustering of cardiometabolic risk factors in pediatric obesity, to provide more efficient, targeted treatment approaches for children with obesity, and to identify the protective factors preserving the MHO profile, avoiding the crossover of MHO to the phenotype with metabolically unhealthy obesity.

Preclinical signs of liver and cardiac damage in youth with metabolically healthy obese phenotype

BACKGROUND AND AIMS

We aimed to evaluate whether the metabolically healthy obese (MHO) phenotype was associated with hepatic steatosis (HS) or left ventricular hypertrophy (LVH) in young people with overweight (OW), obesity (OB) and morbid obesity (MOB) and whether the prevalence of these comorbidities was affected by OB severity.

METHODS AND RESULTS

An abdominal ultrasound was performed in 1769 children and adolescents, mean age 10.6 years (range 5-18) with MHO phenotype, defined as the absence of traditional cardiometabolic risk factors, in order to identify HS. In a subsample of 177 youth the presence of LVH, defined by 95th percentile of LV mass/h^2.7 for age and gender, was also analyzed. The prevalence of HS increased from 23.0% in OW to 27.8% in OB and 45.1% in MOB (P < 0.0001). The proportion of LVH increased from 36.8% in OW to 57.9% in OB and 54.5% in MOB (P < 0.05). As compared with OW, the odds ratio (95% CI) for HS was 2.18 (1.56-3.05), P < 0.0001) in OB and 6.20 (4.26-9.03), P < 0.0001) in MOB, independently of confounding factors. The odds ratio for LVH was 2.46 (1.20-5.06), P < 0.025) in OB and 2.79 (1.18-6.61), P < 0.025) in MOB, as compared with OW.

CONCLUSION

In spite of the absence of traditional cardiometabolic risk factors, the prevalence of HS and LVH progressively increased across BMI categories. MHO phenotype does not represent a "benign" condition in youth.

Risk Factors and Implications of Childhood Obesity

PURPOSE OF REVIEW

This review summarizes our current understanding of factors associated with childhood obesity, including latest prevalence rates, effectiveness of intervention strategies, and risk for concomitant disease later in life.

RECENT FINDINGS

Obesity has reached global dimensions, and prevalence of childhood obesity has increased eightfold since 1975. Interventions for obesity prevention have mainly focused on behavioral settings to date, i.e., interventions that have focused on behavioral changes of the individuum such as increasing daily physical exercise or optimizing diet. However, effects have been very limited worldwide and could not stop the increase of obesity prevalence so fare. Thus, community-based/environment-oriented measures are urgently needed, such as promotion of healthy food choices by taxing unhealthy foods, mandatory standards for meals in kindergarten and schools, increase of daily physical activity at kindergartens, and schools as well as ban on unhealthy food advertisement for children. Restructuring obesity interventions towards community-based/environment-oriented measures to counteract an obesogenic environment is mandatory for sustainable success and to stop the obesity epidemy. There is need to move fast, as already moderate overweight before the start of puberty is associated with significantly increased risk for type 2 diabetes and cardiovascular disease in midlife.

Defining metabolically healthy obesity in children: a scoping review

We conducted a scoping review to identify definitions of metabolically healthy obesity (MHO), describe gaps in the literature, and establish a universal definition of MHO in children. We searched electronic databases from January 1980 to June 2017 and grey literature. Experimental, quasi-experimental, or observational studies were eligible for inclusion if they (i) included a definition of MHO that identified risk factors, cut-off values, and the number of criteria used to define MHO, and (ii) classified 2-18 year olds as overweight or obese. Two reviewers independently screened 1,711 papers for relevance and quality; we extracted data from 39 individual reports that met inclusion criteria. Most (31/39; 79%) definitions of MHO included an absence of cardiometabolic risk factors. Heterogeneity across MHO definitions, obesity criteria, and sample sizes/characteristics resulted in variable prevalence estimates (3-80%). Finally, we convened an international panel of 46 experts to complete a 4-round Delphi process to generate a consensus-based definition of MHO. Based on consensus (≥ 80% agreement), our definition of MHO included: high density lipoprotein-cholesterol > 40 mg/dl (or > 1.03 mmol/l), triglycerides ≤ 150 mg/dl (or ≤ 1.7 mmol/l), systolic and diastolic blood pressure ≤ 90th percentile, and a measure of glycemia. This definition of MHO holds potential universal value to enable comparisons between studies and inform clinical decision-making for children with obesity.

Which predictors differentiate between obese children and adolescents with cardiometabolic complications and those with metabolically healthy obesity?

BACKGROUND/AIMS

Childhood obesity and associated metabolic comorbidities is a major global health concern. Metabolically healthy obesity (MHO) may represent a subgroup of individuals in which excessive body fat accumulation does not lead to adverse metabolic effects. We aimed to determine the prevalence of MHO among obese Israeli children and adolescents and to find predictors for metabolically unhealthy obesity (MUO).

