Comparing BMI with skinfolds to estimate age at adiposity rebound and its associations with cardio-metabolic risk markers in adolescence

Adiposity rebound and body mass index in Japanese patients with congenital hypothyroidism

The long-term prognosis of congenital hypothyroidism (CH) has become apparent since the introduction of newborn screening programs; however, the risk of obesity in patients with CH remains unclear. Early adiposity rebound (AR) is one of the predictors of obesity in adults. This study evaluated AR and the adolescent body mass index (BMI) in Japanese patients with CH. We longitudinally collected anthropometric measurements from 288 patients aged 1-10 yr and plotted their BMI curves to determine the age at onset of AR. We also evaluated the effects of thyroid function, presence of distal femoral epiphysis (DFE) ossification, and disease type on AR age and adolescent BMI. The mean AR ages were determined to be 5.5 ± 1.4 yr in boys and 5.9 ± 1.5 yr in girls. There were no significant differences in AR age or adolescent BMI according to thyroid-stimulating hormone or free T4 levels before treatment initiation or according to disease type. However, at the last visit, more than half of the boys without DFE ossification had higher BMI SD scores than those with DFE ossification. These findings raise the possibility that severe prolonged fetal hypothyroidism may have a lasting influence after birth despite early treatment initiation.

Impact of age on cardiometabolic health in children at adiposity rebound: the role of genetic mechanisms

BACKGROUND

Identifying effective predictors early in life is crucial to enable timely prevention and intervention to improve cardiometabolic health outcomes. Adiposity rebound (AR) is an important period in early life, with earlier AR increasing the risk of cardiometabolic abnormalities. However, the role and mechanism of genetic factors in this association are unclear. Therefore, this study reviews the potential genetic mechanisms influencing the age at AR, as well as the genetic mechanisms linking earlier AR with cardiometabolic abnormalities.

DATA SOURCES

A comprehensive literature search was conducted in PubMed and China National Knowledge Infrastructure databases using a combination of medical subject headings terms and related keywords, including "adiposity rebound", "cardiometabolic", "obesity", "BMI trajectory", "diabetes mellitus", "dyslipidemias", "hypertension", "metabolic syndrome", "genetics", and "epigenetic". Citation tracking was performed as a supplementary search strategy. All potentially relevant articles were subsequently subjected to full-text evaluation for eligibility assessment.

RESULTS

Polymorphisms in the DMRT1, FTO, LEPR, and TFAP2B genes, along with obesity susceptibility, can influence the age at AR. Single-nucleotide polymorphisms associated with the age at AR are enriched in the insulin-like growth factor 1 (IGF-1) signaling pathway, which can be modulated by the LEPR and TFAP2B genes. Shared genetic mechanisms between cardiometabolic abnormalities and the age at AR are influenced by obesity-related genetic variants. These variants regulate the growth hormone (GH)/IGF-1 axis, advancing AR and leading to cardiometabolic abnormalities. Earlier AR alters adiponectin and leptin levels, further activating the GH/IGF-1 axis and creating a vicious cycle. Long-term breastfeeding can counteract the adverse effects of obesity-related genetic susceptibility on AR timing, thereby reducing the genetic risk of cardiometabolic abnormalities.

CONCLUSIONS

Our results support earlier AR as a marker for identifying cardiometabolic risk and screening high-risk populations at the genetic level.

Primary Validation of the Submandibular Skinfold as an Anthropometric Measurement of Cardiometabolic Risk in People with Intellectual Disabilities

The accumulation of body fat is an important cardiometabolic risk factor; however, there is no consensus about which measure is more reliable for the assessment of cardiometabolic risk in people with intellectual disabilities. The aim of the present study was to primarily validate the submandibular skinfold as an anthropometric measurement of cardiometabolic risk in children, adolescents, and adults with intellectual disabilities, using a cross-sectional study made up of 131 people (67.2% men) with mild and moderate intellectual disability. The cardiometabolic risk indicators used were: body mass index (kg/m2), neck circumference (cm), waist circumference (cm), calf circumference (cm) and waist-to-height ratio. Moderate correlations were demonstrated between the submandibular skinfold measure and the anthropometric measurements analyzed in the three age categories, showing the highest correlation (r = 0.70) between the submandibular skinfold and BMI in the adolescent group and waist-to-height ratio in adults. The implementation of the submandibular skinfold measurement is suggested as an easy, fast, and minimally invasive anthropometric measurement as part of the physical and nutritional evaluation for the assessment of cardiometabolic risk in people with intellectual disabilities.

