Body fat percentage is better than indicators of weight status to identify children and adolescents with unfavorable lipid profile

Associations of Body Mass Index Growth Rates and Body Composition With Cardiometabolic Risks in Chinese Preschool Children

OBJECTIVE

To examine the relationship between body mass index (BMI) growth rates, body composition, and cardiometabolic markers in preschool children.

METHODS

Three-year-old children were recruited for this cohort study. BMI and body composition measurements were obtained at enrollment, with multiple BMI measurements spanning ages 1 month to 3 years extracted from medical records. Levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol (non-HDL-C), remnant cholesterol (RC), uric acid (UA), and fasting plasma glucose were measured at 3 years. Data analyses employed piecewise linear mixed models and logistic regression models.

RESULTS

Out of 3822 children recruited, 3015 were included in the analysis. The accelerated BMI z-score growth rate between 6 and 24 months was positively correlated with high TG and LDL-C levels, with sex, birthweight, and size for gestational age disparities. Obesity increased the risks of high TG level and the highest RC quartile in boys. Fat mass index and percentage of fat mass were linked with high UA level and dyslipidemia, particularly high TG and non-HDL-C levels, in boys. Fat-free mass index showed negative associations with high levels of TC and non-HDL-C in boys and high LDL-C level in girls (P < .05).

CONCLUSION

This study underscores the significant impact of BMI growth rates and body composition on cardiometabolic markers in 3-year-old children. The effects of BMI growth rates in specific periods varied by sex, birthweight, and size for gestational age, and boys exhibited a higher susceptibility to adverse outcomes.

Potential alternative and novel biomarkers for paediatric MAFLD: exploratory evidence from a Chinese cohort

BACKGROUND

While the associations between pediatric non-obese metabolic dysfunction-associated fatty liver disease (MAFLD) and multiple diagnostic biomarkers are well-established, the role of a broader range of blood-based, urine-based, and body composition-based biomarkers for monitoring MAFLD are needed.

METHODS

A pediatric cohort was established in Wuxi, China. We measured body composition biomarkers, blood-based and urine-based biomarkers, and liver stiffness in participants to diagnose MAFLD and identify alternative and novel potential biomarkers for MAFLD. Body mass index (BMI), high-density lipoprotein cholesterol (HDLC), triglycerides, glucose, systolic blood pressure (SBP), diastolic blood pressure (DBP), and waist perimeter were used as MAFLD diagnostic biomarkers. To identify alternative biomarkers, we performed correlation analysis to determine biomarkers exhibited strong correlation (|r| > 0.8, p-value < 0.05) with diagnostic biomarkers. To identify novel potential biomarkers, we performed regression analysis to determine biomarkers associated with MAFLD (p-value < 0.05 in stepwise multivariate regression) among the remaining biomarkers that are not related to the diagnostic biomarkers.

RESULTS

Out of 1,108 participants who completed all examinations (N biomarker = 91), 113 participants were diagnosed with MAFLD (prevalence: 14.99% in boys and 5.18% in girls). 27 biomarkers that were strongly correlated with diagnostic biomarkers were identified as alternative biomarkers. A multivariate logistic regression analysis identified 9 novel potential biomarkers including 5 blood-based biomarkers (plateletocrit, calcium, insulin, AST/ALT ratio, total bilirubin), urine pH, and body fat measurements in the arm, leg, and thigh.

CONCLUSIONS

This study illustrated the characteristics and potential alternative and novel biomarkers of MAFLD based on a Chinese paediatric cohort. These findings posed new paths in guiding the prevention and early diagnosis and prevention.

TRIAL REGISTRATION

This trial was registered in the Chinese Clinical Trials Registry (ChiCTR2400080508). The date of first registration, 01/31/2024. Retrospectively registered.

Obesity Influences T CD4 Lymphocytes Subsets Profiles in Children and Adolescent's Immune Response

BACKGROUND

Evidence shows that CD4+ T cells are altered in obesity and play a significant role in the systemic inflammation in adults with the disease.

OBJECTIVES

Because the profile of these cells is poorly understood in the pediatric population, this study aims to investigate the profile of CD4+ T lymphocytes and the plasma levels of cytokines in this population.

METHODS

Using flow cytometry, we compared the expression profile of lymphocyte markers, master transcription factors, cytokines, and molecules involved in the regulation of the immune response in CD4+ T cells from children and adolescents with obesity (OB group, n = 20) with those with eutrophy group (EU group, n = 16). Plasma levels of cytokines in both groups were determined by cytometric bead array (CBA).