METHODS

In a retrospective study, demographic, anthropometric, lifestyle, and cardiometabolic data were retrieved from medical records of patients with a body mass index (BMI) >95th percentile aged 6 to 17.6 years, attending a tertiary pediatric obesity clinic between 2008 and 2015, with at least 1 year of follow-up. Participants were dichotomized as either MHO or MUO based on cardiometabolic risk factor clustering (blood pressure, serum lipids, and glucose). Multivariable logistic regression was used to determine predictors of MUO.

RESULTS

Of the 230 children (median age 9.9 years) fulfilling study criteria, 48 (20.9%) were classified as MHO. Occurrence of MUO was associated with male gender, Arabic ethnicity, higher BMI-SD score, higher tri-ponderal mass index (TMI), and higher insulin resistance (IR) (presence of acanthosis nigricans and a higher level of homeostasis model assessment-IR [HOMA-IR]). Male gender (odds ratio [OR] 2.27, P = .033), presence of acanthosis nigricans at baseline (OR 2.35, P = .035), and a greater increase in BMI-SDS during follow-up (OR 2.82, P = .05) were the best predictors of MUO.

CONCLUSIONS

The MHO phenotype was present in only 20.9% of obese Israeli children. MUO was significantly associated with male gender, with presence of acanthosis nigricans, and with a greater increase in BMI-SDS during follow-up.

Prevalence and predictors of metabolically healthy obesity in adolescents: findings from the national "Jeeluna" study in Saudi-Arabia

BACKGROUND

Obese children and adolescents may vary with respect to their health profile, an observation that has been highlighted by the characterization of metabolically healthy obesity (MHO). The objectives of this study were to examine the prevalence of MHO amongst obese adolescents in Saudi-Arabia, and investigate the anthropometric, socio-demographic, and lifestyle predictors of MHO in this age group.

METHODS

A national cross-sectional school-based survey (Jeeluna) was conducted in Saudi-Arabia in 2011-2012 (n = 1047 obese adolescents). Anthropometric, blood pressure and biochemical measurements were obtained. A multicomponent questionnaire covering socio-demographic, lifestyle, dietary, psychosocial and physical activity characteristics was administered. Classification of MHO was based on two different definitions. According to the first definition, subjects were categorized as MHO based on the absence of the following traditional cardiometabolic risk (CR) factors: systolic blood pressure (SBP) or diastolic blood pressure (DBP) >90th percentile for age, sex, and height; triglycerides (TG) > 1.25 mmol/L; high density lipoprotein-cholesterol (HDL-C) ≤1.02 mmol/L; glucose ≥5.6 mmol/L. The second definition of MHO was based on absence of any cardiometabolic risk factor, according to the International Diabetes Federation (IDF) criteria.

RESULTS

The prevalence of MHO ranged between 20.9% (IDF) and 23.8% (CR). Subjects with MHO were younger, less obese, had smaller waist circumference (WC) and were more likely to be females. Based on stepwise logistic regression analyses, and according to the IDF definition, body mass index (BMI) (OR = 0.89, 95% CI: 0.84-0.93) and WC (OR = 0.97, 95% CI: 0.96-0.98) were the only significant independent predictors of MHO. Based on the CR definition, the independent predictors of MHO included female gender (OR = 1.76, 95% CI: 1.29-2.41), BMI (OR = 0.97, 95% CI: 0.94-1.00), and weekly frequency of day napping (OR = 1.06, 95% CI: 1.00-1.12). Analysis by gender showed that vegetables' intake and sleep indicators were associated with MHO in boys but not in girls.

CONCLUSION

The study showed that one out of five obese adolescents is metabolically healthy. It also identified anthropometric factors as predictors of MHO and suggested gender-based differences in the association between diet, sleep and MHO in adolescents. Findings may be used in the development of intervention strategies aimed at improving metabolic heath in obese adolescents.

Role of Physical Activity and Fitness in the Characterization and Prognosis of the Metabolically Healthy Obesity Phenotype: A Systematic Review and Meta-analysis

The aims of the present article are to systematically review and meta-analyze the existing evidence on: 1) differences in physical activity (PA), sedentary behavior (SB), cardiorespiratory fitness (CRF) and muscular strength (MST) between metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO); and 2) the prognosis of all-cause mortality and cardiovascular disease (CVD) mortality/morbidity in MHO individuals, compared with the best scenario possible, i.e., metabolically healthy normal-weight (MHNW), after adjusting for PA, SB, CRF or MST. Our systematic review identified 67 cross-sectional studies to address aim 1, and 11 longitudinal studies to address aim 2. The major findings and conclusions from the current meta-analysis are: 1) MHO individuals are more active, spend less time in SB, and have a higher level of CRF (yet no differences in MST) than MUO individuals, suggesting that their healthier metabolic profile could be at least partially due to these healthier lifestyle factors and attributes. 2) The meta-analysis of cohort studies which accounted for PA (N = 10 unique cohorts, 100% scored as high-quality) support the notion that MHO individuals have a 24-33% higher risk of all-cause mortality and CVD mortality/morbidity compared to MHNW individuals. This risk was borderline significant/non-significant, independent of the length of the follow-up and lower than that reported in previous meta-analyses in this topic including all type of studies, which could be indicating a modest reduction in the risk estimates as a consequence of accounting for PA. 3) Only one study has examined the role of CRF in the prognosis of MHO individuals. This study suggests that the differences in the risk of all-cause mortality and CVD mortality/morbidity between MHO and MHNW are largely explained by differences in CRF between these two phenotypes.