Why do humans undergo an adiposity rebound? Exploring links with the energetic costs of brain development in childhood using MRI-based 4D measures of total cerebral blood flow

Background

Individuals typically show a childhood nadir in adiposity termed the adiposity rebound (AR). The AR serves as an early predictor of obesity risk, with early rebounders often at increased risk; however, it is unclear why this phenomenon occurs, which could impede understandings of weight gain trajectories. The brain’s energy requirements account for a lifetime peak of 66% of the body’s resting metabolic expenditure during childhood, around the age of the AR, and relates inversely to weight gain, pointing to a potential energy trade-off between brain development and adiposity. However, no study has compared developmental trajectories of brain metabolism and adiposity in the same individuals, which would allow a preliminary test of a brain-AR link.

Methods

We used cubic splines and generalized additive models to compare age trajectories of previously collected MRI-based 4D flow measures of total cerebral blood flow (TCBF), a proxy for cerebral energy use, to the body mass index (BMI) in a cross-sectional sample of 82 healthy individuals (0–60 years). We restricted our AR analysis to pre-pubertal individuals (0–12 years, n = 42), predicting that peak TCBF would occur slightly after the BMI nadir, consistent with evidence that lowest BMI typically precedes the nadir in adiposity.

Results

TCBF and the BMI showed inverse trajectories throughout childhood, while the estimated age at peak TCBF (5.6 years) was close but slightly later than the estimated age of the BMI nadir (4.9 years).

Conclusions

The timing of peak TCBF in this sample points to a likely concordance between peak brain energetics and the nadir in adiposity. Inverse age trajectories between TCBF and BMI support the hypothesis that brain metabolism is a potentially important influence on early life adiposity. These findings also suggest that experiences influencing the pattern of childhood brain energy use could be important predictors of body composition trajectories.

A Mini-Review of Pediatric Anthropometrics as Predictors of Future Insulin Resistance

The impact of rising rates of childhood obesity is far reaching. Metabolic syndrome in children is increasing, yet for most children the consequences of excess adiposity will manifest in adulthood. Excess early fat accrual is a risk factor for future insulin resistance. However, certain types of fat and patterns of fat distribution are more relevant than others to metabolic risk. Therefore, adiposity measures are important. The link between childhood obesity and future insulin resistance was initially established with body mass index (BMI), but BMI is an in imperfect measure of adiposity. It is worthwhile to evaluate other anthropometrics as they may more accurately capture metabolic risk. While measures such as waist to height ratio are established as superior screening measures in adulthood - the findings are not as robust in pediatrics. Emerging evidence suggests that alternative anthropometrics may be slightly superior to BMI in identifying those youth most at risk of developing insulin resistance, but the clinical significance of that superiority appears limited. Increasing study is needed in longitudinal and varied cohorts to identify which pediatric anthropometric best predicts adult insulin resistance. We review alternative anthropometrics as predictors of future insulin resistance and identify current gaps in knowledge and potential future directions of inquiry.

Blood lead level and nutritional status indicators in preadolescent Polish schoolchildren

BACKGROUND

Environmental pollutions with heavy metals may have toxic effects on human health and development. One of the most detrimental is lead exposure, which may disturb neurodevelopment and linear growth in children. However, data on the effect of lead exposure on nutritional and weight status in children are limited, thus this study aimed to assess the effect of blood lead (Pb) level on nutritional and weight status in preadolescent schoolchildren from the industrialized, mining region in southwestern Poland.

