Cardiometabolic Health in Obese Adolescents Is Related to Length of Obesity Exposure: A Pilot Study

Lessons Learned from Telemedicine in Adolescent Obesity: Results of a Pilot Study

The rising prevalence of obesity in children calls for new strategies for the provision of effective care by a multidisciplinary team. Telemedicine has overall proven to be an effective tool for promoting a healthy lifestyle. The main objective of the current paper is to present the protocol of our ongoing CardioMetabolic Prevention (CAMP) study and compare its design with published studies on telemedicine in paediatric obesity. Additionally, we analysed the preliminary anthropometric and laboratory data to test the efficacy of our 12-week intensive program that combines in-person and telemedicine support. The program demonstrated a positive impact on body mass index (BMI) and its z-scores in 21 adolescents, and BMI in 18 participating parents. However, we found no effect on body composition, waist circumference, cardiometabolic parameters, or fitness evaluated via a 6-min walk test in adolescents. In conclusion, the combination of in-person and telemedicine intensive support over 35 h delivered by a multidisciplinary team can be beneficial not only for adolescents with obesity but also for their parents. The ongoing CAMP study serves as a platform for precision medicine in future decisions regarding anti-obesity medication in adolescents with obesity.

Predictive markers of metabolically healthy obesity in children and adolescents: can AST/ALT ratio serve as a simple and reliable diagnostic indicator?

This study aimed to estimate the prevalence of metabolically healthy obesity (MHO) according to two different consensus-based criteria and to investigate simple, measurable predictive markers for the diagnosis of MHO. Five hundred and ninety-three obese children and adolescents aged 6-18 years were included in the study. The frequency of MHO was calculated. ROC analysis was used to estimate the predictive value of AST/ALT ratio, waist/hip ratio, MPV, TSH, and Ft4 cut-off value for the diagnosis of MHO. The prevalence of MHO was 21.9% and 10.2% according to 2018 and 2023 consensus-based MHO criteria, respectively. AST/ALT ratio cut-off value for the diagnosis of MHO was calculated as ≥ 1 with 77% sensitivity and 52% specificity using Damanhoury et al.'s criteria (AUC = 0.61, p = 0.02), and 90% sensitivity and 51% specificity using Abiri et al.'s criteria (AUC = 0.70, p = 0.01). Additionally, using binomial regression analysis, only the AST/ALT ratio is independently and significantly associated with the diagnosis of MHO (p = 0.03 for 2018 criteria and p = 0.04 for 2023 criteria).

CONCLUSION

The ALT/AST ratio may be a useful indicator of MHO in children and adolescents.

WHAT IS KNOWN

• Metabolically healthy obesity refers to people who are obese but do not have any of the standard cardio-metabolic risk factors. • Metabolically healthy obesity is not entirely harmless; the metabolic characteristics of individuals with this phenotype are less favorable than those of healthy lean groups. Moreover, it is not a constant state, and there may be a transition to metabolically unhealthy phenotypes over time.

WHAT IS NEW

• The prevalence of MHO is 21.9% and 10.2% according to 2018 and 2023 consensus-based metabolically healthy obesity criteria, respectively. • The ALT/AST ratio may be a useful indicator of metabolically healthy obesity in children and adolescents.

Predicting Insulin Resistance in a Pediatric Population With Obesity

OBJECTIVES

Insulin resistance (IR) affects children and adolescents with obesity and early diagnosis is crucial to prevent long-term consequences. Our aim was to identify predictors of IR and develop a multivariate model to accurately predict IR.

METHODS

We conducted a cross-sectional analysis of demographical, clinical, and biochemical data from a cohort of patients attending a specialized Paediatric Nutrition Unit in Portugal over a 20-year period. We developed multivariate regression models to predict IR. The participants were randomly divided into 2 groups: a model group for developing the predictive models and a validation group for cross-validation of the study.

RESULTS

Our study included 1423 participants, aged 3-17 years old, randomly divided in the model (n = 879) and validation groups (n = 544). The predictive models, including uniquely demographic and clinical variables, demonstrated good discriminative ability [area under the curve (AUC): 0.834-0.868; sensitivity: 77.0%-83.7%; specificity: 77.0%-78.7%] and high negative predictive values (88.9%-91.6%). While the diagnostic ability of adding fasting glucose or triglycerides/high density lipoprotein cholesterol index to the models based on clinical parameters did not show significant improvement, fasting insulin appeared to enhance the discriminative power of the model (AUC: 0.996). During the validation, the model considering demographic and clinical variables along with insulin showed excellent IR discrimination (AUC: 0.978) and maintained high negative predictive values (90%-96.3%) for all models.

