What use is the BMI?

Ten metabolites-based algorithm predicts the future development of type 2 diabetes in Chinese

INTRODUCTION

Type 2 diabetes (T2D) is a heterogeneous metabolic disease with large variations in the relative contributions of insulin resistance and β-cell dysfunction across different glucose tolerance subgroups and ethnicities. A more precise yet feasible approach to categorize risk preceding T2D onset is urgently needed. This study aimed to identify potential metabolic biomarkers that could contribute to the development of T2D and investigate whether their impact on T2D is mediated through insulin resistance and β-cell dysfunction.

METHODS

A non-targeted metabolomic analysis was performed in plasma samples of 196 incident T2D cases and 196 age- and sex-matched non-T2D controls recruited from a long-term prospective Chinese community-based cohort with a follow-up period of ∼ 16 years.

RESULTS

Metabolic profiles revealed profound perturbation of metabolomes before T2D onset. Overall metabolic shifts were strongly associated with insulin resistance rather than β-cell dysfunction. In addition, 188 out of the 578 annotated metabolites were associated with insulin resistance. Bi-directional mediation analysis revealed putative causal relationships among the metabolites, insulin resistance and T2D risk. We built a machine-learning based prediction model, integrating the conventional clinical risk factors (age, BMI, TyG index and 2hG) and 10 metabolites (acetyl-tryptophan, kynurenine, γ-glutamyl-phenylalanine, DG(18:2/22:6), DG(38:7), LPI(18:2), LPC(P-16:0), LPC(P-18:1), LPC(P-20:0) and LPE(P-20:0)) (AUROC = 0.894, 5.6% improvement comparing to the conventional clinical risk model), that successfully predicts the development of T2D.

CONCLUSIONS

Our findings support the notion that the metabolic changes resulting from insulin resistance, rather than β-cell dysfunction, are the primary drivers of T2D in Chinese adults. Metabolomes as a valuable phenotype hold potential clinical utility in the prediction of T2D.

Changes in the Average Body Mass Index of Fifth- and Sixth-Grade Korean Elementary School Students: The Role of Physical Education in Student Health

This study aimed to emphasize the importance of physical education in maintaining sufficient physical activity by examining the average BMI of fifth- and sixth-grade elementary school students in Korea over multiple years. This study investigated changes in the average BMI of fifth- and sixth-grade elementary school students in Korea. It provided foundational data to suggest the role of physical education in student health and set future directions. The 2019-2021 Physical Activity Promotion System (PAPS) of the Korean Ministry of Education was used. Data corresponding to fifth- and sixth-grade students (124,693 from 2019, 126,226 from 2020, and 117,809 from 2021) in 1208 elementary schools in Korea were collected. Repeated measures ANOVA was conducted for the data analysis. The study findings are as follows: First, the average BMI of fifth- and sixth-grade elementary school students in Korea increased significantly in 2021 compared with 2019 and 2020. Second, changes in the yearly average BMI showed a significant difference depending on gender and grade. Obesity among fifth- and sixth-grade elementary school students in Korea increased steadily during 2019-2021, which may be due to a decrease in students' physical activity. Male students showed a steeper increase regardless of grade. During the study period, limited physical activity at school increased obesity rates. Physical education must play a role in students' health in preparation for future changes.

Childhood Obesity: An Updated Review

BACKGROUND

Childhood obesity is an important and serious public health problem worldwide.

OBJECTIVE

This article aims to familiarize physicians with the evaluation, management, and prevention of childhood.

METHODS

A PubMed search was conducted in May, 2021, in Clinical Queries using the key terms "obesity" OR "obese". The search included clinical trials, randomized controlled trials, case-control studies, cohort studies, meta-analyses, observational studies, clinical guidelines, case reports, case series, and reviews. The search was restricted to English literature and children. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Most obese children have exogenous obesity characterized by a growth rate for height above the 50th percentile, normal intelligence, normal genitalia, and lack of historical or physical evidence of an endocrine abnormality or a congenital syndrome. Obese children are at risk for dyslipidemia, hypertension, diabetes mellitus, non-alcoholic fatty liver disease, obstructive sleep apnea, psychosocial disturbances, impaired quality of life, and shorter life expectancy. The multitude of serious comorbidities necessitates effective treatment modalities. Dietary modification, therapeutic exercise, and behavioral modification are the fundamentals of treatment. Pharmacotherapy and/or bariatric surgery should be considered for obese individuals who do not respond to the above measures and suffer from a serious comorbid condition.

CONCLUSION

Childhood obesity, once established, is often refractory to treatment. Most treatment programs lead to a brief period of weight loss, followed by rapid re-accumulation of the lost weight after the termination of therapy. As such, preventive activity is the key to solving the problem of childhood obesity. Childhood obesity can be prevented by promoting a healthy diet, regular physical activity, and lifestyle modification. Parents should be encouraged to get involved in school and community programs that improve their children's nutritional status and physical activity.

Pediatric Obesity: Complications and Current Day Management

Obesity affects approximately 1 in 5 youth globally and increases the risk of complications during adolescence and young adulthood, including type 2 diabetes, dyslipidemia, hypertension, non-alcoholic fatty liver disease, obstructive sleep apnea, and polycystic ovary syndrome. Children and adolescents with obesity frequently experience weight stigma and have an impaired quality of life, which may exacerbate weight gain. Pediatric obesity is typically defined using sex-, age-, and population-specific body mass index percentiles. Once identified, pediatric obesity should always be managed with lifestyle modification. However, adolescents with obesity may also benefit from anti-obesity medications (AOM), several of which have been approved for use in adolescents by the US Food and Drug Administration, including liraglutide, phentermine/topiramate, and semaglutide. For children with specific, rare monogenic obesity disorders, setmelanotide is available and may lead to significant weight loss. Metabolic and bariatric surgery may be used for the management of severe obesity in youth; though highly effective, it is limited to specialized centers and has had relatively low pediatric uptake. In this narrative review using pediatric-focused data from original research, reviews, clinical practice guidelines, governmental agencies, and pharmaceutical companies, we review obesity-related metabolic complications in youth and management strategies, including AOM and bariatric surgery.

Obesity as an independent risk factor for COVID-19 severity and mortality

BACKGROUND

Since December 2019, the world has struggled with the COVID-19 pandemic. Even after the introduction of various vaccines, this disease still takes a considerable toll. In order to improve the optimal allocation of resources and communication of prognosis, healthcare providers and patients need an accurate understanding of factors (such as obesity) that are associated with a higher risk of adverse outcomes from the COVID-19 infection.

OBJECTIVES

To evaluate obesity as an independent prognostic factor for COVID-19 severity and mortality among adult patients in whom infection with the COVID-19 virus is confirmed.

SEARCH METHODS

MEDLINE, Embase, two COVID-19 reference collections, and four Chinese biomedical databases were searched up to April 2021.

SELECTION CRITERIA

We included case-control, case-series, prospective and retrospective cohort studies, and secondary analyses of randomised controlled trials if they evaluated associations between obesity and COVID-19 adverse outcomes including mortality, mechanical ventilation, intensive care unit (ICU) admission, hospitalisation, severe COVID, and COVID pneumonia. Given our interest in ascertaining the independent association between obesity and these outcomes, we selected studies that adjusted for at least one factor other than obesity. Studies were evaluated for inclusion by two independent reviewers working in duplicate.  DATA COLLECTION AND ANALYSIS: Using standardised data extraction forms, we extracted relevant information from the included studies. When appropriate, we pooled the estimates of association across studies with the use of random-effects meta-analyses. The Quality in Prognostic Studies (QUIPS) tool provided the platform for assessing the risk of bias across each included study. In our main comparison, we conducted meta-analyses for each obesity class separately. We also meta-analysed unclassified obesity and obesity as a continuous variable (5 kg/m2 increase in BMI (body mass index)). We used the GRADE framework to rate our certainty in the importance of the association observed between obesity and each outcome. As obesity is closely associated with other comorbidities, we decided to prespecify the minimum adjustment set of variables including age, sex, diabetes, hypertension, and cardiovascular disease for subgroup analysis.  MAIN RESULTS: We identified 171 studies, 149 of which were included in meta-analyses.  As compared to 'normal' BMI (18.5 to 24.9 kg/m2) or patients without obesity, those with obesity classes I (BMI 30 to 35 kg/m2), and II (BMI 35 to 40 kg/m2) were not at increased odds for mortality (Class I: odds ratio [OR] 1.04, 95% confidence interval [CI] 0.94 to 1.16, high certainty (15 studies, 335,209 participants); Class II: OR 1.16, 95% CI 0.99 to 1.36, high certainty (11 studies, 317,925 participants)). However, those with class III obesity (BMI 40 kg/m2 and above) may be at increased odds for mortality (Class III: OR 1.67, 95% CI 1.39 to 2.00, low certainty, (19 studies, 354,967 participants)) compared to normal BMI or patients without obesity. For mechanical ventilation, we observed increasing odds with higher classes of obesity in comparison to normal BMI or patients without obesity (class I: OR 1.38, 95% CI 1.20 to 1.59, 10 studies, 187,895 participants, moderate certainty; class II: OR 1.67, 95% CI 1.42 to 1.96, 6 studies, 171,149 participants, high certainty; class III: OR 2.17, 95% CI 1.59 to 2.97, 12 studies, 174,520 participants, high certainty). However, we did not observe a dose-response relationship across increasing obesity classifications for ICU admission and hospitalisation.

