High BMI with Adequate Lean Mass Is Not Associated with Cardiometabolic Risk Factors in Children and Adolescents

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.

Association of prepregnancy physical activity with obesity in offspring: The Japan Environment and Children's Study

OBJECTIVE

The aim of this study was to investigate the association between maternal prepregnancy physical activity (PA) and overweight/obesity in 3-year-old children.

METHODS

Using data from the Japan Environment and Children's Study (a birth cohort study), maternal prepregnancy PA was categorized into low, moderate, and high with the International Physical Activity Questionnaire (IPAQ). The reference group was defined as children born to mothers with moderate PA. The association between prepregnancy PA and overweight/obesity or obesity in children was investigated using univariable and multivariable logistic regression analyses.

RESULTS

Of the 65,245 participants, 48.7%, 32.7%, and 18.6% were born to mothers in the low, moderate, and high PA groups, respectively. Furthermore, 24.9%, 24.6%, and 25.9% of children with overweight/obesity and 9.4%, 9.2%, and 10.4% of children with obesity were born to mothers in the low, moderate, and high PA groups, respectively. The adjusted odds ratios for overweight/obesity in the low and high PA groups were 1.02 (95% CI: 0.98-1.06) and 1.04 (95% CI: 0.98-1.09), and those for obesity were 1.03 (95% CI: 0.97-1.09) and 1.08 (95% CI: 0.99-1.16), respectively.

CONCLUSIONS

Maternal prepregnancy PA was not associated with overweight/obesity or obesity in 3-year-old children.

The Incidence of Body Posture Abnormalities in Relation to the Segmental Body Composition in Early School-Aged Children

Children are exposed to multiple factors that contribute to an increase in body mass and the development of posture defects. The aim of the study is to assess the relationship between the segmental distribution of fat mass and muscle mass and the incidence of body posture abnormalities in early school-aged children. A total of 190 children aged 7-9 were included in the research project. The examined children were divided according to age (class level) into three groups. Height, weight and body composition, BMI, and body posture were determined. Thoracic and lumbar spine abnormalities occurred most frequently in the examined children (7-95%, 8-92%, 9-89.5%). During the assessment of the segmental body composition, the lowest fat-fat-free index was found in the trunk. The number of abnormalities of the cervical spine, pelvis, and lower extremities increases with age. The number of abnormalities of the thoracic and lumbar spine, as well as of upper extremities and the pectoral girdle decreases with age. Body posture abnormalities are correlated with body composition and in particular with the fat mass percentage. The segmental body com-position analyzer can be used to screen for posture defects.

Association of the triglyceride-glucose index with weight-adjusted appendicular lean mass in Chinese adolescents aged 12-18 years old

There is no study exploring the association between triglyceride-glucose (TyG) index and skeletal muscle mass in Chinese adolescents. Therefore, the objective of this study is to explore the association between TyG index and appendicular lean mass (ALM) in Chinese adolescents. In this study, 1336 adolescents (805 boys, 60.25%) aged 12-18 years in China were randomly selected through a stratified cluster sampling. According to the tertiles of TyG index, we separated all participants into three groups, and LM was measured by Bioelectrical Impedance Analysis. The TyG index was negatively related to ALM/weight in Chinese adolescents whether stratified by gender (boys: β = - 0.293; girls: β = - 0.195; all P < 0.001). After adjusting for age and BMI, a significant correlation between the TyG index and ALM/weight was observed only in boys (β = - 0.169, P = 0.001). The highest TyG index tertile was significantly associated with low ALM/weight after adjusting for all covariates in the full sample (OR = 3.04, 95% CI 1.12-8.26, P = 0.029) and boys (OR = 4.68, 95% CI 1.22-17.95, P = 0.025) only in overweight/obese group. Our findings suggested elevated levels of TyG index may be a risk factor of low ALM/weight in Chinese adolescents, especially in boys.

Fat-free/lean body mass in children with insulin resistance or metabolic syndrome: a systematic review and meta-analysis

BACKGROUND

Lean / Fat Free Body Mass (LBM) is metabolically involved in active processes such as resting energy expenditure, glucose uptake, and myokine secretion. Nonetheless, its association with insulin sensitivity / resistance / glucose tolerance and metabolic syndrome remains unclear in childhood.