CONCLUSION

Models based on demographic and clinical variables can be advantageously used to identify children and adolescents at moderate/high risk of IR, who would benefit from fasting insulin evaluation.

Assessment of a consensus definition of obesity and metabolic health phenotypes in children at different pubertal stages

Not all individuals with obesity develop metabolic complications, which has brought about the concepts of metabolically healthy and unhealthy obesity (MHO/MUO). However, inconsistent definitions of these conditions have limited their understanding. We assessed whether a recently-proposed consensus definition for MHO/MUO correlates with adiposity and reflects metabolic risk parameters during puberty. Low-middle income children from the Growth and Obesity Cohort Study (Santiago, Chile) were included (n = 949; 1692 visits at Tanner (T)2, T4 and/or one-year post menarche (1YPM)). Anthropometry, body composition and metabolic parameters were compared between MUO and MHO, and also in children without obesity. The risk for presenting MUO phenotype was significantly elevated with higher waist-height ratio (T2), zBMI (T2, T4), trunk fat, and C-reactive protein (T4). Elevated cardiometabolic indices were important predictors of the "unhealthy" phenotype allocation in children with or without obesity. Our observations suggest that the consensus definition in children at T2, T4 and 1YPM reflects metabolic risk and central obesity. Metabolic health phenotype allocation by this equation enables easy detection of risk factors that call for action to prevent long-term metabolic derangements in children with obesity and, importantly, also those without obesity.

The fatty acid composition of serum phospholipids in adolescents is associated with body composition in early adulthoods: an eight-year follow-up study

The fatty acid composition is associated with obesity. Omega 3 polyunsaturated fatty acid (PUFA) could have a beneficial role in the prevention and treatment of many disorders, including cardiometabolic diseases. A cohort of 84 men and 131 women were examined in adolescence and after 8 years. Body weight (BW) and fat mass (FM) were measured. The composition of fatty acids (FAs) of serum phospholipids was assessed using gas chromatography. Statistics: PLS method. Aim: to determine the relationships between FAs in adolescence and FM (explanatory variable 1, EV1) and BW (explanatory variable 2, EV2) in adulthood. In the predictive models, a cluster of FAs in boys explained 47.2 % of EV1 and a cluster of 6 FAs in girls explained 32.3 % of EV1 measured in adulthood. FAs measured in adolescents explained 23.7 % of EV2 in early adults regardless of gender. A significant negative association was found between 18:1n-9c and EV1 in males and EV2 in both genders. We found a significant negative association between 18:2n-6 and 20:0 and both EV1 and EV2. In all analyses, we found a significant negative association of 20:1n-9 and 18:3n-3 with EV1-2 in both genders. A significant positive association was found in 20:3n-6 with EV1 and EV2 in males. 20:4n-6 was positively associated with EV1 in females and EV2 in both genders. A positive association between FM and very long chain n- 6 PUFAs was also observed. It is concluded that serum MUFAs and essential PUFAs in adolescence are associated with lower BW and FM in adulthood.

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.

Contribution of 20-year body mass index and waist circumference history to poor cardiometabolic health in overweight/obese and normal weight adults: A cohort study

BACKGROUND AND AIMS

We investigated the associations of 20-year body mass index (BMI) and waist circumference (WC) histories with risk of being 1) metabolically unhealthy overweight/obese (MUOO) vs metabolically healthy overweight/obese (MHOO) and 2) metabolically unhealthy normal weight (MUNW) vs metabolically healthy normal weight (MHNW).

METHODS AND RESULTS

Participants comprised 3018 adults (2280 males; 738 females) with BMI and WC measured, every ~5 years, in 1991-1994, 1997-1999, 2002-2004, 2007-2009, and 2012-2013. Mean age in 2012-2013 was 69.3 years, with a range of 59.7-82.2 years. Duration was defined as the number of times a person was overweight/obese (or centrally obese) across the 5 visits, severity as each person's mean BMI (or WC), and variability as the within-person standard deviation of BMI (or WC). At the 2013-2013 visit, participants were categorised based on their weight (overweight/obese or normal weight; body mass index (BMI) ≥25 kg/m2) and health status (healthy or unhealthy; two or more of hypertension, low high-density lipoprotein cholesterol, high triglycerides, high glucose, and high homeostatic model assessment of insulin resistance). Logistic regression was used to estimate associations with the risk of being MUNW (reference MHNW) and MUOO (reference MHOO) at the last visit. BMI and WC severity were each related to increased risk of being unhealthy, with estimates being stronger among normal weight than overweight/obese adults. The estimates for variability exposures became null upon adjustment for severity. Individuals who were overweight/obese at all 5 time points had a 1.60 (0.96-2.67) times higher risk of being MUOO than MHOO compared to those who were only overweight/obese at one (i.e., the last) time point. The corresponding estimate for central obesity was 4.20 (2.88-6.12). Greater duration was also related to higher risk of MUNW than MHNW.