AUTHORS' CONCLUSIONS

Our findings suggest that obesity is an important independent prognostic factor in the setting of COVID-19. Consideration of obesity may inform the optimal management and allocation of limited resources in the care of COVID-19 patients.

Swimmers with Down Syndrome Are Healthier and Physically Fit than Their Untrained Peers

While there are positive benefits from physical activity participation for individuals with Down syndrome, little is known about the effects of swimming training. The aim of this study was to compare the body composition and physical fitness profile of competitive swimmers and moderately active (untrained) individuals with Down syndrome. The Eurofit Special test was applied to a group of competitive swimmers (n = 18) and a group of untrained individuals (n = 19), all with Down syndrome. In addition, measurements were taken to determine body composition characteristics. The results showed differences between swimmers and untrained subjects in height, sum of the four skinfolds, body fat %, fat mass index and all items of the Eurofit Special test. Swimmers with Down syndrome exhibited physical fitness levels near to the Eurofit standards, although lower fitness levels were attained by these persons when compared to athletes with intellectual disability. It can be concluded that the practice of competitive swimming seems to counteract the tendency for obesity in persons with Down syndrome and also helps to increase strength, speed and balance.

Association between hemoglobin glycation index and non-alcoholic fatty liver disease

OBJECTIVE

The hemoglobin glycation index (HGI) reflects biological variability in hemoglobin A1c. Even so, studies on the relationship between HGI and non-alcoholic fatty liver disease (NAFLD) are limited. Therefore, this study aimed to explore the relationship between HGI and NAFLD. In addition, the study also aimed to provide new methods to identify patients with a high risk for the development of NAFLD.

METHODS

This was a retrospective study based on physical examination data from Japan. Patients were divided into quartiles (Q1-Q4) according to their HGI level; the lowest quartile (Q1) was used as the reference group. Patents were also classified into two subgroups based on the presence or absence of NAFLD. Baseline characteristics between the groups were compared. Multivariate logistic regression analysis was used to investigate the association between the HGI and NAFLD. A mediation analysis examined the mediation relationship between HGI and NAFLD. Subgroup analyses were performed to the reliability of the results.

RESULTS

A total of 14280 patients were eligible for inclusion in this study; 2515 had NAFLD. Patients in the NAFLD group had higher levels of HGI than patients in the non-NAFLD group. Increases in HGI correlated with an increased risk of NAFLD. After adjusting for confounding factors, the multivariate logistic regression analysis revealed that HGI was positively related to the prevalence of NAFLD. In addition, mediation analysis showed that body mass index (BMI) partly mediated the indirect impact of HGI on NAFLD preference. Subgroup analyses were performed according to age, sex, smoking status, and waist circumference. Our results indicated that HGI significantly correlated with NAFLD in patients with one of the following factors: age ≤60 years, BMI >28 kg/m², female sex, a history of smoking, and abdominal obesity.

CONCLUSIONS

HGI was an independent risk factor for NAFLD, and BMI partly mediated the association between HGI and NAFLD.

The Association of Body Mass Index and Fat Mass with Health-Related Physical Fitness among Chinese Schoolchildren: A Study Using a Predictive Model

Body fat mass (FM) has advantages over body mass index (BMI) in terms of accuracy of fitness assessment and health monitoring. However, the relationship between FM and fitness in Chinese children has not yet been well studied. This study aimed to investigate the relationship between health-related physical fitness, BMI, and FM, which was estimated using a predictive model among elementary schoolchildren in China. This cross-sectional study included 2677 participants (boys, 53.6%; girls, 46.4%) who underwent anthropometric measurements (height, weight, BMI, and FM) and five health-related fitness tests: 50-m sprint (speed), sit and reach (flexibility), timed rope-skipping (coordination), timed sit-ups (muscular endurance), and 50-m × 8 shuttle run (endurance). In boys, BMI showed a positive correlation with speed (p < 0.001) and endurance (p < 0.006) tests and a negative correlation with flexibility (p < 0.004) and coordination (p < 0.001) tests. In girls, a positive correlation between speed (p < 0.001) and endurance (p < 0.036) tests was observed. Both BMI and FM (estimated using the predictive model) were strongly associated with the health-related physical fitness of elementary schoolchildren. Our findings indicate that health-related physical fitness was similarly affected by FM and BMI. As FM can be quantified, it could therefore be used to develop strategies and intervention programs for the prevention and management of obesity in children.

Association between prepregnancy and newborn body mass index

Abstract Objectives: to investigate the association between prepregnancy body mass index (BMI) and newborns’ (NB) BMI. Methods: cohort study with 1,365 pregnant women and their newborns from the BRISA survey (Brazilian Ribeirão Preto and São Luís Birth Cohort Studies) in São Luís-MA. Prepregnancy BMI was self-reported, and newborns’ BMI was estimated using the weight and length measured at birth. A directed acyclic graph (DAG) was developed to identify the adjustment variables. The association between the prepregnancy BMI and newborns’ BMI were analyzed using multiple linear and Poisson regression with robust variance estimation. Results: NBs had 13.4±1.7kg/m2 average BMI at birth. In the linear analysis, we observed that as the prepregnancy BMI increases, the NBs BMI also increases (ß=0.07; CI95%=0.05–0.09;p<0.001). Newborns of mothers with prepregnancy overweight were 3.58 times more likely to be overweight. Conclusion: prepregnancy BMI can affect newborn’s BMI early. Thus, women planning to become pregnant should consider conducting nutritional planning to maintain or obtain a healthy weight to minimize the risk of overweight for the newborn.

Relation between Demographics and Physical Activity among Preschoolers Attending Head Start

Limited empirical evidence is available about preschoolers' sedentary behavior (SB) and physical activity (PA) patterns in Head Start programs, we explored (a) preschoolers' SB and PA patterns (ranging from SB to light-moderate-vigorous physical activity [LMVPA]) and (b) their relationships with sociodemographic factors, weight status, and motor development. Participants included 216 preschoolers (M age = 4.32 ± 0.63; girls 56.5%) from six Head Start centers in an urban area in the southwestern region of the United States, assessing Actical® activity monitor-based PA, weight status, and motor development. The findings revealed preschoolers who were female, Hispanic/Latinx, with an at risk weight level, and/or in the below average motor development group tended to engage in less MVPA/LMVPA and also had higher SB patterns while participating in the Head Start program (p < 0.05-0.001, d ranged from 0.23 to 0.62). Head Start stakeholders (e.g., policymakers, leaders, curriculum coordinators, health professionals, and teachers) need to acknowledge the PA and health disparities, and intervene in underserved preschoolers' health-promoting behaviors.

External validation of a prediction model for estimating fat mass in children and adolescents in 19 countries: individual participant data meta-analysis

OBJECTIVE

To evaluate the performance of a UK based prediction model for estimating fat-free mass (and indirectly fat mass) in children and adolescents in non-UK settings.

DESIGN

Individual participant data meta-analysis.

SETTING

19 countries.

PARTICIPANTS

5693 children and adolescents (49.7% boys) aged 4 to 15 years with complete data on the predictors included in the UK based model (weight, height, age, sex, and ethnicity) and on the independently assessed outcome measure (fat-free mass determined by deuterium dilution assessment).

MAIN OUTCOME MEASURES

The outcome of the UK based prediction model was natural log transformed fat-free mass (lnFFM). Predictive performance statistics of R², calibration slope, calibration-in-the-large, and root mean square error were assessed in each of the 19 countries and then pooled through random effects meta-analysis. Calibration plots were also derived for each country, including flexible calibration curves.

RESULTS

The model showed good predictive ability in non-UK populations of children and adolescents, providing R² values of >75% in all countries and >90% in 11 of the 19 countries, and with good calibration (ie, agreement) of observed and predicted values. Root mean square error values (on fat-free mass scale) were <4 kg in 17 of the 19 settings. Pooled values (95% confidence intervals) of R², calibration slope, and calibration-in-the-large were 88.7% (85.9% to 91.4%), 0.98 (0.97 to 1.00), and 0.01 (-0.02 to 0.04), respectively. Heterogeneity was evident in the R² and calibration-in-the-large values across settings, but not in the calibration slope. Model performance did not vary markedly between boys and girls, age, ethnicity, and national income groups. To further improve the accuracy of the predictions, the model equation was recalibrated for the intercept in each setting so that country specific equations are available for future use.