Associations of Early to Mid-Childhood Adiposity with Elevated Mid-Childhood Alanine Aminotransferase Levels in the Project Viva Cohort

OBJECTIVES

To examine the longitudinal relationship of early to mid-childhood adiposity measures with mid-childhood alanine aminotransferase (ALT) levels.

STUDY DESIGN

We studied 635 children in the Project Viva cohort. Research staff measured weight, height, skinfolds thicknesses, and waist and hip circumferences at early (median 3.2 years) and mid-childhood (median 7.7 years) visits. At mid-childhood, we collected blood for ALT analysis. We used established sex-specific ALT cut-offs to define elevated ALT. In multivariable linear and logistic regression models, we assessed the association of adiposity measures from early to mid-childhood with mid-childhood ALT level, adjusting for confounders.

RESULTS

Children were 48% female, 59% white, 21% black, 6% Hispanic/Latino, and 3% Asian. At early childhood, 29% had overweight/obesity and mean waist circumference was 51.5 (SD 3.8) cm. At mid-childhood, mean ALT was 20.3 (SD 7.3) units/L, and 23% had an elevated ALT. In multivariable-adjusted regression models, each additional 10-cm greater waist circumference at early childhood was associated with 1.99 (95% CI 1.19-3.33) greater odds of elevated ALT at mid-childhood. Greater increases from early to mid-childhood in body mass index z score, sum of subscapular and triceps skinfold thicknesses, waist circumference, and hip circumference were associated with greater ALT at mid-childhood.

CONCLUSIONS

In this prospective cohort, greater waist circumference at early childhood and greater increases in adiposity measures from early to mid-childhood were associated with greater ALT levels at mid-childhood.

Effect of Serum Adiponectin Levels on the Association Between Childhood Body Mass Index and Adulthood Carotid Intima-Media Thickness

Childhood obesity predicts adult cardiovascular risk. We hypothesized that the association between childhood body mass index (BMI) and adult carotid intima-media thickness (CIMT) may be modified by levels of adiponectin, an adipocytokine that connects body fatness with cardiovascular risk. The study sample included 1,052 adults (71% white and 29% black, 57% female) aged 23.8 to 43.5 years who were previously examined as children in the Bogalusa Heart Study cohort, with an average follow-up period of 26.5 (range 14.1 to 29.6) years. Childhood BMI, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and systolic blood pressure were standardized to age-specific z-scores. General linear models were used for data analyses. Childhood BMI (p = 0.034), low-density lipoprotein cholesterol (p <0.001), and systolic blood pressure (p = 0.005), along with adult adiponectin levels (p = 0.002) were associated with adult CIMT, adjusted for race, sex, adult age, and cigarette smoking. Further, adult adiponectin levels significantly modified the association between childhood BMI and adult CIMT (P for interaction = 0.0003) such that a significant association between childhood BMI and adult CIMT (p <0.0001) was only observed in those with adiponectin levels below the median. In conclusion, these results suggest that serum adiponectin levels modify the association between childhood obesity and adult atherosclerosis, which has implications for risk stratification and targeted intervention for obese children with low levels of adiponectin.

Lower Performance in the Six-Minute Walk Test in Obese Youth With Cardiometabolic Risk Clustering

Background: Physical fitness is an important index of health. Our aim was to assess whether cardiorespiratory and/or musculoskeletal components of physical fitness were associated with cardiometabolic risk clustering in obese youth, using adapted and validated field tests. Methods: We evaluated 252 children and adolescents (132 males, 120 females), mean age 10.9 ± 1.9 years with primary obesity. All subjects performed the six-minute walk test (6MWT) for assessing aerobic fitness, the standing broad jump, and the 30 s-chair stand tests for lower-body muscular strength, and the handgrip test for upper body isometric strength. Cardiometabolic risk (CMR) clustering was defined as having two or more of the following risk factors: high SBP and/or DBP, impaired fasting glucose, high triglycerides (TGs), and low HDL-Cholesterol. Results: CMR clustering was found in 44 (17.5%) obese youth. Youth with CMR clustering had a lower cardiorespiratory fitness, as assessed by 6MWT, compared to those without CMR clustering. On the contrary, no difference was found with respect to musculoskeletal fitness. The six-minute walk (6MW) distance was negatively associated with sedentary time, controlling for age and height. CMR factors clustering was significantly associated with BMI standard deviation score (SDS) and negatively with 6MW distance: for each 10-m increase in the 6MW distance, a reduction of about 9% in the prevalence of CMR clustering was expected. Conclusions: A lower performance in the 6MWT may be considered as an additional trait of CMR clustering in obese youth. The 6MWT may represent a valuable, simple and low cost test to estimate the cardiorespiratory fitness in youth with obesity.