CONCLUSION

Being overweight/obese yet healthy seems to be partially attributable to lower exposure to adiposity across 20 years of adulthood. The results highlight the importance of maintaining optimum and stable BMI and WC, both in adults who become and do not become overweight/obese.

Insulin Resistance as a Diagnostic Criterion for Metabolically Healthy Obesity in Children

OBJECTIVES

In recent years, a subgroup of individuals with obesity has been described as having a lower risk of metabolic and cardiovascular complications. These individuals have what is referred to as metabolically healthy obesity (MHO), which has a favorable metabolic profile and a lower probability of long-term complications. The definition of this subtype in children is not clear. The aim of the present study was to determine whether Homeostasis Model Assessment (HOMA) above a set threshold could be the marker of metabolically unhealthy obesity (MUO) in children, or a parameter that can be used in the overall assessment. It is intended to compare the International Diabetes Federation (IDF) criteria against HOMA in the diagnosis of MUO.

METHODS

This observational, retrospective, cohort study included children with obesity and analyzed their metabolic state by means of blood testing and dual-energy X-ray absorptiometry.

RESULTS

A total of 96 patients were included, 44.8% boys and 55.2% girls, ages 6-17 years. The patients with MHO according to the HOMA criterion were younger (P = 0.001), had a lower body mass index (BMI) z score (P = 0.006), waist-height index (P = 0.009), hip-height index (P = 0.010), blood glucose (P = 0.003), insulin (P < 0.001), and lower percentages of total fat (P = 0.002), trunk fat (P = 0.001), and android fat (P = 0.009) than those with MUO. The logistic regression analysis according to IDF criteria detected an area under the receiver operating characteristic (ROC) curve of 0.659 (95% CI 0.546-0.771; P = 0.009) versus the area under the ROC curve of 0.854 (95% CI 0.777-0.931; P < 0.001) for the HOMA definition. Therefore, the determination of the metabolic state according to HOMA has greater sensitivity and specificity than the IDF criteria. The multivariate analysis in children classified according to HOMA revealed that the percentage of total fat and gynoid fat distributions and triglyceride level could be markers of a healthy or unhealthy metabolic state in children with obesity (P < 0.001).

CONCLUSIONS

The use of HOMA as a single criterion was demonstrated to be an effective and simple detector of adiposity, which predicts the metabolically healthy obesity in children.

Body Mass Index Trajectories and Duration of Obesity in Thai Children Diagnosed with Hypertension

This study explored the relationship between BMI trajectories and the duration of obesity in Thai children diagnosed with hypertension. Demographic and blood pressure data from 536 children (270 boys, 50.3%) from a school in Bangkok, Thailand were collected. Hypertension was defined as blood pressure above the cutoff values specified in the 2017 American Academy of Pediatrics guidelines on 3 occasions. Records of BMI over the previous 3 years were reviewed. The prevalence of hypertension was 2.61% (14/536). Complete data on BMI trajectories were available in 421 non-hypertensive and 12 hypertensive children. The increase in BMI z-score over the previous 3 years was significantly greater in the hypertensive group than the non-hypertensive group, 1.45 (95% CI 0.42 to 1.88) versus 0.09 (95% CI: -0.35, 0.65), P = .008. In conclusion, children with a confirmed diagnosis of hypertension had a greater increase in BMI over the past 3 years than non-hypertensive children.