RESULTS

The OB group presents a lower frequency of CD3+ T cells, as well as a decreased frequency of CD4+ T cells expressing CD28, IL-4, and FOXP3, but an increased frequency of CD4+IL-17A+ cells compared with the EU group. The frequency of CD28 is increased in Th2 and Treg cells in the OB group, whereas CTLA-4 is decreased in all subpopulations compared with the EU group. Furthermore, Th2, Th17, and Treg profiles can differentiate the EU and OB groups. IL-10 plasma levels are reduced in the OB group and negatively correlated with adiposity and inflammatory parameters.

CONCLUSIONS

CD4+ T cells have an altered pattern of expression in children and adolescents with obesity, contributing to the inflammatory state and clinical characteristics of these patients.

Unravelling the obesity maze in diabetic patients: A comparative analysis of classification methods

Background

Obesity is a significant health concern among individuals with type 2 diabetes mellitus (T2DM). Emerging evidence suggests that alternative measures, such as abdominal girth (AG) and body fat percentage (BF%), can provide a more accurate reflection of obesity-related metabolic risks in diabetic populations. This study aimed to compare the accuracy of different obesity classification methods, including BMI, AG, and BF%, among individuals with T2DM.

Methodology

This was an observational cross-sectional study conducted among T2DM patients who came to the non-communicable diseases clinic of GG Govt Hospital, Jamnagar, Gujarat during the period of March-April 2023. Demographic and anthropometric information was collected. Body fat analysis was done using a validated Omron fat analyzer.

Results

The study found the sensitivity of BMI in males and females as 41.6% and 45% against BF%, respectively. It also showed that the sensitivity of BMI in males and females was 38% and 40.7%, respectively, against AG. The present study also found a moderate positive correlation (r = 0.575) between AG and BF% in individuals with T2DM.

Conclusion

The findings indicate that BF% and AG provide valuable insights into adiposity, surpassing the limitations of BMI as a measure of body composition. BF% is an indicator of body fat content, whereas AG serves as a proxy for central adiposity. The correlations between BF% and AG suggest that excess abdominal fat accumulation signifies increased body fat. By incorporating measures such as BF% and AG alongside BMI, clinicians can obtain a more comprehensive understanding of body composition and its relationship with metabolic abnormalities.

Association between Urinary Sodium Excretion and Body Fat in School-Aged Children: Insights from the ARIA Study

Childhood obesity has been associated with increased sodium intake. Nonetheless, evidence linking sodium intake to Body Mass Index (BMI) and Body Fat Mass Percentage (%BF) remains limited, especially in the pediatric age group. Therefore, this study aims to investigate whether there is an association between 24 h urinary sodium excretion with BMI and %BF in a sample group of children from the ARIA study. This cross-sectional analysis included 303 children aged 7 to 12 from across 20 public schools in Porto, Portugal. Weight and %BF were assessed using the Tanita™ BC-418 Segmental Body Analyzer. Children's Total Energy Intake (TEI) was estimated through a single 24 h Recall Questionnaire, and urinary sodium and potassium excretion was estimated by a 24 h urine collection. The association of %BF and BMI with 24 h sodium excretion was estimated by a binary logistic regression adjusted for sex, age, physical activity, total energy intake, parental education, and 24 h urinary excreted potassium. There was a significant positive association between higher levels of urinary sodium excretion and higher %BF values, even after adjusting for confounders. However, the same was not observed for BMI. Our findings suggest that higher sodium intake is associated with higher values of %BF among children, regardless of TEI and potassium intake.

Agreement Between Body Mass Index and Body Fat in Adolescents With Different Physical Activity Levels

Purpose: This study aimed to verify the agreement between body mass index (BMI) and body fat in adolescents with different physical activity (PA) levels. Method: This cross-sectional study collected body fat data in 118 adolescents (aged 10 to 14 years) estimated using air-displacement plethysmography (ADP). Body mass 10 and height were used to calculate BMI. Physical activity levels were measured objectively by accelerometers. Results: For boys with low PA, BMI overestimated body fat values measured by ADP (mean error = -0.42; p = .018) which also occurred in group high PA (mean error = -0.76; p = .001). For girls, BMI underestimated body fat values measured by ADP values in group high PA (mean error = 0.43; p = .001) and low PA (mean error = 0.72; p < .001). Conclusion: It is recommended that researchers and practitioners 15 cautiously interpret BMI results, especially considering that most adolescents do not practice enough PA.

Percent body fat, but not body mass index, is associated with cardiometabolic risk factors in children and adolescents

Background

The epidemic of overweight and obesity has become a worldwide public health problem. Cardiometabolic diseases may originate in childhood. We investigated the association between percent body fat (PBF) measured by the bioelectrical impedance assay and cardiometabolic risk (CMR) in pediatrics.