METHODS

Our study sample involved N = 709 schoolchildren (402 boys and 307 girls) in the preadolescent developmental period (7-11 years of age for boys and 7-10 years of age for girls). Anthropometric measurements were used to assess nutritional and weight status: body mass index (BMI), mid-upper arm circumference (MUAC) and skinfolds thicknesses (triceps, subscapular, abdominal and the sum of skinfolds). Blood Pb level was evaluated and divided into two groups: above (>3.7 μg/dL) and below median value (≤3.7 μg/dL).

RESULTS

Analysis of covariance (with children's age controlled as a covariate) revealed that children with blood Pb level above median value had significantly lower values of BMI, MUAC and all skinfolds (at least p < 0.01). However, this effect was significant only in boys, whereas in girls differences were non-significant (p > 0.05). The highest effect size of blood Pb level was noted for skinfolds thicknesses (partial η²: 0.015 for the sum of skinfolds).

CONCLUSIONS

Nutritional status in children with higher blood Pb level is significantly impaired in preadolescent boys, who appear to be more sensitive to this environmental factor. Our findings indicate a particular need for nutritional and environmental interventions among preadolescent children in regions with higher lead exposure.

Anthropometric Development in Children: Possible Changes in Body Mass, Basal Metabolic Rate and Inflammatory Status

(1) Background: Worldwide, public health policies focus on studying dietary patterns and the related anthropometric changes in children. Their aim is to improve the measures meant to reduce global malnutrition rates. Our goal was to study the main changes in the inflammatory status related to anthropometric changes and total daily energy intake. (2) Methods: We tested the study hypothesis by analyzing serum IL-6 and IL-8 levels, cholesterol and triglycerides values, as well as total proteins and creatinine levels, RMR, and food journals in a sample of 160 healthy subjects aged between 6 and 12 years old. (3) Results: IL-6 was correlated with the skinfold values. Changes in the skinfolds were significantly correlated with total proteins and triglycerides. Both weight for age and height for age were related to the skinfold values. Through the BMR measurements, peak carbohydrate metabolism changed significantly based upon IL-6 values, which were significantly correlated with the respiratory coefficient values. Based on the basal metabolic rate, an increased IL-8 ratio was related to the RQ value. (4) Conclusions: Skinfolds have been significantly correlated with IL-6 and IL-8 levels. With changes in body weight, we encountered differences in both serum cholesterol and serum triglycerides values, unlike total proteins and creatinine, which failed to change.

Adiposity rebound and cardiometabolic health in childhood: results from the Generation XXI birth cohort

BACKGROUND

We aimed to evaluate the association of adiposity rebound (AR) timing on cardiometabolic health in childhood.

METHODS

Participants were part of the Generation XXI birth cohort, enrolled in 2005/2006 in Porto. All measurements of the child's weight and height performed by health professionals as part of routine healthcare were collected. Individual body mass index (BMI) curves were fitted for 3372 children, using mixed-effects models with smooth spline functions for age and random effects. The AR was categorized into very early (<42 months), early (42-59 months), normal (60-83 months) and late (≥84 months). At age 10 years, cardiometabolic traits were assessed and age- and sex-specific z-scores were generated. Adjusted regression coefficients and 95% confidence intervals [β (95% CI)] were computed.