Osteopontin's relationship with malnutrition and oxidative stress in adolescents. A pilot study

Osteopontin (OPN) is a protein involved in inflammatory illnesses such as fibrosis and cancer; its overexpression in cardiovascular diseases promotes the biomineralization of blood vessels and other soft tissues. Moreover, there is an active component of oxidative stress related with those diseases. The present study relates serum OPN levels with nutritional condition and oxidative stress in a group of adolescents. Anthropometric measurements were performed, and fasting blood samples were analyzed to determine OPN concentrations, blood chemistry parameters (glucose, triglycerides, total cholesterol, urea, uric acid, and creatinine) and oxidative stress biomarkers (Paraoxonase-1, Glutathione S-Transferase, Catalase, NAD(P)H Quinone Oxidoreductase, free carbonyl groups and malondialdehyde). Adolescents were categorized according to body mass index (BMI) and metabolic syndrome (MetS) criteria. We found increased OPN serum concentrations in overweight and obese adolescents, as well as in adolescents with MetS. Rises in OPN correlated with arm circumference and biomarkers of lipid peroxidation; with regard to serum glucose there was a trend to positive correlation. Our results suggest that serum OPN is associated to nutritional status and could be considered as an early biomarker of low-grade inflammation and probably the early biomineralization of soft tissues in adolescence.

Metabolically healthy overweight in young adulthood: is it a matter of duration and degree of overweight?

BACKGROUND AND AIM

Given the controversy regarding metabolically healthy obesity, we studied the association between duration and degree of body mass index (BMI) from adolescence to early adulthood and metabolic status of both overweight/obese and under/normal weight subjects.

METHODS AND RESULTS

Participants of the EPITeen cohort were evaluated at 13, 17, 21 and 24 years (n = 1040). Duration and degree of BMI in the 11-year period was summarized through the area under the curve of BMI (BMI_AUC). Metabolic health at 24 y was defined as optimal levels of lipids, blood pressure and glucose. The association between BMI_AUC per year and metabolic health was estimated through binary logistic regression models, adjusted for confounders and stratified by BMI. The proportion of metabolically healthy overweight/obesity at 24 y was 13.4%. After adjustment for sociodemographic and behavioural factors, the increase of one kg/m² in BMI on average per year during the period between 13 and 24 y was associated with 14% lower odds of being metabolically healthy among under/normal weight participants (OR = 0.86, 95% CI 0.78-0.94); and 8% lower odds of metabolic health among obese/overweight participants (OR = 0.92, 95% CI 0.85-1.00). After additional adjustment for waist circumference, the association was attenuated, especially in the obese/overweight group (OR = 1.03, 95% CI 0.93-1.14). About 20% of the metabolically healthy obese/overweight at 13 y transitioned to metabolically unhealthy obesity/overweight at 24 y.

CONCLUSION

The results support the hypothesis that the healthy obesity phenotype could be explained by a lower exposure to adiposity, either by shorter time or lower quantity, and a more favourable body fat distribution.

The Relationship of Early-Life Adversity With Adulthood Weight and Cardiometabolic Health Status in the 1946 National Survey of Health and Development

OBJECTIVE

Evidence linking early-life adversity with an adverse cardiometabolic profile in adulthood is equivocal. This study investigates early-life adversity in relation to weight and cardiometabolic health status at ages 60 to 64 years.

METHODS

We included 1059 individuals from the 1946 National Survey of Health and Development. Data on adversity between ages 0 to 15 years were used to create a cumulative childhood psychosocial adversity score and a socioeconomic adversity score. Cardiometabolic and weight/height data collected at ages 60 to 64 years were used to create four groups: metabolically healthy normal weight, metabolically unhealthy normal weight, metabolically healthy overweight/obese, and metabolically unhealthy overweight/obese. Associations between the two exposure scores and weight/health status were examined using multinomial logistic regression, with adjustment for sex and age at the outcome visit.

RESULTS

Sixty-two percent of normal-weight individuals were metabolically healthy, whereas only 34% of overweight/obese individuals were metabolically healthy. In a mutually adjusted model including both exposure scores, a psychosocial score of ≥3 (compared with 0) was associated with increased risk of being metabolically unhealthy (compared with healthy) in both normal-weight adults (relative risk = 2.49; 95% confidence interval = 0.87-7.13) and overweight/obese adults (1.87; 0.96-3.61). However, the socioeconomic adversity score was more strongly related to metabolic health status in overweight/obese adults (1.60; 0.98-2.60) than in normal-weight adults (0.95; 0.46-1.96).

CONCLUSIONS

Independently of socioeconomic adversity, psychosocial adversity in childhood may be associated with a poor cardiometabolic health profile, in both normal-weight and overweight/obese adults.

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.

Duration and stability of metabolically healthy obesity over 30 years

BACKGROUND

Obese adults who are free from metabolic risk factors may develop risk factors over time. Our objective was to characterize development of obesity and duration of metabolically healthy obese (MHO) over 30 years.