Methods

This cross-sectional study involved 3819 subjects (6-17 years old) in Shanghai. We assessed the association between PBF and body mass index (BMI) with multiple CMR factors. We examined the risk for cardiometabolic abnormalities attributable to overweight and obesity based on age- and sex-specific PBF Z-scores and BMI Z-scores, respectively.

Results

PBF, but not BMI, was positively associated with multiple CMR factors in males and females except for total cholesterol in females (all p < 0.05). Compared with the non-overweight group based on PBF, overweight and obese subjects had increasingly higher odds ratio of dyslipidemia (2.90 (1.99-4.23), 4.59 (2.88-7.32) for males and 1.82 (1.20-2.75), 2.46 (1.47-4.11) for females) and elevated blood pressure (BP) (3.26 (2.35-4.51), 4.55 (2.92-7.09) for males and 1.59 (1.07-2.34), 3.98 (2.27-6.17) for females). Obesity females showed a higher likelihood for hyperglycemia (2.19 (1.24-3.84)) than non-overweight females. In both sexes, the predictive effect of PBF on dyslipidemia and elevated BP in adolescents was better than that in children. For hyperglycemia, the predictive effect of PBF was better in male adolescents and female children. There was no risk difference for cardiometabolic abnormalities attributable to BMI-based obesity categories.

Conclusions

PBF but not BMI was associated with CMR. Overweight and obesity categories based on PBF had an increased risk for cardiometabolic abnormalities in children and adolescents.

Sex differences in the relationship between body composition and biomarkers of bone and fat metabolism in obese boys and girls

Whether a body mass derived from extremes of body weight is beneficial to bone remains controversial. When fat accumulation reaches excessive levels and induces changes in hormonal factors and adipokines, it may affect bone accrual during growth. This study evaluated the relationships between body composition and key biomarkers in relation to bone and fat metabolism in obese Thai boys and girls. Subjects aged 12-14 years were grouped by body mass index (BMI) and percentage of body fat (%Fat). Body composition and heel bone Z-score and speed of sound (SOS) were assessed by bioelectrical impedance analysis and calcaneus bone densitometry, respectively. Serum osteocalcin (OC), adiponectin, leptin, insulin, and 25 hydroxyvitamin D (25(OH)D) were measured by ELISA. Their correlations were analyzed and compared between sexes. The results showed that the obese groups had no differences in mean BMIs and body composition, except that boys had more muscle mass than girls. Boys had lower serum OC and leptin levels than girls. Positive correlations of leptin with %Fat and FM were found in both sexes, while positive associations of %Fat with OC and insulin were found only in boys. Bone Z-score and SOS positively correlated with OC in boys but negatively correlated with 25(OH)D in girls. When classifying the obese group using %Fat ≥25, the positive correlations between %Fat and insulin and the negative associations between %Fat and adiponectin in girls were more pronounced. These results suggest that the associations of body fat and bone parameters with OC, adiponectin, 25(OH)D, and insulin were sex-specific, with greater clarity when %Fat was used instead of BMI to classify obesity.

Uric acid reference values: report on 1750 healthy Brazilian children and adolescents

BACKGROUND

Our purpose was to determine reference values and determinants of serum uric acid (SUA) in children and adolescents.

METHODS

A fasting blood sample was collected from 1750 schoolchildren and adolescents (6-17 years). Puberty was defined according to the Tanner scale. Bodyweight, muscle mass, and body fat percentage were determined by bioimpedance. Data are given as cut-offs and mean ± standard deviation.

RESULTS

SUA level was higher in children that had already entered puberty (4.2 ± 1.1 mg/dL) than among prepubescent (3.6 ± 0.8 mg/dL; p < 0.01). Considering the 90 percentile (p90) as the upper reference value, the following values are proposed for boys and girls, respectively: <10 years or prepubescent: ≤4.5 mg/dL and ≤4.8 mg/dL; from 10 to 13 years: ≤5.7 mg/dL and ≤5.2 mg/dL; from 14 to 17 years: ≤6.4 mg/dL and ≤5.3 mg/dL. Muscle mass explained part of the variability in SUA after pubescence, acting as an independent variable for higher levels of SUA.

CONCLUSIONS

The sex, age, and phase of puberty influence SUA reference levels, and part of this influence could be explained by the higher muscle mass, mainly after the adolescence onset.