RESULTS

The mean age at AR was 61.9 months (standard deviations 15.7). Compared with children with normal AR, children with very early or early AR had higher z-scores for BMI [β = 0.40 (95% CI: 0.28; 0.53); β = 0.21 (95% CI: 0.12; 0.30)], waist circumference [β = 0.33 (95% CI: 0.23; 0.43); β = 0.18 (95% CI: 0.10; 0.25)], waist-height ratio [β = 0.34 (95% CI: 0.24; 0.44); β = 0.14 (95% CI: 0.07; 0.22)], fat mass index [β = 0.24 (95% CI: 0.15; 0.33); β = 0.14 (95% CI: 0.08; 0.21)], fat-free mass index [β = 0.25 (95% CI: 0.14; 0.35); β = 0.11 (95% CI: 0.03; 0.19)], systolic blood pressure [β = 0.10 (95% CI: 0.01; 0.20); β = 0.08 (95% CI: 0.01; 0.15)], insulin [β = 0.16 (95% CI: 0.04; 0.29); β = 0.10 (95% CI: 0.01; 0.19)], HOMA-IR [β = 0.17 (95% CI: 0.04; 0.29); β = 0.10 (95% CI: 0.03; 0.19)] and C-reactive protein [β = 0.14 (95% CI: 0.02; 0.26); β = 0.10 (95% CI: 0.01; 0.19)]. Children with very early AR also had worse levels of diastolic blood pressure [β = 0.09 (95% CI: 0.02; 0.16)], triglycerides [β = 0.21 (95% CI: 0.08; 0.34)] and high-density lipoprotein cholesterol [β=-0.18 (95% CI: -0.31; -0.04)]. When analysed continuously, each additional month of age at the AR was associated with healthier cardiometabolic traits.

CONCLUSION

The earlier the AR, the worse the cardiometabolic health in late childhood, which was consistently shown across a wide range of outcomes and in the categorical and continuous approach.

Pre-Birth and Early-Life Factors Associated With the Timing of Adiposity Peak and Rebound: A Large Population-Based Longitudinal Study

Background: The late occurrence of adiposity peak (AP) and the early occurrence of adiposity rebound (AR) are considered the earliest indicators for obesity and its related health conditions later in life. However, there is still limited information for their upstream factors. Therefore, in this study, we aimed to identify the parental and child factors associated with the timing of AP and AR in the early stage of life. Methods: This is a population-based longitudinal study conducted in Shanghai, China. The BMI data of children born between September 2010 and October 2013 were followed from birth to 80 months. Subject-specific body mass index trajectories were fitted by non-linear mixed-effect models with natural cubic spline functions, and the individual's age at AP and AR was estimated. The generalized linear regression models were applied to identify the upstream factors of late occurrence of AP and early occurrence AR. Results: For 7,292 children with estimated AP, boys were less likely to have a late AP [adjusted risk ratio (RR) = 0.83, 95% confidence interval (CI): 0.77-0.90, p < 0.001], but preterm born children had a higher risk of a late AP (adjusted RR = 1.25, 95% CI: 1.07-1.47, p < 0.01). For 10,985 children with estimated AR, children with breastfeeding longer than 4 months were less likely to have an early AR (adjusted RR = 0.80, 95% CI: 0.73-0.87, p < 0.001), but children who were born to advanced-age mothers and who were born small for gestational age had a higher risk of having an early AR (adjusted RR = 1.21, 95% CI: 1.07-1.36, p < 0.01; adjusted RR = 1.20, 95% CI: 1.04-1.39, p = 0.01). Conclusions: Modifiable pre-birth or early-life factors associated with the timing of AP or AR were found. Our findings may help develop prevention and intervention strategies at the earliest stage of life to control later obesity and the health conditions and diseases linked to it.

Gestational perfluoroalkyl substance exposure and body mass index trajectories over the first 12 years of life

BACKGROUND/OBJECTIVES

Gestational exposure to perfluoroalkyl substances (PFAS), a ubiquitous class of persistent endocrine disrupting chemicals, is associated with increased risk of obesity and cardiometabolic disease. However, it is unclear if gestational PFAS exposure is associated with adiposity trajectories related to adult obesity and cardiometabolic health.

SUBJECTS/METHODS

We measured perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononaoic acid, and perfluorohexanesulfonic acid (PFHxS) concentrations in maternal serum collected between 16 weeks gestation and delivery in a cohort of 345 mother-child pairs in Cincinnati, OH (enrolled 2003-06). From age 4 weeks to 12 years, we measured weight and length or height up to eight times and calculated child body mass index (BMI) (1865 repeated measures). Using covariate-adjusted linear mixed models and splines to account for repeated BMI measures and nonlinear BMI patterns, respectively, we estimated the age/magnitude of infancy BMI zenith (~1 year) and childhood BMI nadir (~5 years), BMI accrual from 8 to 12 years, and BMI at age 12 years by PFAS terciles.