METHODS

Participants in CARDIA who developed obesity (BMI ≥ 30 kg/m2) at follow-up exams during years 7, 10, 15, 20, 25, and 30 were analyzed. MHO was defined as obese and having 0 or 1 risk factor: ≥SBP/DBP 130/85 mmHg; fasting glucose ≥100 mg/dL/5.55 mmol/L; fasting triglycerides (≥150 mg/dL/1.69 mmol/L); and HDL-C (men <40 mg/dL/1.036 mmol/L, women <50 mg/dL/1.295 mmol/L) or on any medication(s) for these conditions. MHO duration (years) and obesity duration (years) were estimated for each subsequent time-point; and an overall cumulative duration was also calculated over available follow-up. MHO duration (%) was approximated as MHO duration ÷ obesity duration. Stable MHO was defined as 100% MHO duration over follow-up, while transient MHO was defined as <1-99%. Chi-squared tests were used to compare proportions by sex and race across obesity phenotypes. Multivariable-adjusted ANCOVA, adjusting for baseline BMI, age, race, and sex, was used to analyze obesity duration in all individuals who developed obesity, and also compare MHO duration (%) across race and sex in transient MHO individuals.

RESULTS

Of the 987 eligible participants who developed obesity, 51% were African American (AA), 56% were women. Higher percentages of AA were classified as transient MHO, and higher proportions of females were MHO (both p < 0.0001). Obesity duration (years) was higher in transient MHO compared with stable MHO (mean difference: 6.2 ± 0.5 years, p < 0.0001). Of those with transient MHO, African Americans (51.4 ± 1.6%) were more likely to have longer MHO duration compared to Caucasians (44.4 ± 1.9%, p = 0.005).

CONCLUSION

MHO status can be a transient phenotype which differs by sex and race. Future studies are needed to explore modifiable lifestyle/behavioral predictors associated with longer MHO duration.

Invited Commentary: The Causal Association Between Obesity and Stillbirth-Strengths and Limitations of the Consecutive-Pregnancies Approach

There has been a resurgence in analyses of consecutive pregnancies (or similarly, sibling designs) in perinatal and pediatric epidemiology. These approaches have attractive qualities for estimating associations with complex multifactorial exposures like obesity. In an article appearing in this issue of the Journal, Yu et al. (Am J Epidemiol. 2019;188(7):1328-1336) apply a consecutive-pregnancies approach to characterize the risk of stillbirth among women who develop obesity between pregnancies ("incident obesity"). Working within a causal framework and using parametric and nonparametric estimation techniques, the authors find an increase in stillbirth risk associated with incident obesity. Risk differences varied between 0.4 per 1,000 births (95% confidence interval (CI): 0.1, 0.7) and 6.9 per 1,000 births (95% CI: 3.7, 10.0), and risk ratios ranged from 1.12 (95% CI: 1.02, 1.23) to 2.99 (95% CI: 2.19, 4.08). The strengths of this approach include starting from a clearly defined causal estimand and exploring the sensitivity of parameter estimates to model selection. In this commentary, we put these findings in the broader context of research on obesity and birth outcomes and highlight concerns regarding the generalizability of results derived from within-family designs. We conclude that while causal inference is an important goal, in some instances focusing on formulation of a causal question drives results away from broad applicability.

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.

Examining the relationship between body mass index and adverse cardio-metabolic profiles among Australian Indigenous and non-Indigenous young adults

Australian Indigenous young people have a 10-fold excess of deaths from ischaemic heart disease compared with non-Indigenous Australians, yet the reasons behind this remain understudied. This paper aims to describe cardio-metabolic profiles among Australian Indigenous (n = 459) and non-Indigenous (n = 117) young adults (21-27 years). The association between body size and an adverse cardio-metabolic profile (≥3 abnormal cardio-metabolic markers) is assessed by gender and urban/rural residence, employing regression analyses. The prevalence of obesity was highest among urban Indigenous participants, both males and females (22% and 23%, respectively). Overall, BMI showed a significant positive association with an adverse cardio-metabolic profile. Moreover, adverse cardio-metabolic profile was present in a substantial proportion of Indigenous participants even in overweight and normal BMI categories. Among females, this could reflect elevated waist circumference, which was present in half of those of normal weight. Remote Indigenous females had the highest predicted probability of having an adverse cardio-metabolic profile across all BMI categories (13% for underweight, 54% for normal BMI, 93% for overweight, and 99% for obese). Our findings highlight the associations between obesity and adverse cardio-metabolic profiles among Indigenous and non-Indigenous youth. Culturally-relevant strategies that address lifestyle risks, including access to healthy food, are urgently needed in this age group.