CONCLUSION

The UK based prediction model, which is based on readily available measures, provides predictions of childhood fat-free mass, and hence fat mass, in a range of non-UK settings that explain a large proportion of the variability in observed fat-free mass, and exhibit good calibration performance, especially after recalibration of the intercept for each population. The model demonstrates good generalisability in both low-middle income and high income populations of healthy children and adolescents aged 4-15 years.

Improving the accuracy of self-reported height and weight in surveys: an experimental study

Background

Many studies rely on self-reported height and weight. While a substantial body of literature exists on misreporting of height and weight, little exists on improving accuracy. The aim of this study was to determine, using an experimental design and a comparative approach, whether the accuracy of self-reported height and weight data can be increased by improving how these questions are asked in surveys, drawing on the relevant evidence from the psychology and survey research literatures.

Methods

Two surveys from two separate studies were used to test our hypotheses (Science Survey, n = 1,200; Eating Behaviours Survey, n = 200). Participants were randomly assigned to one of six conditions, four of which were designed to improve the accuracy of the self-reported height and weight data (“preamble”), and two of which served as the control conditions ( “no preamble”). Four hypotheses were tested: (H1) survey participants read a preamble prior to being asked their height and weight will report lower heights and higher weights than those not read a preamble; (H2) the impact of question-wording (i.e., preamble vs. no preamble) on self-reported weight will be greater for participants with higher BMIs; (H3) the impact of question-wording on height will be greater for older participants; (H4) either version of the weight question – standard or “weight-specific”—may result in participants reporting more accurate self-reported weight. One-way MANOVA was conducted to test Hypothesis 1; two-way analysis of variance were conducted to test Hypothesis 2; moderation analysis was used to test Hypothesis 3; independent samples t-test was conducted to test Hypothesis 4.

Results

None of the hypotheses was supported.

Conclusions

This paper provides an important starting point from which to inform further work exploring how question wording can improve self-reported measurement of height and weight. Future research should explore how question preambles may or may not operationalise hypothesised underlying mechanisms, the sensitivity or intrusiveness of height and weight questions, individual beliefs about one’s height and weight, and survey context.

The Impact of Obesity on the Fitness Performance of School-Aged Children Living in Rural Areas-The West Attica Project

This study aimed to investigate the relationship of body mass index (BMI) with muscle and cardiorespiratory fitness in children living within rural areas (regional unit of West Attica) in Greece. Participants included 399 students (187 boys, 212 girls), ages 8-12 years old, and were evaluated in physical performance tests. The point prevalence of overweight and obesity was 21.39% and 26.20% in boys, and 19.90% and 23.79% in girls. Significant differences were observed in all physical performance tests (handgrip, long jump, shuttle run, trunk flexors, and extensors endurance) between normal weight and obese participants. BMI was positively correlated with handgrip (r = 0.442-0.462, p < 0.001). There was a negative association with long jump (r = -0.206, p < 0.001), 20 m shuttle run (r = -0.394, p < 0.001), trunk flexors (r = -0.403, p < 0.001) and trunk extensors endurance (r = -0.280, p < 0.001). The regression analysis showed that 20-30% of the overall variation for physical performance assessments could be accounted for by BMI, age, and sex. With the exception of the long jump and the endurance of the trunk extensors, BMI alone may explain more than 10% of the outcome of most tests. This study highlights the determinant of BMI on muscle and cardiorespiratory fitness. The management of obesity should begin early in childhood to prevent adult chronic cardiovascular and metabolic diseases.

Sex differences in the detection of motor unit action potentials identified using high-density surface electromyography

Sex-related disparities in force production of humans have been widely observed. Previous literature has attributed differences in peripheral traits, such as muscle size, to explain these disparities. However, less is known about potential sex-related differences in central neuromuscular traits and many comparable studies, not exploring sex-related differences, exhibit a selection-bias in the recruitment of subjects making the generalization of their findings difficult. Utilizing high-density electromyography arrays and motor unit (MU) decomposition, the aim of the current study is to compare MU yield and discharge properties of the tibialis anterior between male and female humans. Twenty-four subjects (10 females) performed two submaximal (20%) isometric dorsiflexion contractions. On average, males yielded nearly twice the amount of MUs as females. Further, females had significantly higher MU discharge rate, lower MU action potential amplitude, and lower MU action potential frequency content than males despite similar levels of torque and MU discharge variability. These findings suggest differences in central neuromuscular control of force production between sexes; however, it is unclear how lower yield counts affect the accuracy of these results.

Children's Motivation Profiles in Sports and Physical Activities: A Latent Profile Analysis and Self-Determination Theory Approach

Using latent profile analysis and self-determination theory, the present study aimed to examine younger children's motivation profiles in sports and physical activities and the relations of those profiles to various predictors and achievement outcomes. A total of 1,116 German children from Grade 2 participated in this study. Latent-profile-analysis solutions based on five behavioral-regulation types covered in self-determination theory (i.e., intrinsic, identified, introjected, external, amotivation) were tested. Results favored a three-profile solution, showing three theoretically meaningful and distinct motivation profiles labeled "amotivated," "non-self-determined," and "self-determined." Older children and children with a lower physical self-concept were more likely to be members of the amotivated profile relative to the other profiles than younger children and children with a higher physical self-concept. Furthermore, children of the self-determined profile demonstrated the best physical performance in various motor-skills tests.

Prevalence of Overweight and Obesity in Children: Variation in Different Ethnicities, Age, and Sex in North Macedonia

Childhood obesity is assuredly one of the most important health challenges of the 21st century, particularly regarding long-term metabolic complications. In the last four decades, there has been a tenfold increase in childhood and adolescence obesity. This cross-sectional study aimed to show the prevalence of overweight and obesity compared by age, sex, and ethnicity in n=1034 healthy male and female children, aged 6-13 years in North Macedonia. Out of the total 1034 children included in the study, 589 (57.0%) were observed with normal weight, 202 (19.5%) children were obese, 140 (13.5%) children were overweight and, 103 (10.0%) children underweight. The study presents an insight that 33% of primary school children are at >85th percentile overweight; or at ≥95th percentile with increased weight due to obesity. The data show that boys have a higher prevalence of obesity and overweight with 37.1%, compared to girls with 29.1%. Also, all age groups demonstrate an exponential increase of the prevalence of overweight: in 6-7 years (5.8%); 8-9 years (12%); 10-11 years (15%); and, 12-13 years old with 19.5%. A jump of prevalence of overweight and obesity between the age groups of 6-7 years, and 8-9 years was observed (17.9% to 25.4% obese and 5.8% to 12.0% overweight). The onset of puberty may be the possible cause. According to the Global Atlas of Childhood Obesity, North Macedonia is graded with a risk index of 7/11; i.e. it is expected that in the next decade until 2030 the obesity rate will rise to 52.5% for children aged 5-19 years old. It is with utmost importance to emphasize that continuous monitoring of children's nutritional status and their risk of obesity is essential, as to further prevent obesity and overweight in the pediatric population.

Psychosocial and energetic factors on human female pubertal timing: a systematized review

Childhood psychosocial stressors have been proposed to favour fast life history strategies promoting earlier puberty in females. However, studies demonstrating this association often do not elucidate causal mechanisms, nor account for greater childhood energetic availability - also known to promote rapid growth and earlier puberty. To assess the extent to which such confounding has been considered, we conducted a systematized review to identify studies examining measures of both prepubertal growth (e.g. weight, height) and psychosocial stressors (e.g. adversity, father absence) in relation to female pubertal timing. A total of 1069 non-duplicated studies were identified across five databases. Twenty studies met selection criteria for critical review following independent screening of titles, abstracts and manuscripts. Within these studies, measures indicative of rapid childhood growth were more consistently associated with earlier pubertal timing than were measures of psychosocial stress. We discuss future research directions to investigate the impact of psychosocial stress on pubertal timing more robustly, including methodological and mechanistic considerations, and contextualization of findings by socioecological environments.