Physical Activity and Sedentary Patterns among Metabolically Healthy Individuals Living with Obesity

BACKGROUND

Some individuals living with obesity are free from typical cardiometabolic risk factors and are termed metabolically healthy obese (MHO). The patterns of physical activity and sedentary behaviors among MHO are currently unknown.

METHODS

This study includes 414 youth (12-18 years old), 802 adults (19-44 years old), and 1230 older adults (45-85 years old) living with obesity from the 2003-2004 or 2005-2006 NHANES cycles. Time spent in bouts of 1, 5, 10, 30, and 60 minutes for moderate-to-vigorous physical activity (MVPA) and sedentary time was measured objectively using accelerometers. Participants were categorized as MHO if they had no cardiometabolic risk factors above the identified thresholds (triglycerides, high-density lipoprotein cholesterol, systolic blood pressure, diastolic blood pressure, and glucose).

RESULTS

The proportion of MHO was 19%, 14%, and 12% in youth, adults, and older adults, respectively. MHO adults displayed a higher 1-minute bout of MVPA per day compared to non-MHO (p = 0.02), but no difference was observed for MVPA and sedentary behavior patterns for youth and older adults. When adjusted for confounders, all bouts of sedentary behavior patterns in youth were significantly associated with being classified as MHO.

CONCLUSION

This study suggests that greater sedentary time is associated with cardiometabolic risk factors in youth even if they are physically active.

Inflammation in metabolically healthy and metabolically abnormal adolescents: The HELENA study

BACKGROUND AND AIMS

Inflammation may influence the cardio-metabolic profile which relates with the risk of chronic diseases. This study aimed to assess the inflammatory status by metabolic health (MH)/body mass index (BMI) category and to assess how inflammatory markers can predict the cardio-metabolic profile in European adolescents, considering BMI.

METHODS AND RESULTS

A total of 659 adolescents (295 boys) from a cross-sectional European study were included. Adolescents were classified by metabolic health based on age- and sex-specific cut-off points for glucose, blood pressure, triglycerides, high density cholesterol and BMI. C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), interleukin (IL-6), complement factors (C3, C4) and cell adhesion molecules were assessed.

RESULTS

Metabolically abnormal (MA) adolescents had higher values of C3 (p < 0.001) and C4 (p = 0.032) compared to those metabolically healthy (MHy). C3 concentrations significantly increased with the deterioration of the metabolic health and BMI (p < 0.001). Adolescents with higher values of CRP had higher probability of being in the overweight/obese-MH group than those allocated in other categories. Finally, high C3 and C4 concentrations increased the probability of having an unfavorable metabolic/BMI status.

CONCLUSIONS

Metabolic/BMI status and inflammatory biomarkers are associated, being the CRP, C3 and C4 the most related inflammatory markers with this condition. C3 and C4 were associated with the cardio-metabolic health consistently.

Prevalence and Clinical Characteristics of Metabolically Healthy Obesity in Korean Children and Adolescents: Data from the Korea National Health and Nutrition Examination Survey

Metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO) are differentiated by the presence of cardiometabolic risk factors (CMRFs) and insulin resistance (IR). This study aimed to evaluate the prevalence and clinical characteristics of MHO in Korean children and adolescents and to investigate the anthropometric, laboratory, and lifestyle predictors of MHO. This study included data from 530 obese subjects, aged 10-19 years, obtained from the Fourth Korea National Health and Nutrition Examination Survey. Subjects were classified into MHO and MUO groups according to the presence of CMRF (MHO(CMRF)/MUO(CMRF)) and degree of IR (MHO(IR)/MUO(IR)). Demographic, anthropometric, cardiometabolic, and lifestyle factors were compared between the groups. Logistic regression analysis and receiver operating characteristic curve analysis were performed to identify factors that predicted MHO. The prevalence of MHO(CMRF) and MHO(IR) in obese Korean youth was 36.8% (n = 197) and 68.8% (n = 356), respectively. CMRF profiles were significantly less favorable in MUO children. Longer and more vigorous physical activity and less protein intake were associated with MHO(CMRF) phenotype. The best predictors of MHO(CMRF) and MHO(IR) were waist circumference (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.77-0.88; P < 0.001) and body mass index (BMI) standard deviation score (OR, 0.24; 95% CI, 0.15-0.39; P < 0.001), respectively. The prevalence of MHO differed depending on how it was defined. To adequately manage obesity in youth, the approach to individuals with MHO and MUO should be personalized due to variation in clinical characteristics. Longitudinal studies are needed to evaluate long-term consequences of MHO.

Physical Activity and Sedentary Time Associations with Metabolic Health Across Weight Statuses in Children and Adolescents

OBJECTIVE

The aim of this study was to examine the prevalence of metabolic health across weight statuses and the associations of physical activity and sedentary time within and across metabolic health-weight status groups.