Intrauterine metformin exposure and offspring cardiometabolic risk factors (PedMet study): a 5-10 year follow-up of the PregMet randomised controlled trial

BACKGROUND

Metformin is increasingly used to treat gestational diabetes and type 2 diabetes in pregnancy, and in attempts to improve pregnancy outcomes in polycystic ovary syndrome and obesity. It passes across the placenta with possible long-term consequences for the offspring. We previously explored the effect of metformin, given to women with polycystic ovary syndrome during pregnancy, on children's growth up to 4 years of age. In this 5-10 year follow-up, we examined the cardiometabolic risk factors in these children.

METHODS

This is a follow-up of children from the PregMet study, a double-blind, randomised controlled trial comparing metformin with placebo in polycystic ovary syndrome pregnancies. In the PregMet study, between Feb 4, 2005, and Jan 27, 2009, 257 pregnant women aged 18-45 years with polycystic ovary syndrome according to the Rotterdam criteria were included with 274 singleton pregnancies at 5-12 weeks of gestation at 11 study centres in Norway. 17 women participated twice. Pregnant women were randomised to metformin (2000 mg/day) or placebo from inclusion in the first trimester to birth. Randomisation was stratified according to metformin use at conception. In this follow-up, the primary endpoint was body-mass index (BMI) in the offspring at 5-10 years of age assessed by the standard deviation score (Z score). The primary endpoint was analysed with independent sample t tests. ClinicalTrials.gov number NCT00159536.

FINDINGS

Of the 255 invited children from the PregMet study, 141 (55%) consented to participate and were included between April 29, 2014, and July 12, 2016. Maternal baseline characteristics in the first trimester were similar between groups. Children in the metformin group had a higher BMI Z score than those in the placebo group (difference in means=0·41, 95% CI 0·03-0·78, p=0·03).

INTERPRETATION

The increased BMI in metformin-exposed children might indicate a potential risk of inferior cardiometabolic health. Implications for adult health cannot be excluded.

FUNDING

The Research Council of Norway, Novo Nordisk Foundation, St Olavs University Hospital, and the Norwegian University of Science and Technology.

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.

Obesity as the Main Risk Factor for Metabolic Syndrome in Children

Obesity in childhood is the main determinant of whole body reduced insulin sensitivity. This association has been demonstrated in multiple adult and pediatric cohorts. The mechanistic link explaining this association is the pattern of lipid partitioning in the face of excess calories and energy surplus. A tight relation exists between typical lipid deposition patterns, specifically within the skeletal muscle and liver, as well as the intra-abdominal compartment and whole body insulin sensitivity. The impact of lipid deposition within insulin responsive tissues such as the liver and skeletal muscle relates to the ability of fatty acid derivates to inhibit elements of the insulin signal transduction pathway. Strengthening the relation of obesity and reduced insulin sensitivity are the observations that weight gain reduces insulin sensitivity while weight loss increases it. This manifests as the appearance of cardiovascular risk factor clustering with weight gain and its recovery in the face of weight loss. Both obesity per se, via the adipocytokine profile it induces, and low insulin sensitivity, are independent determinants of the adverse metabolic phenotype characteristic of the metabolic syndrome.

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.

Prevalence of different metabolic phenotypes of obesity in Iranian children and adolescents: the CASPIAN V study

Background

Pediatric metabolic disorders are a major health problem. The prevalence of child and adolescent metabolic disorders particularly obesity has globally shown a growing pattern. The aims of this study were to estimate the prevalence of different metabolic phenotypes of obesity in children and adolescents.

Methods

This multi-centric cross-sectional study was conducted in 2015 in 30 provinces of Iran. Participants consisted of 4200 school students aged 7-18 years, studied in a national school-based surveillance program (CASPIAN- V) in Iran. Metabolic syndrome (MetS) and obesity was defined according to ATP III and WHO criteria respectively. Subjects were classified into four different metabolic phenotypes of obesity; metabolically healthy nonobese (MHNO), metabolically healthy obese (MHO), metabolically non-healthy non-obese (MNHNO) and metabolically non-healthy obese (MNHO). Moreover students were classified in four different phenotypes of obesity; normal; only abdominal obesity (AO), only generalized obesity (GO) and combined obesity (CO).