Improvement in the metabolic markers of prediabetic subjects due to the partial substitution of Taiken9 rice by RD43 rice in their daily diet: a randomized clinical trial

Although RD43 rice is characterized by high amounts of undigestible starch, its potential health benefits for prediabetic individuals remain unknown. Thus, the effect of regular consumption of RD43 rice on the glycemic response, body composition, and metabolic markers was investigated in a sample of 34 participants with prediabetes (aged from 32 to 68 years) who were randomly allocated to either the treatment or the control group. The first were required to consume RD43 rice (Glycemic Index [GI] = 78) containing 14.1 g of undigestible starch daily as a substitute for two meals per day while the second were given the Taiken9 rice (GI = 98) for 12 continuous weeks. The evaluations were performed at baseline, at the end of week 6 and 12, and at follow-up conducted two weeks after the intervention had ended. The results obtained at the week 12 assessment clearly showed a significant decrease in fasting plasma glucose, insulin, HbA1c, and HOMA-IR in the group that consumed RD43 rice. In addition, daily ingestion of RD43 rice markedly reduced body weight, Body Mass Index (BMI), total fat mass, and waist circumference at both week 6 and 12 compared with the baseline. When compared with the controls, the treatment group also exhibited a significant decrease in fasting plasma insulin and HOMA-IR at week 12. However, no significant inter- or intra-group differences in lipid profiles were detected. These findings suggest that RD43 rice could be a potential staple food with the capacity to improve glycemic control and body composition in prediabetic individuals.

Development and Validation of a Prediction Model for Infant Fat Mass

OBJECTIVES

To develop and validate a prediction model for fat mass in infants ≤12 kg using easily accessible measurements such as weight and length.

STUDY DESIGN

We used data from a pooled cohort of 359 infants age 1-24 months and weighing 3-12 kg from 3 studies across Southern California and New York City. The training data set (75% of the cohort) included 269 infants and the testing data set (25% of the cohort) included 90 infants age 1-24 months. Quantitative magnetic resonance was used as the standard measure for fat mass. We used multivariable linear regression analysis, with backwards selection of predictor variables and fractional polynomials for nonlinear relationships to predict infant fat mass (from which lean mass can be estimated by subtracting resulting estimates from total mass) in the training data set. We used 5-fold cross-validation to examine overfitting and generalizability of the model's predictive performance. Finally, we tested the adjusted model on the testing data set.

RESULTS

The final model included weight, length, sex, and age, and had high predictive ability for fat mass with good calibration of observed and predicted values in the training data set (optimism-adjusted R2: 92.1%). Performance on the test dataset showed promising generalizability (adjusted R2: 85.4%). The mean difference between observed and predicted values in the testing dataset was 0.015 kg (-0.043 to -0.072 kg; 0.7% of the mean).

CONCLUSIONS

Our model accurately predicted infant fat mass and could be used to improve the accuracy of assessments of infant body composition for effective early identification, surveillance, prevention, and management of obesity and future chronic disease risk.

Physical fitness and activities of daily living in primary ciliary dyskinesia: A retrospective study

BACKGROUND

Primary ciliary dyskinesia (PCD) is a rare, hereditary, autosomal recessive disorder characterized by recurrent upper and lower respiratory tract infections. This study aimed to compare pulmonary function, respiratory muscle strength, exercise capacity, physical fitness, and activities of daily living (ADLs) retrospectively between patients with PCD and healthy controls.

METHODS

Data from 20 patients with PCD and 20 matched, healthy counterparts recorded between July 2015 and January 2017 were analyzed. The data evaluated and recorded included pulmonary function using a portable spirometer, respiratory muscle strength (using a mouth pressure device, exercise capacity using the incremental shuttle walk test,), physical fitness (using the Munich Fitness Test), and ADLs (using the Glittre ADL test).

RESULTS

Pulmonary function, respiratory muscle strength, incremental shuttle walk test scores (all parameters), and total Munich Fitness Test scores were lower in the PCD group relative to controls (P < 0.05). The duration to complete the Glittre ADL test was higher in PCD patients than in healthy subjects (P < 0.05).

CONCLUSIONS

Pulmonary function, respiratory muscle strength, exercise capacity, physical fitness, and ADL were affected by PCD. Thus, pulmonary rehabilitation regimens should be tailored according to these impacts.

Peripheral Quantitative Computed Tomography Derived Muscle Density Is Associated With Physical Performance in Older Adults

PURPOSE

The assessment of body composition is an integral part in diagnosing sarcopenia. The purpose of this study was to determine the relationships between peripheral quantitative computed tomography (pQCT)-derived measures of body composition and measures of physical performance in older adults.

METHODS

Muscle density, muscle area, and fat area of 168 patients aged 65 years and older (76.3±6.5) were measured with pQCT at the distal forearm additionally to clinical assessment consisting of medical history, physical examination and physical assessment including hand grip strength, gait speed and chair rise tests. Regression analyses assessed associations between patients' physical performance and pQCT derived data.

RESULTS

Among the three pQCT parameters, especially muscle density was significantly correlated with all of the three measures of physical performance even after adjusting for sex, age, BMI, vitamin D serum level and the level of physical activity. The same analysis for muscle area achieved significance level only for handgrip strength but not for gait speed nor for chair rise time. Fat area was significantly correlated only with gait speed after adjusting for sex and age. The association of muscle density with physical performance held up in an additional subanalysis stratified by body mass index.

CONCLUSION

Muscle density, a proxy for muscle fat infiltration, seems to be better than muscle area or fat area at assessing muscle quality and physical performance in older adults. This association seems to be independent of the body mass index.

An assessment of anthropometric indices and its association with NCDs among the older adults of India: evidence from LASI Wave-1

BACKGROUND

The purpose of this study is to assess the status of physical body indices such as body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR) among the older adults aged 45 and above in India. Further, to explore the association of anthropometric indices with various non-communicable morbidities.

METHODS

The study uses secondary data of the Longitudinal Ageing Survey's first wave in India (2017-18). The national representative sample for older adults 45 and above (65,662) considered for the analysis. The prevalence of the non-communicable diseases (NCDs) included in the study is based on the self-reporting of the participants. Diseases included are among the top ten causes of death, such as cancer, hypertension, stroke, chronic heart diseases, diabetes, chronic respiratory diseases, and multi-morbidity. Multi-morbidity is a case of having more than one of the morbidities mentioned above. BMI-obese indicates an individual having a BMI ≥30, and the critical threshold value for high-risk WC for men is ≥102 cm while for women is ≥88 cm. The critical limit for the high-risk WHR for men and women is ≥0.90 and ≥ 0.85, respectively. Descriptive statistics and multiple logistic regressions are used to assess the association BMI, WC, and WHR with non-communicable morbidities.

RESULTS

Based on the multivariate-adjusted model, odds shows that an Indian older adult aged 45 and above is 2.3 times more likely (AOR: 2.33; 95% CI (2.2, 2.5)) by obesity, 61% more likely (AOR: 1.61; 95% CI (1.629, 1.631)) by high-risk WHR and 98% more likely (AOR: 1.98; 95% CI (1.9, 2.1)) by high-risk WC to develop CVDs than their normal counterparts. Similarly, significant positive associations of obesity, high-risk WC, and high-risk WHR were observed with other NCDs and multi-morbidity.

CONCLUSION

Our study shows that obesity, high-risk WC, and high-risk WHR are significant risks for developing NCDs and multi-morbidity among the older adults in India. There is a need for a multi-sectoral approach to reduce the share of the elderly population in high-risk groups of BMIs, WHR, and WC.

Phenome-wide screening of GWAS data reveals the complex causal architecture of obesity

OBJECTIVE

In the present study, we sought to identify causal relationships between obesity and other complex traits and conditions using a data-driven hypothesis-free approach that uses genetic data to infer causal associations.

METHODS

We leveraged available summary-based genetic data from genome-wide association studies on 1498 phenotypes and applied the latent causal variable method (LCV) between obesity and all traits.

RESULTS

We identified 110 traits causally associated with obesity. Of those, 109 were causal outcomes of obesity, while only leg pain in calves was a causal determinant of obesity. Causal outcomes of obesity included 26 phenotypes associated with cardiovascular diseases, 22 anthropometric measurements, nine with the musculoskeletal system, nine with behavioural or lifestyle factors including loneliness or isolation, six with respiratory diseases, five with body bioelectric impedances, four with psychiatric phenotypes, four related to the nervous system, four with disabilities or long-standing illness, three with the gastrointestinal system, three with use of analgesics, two with metabolic diseases, one with inflammatory response and one with the neurodevelopmental disorder ADHD, among others. In particular, some causal outcomes of obesity included hypertension, stroke, ever having a period of extreme irritability, low forced vital capacity and forced expiratory volume, diseases of the musculoskeletal system, diabetes, carpal tunnel syndrome, loneliness or isolation, high leukocyte count, and ADHD.

CONCLUSIONS

Our results indicate that obesity causally affects a wide range of traits and comorbid diseases, thus providing an overview of the metabolic, physiological, and neuropsychiatric impact of obesity on human health.