METHODS

Six studies (n = 4,581) from the International Children's Accelerometry Database were used. Sedentary time, light physical activity, and moderate to vigorous physical activity (MVPA) were accelerometer derived. Individuals were classified with normal weight (NW), overweight, or obesity. Strict and lenient composite definitions of metabolic health were created. Binomial and multinomial logistic regressions controlling for age, sex, study, and accelerometer wear time were conducted.

RESULTS

The metabolically unhealthy (MU) prevalence was 26.4% and 45.6% based on two definitions. Across definitions, more sedentary time was associated with higher odds of MU classification compared with metabolically healthy (MH) classification for the NW group. More MVPA was associated with lower odds of MU classification than MH classification for NW and overweight groups. For multinomial logistic regressions, more MVPA was associated with lower odds of MH-obesity classification, as well as MU-NW, -overweight, and -obesity classifications, compared with the MH-NW group. Furthermore, more sedentary time was associated with higher odds of MU-NW classification compared with the MH-NW group.

CONCLUSIONS

More MVPA was beneficial for metabolic health and weight status, whereas lower sedentary time was beneficial for metabolic health alone, although associations were weak.

Long-term metabolic risk for the metabolically healthy overweight/obese phenotype

BACKGROUND/OBJECTIVES

The clinical relevance of the metabolically healthy overweight/obese (MHO) phenotype is controversial and the relationships between weight change and the development of cardiometabolic risk factors is unknown. Therefore, we aim to: (1) Assess the long-term risk of developing one or more components of the metabolic syndrome in MHO adults compared with metabolically healthy normal weight (MHNW); (2) Evaluate risk of a composite of death, cardiovascular disease (CVD), and risk of developing type 2 diabetes between adults defined according to baseline body mass index and metabolic health.

SUBJECTS/METHODS

Retrospective cohort study of adults 18-65 years of age seen at our institution between 1998 and 2000 who lived in Olmsted County. Metabolically healthy was defined as the absence of all components of the metabolic syndrome (except for waist circumference). Main outcome was the development of metabolic risk factors. The secondary outcome was a composite of mortality, CVD and heart failure.

RESULTS

Of the 18 070 individuals with complete data at baseline, 1805 (10%) were MHO (mean age 38±11 years) and 3047 were MHNW (mean age 35±11 years). After a median follow-up of 15 years, interquartile range 10-17, 80% of MHO vs 68% of MHNW developed at least one cardiometabolic risk factor (P<0.001). In multivariate analysis, MHO individuals who gained ⩾10% of their body weight were more likely to have developed metabolic complications compared to MHO individuals that did not gain weight (P=0.001 for 10-15%, P<0.001 for >15% weight gain). The risk for the secondary composite end point was similar between MHO and MHNW, number of events 218/1805 vs 217/3048 for MHO and MHNW, respectively, (hazard ratio: 1.16, 95% confidence interval: 0.96-1.40).

CONCLUSIONS

MHO are more likely to develop metabolic complications than MHNW, especially if they gain weight.

Prevention of diabetes in overweight/obese children through a family based intervention program including supervised exercise (PREDIKID project): study protocol for a randomized controlled trial

BACKGROUND

The global pandemic of obesity has led to an increased risk for prediabetes and type-2 diabetes (T2D). The aims of the current project are: (1) to evaluate the effect of a 22-week family based intervention program, including supervised exercise, on insulin resistance syndrome (IRS) risk in children with a high risk of developing T2D and (2) to identify the profile of microRNA in circulating exosomes and in peripheral blood mononuclear cells in children with a high risk of developing T2D and its response to a multidisciplinary intervention program including exercise.

METHODS

A total of 84 children, aged 8-12 years, with a high risk of T2D will be included and randomly assigned to control (N = 42) or intervention (N = 42) groups. The control group will receive a family based lifestyle education and psycho-educational program (2 days/month), while the intervention group will attend the same lifestyle education and psycho-educational program plus the exercise program (3 days/week, 90 min per session including warm-up, moderate to vigorous aerobic activities, and strength exercises). The following measurements will be evaluated at baseline prior to randomization and after the intervention: fasting insulin, glucose and hemoglobin A1c; body composition (dual-energy X-ray absorptiometry); ectopic fat (magnetic resonance imaging); microRNA expression in circulating exosomes and in peripheral blood mononuclear cells (MiSeq; Illumina); cardiorespiratory fitness (cardiopulmonary exercise testing); dietary habits and physical activity (accelerometry).

DISCUSSION

Prevention and identification of children with a high risk of developing T2D could help to improve their cardiovascular health and to reduce the comorbidities associated with obesity.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03027726 . Registered on 16 January 2017.

Prevalence of Metabolically Healthy but Overweight/Obese Phenotype and Its Association With Sedentary Time, Physical Activity, and Fitness

PURPOSE

Childhood obesity is one of the major concerns in the last years due to the association with future health problems and all-cause mortality. However, there is a subset of adolescents with overweight/obesity who present a metabolic healthy profile. Therefore, the aim of this study was to examine the prevalence of metabolically healthy but overweight/obese adolescents and whether sedentary time, physical activity, and fitness differ between metabolically healthy and nonmetabolically healthy phenotypes.