IMPACT

The key message of this study is that high levels of uric acid in the blood are associated with metabolic syndrome and cardiovascular risk factors. These diseases should be prevented since the infancy However, it is necessary to establish reference values of uric acid (SUA) for children and adolescents. The Brazilian population is highly admixed and these values were not determined so far. We studied a robust sample of Brazilian schoolchildren and adolescents (6-17 years) and defined the 90th percentile of uric acid as the upper limit of normality for sex, age, and pubertal stage. These values can be used as a reference for other populations with similar characteristics.

Obese Animals as Models for Numerous Diseases: Advantages and Applications

With the advances in obesity research, a variety of animal models have been developed to investigate obesity pathogenesis, development, therapies and complications. Such obese animals would not only allow us to explore obesity but would also represent models to study diseases and conditions that develop with obesity or where obesity represents a risk factor. Indeed, obese subjects, as well as animal models of obesity, develop pathologies such as cardiovascular diseases, diabetes, inflammation and metabolic disorders. Therefore, obese animals would represent models for numerous diseases. Although those diseases can be induced in animals by chemicals or drugs without obesity development, having them developed as consequences of obesity has numerous advantages. These advantages include mimicking natural pathogenesis processes, using diversity in obesity models (diet, animal species) to study the related variabilities and exploring disease intensity and reversibility depending on obesity development and treatments. Importantly, therapeutic implications and pharmacological tests represent key advantages too. On the other hand, obesity prevalence is continuously increasing, and, therefore, the likelihood of having a patient suffering simultaneously from obesity and a particular disease is increasing. Thus, studying diverse diseases in obese animals (either induced naturally or developed) would allow researchers to build a library of data related to the patterns or specificities of obese patients within the context of pathologies. This may lead to a new branch of medicine specifically dedicated to the diseases and care of obese patients, similar to geriatric medicine, which focuses on the elderly population.

Association of uric acid with cardiovascular risk in Brazilian children and adolescents

BACKGROUND AND AIM

Hyperuricemia in adults is associated with cardiovascular risk factors. However, there is less data regarding this association in children and adolescents. Our purpose was to determine association between serum uric acid (SUA) and cardiovascular risk.

METHODS AND RESULTS

A fasting blood sample was collected from 1750 participants aged 6-17 years enrolled in a social project and public schools in Espírito Santo, Brazil. Internal cut-offs were generated to define high SUA (≥90th percentile of SUA concentration for sex and age group). Body mass index percentile (pBMI), body fat percentage (BFP) and muscle mass were determined by bioimpedance. Data are given as mean ± standard deviation. High SUA was associated with overweight/obesity (OR 3.7 CI 95% 2.7-5.0), high waist circumference (WC) (OR 3.9 CI 95% 2.9-5.4), low HDL (OR 2.0 CI 95% 1.5-2.8), high blood pressure (BP) (OR 1.8 CI 95% 1.1-3.2), high BFP (OR 4.1 CI 95% 2.7-6.4), metabolic syndrome (MetS) (OR 3.6 CI 95% 1.8-7.1) and insulin resistance (OR 1.7 CI 95% 1.1-2.7). Individuals in the fourth quartile of SUA, compared to those in the first quartile, showed higher age, pBMI, WC, BFP and muscle mass. Using a reference value of 5.5 mg/dL, the prevalence of hyperuricemia in the sample was 10.3% (CI 95% 8.9-11.7%).

CONCLUSION

Higher SUA values are associated with higher cardiovascular risk in childhood and adolescence. The main cardiovascular risk factors associated with hyperuricemia were overweight/obesity, high WC, dyslipidemia, high BFP, high BP, insulin resistance and MetS.

Added sugar and trans fatty acid intake and sedentary behavior were associated with excess total-body and central adiposity in children and adolescents with congenital heart disease

BACKGROUND

Over the past three decades, the prevalence rate of overweight and obesity has increased in survivors with congenital heart disease, and little is known about the body composition and its association with clinical characteristics and lifestyle factors.

OBJECTIVES

To evaluate excess total-body adiposity and central adiposity and, to describe associated factors.

METHODS

Cross-sectional study with children and adolescents who underwent procedure to treat congenital heart disease, from January to July 2017. Sociodemographic and clinical characteristics, and lifestyle factors (dietary intake, physical activity, and sedentary behavior) were assessed. Adiposity was assessed using air-displacement plethysmography and waist circumference. Factors associated with excess total-body adiposity and central adiposity were analyzed using logistic regression models.

RESULTS

Of 232 patients, 22.4% were identified with excess total-body adiposity and 24.6% with central adiposity. Significant factors positively associated with excess total-body adiposity were intake of added sugar and trans fatty acids, adjusted for confounding factors. Similarly, lifestyle factors were positively associated with central adiposity: intake of added sugar and trans fatty acids, sedentary behavior, and family history of obesity.