RESULTS

BMI trajectories varied by PFOA concentrations (age × PFOA interaction p value = 0.03). Children born to women with higher PFOA concentrations had lower infancy and early childhood BMI, earlier BMI nadir, accelerating BMI gains in mid-childhood and adolescence, and higher BMI at age 12 years. Some of these associations were non-monotonic. PFOS and PFHxS were not associated with alterations in BMI trajectories, but were monotonically associated with lower BMI across infancy, childhood, and adolescence. Compared to children in the first PFOS tercile, those in the second (β: -0.83; 95% confidence interval (CI): -2.11, 0.51 kg/m2), and third (β: -1.41; 95% CI: -2.65, -0.14 kg/m2) had lower BMI at age 12 years.

CONCLUSIONS

These results suggest that gestational PFOA exposure may be associated with BMI trajectories related to adult obesity and cardiometabolic disease, while PFOS and PFHxS exposure is associated with lower BMI in the first 12 years of life.

Comparison between type A and type B early adiposity rebound in predicting overweight and obesity in children: a longitudinal study

Early adiposity rebound (EAR) predicts paediatric overweight/obesity, but current approaches do not consider both the starting point of EAR and the BMI trajectory. We compared the clinical characteristics at birth, age 3-5 and 6-8 years of children, according to the EAR and to its type (type A/type B-EAR). We assessed the children's odds of being classified as overweight/obese at age 6-8 years, according to the type of EAR as defined at age 3-5 years. As part of this two-wave observational study, 1055 children were recruited and examined at age 3-5 years. Antenatal and postnatal information was collected through interviews with parents, and weight and height from the health records. Type A and type B-EAR were defined in wave 1 according to the BMI nadir and the variation of BMI z-score between the starting point of the adiposity rebound and the last point on the curve. At 6-8 years (wave 2), 867 children were followed up; 426 (40·4 %) children demonstrated EAR. Among them, 172 had type A-EAR, higher rates of parental obesity (P < 0·05) and greater birth weight compared with other children (P < 0·001). Odds for overweight/obesity at 6-8 years, when adjusting for antenatal and postnatal factors, was 21·35 (95 % CI 10·94, 41·66) in type A-EAR children and not significant in type B-EAR children (OR 1·76; 95 % CI 0·84, 3·68) compared with children without EAR. Classification of EAR into two subtypes provides physicians with a reliable approach to identify children at risk for overweight/obesity before the age of 5 years.

Anthropometric indices for predicting cardiovascular risk factors: Ellisras longitudinal study

OBJECTIVES

The aim of the study was to determine which anthropometric indices can best predict the presence of common cardiovascular risk factors among young adults in the rural village of Ellisras in the Limpopo Province, South Africa.

METHODS

A total of 624 young adults (306 males and 318 females) aged 18 to 29 years took part in this cross-sectional study. Anthropometrics were measured according to the standard procedures. Blood pressure and blood parameters were collected and measured. The stepwise logistic regression was used to determine anthropometric indices that can predict the presence of common cardiovascular risk factors and a receiver-operating characteristic (ROC) curve was plotted to assess discrimination abilities of anthropometric indices for cardiovascular risk factors.

RESULTS

The waist-to-hip ratio (WHR) in multivariable adjusted models was not found to be associated with cardiovascular risk factors compared to body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR). The area below the ROC curve for the abovementioned indices was above 0.62.

CONCLUSIONS

The central obesity indices, WC and WHtR, are better predictors of dyslipedemia and hypercholesterolemia, whereas BMI was a better predictor of hypertension among young adults living in rural South Africa between the ages of 18 and 29 years.