METHODS

A subsample of 237 European adolescents from the HEalthy Lifestyle in Europe by Nutrition in Adolescence study (n = 3,528, participation rate: 61.3%) with overweight/obesity were included. The study sample was not fully representative for the European adolescent population. Based on sex- and age-specific metabolic syndrome cutoff points for triglycerides, glucose, blood pressure, and high-density cholesterol participants were classified as metabolically healthy or nonmetabolically healthy. Sedentary time, physical activity, and fitness were assessed by accelerometry and the Alpha battery, respectively.

RESULTS

The prevalence of metabolically healthy status in adolescents with overweight and obesity was higher in girls (87%) than in boys (74%, p = .019), being similar when only obesity was considered. Sedentary time was lower in metabolically healthy overweight/obese than in nonmetabolically healthy participants (mean difference = 48.0 minutes, p = .012). Moderate and moderate-to-vigorous physical activity were higher (p's < .05) in metabolically healthy than in nonmetabolically healthy adolescents with overweight/obesity (mean difference = 7.9 min/day and 10.9 min/day, respectively). No significant differences were found in fitness. Overall, these results persisted when only adolescents with obesity were included in the analyses.

CONCLUSIONS

Metabolically healthy adolescents with overweight/obesity are less sedentary and more active than their nonmetabolically healthy peers with overweight/obesity, yet consistent differences in fitness were not observed.

Adiposity as a full mediator of the influence of cardiorespiratory fitness and inflammation in schoolchildren: The FUPRECOL Study

BACKGROUND AND AIMS

Studies in the paediatric population have shown inconsistent associations between cardiorespiratory fitness and inflammation independently of adiposity. The purpose of this study was (i) to analyse the combined association of cardiorespiratory fitness and adiposity with high-sensitivity C-reactive protein (hs-CRP), and (ii) to determine whether adiposity acts as a mediator on the association between cardiorespiratory fitness and hs-CRP in children and adolescents.

METHODS AND RESULTS

This cross-sectional study included 935 (54.7% girls) healthy children and adolescents from Bogotá, Colombia. The 20 m shuttle run test was used to estimate cardiorespiratory fitness. We assessed the following adiposity parameters: body mass index, waist circumference, and fat mass index and the sum of subscapular and triceps skinfold thickness. High sensitivity assays were used to obtain hs-CRP. Linear regression models were fitted for mediation analyses examined whether the association between cardiorespiratory fitness and hs-CRP was mediated by each of adiposity parameters according to Baron and Kenny procedures. Lower levels of hs-CRP were associated with the best schoolchildren profiles (high cardiorespiratory fitness + low adiposity) (p for trend <0.001 in the four adiposity parameters), compared with unfit and overweight (low cardiorespiratory fitness + high adiposity) counterparts. Linear regression models suggest a full mediation of adiposity on the association between cardiorespiratory fitness and hs-CRP levels.

CONCLUSIONS

Our findings seem to emphasize the importance of obesity prevention in childhood, suggesting that having high levels of cardiorespiratory fitness may not counteract the negative consequences ascribed to adiposity on hs-CRP.

Cardiorespiratory fitness, waist circumference and liver enzyme levels in European adolescents: The HELENA cross-sectional study

OBJECTIVES

(1) To examine whether cardiorespiratory fitness (CRF) is related to liver enzyme levels independent of waist circumference (WC), and (2) To test whether having a high CRF is associated with an improved liver enzyme profile with a high WC.

DESIGN

Cross-sectional.

METHODS

CRF (20m-shuttle-run test) and WC were assessed in 811 European adolescents (48.5% males) aged 12.5-17.5 years. Fatty liver biomarkers included fasting serum alanine-aminotransferase (ALT), gamma-glutamyl-transpeptidase (GGT) and the aspartate-aminotransferase to ALT (AST/ALT) ratio. Participants were categorized as fit or unfit (CRF below or above 43.8mL/kg/min and 34.6mL/kg/min, for boys and girls, respectively) and as high or non-high WC (sex and age-specific cut-offs).

RESULTS

CRF was associated with ALT (β=-0.106; p=0.049) and GGT levels (β=-0.225; p<0.001) and AST/ALT ratio (β=0.234; p<0.001), yet these relationships were attenuated after further controlling for WC (all p>0.1). High WC and fit adolescents had lower ALT levels (28±1U/L vs. 23±2U/L, unfit and fit respectively, p=0.018) and higher AST/ALT ratio (0.94±0.04 vs. 1.10±0.06, unfit and fit respectively, p=0.010) than those who were high WC but unfit.