CONCLUSIONS

Lifestyle factors were associated with excess total-body adiposity and central adiposity. Assessment of body composition and healthy-lifestyle counseling into outpatient care may be the key point to prevent obesity in children and adolescents with congenital heart disease.

[Value of body fat mass measured by bioelectrical impedance analysis in predicting abnormal blood pressure and abnormal glucose metabolism in children]

OBJECTIVE

To study the value of body fat mass measured by bioelectrical impedance analysis (BIA) in predicting abnormal blood pressure and abnormal glucose metabolism in children.

METHODS

Stratified cluster sampling was used to select the students aged 6-16 years, and a questionnaire survey and physical examination were performed. The BIA apparatus was used to measure body fat mass. Body mass index (BMI), body fat mass index (FMI), and fat mass percentage (FMP) were calculated. Fasting blood glucose level were measured.

RESULTS

A total of 14 293 children were enrolled, among whom boys accounted for 49.89%. In boys and girls, the percentile values (P₆₀, P₆₅, P₇₀, P₇₅, P₈₀, P₈₅, P₉₀, P₉₅) of FMI and FMP fitted by the LMS method were taken as the cut-off values. Based on the receiver operating characteristic curve analysis, the P₇₀ values with a better value in predicting abnormal blood pressure and blood glucose metabolism were selected as the cut-off values for excessive body fat. When FMI or FMP was controlled below P₇₀, the incidence of abnormal blood pressure or abnormal glucose metabolism may be decreased in 8.25%-43.24% of the children.

CONCLUSIONS

The evaluation of obesity based on FMI and FMP has a certain value in screening for hypertension and hyperglycemia in children, which can be further verified in the future prevention and treatment of obesity and related chronic diseases in children.

Association Between Weight Status and Executive Function in Young Adults

Background and objectives: To explore the association between weight status and executive function in young adults. Materials and Methods: Ninety-seven young males (age 17–26 years) underwent adiposity and body composition measurements using body composition analyzer. Inhibitory control and working memory were measured using the Cambridge Neuropsychological Test Battery (CANTAB). Results: Multiple linear regression using both unadjusted and adjusted analyses revealed no association between adiposity and body composition variables with executive tasks, apart from a significant association between skeletal muscle mass (SMM) and mean reaction time on go trial (standardized B = -0.28; p = 0.02). Multivariate analysis of covariance (MANCOVA) revealed that underweight participants presented inferior working memory compared to their normal weight (p = 0.001) or overweight peers (p = 0.008). However, according to the percentage fat quartiles (Q) participants with the highest quartile (Q4) were inferior in inhibitory control than their peers with Q2 (p = 0.04), and participants with the lowest quartile (Q1) were inferior in working memory compared with their peers with Q2 (p = 0.01) or Q3 (p = 0.02). A worse inhibitory control was observed for participants with the highest fat/SMM (Q4) compared to participants in Q3 (p = 0.03), and in contrast worse working memory was observed for participants with the lowest fat/SMM (Q1) compared to participants in Q2 (p = 0.04) or Q3 (p = 0.009). Conclusions: Low adiposity is associated with worse working memory, whereas high adiposity is associated with worse inhibitory control. Therefore, our findings show that normal adiposity, but greater SMM may have a positive impact on executive function in young adults.

Body fat indicators perform better than body mass index in identifying abnormal lipid profiles in boys but not in girls

BACKGROUND

BMI as a body weight indicator, may inadequately represent the biological effect of body fat on lipid profiles. This study aims to assess whether body fat indicators were superior to BMI for recognizing children with dyslipidemia.

METHODS

A nationwide cross-sectional study involving 8944 pediatric participants aged 6-18 years. Measures of fat mass index (FMI), fat mass percentage (FMP), BMI, and four lipid profiles were obtained.

RESULTS

Among boys, the standard multi-linear regression coefficients of FMI for TC, LDL-C, and TG were higher than those of BMI (P < 0.01), but not for HDL-C. Also, the prevalence ratios and area under curves (AUCs) of excess fat classified by FMI for specific abnormal lipid profiles (except for HDL-C) were greater than overweight classified by BMI. The AUCs for detecting children with abnormal TC, LDL-C, and TG of FMI-based excess fat were 3.9%, 5.6%, and 2.8% higher than those of BMI-based overweight, respectively, all P < 0.01. Among girls, the associations of BMI with lipid profiles were substantially similar to FMI. All these results were almost identical when FMP was used instead of FMI.

CONCLUSIONS

DXA measured body fat performs better than BMI in identifying abnormal lipid profiles in boys but not in girls.