Sociodemographic characteristics are associated with prevalence of high-risk waist circumference and high-risk waist-to-height ratio in U.S. adolescents

BACKGROUND

Adiposity status in adolescence is associated with various health outcomes in adulthood. Waist circumference [WC] and waist-to-height ratio [WHtR] are measures of abdominal obesity and have shown to be valid predictors of future chronic diseases. However, the relationship between sociodemographic characteristics and WC, as well as WHtR in U.S. adolescents remain unclear. Thus, the study aims to examine associations between sociodemographic characteristics and abdominal obesity among a nationally representative sample of U.S. adolescents.

METHODS

The sample included 4712 adolescents (12-19 years) in the 2007-2016 National Health and Nutrition Examination Survey. Associations between sociodemographic characteristics and abdominal obesity (WC and WHtR) were examined using multiple logistic regression models, adjusted for age, physical activity level, and sedentary activity.

RESULTS

Around 18% of adolescents had high-risk WC (≥90th percentile) and 34% had high-risk WHtR (≥0.5). Females had higher odds of high-risk WHtR compared to males (OR = 1.46, 95%CI = 1.23-1.72). Mexican American adolescents had higher odds of high-risk WHtR compared to non-Hispanic White (OR = 1.66, 95%CI = 1.24-2.20), non-Hispanic Black (OR = 1.73, 95%CI = 1.26-2.36), and other race/multi-racial adolescents (OR = 1.84, 95%CI = 1.21-2.80). When their parent were college graduates, adolescents had lower odds for high-risk WC compared to when the parent had some college education (OR = 0.68, 95%CI = 0.49-0.93) or a high school degree or less (OR = 0.70, 95%CI = 0.51-0.97). Similar associations were seen between parental education level and high-risk WHtR, as well as between household income and high-risk WHtR.

CONCLUSIONS

Measures of abdominal obesity should be considered to assess burden of adiposity, especially among female adolescents, adolescents from racial/ethnic minority and low socioeconomic status backgrounds. Additionally, future health interventions should consider including changes in WC and WHtR to measure the impact of these interventions.

Accuracy of self-reported height, weight and BMI in a multiethnic Asian population

Introduction: The study assessed whether self-reported height, weight and derived body mass index (BMI) can provide an accurate measure of anthropometric data in a multiethnic adult population in Singapore. Methods: Standardised anthropometric measurements were compared against the self-reported values from 5,132 adult residents in a cross-sectional, epidemiological survey. Discrepancies in self-reports from measurements were examined by comparing overall mean differences. Intraclass correlations, Cohen’s kappa and Bland-Altman plots with limits of agreement, and sub-analysis by sex and ethnicity were also explored. Results: Data were obtained from 5,132 respondents. The mean age of respondents was 43.9 years. Overall, the height was overestimated (0.2cm), while there was an underestimation of weight (0.8kg) and derived BMI (0.4kg/m2). Women had a larger discrepancy in height (0.35cm, 95% confidence interval [CI] 0.22 to 0.49), weight (-0.95kg, 95% CI -1.11 to -0.79) and BMI (-0.49kg/m2, 95% CI -0.57 to -0.41) compared with men. Height reporting bias was highest among Indians (0.28cm, 95% CI 0.12 to 0.44) compared with Chinese and Malays, while weight (-1.32kg, 95% CI -1.53 to -1.11) and derived BMI (-0.57kg/m2, 95% CI -0.67 to -0.47) showed higher degrees of underreporting among Malays compared with Chinese and Indians. Substantially high self-reported versus measured values were obtained for intraclass correlations (0.96–0.99, P<0.001) and kappa (0.74). For BMI categories, good to excellent kappa agreement was observed (0.68–0.81, P<0.0001). Conclusion: Self-reported anthropometric estimates can be used, particularly in large epidemiological studies. However, sufficient care is needed when evaluating data from Indians, Malays and women as there is likely an underestimation of obesity prevalence. Keywords: Body mass index, epidemiology, public health, self-report, validity

Cross-Sectional and Longitudinal Associations between Non-School Time Physical Activity, Sedentary Time, and Adiposity among Boys and Girls: An Isotemporal Substitution Approach

This study investigated the cross-sectional and longitudinal associations of the substitution of non-school time light physical activity (LPA), moderate-to-vigorous physical activity (MVPA), and sedentary time (ST) with adiposity in boys and girls. Boys (n = 65, baseline Mage= 9.93 ± 0.86 years) and girls (n = 77, baseline Mage = 10.17 ± 0.95 years) wore waist-worn accelerometers (ActiGraph GT3X) at baseline and at a 30-month follow-up, from which non-school time LPA, MVPA, ST, and total device wear were quantified. Body mass index (BMI) and waist-to-height-ratio (WHR) were measured at baseline and follow-up. Body fat percent (BF%) was obtained at follow-up only. Isotemporal substitution models assessed the cross-sectional and longitudinal associations of reallocating non-school time activity with BMI, WHR and BF%. In boys, replacing 30 min/day of LPA with MVPA was cross-sectionally (β = -8.26, p < 0.05) associated with a lower BF%. Replacing 30 min/day of ST with MVPA was cross-sectionally (β = -6.02, p < 0.05) associated with a lower BF% in boys. Longitudinally in boys, replacing 30 min of change in LPA with MVPA (β = -7.42, p < 0.10) and replacing 30 min of change in MVPA with ST (β = 5.78, p < 0.10) over 30 months was marginally associated with less BF%. Associations were null in girls (p > 0.05). These results may support targeting activity reallocation during non-school time for the purposes of adiposity improvement in boys. A multi-behavioral approach may be more appropriate for girls, as non-school time activity may not be driving adiposity status.

Fat mass and vascular health in overweight/obese children

BACKGROUND AND AIM

Childhood obesity is one of the most serious public health challenges of the 21st century. Body mass index (BMI), the most widely used marker of body fatness, has serious limitations, particularly in children, since it does not accurately discriminate between lean and fat mass. Aim of our study was to investigate if the estimate of fat mass, as derived by a new prediction model, was associated with carotid intima media thickness (IMT) and the cross-sectional area of the intima media complex (CSA-IMC) in overweight or obese children.

METHODS AND RESULTS

As many as 375 overweight/obese Italian children, 54.7% males, aged 5-15 years, admitted to a tertiary care hospital, were consecutively enrolled in a study on cardiovascular markers of atherosclerosis. All children underwent an ultrasound carotid examination. Mean weight was 62.2 ± 20.8 Kg and fat-mass was 26.2 ± 10.7 Kg. Multiple regression analyses showed a significant association of fat mass with carotid IMT (β 0.156, p 0.01) and CSA-IMC (β 0.216, p < 0.001); these associations remained significant after controlling for the main cardiovascular risk factors (age, sex, blood pressure, HOMA-index, triglycerides, LDL-cholesterol, HDL-cholesterol, birth weight and high-sensitivity C-reactive protein).

CONCLUSION

Fat mass calculated with the new formula is independently associated with subclinical atherosclerosis in overweight/obese children.

Association of Childhood Fat Mass and Weight With Adult-Onset Type 2 Diabetes in Denmark

IMPORTANCE

Childhood obesity, defined by cutoffs based on the weight-based marker of body mass index, is associated with adult type 2 diabetes (T2D) risk. Whether childhood fat mass (FM) is the driver of these associations is currently unknown.

OBJECTIVE

To quantify and compare height-independent associations between childhood FM and weight with adult T2D risk in a historic Danish cohort.

DESIGN, SETTING, AND PARTICIPANTS

This population-based retrospective cohort study included schoolchildren from The Copenhagen School Health Records Register born between January 1930 and December 1985 with follow-up to adulthood through December 31, 2015. Analyses were based on 269 913 schoolchildren aged 10 years with 21 896 established adult T2D cases and 261 192 children aged 13 years with 21 530 established adult T2D cases for whom childhood height and weight measurements, as well as predicted FM, were available. Statistical analyses were performed between April 2019 to August 2020.

EXPOSURES

Childhood FM and weight at ages 10 and 13 years.

MAIN OUTCOMES AND MEASURES

Diagnoses of T2D were established by linkage to national disease registers for adults aged at least 30 years. Sex-specific Cox regression quantified associations, adjusted for childhood height, which were evaluated within 5 birth-cohort groups. Group-specific results were pooled using random-effects meta-analyses accounting for heterogeneity across group-specific associations.