Results

The prevalence (95% confidence interval) of different metabolic phenotypes of obesity, MHO 10.35 (9.1, 11.8), MNHNO 3.31 (2.6, 4.2) and MNHO 2.19 (1.6, 2.9) was found in boys, while the prevalence of these phenotypes was significantly lower in girls (7.74 (6.6, 9.1), 3.11 (2.4,5.1) and 1.41 (0.9,2.1) respectively). The prevalence of only AO, only GO and CO was 12.17% (11.6, 12.7), 2.51% (2.3,2.8), and 8.86% (8.4,9.3), respectively. Based on gender differences, the prevalence of AO was significantly higher among girls than boys (12.4% of girls vs. 11.9% of boys).

Conclusions

Healthy lifestyle education and program interventions are necessary for children with different metabolic phenotypes of obesity, as there is a high probability that they may suffer from poor health in the future.

Body size trajectories and cardio-metabolic resilience to obesity

Individuals with obesity do not represent a single homogenous group in terms of cardio‐metabolic health prospects. The concept of metabolically healthy obesity is a crude way of capturing this heterogeneity and has resulted in a plethora of research linking to future outcomes to show that it is not a benign condition. By contrast, very few studies have looked back in time and modelled the life course processes and exposures that explain the heterogeneity in cardio‐metabolic health and morbidity and mortality risk among people with the same body mass index (BMI) (or waist circumference or percentage body fat). The aim of the Medical Research Council New Investigator Research Grant (MR/P023347/1) ‘Body size trajectories and cardio‐metabolic resilience to obesity in three United Kingdom birth cohorts’ is to reveal the body size trajectories, pubertal development patterns and other factors (e.g. early‐life adversity) that might attenuate the positive associations of adulthood obesity makers (e.g. BMI) with cardio‐metabolic disease risk factors and other outcomes, thereby providing some degree of protection against the adverse effects of obesity. This work builds on the Principle Investigator's previous research as part of the Cohort and Longitudinal Studies Enhancement Resources initiative and focuses on secondary data analysis in the nationally representative UK birth cohort studies (initiated in 1946, 1958 and 1970), which have life course body size and exposure data and a biomedical sweep in adulthood. The grant will provide novel evidence on the life course processes and exposures that lead to some people developing a cardio‐metabolic complication or disease or dying while other people with the same BMI do not. This paper details the grant's scientific rationale, research objectives and potential impact.

Metabolically healthy and metabolically unhealthy obese children both have increased carotid intima-media thickness: a case control study

BACKGROUND

The cardiovascular disease risk was assessed in metabolically healthy obese (MHO) children, obese children with metabolic disorders (MUO), and to a control group of normal-weight children using carotid intima-media thickness (CIMT).

METHODS

Participants were 204 obese children (114 M, 90 F), including 162 MUO (74 M, 88 F) and 42 MHO (24 M, 18 F), and 99 gender- and age-matched controls (45 M, 54 F). Glucose, triglycerides, total cholesterol, high-density and low-density lipoprotein cholesterol, and other serum values were determined in peripheral blood. Anthropometric parameters, blood pressure, and a carotid Doppler ultrasound scan were also acquired. The mean CIMT of obese subjects and controls was compared by analysis of variance. Abnormality of even one of the metabolic parameters assessed involved assignation to the MUO group. Mean CIMT was compared in MHO and MUO children.

RESULTS

Mean CIMT in control children was 402.97 ± 53.18 μm (left carotid artery) and 377.85 ± 52.47 μm (right carotid artery). In MHO and MUO patients CIMT was respectively 453.29 ± 62.04 and 460.17 ± 92.22 μm (left carotid artery) and 446.36 ± 49.21 and 456.30 ± 85.7 μm (right carotid artery). The mean CIMT was not significantly different in MUO and MHO children, whereas it showed a significant difference between both groups of obese children and controls (p < 0.01).

CONCLUSION

CIMT was significantly greater in obese patients, also in those without metabolic alterations, than in normal-weight children. Obesity is therefore an important risk factor for cardiovascular disease in itself, also in the absence of metabolic abnormalities.

Insulin Resistance, Prediabetes, Metabolic Syndrome: What Should Every Pediatrician Know?