CONCLUSIONS

The results showed that CRF is not independently associated with liver enzymes, and that WC is a stronger predictor in adolescents. These findings also suggest that high CRF may have specific protective effects on liver enzyme levels in adolescents with high WC. Exercise programs focused on increasing CRF and decreasing abdominal adiposity could be a good alternative in the treatment and prevention of obesity related fatty liver disease in adolescents.

Risk factors that affect metabolic health status in obese children

BACKGROUND

While some obese children are metabolically healthy (MHO), some have additional health problems, such as hypertension, dyslipidemia, insulin resistance, and hepatosteatosis, which increase mortality and morbidity related to cardiovascular diseases (CVD) during adulthood. These children are metabolically unhealthy obese (MUO) children. In this study we assessed the factors that affect metabolic health in obesity and the clinical and laboratory findings that distinguish between MHO and MUO children.

METHODS

In total, 1085 patients aged 6-18 years, with age- and sex-matched BMI exceeding the 95th percentile were included in the study (mean 11.1±2.9 years, 57.6% female, 59.7% pubertal). Patients without dyslipidemia, insulin resistance, hepatosteatosis, or hypertension were considered as MHO. Dyslipidemia was defined as total cholesterol level over 200 mg/dL, triglyceride over 150 mg/dL, LDL over 130 mg/dL, or HDL under 40 mg/dL. Insulin resistance was calculated using the homeostasis model of assesment for insulin resistance (HOMA-IR) index. Hepatosteatosis was evaluated with abdominal ultrasound. Duration of obesity, physical activity and nutritional habits, screen time, and parental obesity were questioned. Thyroid and liver function tests were performed.

RESULTS

Six hundred and forty-two cases (59.2%) were MUO. Older age, male sex, increased BMI-SDS, and sedentary lifestyle were associated with MUO. Excessive junk food consumption was associated with MUO particularly among the prepubertal obese patients.

CONCLUSIONS

Our results revealed that the most important factors that affect metabolic health in obesity are age and BMI. Positive effects of an active lifestyle and healthy eating habits are prominent in the prepubertal period and these habits should be formed earlier in life.

Metabolically healthy obesity across the life course: epidemiology, determinants, and implications

In recent years, different subphenotypes of obesity have been described, including metabolically healthy obesity (MHO), in which a proportion of obese individuals, despite excess body fat, remain free of metabolic abnormalities and increased cardiometabolic risk. In the absence of a universally accepted set of criteria to classify MHO, the reported prevalence estimates vary widely. Our understanding of the determinants and stability of MHO over time and the associated cardiometabolic and mortality risks is improving, but many questions remain. For example, whether MHO is truly benign is debatable, and whether risk stratification of obese individuals on the basis of their metabolic health status may offer new opportunities for more personalized approaches in diagnosis, intervention, and treatment of diabetes remains speculative. Furthermore, as most of the research to date has focused on MHO in adults, little is known about childhood MHO. In this review, we focus on the epidemiology, determinants, stability, and health implications of MHO across the life course.

Variations in the prevalence and predictors of prevalent metabolically healthy obesity in adolescents

BACKGROUND

Obesity is a heterogeneous condition, which includes a subset of individuals that can be classified as having metabolically healthy obesity (MHO), but there is no consensus on what constitutes MHO. Thus, the objective of the study is to examine the prevalence and predictors of prevalent MHO in adolescents using various definitions of MHO.

METHODS

Cross-sectional data from the 1999-2010 National Health and Nutrition Examination Surveys were used. Participants included 316 male and 316 female adolescents aged 12-19 years with a BMI ≥ 95th percentile. Two definitions were used to define MHO. First, MHO was defined as having ≤1 metabolic syndrome criteria (excluding waist) and being free of type 2 diabetes, hypertension and dyslipidemia. Second, MHO was defined as being free of all metabolic syndrome criteria, insulin resistance and inflammation.

RESULTS

The prevalence of MHO was 42% (male) and 74% (female) using the first definition and 7% (male) and 12% (female) using the second more conservative definition. Lower abdominal obesity (waist circumference) and lower insulin resistance predicted prevalent MHO in male and female adolescents for both definitions (p < 0.01). Associations between dietary components and MHO were weak and inconsistent, while physical activity and inflammation were not associated with MHO in male and female adolescents for both definitions (p > 0.05).

CONCLUSIONS

The prevalence of MHO in adolescents varied across definitions, with lower levels of abdominal obesity and insulin resistance as the most consistent predictors of prevalent MHO status.

Longitudinal associations of lifestyle factors and weight status with insulin resistance (HOMA-IR) in preadolescent children: the large prospective cohort study IDEFICS

Background

This study investigates prospective associations of anthropometrical and lifestyle indices with insulin resistance (IR) in European children from the IDEFICS cohort. Insulin resistance (IR) is a growing concern in childhood obesity and a central aspect of the metabolic syndrome (MS). It most likely represents the link between obesity and type 2 diabetes.