RESULTS

This cohort study analyzed data from 269 913 children aged 10 years (135 940 boys [50.4%]) with 21 896 established adult T2D cases and 261 192 children aged 13 years (131 025 boys [50.2%]) with 21 530 established adult T2D cases. After adjusting for childhood height, increases in FM and weight (per kilogram) among boys aged 10 years were associated with elevated T2D risks at age 50 years of 12% (hazard ratio [HR], 1.12; 95% CI, 1.10-1.14) and 7% (HR, 1.07; 95% CI, 1.05-1.09), respectively, and among girls aged 10 years of 15% (HR, 1.15; 95% CI, 1.13-1.17) and 10% (HR, 1.10; 95% CI, 1.08-1.11), respectively. Among children aged 13 years, increases in FM and weight (per kilogram) were associated with increased T2D risks at age 50 years of 10% (HR, 1.10; 95% CI, 1.09-1.10) and 6% (HR, 1.06; 95% CI, 1.05-1.07) for boys, respectively, and of 10% (HR, 1.10; 95% CI, 1.10-1.11) and 7% (HR, 1.07; 95% CI, 1.06-1.08), respectively, for girls.

CONCLUSIONS AND RELEVANCE

This cohort study found that a 1-kg increase in childhood FM was more strongly associated with increased adult T2D risk than a 1-kg increase in weight, independent of childhood height. Information on FM, rather than weight-based measures, focuses on a modifiable component of weight that may be associated with adult T2D risk. These findings support the assessment of childhood FM in adiposity surveillance initiatives in an effort to reduce long-term T2D risk.

Early childhood factors associated with obesity at age 8 in Vietnamese children: The Young Lives Cohort Study

Background

Over recent decades, Vietnam has experienced rapid economic growth, a nutrition transition from the traditional diet to highly-processed and calorie-dense foods and beverages, and an increasing prevalence of childhood overweight/obesity (ow/ob). The goal of this study is to describe the patterns of ow/ob in a longitudinal sample of Vietnamese children from ages 1 to 8, and the sociodemographic and behavioral factors associated with ow/ob at age 8.

Methods

This study is a secondary data analysis of a geographically-representative, longitudinal cohort of 1961 Vietnamese children from the Young Lives Cohort Study from 2002 to 2009. Thirty-one communities were selected with oversampling in rural communities, and children age 1 were recruited from each community using simple random sampling. Surveys of families and measurements of children were collected at child ages 1, 5, and 8. Our specified outcome measure was childhood ow/ob at age 8, defined by the World Health Organization’s thresholds for body-mass-index (BMI) for age Z-scores. Associations between early and concurrent socio-behavioral factors, childhood nutrition and physical activity variables were analyzed using STATA 15. Bivariate and multivariable analyses were completed utilizing logistic regression models.

Results

The prevalence of ow/ob increased from 1.1% in both sexes at age 1 to 7% in females and 13% in males at age 8. Bivariate analyses show greater likelihood of ow/ob at age 8 was significantly associated with early life sociodemographic factors (at age 1), male sex (OR = 2.2, 1.6–3.1), higher wealth (OR = 1.1–1.4), and urban residence (OR = 4.3, 3–6). In adjusted analyses, ow/ob at age 8 was associated with early nutrition practices at age 5, including frequent consumption of powdered milk (OR = 2.8, 1.6–4.6), honey/sugar (OR = 2.7, 1.8–4.1), prepared restaurant/fast foods (OR = 4.6, 2.6–8.2), and packaged sweets (OR = 3.4, 2.3–4.9). In addition, breastfeeding for 6 months or longer was protective against obesity at age 8 (OR = 0.3, 0.1–0.9).

Conclusions

We found that increased consumption of powdered milk, honey/sugar, packaged sweets, and prepared restaurants/fast foods are associated with childhood ow/ob. In contrast, breastfeeding for 6 months or longer was protective against childhood ow/ob. These findings suggest that public health programs and campaigns aimed to prevent childhood ow/ob in Vietnam should target early feeding practices.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10292-z.

Body Composition versus BMI as Measures of Success in a Clinical Pediatric Weight Management Program

The high rates and long-term medical consequences of childhood obesity make it a public health crisis requiring effective diagnosis, treatment, and prevention. Although BMI is an adequate screening tool for obesity, monitoring BMI change is not always the best measure of success in treating patients in a pediatric weight management program. Our retrospective study evaluated the proportion of patients that achieved favorable changes in body composition by bioelectrical impedance analysis in the absence of improvements in BMI, BMI percentile, or percent of the 95th percentile for BMI. It was found that 30% of patients whose BMI increased by 1.0 kg/m2 or more, 31.6% of patients with stable or increasing BMI percentiles, and 28% with stable or increasing percent of the 95th percentile for BMI demonstrated an improvement in body composition (skeletal muscle mass and body fat percentage). Body composition is an important measure of success for a subset of patients who otherwise may believe that their efforts in lifestyle change have not been effective. Our results suggest that including body fat percentage as a measure of success in evaluating the progress of patients participating in a pediatric weight management program is appropriate and may more accurately track success than change in BMI or BMI percentile alone.

Health-Related Behaviors in Adolescents Mediate the Association between Subjective Social Status and Body Mass Index

The aim of this study was to explore the association between adolescent subjective social status (SSS) and body mass index (BMI) at two different time points and to determine whether this association was mediated by health-related behaviors. In 2002 (n = 1596) and 2017 (n = 1534), tenth-grade students (15-16 years old) in schools in the District of Oppland, Norway, completed a survey. Four categories of perceived family economy were measured as SSS, and structural equation modeling was performed, including a latent variable for unhealthy behavior derived from cigarette smoking, snuff-use, and alcohol-drinking as well as dietary and exercise as mediators. No linear association was found between SSS and BMI in 2002 (standardized ß -0.02, (95% confidence interval (CI) -0.07, 0.03)). However, an association was present in 2017 (standardized ß -0.05 (95% CI -0.10, -0.001)), indicating that BMI decreased by 0.05 standard deviations (0.05 × 3.1 = 0.16 BMI unit) for every one-category increase in SSS. This association was mediated by exercise (standardized ß -0.013 (95% CI -0.02, -0.004) and unhealthy behavior (standardized ß -0.009 (95% CI -0.002, -0.04)). In conclusion, a direct association between SSS and BMI was found in 2017 in this repeated cross-sectional survey of 15-16-year-old Norwegian adolescents. This association was mediated through health-related behavior.

Cost-utility analysis of second-line anti-diabetic therapy in patients with type 2 diabetes mellitus inadequately controlled on metformin

BACKGROUND

There are significant differences in costs and effectiveness among the second-line treatment options for type 2 diabetes (T2DM). We aimed to evaluate the cost-effectiveness of the second-line anti-diabetic therapy in T2DM patients inadequately controlled on metformin (MET) in Taiwan from the perspective of the National Health Insurance (NHI).

METHODS

The Cardiff T2DM model was used to predict the occurrence of mortality, diabetes-related complications, and drug adverse events. Five second-line treatments were selected for the analysis: sodium-glucose cotransporter 2 inhibitors (SGLT-2-i), glucagon-like peptide-1 receptor agonists (GLP-1-RA), dipeptidyl peptidase-4 inhibitor (DPP-4-i), sulfonylurea (SU), and insulin (INS). Treatment efficacy data were obtained from meta-analyses and randomized clinical trials, whereas cost data were derived from the NHI databases.

RESULTS

The analysis found that SU + MET (DPP-4-i as triple therapy) had the lowest cost, and SU + MET (SGLT-2-i as triple therapy) was associated with a mean incremental benefit of 0.47 quality-adjusted life years (QALYs) at an incremental cost of NT$2769, resulting in an incremental cost-effectiveness ratio (ICER) of NT$5840/QALY. Compared to their next less costly strategies, SGLT-2-i + MET (SU as triple therapy) and SGLT-2-i + MET (DPP-4-i as triple therapy) had ICER values of NT$63,170/QALY and NT$64,090/QALY, respectively. These results were fairly robust to extensive sensitivity analyses, but were relatively sensitive to baseline HbA1c, HbA1c threshold, and utilities.

CONCLUSION

The addition of either SU or SGLT-2-i to MET was found to be cost-effective, using the 2019 forecast for GDP per capita of Taiwan (NT$770,770) as the willingness to pay (WTP) threshold.