The Metabolic syndrome describes a clustering of typical cardiovascular risk factors. The syndrome is also known as "Insulin Resistance syndrome" as a substantial part of the pathophysiology is driven by resistance to the metabolic effects of insulin. The major cause of insulin resistance in childhood is a typical lipid partitioning pattern characterized by increased deposition of lipids within insulin responsive tissues, such as the liver and skeletal muscle and within the viscera. This lipid deposition pattern is also associated with infiltration of intra-abdominal tissues with cells of the immune system, inducing systemic, low-grade inflammation typically observed in insulin resistant obese children and adolescents. Several clues derived from a careful history and physical examination, along with a basic laboratory workup, provide clues in regards to risk stratification in obese children.

Urinary Excretion of Sodium, Nitrogen, and Sugar Amounts Are Valid Biomarkers of Dietary Sodium, Protein, and High Sugar Intake in Nonobese Adolescents

Background: Objective indicators of dietary intake (e.g., biomarkers) are needed to overcome the limitations of self-reported dietary intake assessment methods in adolescents. To our knowledge, no controlled feeding studies to date have evaluated the validity of urinary sodium, nitrogen, or sugar excretion as dietary biomarkers in adolescents.Objective: This investigation aimed to evaluate the validity of urinary sodium, nitrogen, and total sugars (TS) excretion as biomarkers for sodium, protein, and added sugars (AS) intake in nonobese adolescents.Methods: In a crossover controlled feeding study design, 33 adolescents [12-18 y of age, 47 ± 25th percentile (mean ± SD) of body mass index (BMI; in kg/m²) for age] consumed 5% AS [low added sugars (LAS)] and 25% AS [high added sugars (HAS)] isocaloric, macronutrient-matched (55% carbohydrate, 30% fat, and 15% protein) diets for 7 d each, in a randomly assigned order, with a 4-wk washout period between diets. On the final 2 d of each diet period, 24-h urine samples were collected. Thirty-two adolescents completed all measurements (97% retention).Results: Urinary sodium was not different from the expected 90% recovery (mean ± SD: 88% ± 18%, P = 0.50). Urinary nitrogen was correlated with protein intake (r = 0.69, P < 0.001), although it was below the 80% expected recovery (62% ± 7%, P < 0.001). Urinary TS values were correlated with AS intake during the HAS diet (r = 0.77, P < 0.001) and had a higher R² value of 0.28 than did AS intake (R² = 0.36). TS excretion differed between LAS (0.226 ± 0.09 mg/d) and HAS (0.365 ± 0.16 mg/d) feeding periods (P < 0.001).Conclusions: Urinary sodium appears to be a valid biomarker for sodium intake in nonobese adolescents. Urinary nitrogen is associated with protein intake, but nitrogen excretion rates were less than previously reported for adults, possibly owing to adolescent growth rates. TS excretion reflects AS at 25% AS intake and was responsive to the change in AS intake. Thus, urinary biomarkers are promising objective indicators of dietary intake in adolescents, although larger-scale feeding trials are needed to confirm these findings. This trial was registered at clinicaltrials.gov as NCT02455388.

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.

Impact of dietary intake, lifestyle and biochemical factors on metabolic health in obese adolescents

BACKGROUND AND AIMS

Obesity devoid of metabolic abnormalities is known as metabolically healthy obesity (MHO). The aim of the study was to examine determinants of MHO during adolescence.

METHODS AND RESULTS

From among 710 obese adolescents, 43 girls and 57 boys were classified as metabolically unhealthy (abdominal obesity and ≥2 risk components of metabolic syndrome). MHO (absence of any cardiometabolic risk factor) was found in 211 girls and 131 boys (regardless of waist circumference) and in 33 girls and 27 boys (without abdominal obesity). Laboratory and anthropometric parameters, dietary records and various lifestyle factors were compared between MHO vs. those unhealthy. The prevalence of MHO regardless of waist circumference was higher in girls than in boys (53.1 vs. 41.9%) but comparable when abdominal obesity was excluded (8.3 vs. 8.6%). Anthropometric variables, levels of gamma-glutamyl transferase, total and low-density lipoprotein cholesterol in both genders, hs-C-reactive protein in girls and alanine aminotransferase in boys differentiated the two metabolic phenotypes. Uric acid was related to metabolic health only in the analysis of MHO without abdominal obesity. Total hours of sleep, bedtime, time of the last daily meal, regular meal consumption and protein intake in boys and screen time, the score of disinhibition and diet composition in girls were found to impact cardiometabolic health.

CONCLUSIONS

In obese adolescents, metabolic health was related to anthropometric and biochemical parameters and only weak associations were found with most of the lifestyle factors studied. Uric acid concentration associated with metabolic health when abdominal obesity was excluded.

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.