Methods

This longitudinal study included 3348 preadolescent children aged 3 to 10.9 years from 8 European countries who were observed from 2007/2008 to 2009/2010. The main outcome measure in the present analysis is HOMA-IR (homeostasis model assessment as a common proxy indicator to quantify IR) at follow-up and in its longitudinal development. Anthropometrical measures and lifestyle indices, including objectively determined physical activity, were considered, among others factors, as determinants of IR. Prospective associations between IR at follow-up and anthropometrical and lifestyle indices were estimated by logistic regression models.

Results

Country-specific prevalence rates of IR in the IDEFICS cohort of European children showed a positive trend with weight category. Prospective multivariate analyses showed the strongest positive associations of IR with BMI z-score (OR = 2.6 for unit change from the mean, 95 % CI 2.1–3.1) and z-score of waist circumference (OR = 2.2 for unit change from the mean, 95 % CI 1.9–2.6), which were analysed in separate models, but also for sex (OR = 2.2 for girls vs. boys, 95 % CI 1.5–3.1 up to OR 2.5, 95 % CI 1.8–3.6 depending on the model), audio-visual media time (OR = 1.2 for an additional hour per day, 95 % CI 1.0–1.4 in both models) and an inverse association of objectively determined physical activity (OR = 0.5 for 3^rd compared to 1^st quartile, 95 % CI 0.3–0.9 in both models). A longitudinal reduction of HOMA-IR was accompanied with a parallel decline in BMI.

Conclusions

This study is, to our knowledge, the first prospective study on IR in a preadolescent children’s population. It supports the common hypothesis that overweight and obesity are the main determinants of IR. Our data also indicate that physical inactivity and a sedentary lifestyle are likewise associated with the development of IR, independent of weight status. The promotion of physical activity should thus be considered as an equal option to dietary intervention for the treatment of IR in the paediatric practice.

Cardiometabolic risk: leg fat is protective during childhood

BACKGROUND

Childhood obesity is associated with early cardiometabolic risk (CMR), increased risk of adulthood obesity, and worse health outcomes. Leg fat mass (LFM) is protective beyond total fat mass (TFM) in adults. However, the limited evidence in children remains controversial.

OBJECTIVE

We investigated the relationship between LFM and CMR factors in youth.

SUBJECTS

A total of 203 overweight/obese children, 7-17-yr-old, followed in the Pediatric Clinic, Luxembourg.

METHODS

TFM and LFM by dual energy x-ray absorptiometry and a detailed set of CMR markers were analyzed.

RESULTS

After TFM, age, sex, body mass index (BMI) Z-score, sexual maturity status, and physical activity adjustments, negative significant partial correlations were shown between LFM and homeostasis model assessment of insulin resistance (HOMA) (variance explained: 6.05% by LFM*; 7.18% by TFM**), fasting insulin (variance explained: 5.71% by LFM*; 6.97% by TFM**), triglycerides (variance explained: 3.96% by LFM*; 2.76% by TFM*), systolic blood pressure (variance explained: 2.68% by LFM*; 4.33% by TFM*), C-reactive protein (variance explained: 2.31% by LFM*; 4.28% by TFM*), and resistin (variance explained: 2.16% by LFM*; 3.57% by TFM*). Significant positive partial correlations were observed between LFM and high-density lipoprotein (HDL) cholesterol (variance explained: 4.16% by LFM*) and adiponectin (variance explained: 3.09% by LFM*) (*p-value < 0.05 and **p-value < 0.001). In order to adjust for multiple testing, Benjamini-Hochberg method was applied and the adjusted significance level was determined for each analysis. LFM remained significant in the aforementioned models predicting HOMA, fasting insulin, triglycerides, and HDL cholesterol (Benjamini and Hochberg corrected p-value < 0.01).

CONCLUSIONS

LFM is protective against CMR in children, at least in terms of insulin resistance and adverse blood lipid profiles.

Obesity and Cardiovascular Disease

The prevalence of obesity has increased worldwide over the past few decades. In 2013, the prevalence of obesity exceeded the 50% of the adult population in some countries from Oceania, North Africa, and Middle East. Lower but still alarmingly high prevalence was observed in North America (≈30%) and in Western Europe (≈20%). These figures are of serious concern because of the strong link between obesity and disease. In the present review, we summarize the current evidence on the relationship of obesity with cardiovascular disease (CVD), discussing how both the degree and the duration of obesity affect CVD. Although in the general population, obesity and, especially, severe obesity are consistently and strongly related with higher risk of CVD incidence and mortality, the one-size-fits-all approach should not be used with obesity. There are relevant factors largely affecting the CVD prognosis of obese individuals. In this context, we thoroughly discuss important concepts such as the fat-but-fit paradigm, the metabolically healthy but obese (MHO) phenotype and the obesity paradox in patients with CVD. About the MHO phenotype and its CVD prognosis, available data have provided mixed findings, what could be partially because of the adjustment or not for key confounders such as cardiorespiratory fitness, and to the lack of consensus on the MHO definition. In the present review, we propose a scientifically based harmonized definition of MHO, which will hopefully contribute to more comparable data in the future and a better understanding on the MHO subgroup and its CVD prognosis.