Quantifying childhood fat mass: comparison of a novel height-and-weight-based prediction approach with DXA and bioelectrical impedance

Accurate assessment of childhood adiposity is important both for individuals and populations. We compared fat mass (FM) predictions from a novel prediction model based on height, weight and demographic factors (height–weight equation) with FM from bioelectrical impedance (BIA) and dual-energy X-ray absorptiometry (DXA), using the deuterium dilution method as a reference standard. FM data from all four methods were available for 174 ALSPAC Study participants, seen 2002–2003, aged 11–12-years. FM predictions from the three approaches were compared to the reference standard using; R², calibration (slope and intercept) and root mean square error (RMSE). R² values were high from ‘height–weight equation’ (90%) but lower than from DXA (95%) and BIA (91%). Whilst calibration intercepts from all three approaches were close to the ideal of 0, the calibration slope from the ‘height–weight equation’ (slope = 1.02) was closer to the ideal of 1 than DXA (slope = 0.88) and BIA (slope = 0.87) assessments. The ‘height–weight equation’ provided more accurate individual predictions with a smaller RMSE value (2.6 kg) than BIA (3.1 kg) or DXA (3.4 kg). Predictions from the ‘height–weight equation’ were at least as accurate as DXA and BIA and were based on simpler measurements and open-source equation, emphasising its potential for both individual and population-level FM assessments.

BMI and inverted BMI as predictors of fat mass in young people: a comparison across the ages

Background: The use of body mass index (BMI) could lead to over/under estimation of fat mass percentage (FM%). An alternative index (inverted BMI, iBMI) has been proposed as a better estimator of FM% in adults, while its practical feasibility in children and adolescents has not been fully investigated.Aim: To examine if iBMI can better estimate FM% than BMI in children/adolescents.Subjects and methods: Height, weight, and triceps and subscapularis skinfolds were measured in 6686 schoolchildren aged 11-14-years-old. BMI and iBMI (squared height/weight) were calculated; FM% was estimated by skinfold thicknesses. The Pearson correlation coefficient and the coefficient of determination were obtained to test the best regression model between the indexes and FM%.Results: FM% was linearly related to both indexes with R2 values that were overall > 0.7. No significant differences among the R2 values were found (p value = .2, ANOVA).Conclusion: BMI persists as a robust index for health surveillance screening in children/adolescents, being very intuitive and ready-to-use. Inverted BMI may be more accurate within a cohort of adults who experience only ponderal modifications, directly implicated in the variation of FM. In conclusion, the BMI remains a quick, handy and intuitive predictor of FM%.

Is There a Prescription to Treat Pediatric Obesity?

Pediatric obesity is complex-in every way. The pathogenesis, which is a result of a multitude of factors combined with social and environmental factors makes it a crisis with overwhelming challenges. It is difficult to treat pediatric obesity; however, guidelines attempt to clarify how to approach treatment. These strategies are mostly interventions in lifestyle because only 1 medication is approved for treating obesity in children. The approach to the treatment of pediatric obesity will need to be a one that relies on the available data, a continued drive for additional research and publication, sharing of practice experience, and continued efforts at prevention.

Socioeconomic disparities in unhealthy weight: A need for health promotion among school-aged children

INTRODUCTION

Overweight and obesity as a major public health issue can lead to adverse health consequences during the life span. This study aimed to measure socioeconomic inequality in unhealthy weight among school students in Kermanshah, west of Iran.

METHODS

The cross-sectional study measured the socioeconomic-related inequalities in unhealthy weight among 1404 secondary school students aged 11-16 years in Kermanshah in 2018. Unhealthy weight is defined as body mass index of >25 kg/m² in the study. Socioeconomic-related inequality in unhealthy weight was calculated using the concentration index (C_n). A logistic regression model was used to estimate the marginal effect of independent variables.

RESULTS

The prevalence of unhealthy weight for the total sample was 0.13 (95% confidence interval [CI]: 0.11 -0.14). Of these, the prevalence of unhealthy weight for girls and boys was 0.11 (95% CI: 0.09-0.14) and 0.15 (95% CI: 0.12-0.18), respectively. The value of C_n for the total sample was 0.12 (95% CI: 0.03-0.2), which indicates a higher concentration of unhealthy weight among the high socioeconomic status (SES) students. Two factors of SES (49.11%) and gender (40.08%) had the largest contribution to socioeconomic inequality in unhealthy weight among the study students.

CONCLUSIONS

Socioeconomic-related inequality in unhealthy weight was concentered among high-SES students in the study. Thus, public health policies need to be formulated to change sedentary lifestyles and unhealthy dietary patterns among students with higher SES.

Anthropometric heritability and child growth in a Caribbean village: A quantitative genetic analysis of longitudinal height, weight, and body mass index in Bwa Mawego, Dominica

OBJECTIVES

Body size and composition vary widely among individuals and populations, and long-term research in diverse contexts informs our understanding of genetic, cultural, and environmental impacts on this variation. We analyze longitudinal measures of height, weight, and body mass index (BMI) from a Caribbean village, estimating the extent to which these anthropometrics are shaped by genetic variance in a small-scale population of mixed ancestry.

MATERIALS AND METHODS

Longitudinal data from a traditionally horticultural village in Dominica document height and weight in a non-Western population that is transitioning to increasingly Westernized lifestyles, and an 11-generation pedigree enables us to estimate the proportions of phenotypic variation in height, weight, and BMI attributed to genetic variation. We assess within-individual variation across growth curves as well as heritabilities of these traits for 260 individuals using Bayesian variance component estimation.

RESULTS

Age, sex, and secular trends account for the majority of anthropometric variation in these longitudinal data. Independent of age, sex, and secular trends, our analyses show high repeatabilities for the remaining variation in height, weight, and BMI growth curves (>0.75), and moderate heritabilities (h² _height = 0.68, h² _weight = 0.64, h² _BMI = 0.49) reveal clear genetic signals that account for large proportions of the variation in body size observed between families. Secular trends show increases of 6.5% in height and 16.0% in weight from 1997 to 2017.

DISCUSSION

This horticultural Caribbean population has transitioned to include more Westernized foods and technologies over the decades captured in this analysis. BMI varies widely between individuals and is significantly shaped by genetic variation, warranting future exploration with other physiological correlates and associated genetic variants.

Body Mass Index Z-Score Modifies the Association between Added Sugar Intake and Arterial Stiffness in Youth with Type 1 Diabetes: The Search Nutrition Ancillary Study

The relationship between added sugar and arterial stiffness in youth with type 1 diabetes (T1D) has not been well-described. We used data from the SEARCH for Diabetes in Youth Study (SEARCH), an ongoing observational cohort study, to determine the association between added sugar and arterial stiffness in individuals diagnosed with T1D <20 years of age (n = 1539; mean diabetes duration of 7.9 ± 1.9 years). Added sugar intake was assessed by a food frequency questionnaire, and arterial stiffness measures included pulse wave velocity (PWV) and augmentation index. Separate multivariate linear regression models were used to evaluate the association between added sugar and arterial stiffness. Separate interaction terms were included to test for effect modification by body mass index (BMI) z-score and physical activity (PA). Overall, there was no association between added sugar and arterial stiffness (P > 0.05); however, the association between added sugar and arterial stiffness differed by BMI z-score (P for interaction = 0.003). For participants with lower BMI z-scores, added sugar intake was positively associated with PWV trunk measurements, whereas there was no association for those who had a higher BMI z-score. PA did not significantly modify the association between added sugar and arterial stiffness. Further research is needed to determine the longitudinal relationship and to confirm that obesity differentially affects this association.

Development and validation of a prediction model for fat mass in children and adolescents: meta-analysis using individual participant data

OBJECTIVES

To develop and validate a prediction model for fat mass in children aged 4-15 years using routinely available risk factors of height, weight, and demographic information without the need for more complex forms of assessment.

DESIGN

Individual participant data meta-analysis.

SETTING

Four population based cross sectional studies and a fifth study for external validation, United Kingdom.

PARTICIPANTS

A pooled derivation dataset (four studies) of 2375 children and an external validation dataset of 176 children with complete data on anthropometric measurements and deuterium dilution assessments of fat mass.

MAIN OUTCOME MEASURE

Multivariable linear regression analysis, using backwards selection for inclusion of predictor variables and allowing non-linear relations, was used to develop a prediction model for fat-free mass (and subsequently fat mass by subtracting resulting estimates from weight) based on the four studies. Internal validation and then internal-external cross validation were used to examine overfitting and generalisability of the model's predictive performance within the four development studies; external validation followed using the fifth dataset.

RESULTS

Model derivation was based on a multi-ethnic population of 2375 children (47.8% boys, n=1136) aged 4-15 years. The final model containing predictor variables of height, weight, age, sex, and ethnicity had extremely high predictive ability (optimism adjusted R²: 94.8%, 95% confidence interval 94.4% to 95.2%) with excellent calibration of observed and predicted values. The internal validation showed minimal overfitting and good model generalisability, with excellent calibration and predictive performance. External validation in 176 children aged 11-12 years showed promising generalisability of the model (R²: 90.0%, 95% confidence interval 87.2% to 92.8%) with good calibration of observed and predicted fat mass (slope: 1.02, 95% confidence interval 0.97 to 1.07). The mean difference between observed and predicted fat mass was -1.29 kg (95% confidence interval -1.62 to -0.96 kg).

CONCLUSION

The developed model accurately predicted levels of fat mass in children aged 4-15 years. The prediction model is based on simple anthropometric measures without the need for more complex forms of assessment and could improve the accuracy of assessments for body fatness in children (compared with those provided by body mass index) for effective surveillance, prevention, and management of clinical and public health obesity.

The effect of personalised weight feedback on weight loss and health behaviours: Evidence from a regression discontinuity design

Using a regression-discontinuity approach on a U.K. longitudinal dataset, this research analyses whether personalised weight feedback resulted in individuals losing weight over a period of between 2 and 7 years. The analysis presented here finds that being told one was "overweight" had, on average, no effect on subsequent weight loss; however, being told one was "very overweight" resulted in individuals losing, on average, approximately 1% of their bodyweight. The effect of feedback was found to be strongly moderated by household income, with those in higher income households accounting for seemingly all of the estimated effect due, in part, to increased physical activity. These findings suggest that the provision of weight feedback may be a cost-effective way to reduce obesity in adults. They do however also highlight that the differential response to the provision of health information may be a driver of health inequalities and that the provision of feedback may bias longitudinal health studies.

Influence of the Spectral Quality of Light on Daytime Alertness Levels in Humans

Exposure to light is very important for human health. However, the characteristics of the light stimulus and the appropriate timing of such exposure are essential. Studies that have used monochromatic light exposure have shown no systematic patterns for the effects of blue light compared to longer wavelengths. Previous studies have shown that red light exposure increases objective and subjective measures of alertness at night without suppressing nocturnal melatonin or inducing circadian disruption. The present study investigated whether noon time exposure to red light would increase both objective and subjective measures of alertness such as those measured by EEG, cognitive-behavioral performance, and subjective sleepiness. The three lighting conditions were as follows: dim light (< 0.01 lux at cornea), blue light (465 nm, 72 μW/cm2), and red light (625 nm, 18 μW/cm2), both at 40 lux. The results of the EEG data showed an increase in theta power over time in dim light only. In red light, alpha power showed a decrease over time. The impact of red light was observed in the performance measures: The only significant effect was a deterioration in the continuous performance test after red light exposure. Subjective measures of alertness were not affected by light in either condition, in contrast to darkness, when subjects reported greater sleepiness than before. None of the changes in objective measures of alertness induced by red light exposure translated into subjective sleepiness at noon. Thus, we concluded that behavioral effects of light at noon are very limited at best.

Body mass index trajectories during the first year of life and their determining factors

OBJECTIVE

The purpose of this study was to examine the trajectories of body mass index (BMI) in the first year of life and their determining factors.

METHODS

We used data from the Infant Feeding Practices Survey II restricted to children with 2 or more time points of BMI data during follow-up visits within the first year of life (n = 2320). Latent class growth analysis was used to identify distinct BMI trajectories. Using multinomial logistic regression, we examined the prenatal and early life determinants of the identified trajectories.

RESULTS

Three BMI trajectories were identified during the first year of life: "low-stable" (81.6%), "high-stable" (15.6%), and "rising" (2.8%) trajectories. Boys, preterm infants, infants born to overweight mothers, Hispanic mothers, non-Hispanic Black mothers, and mothers who smoked during pregnancy were significantly more likely to have high-stable versus low-stable trajectories. Infants born to non-Hispanic Black mothers were more likely to have a rising versus a low-stable trajectory. Household income ≥350% of the federal poverty level and full adherence to the guidelines of the American Academy of Pediatrics for both breastfeeding exclusivity and duration reduced the likelihood of infants being in the rising versus the low-stable trajectory.

CONCLUSION

Distinct BMI trajectories were evident as early as infancy. The predictors of these trajectories offer information about high-risk groups, and important and preventable prenatal and postnatal risk factors for future intervention programs.

BMI z-score in obese children is a poor predictor of adiposity changes over time

Background

The age and sex standardized body mass index (BMIz) is a simple and widely utilized screening tool for obesity in children and adolescents. The purpose of this study was to evaluate the relationship between the BMIz trajectory versus the percent body fat (%FAT) trajectory, and if BMIz could predict significant changes in %FAT in a sample of obese children and adolescents.

Methods

In this longitudinal observational study, body composition was measured by dual energy x-ray absorptiometry (DXA) in obese children within a multidisciplinary pediatric fitness clinic at an academic medical center over a 3-year time period. Regression analyses were conducted to evaluate the association between changes in BMIz and changes in %FAT.

Results

Baseline assessment was obtained from 515 participants. The reduction observed in BMIz (2.20 to 2.08, p < 0.0001) correlated with the reduction in %FAT (38.5 to 35.8%, p < 0.05) in the first two years. The overall correlation between the slope in BMIz reduction versus %FAT reduction was moderate (r = 0.36, p < 0.0001) over the 3-year follow-up period. The sensitivity of BMIz changes for predicting a decrease in %FAT was acceptable (70, 95% CI: 61–78%), however the specificity was poor (42, 95% CI: 31–54%).

Conclusions

These findings advance the understanding of the utility and limitations of BMIz in children and adolescents. While BMIz may be sensitive to changes in adiposity, it is a weak predictor of these changes in total body fat (%FAT) due to the poor specificity. Therefore, clinicians must exercise caution when monitoring changes in a growing child’s body composition to avoid misclassifying or missing substantial change when utilizing BMIz alone.

The Relationship Between Hofstede's Cultural Dimensions, Schwartz's Cultural Values, and Obesity

According to the World Health Organization, obesity is a major public health issue. In 2014, there were more than 600 million obese people around the world. According to the data of the World Health Organization, obesity rates differ among countries. One possible underlying reason of the difference can be culture, more specifically shared cultural values. The strategies and policies regarding obesity were developed; however, the effect of culture is not adequately considered. The aim of the study is to investigate the relationship between obesity rates of countries, Hofstede's cultural dimensions, Schwartz's values, and Gross National Income per capita per country. The data consist of obesity ranking (i.e., the percentage of the population with a body mass index of 30 kg/m² or higher), Gross National Income per capita for each country, and cultural variables (i.e., Hofstede's cultural dimensions for 54 nations and Schwartz's cultural values for 57 nations). Hierarchical regression analysis results revealed that Gross National Income per capita was not a significantly related obesity at the aggregated level. Among Hofstede's dimensions, individualism and uncertainty avoidance were positively associated with obesity, and long-term orientation was negatively associated with obesity. The relationship between Schwartz's cultural values and obesity was not found to be significant. Findings suggest that Hofstede's cultural dimensions should be considered when developing national level strategies and campaigns to decrease obesity.

Associations of out of school physical activity, sedentary lifestyle and socioeconomic status with weight status and adiposity of Cameroon children

BACKGROUND

Low physical activity and a sedentary lifestyle are contributing to overweight/obesity in children. This study aims to explore relationships between out of school physical activity, sedentary lifestyle and socioeconomic status indicators with children's weight status and adiposity.

METHODS

Five hundred twenty-two children of ages 5 to 12 years were randomly selected in a school-based cross sectional study in Bamenda, Cameroon. Weight and height were measured and BMI calculated. These variables were standardized for age and gender. Socioeconomic variables and proxy measures of physical activity and sedentary lifestyle of children were reported by parents using a structured questionnaire. Bivariate and multivariable logistic regression was used to calculate odds ratios.Quantile regression was used to compare median values of triceps skinfold thickness across the different factors.

RESULTS

In bivariate analysis, physical activity > 4 - 7 times/week was significantly (p = 0.010) associated with a lower prevalence (5.9%) of overweight/obesity. In multivariable analysis, physical activity > twice a week (OR 0.1, 95% CI 0.05 - 0.3), sedentary lifestyle > 3 h/day (OR 2.4, 95% CI 1.2 - 4.3) and being in the high occupation class (OR 4.3, 95% CI 2.2 - 8.1) independently predicted overweight/obesity. With quantile regression, physical activity > 4 - 7 times/week was significantly (p = 0.023) associated with a 1.36 mm decrease in median triceps skinfold thickness, while sedentary lifestyle (> 3 h/day) (p = 0.026) and being in the high occupation class (p = 0.007) were significantly associated with a 1.37 mm and 1.86 mm increase in median triceps skinfold thickness respectively.

CONCLUSION

Physical activity is inversely related to BMI-defined overweight/obesity and triceps skinfold thickness. Also, a high sedentary lifestyle and a high occupation class were associated with overweight/obesity and had the largest significant relationship with triceps skinfold thickness. There is need to objectively assess physical activity and sedentary lifestyle in our setting, in and out of school. Also longitudinal studies are warranted to understand the influence of cultural and behavioral drivers of physical activity and sedentary lifestyle.