METHODS

The current investigation aimed to examine the differences in fat-free mass /lean body mass according to the presence of insulin sensitivity/insulin resistance/glucose tolerance/metabolic syndrome in children. A systematic search was carried out in Medline/PubMed, Embase, Scopus, Web of Science, and SciELO, covering the period from each database's respective start to 21 June 2021. Two researchers evaluated 7111 studies according to the inclusion criteria: original human studies, written in English or Spanish, evaluating fat-free mass/lean body mass in children and adolescents including both with and without insulin sensitivity/insulin resistance /glucose tolerance and metabolic syndrome and reported the differences between them in terms of fat free mass/lean body mass. The results of the studies were combined with insulin sensitivity, insulin, resistance, glucose tolerance and metabolic syndrome. The standardized mean difference (SMD) in each study was calculated and combined using the random-effects model. Heterogeneity between studies was tested using the index of heterogeneity (I2), leave-one-out sensitivity analyses were performed, and publication bias was assessed using the Egger and Begg tests.

RESULTS

Finally, 15 studies which compared groups defined according to different glucose homeostasis criteria or metabolic syndrome out of 103 eligible studies were included in this systematic review and 12 studies in the meta-analysis. Meta-analysis showed lower fat-free mass/lean body mass percentage in participants with insulin resistance/glucose tolerance/metabolic syndrome (SMD -0.47; 95% CI, - 0.62 to - 0.32) while in mass units (kg), higher values were found in the same group (SMD, 1.01; 95% CI, 0.43 to 1.60).

CONCLUSIONS

Our results identified lower values of fat-free mass/lean body mass (%) in children and adolescents with insulin resistance/glucose tolerance/metabolic syndrome and higher values of fat-free mass/lean body mass when these are expressed in kg. The evidence of the impact of lean mass on children's glucose homeostasis or metabolic syndrome is limited, so future studies research should focus on explaining the effect of fat-free mass/lean body mass on different metabolic outcomes. Moreover, it may be interesting to evaluate the quality (muscle density) or functional (muscle strength) outcomes in addition to both absolute (kg) and relative (%) values in future studies. The systematic review was prospectively registered at PROSPERO (registration number CRD42019124734; available at: http://www.crd.york.ac.uk/prospero [accessed: 05 April 2019]).

Long-term changes in body composition and their relationships with cardiometabolic risk factors: A population-based cohort study

The aim of the present study was to classify the latent body fat trajectories of Chinese adults and their relationships with cardiometabolic risk factors. Data were obtained from the China Health Nutrition Survey for 3,013 participants, who underwent six follow-up visits between 1993 and 2009. Skinfold thickness and other anthropometric indicators were used to estimate body composition. The latent growth model was used to create fat mass to fat-free mass ratio (F2FFMR) trajectory groups. Blood pressure, fasting plasma glucose, total cholesterol, triglycerides, and high- and low-density lipoprotein-cholesterol were measured in venous blood after an overnight fast. Logistic regression was used to explore the relationships of F2FFMR trajectory with cardiometabolic risk factors. In men, four types of F2FFMR trajectory were identified. After adjustment for behavioral and lifestyle factors, age, and weight status, and compared with the Low stability group, the High stability group showed a significant association with diabetes. In women, three types of F2FFMR trajectory were identified. Compared to the Low stability group, the High stability group showed significant associations with diabetes and hypertension after adjustment for the same covariates as in men. Thus, in this long-term study we have identified three F2FFMR trajectory groups in women and four in men. In both sexes, the highly stable F2FFMR is associated with the highest risk of developing diabetes, independent of age and body mass. In addition, in women, it is associated with the highest risk of hypertension, independent of age and body mass.

Case Report: Low Bone and Normal Lean Mass in Adolescents With Complete Androgen Insensitivity Syndrome

INTRODUCTION

Osteopenia and osteoporosis have been reported in adults with Complete Androgen Insensitivity Syndrome (CAIS). Little is known about changes in bone mineral density (BMD) in adolescents with CAIS and whether it is affected by early gonadectomy. Body composition data have not been reported.

METHODS

Single-center, retrospective study of CAIS adolescents who underwent dual-energy x-ray absorptiometry (DXA) (Hologic, Horizon A). Body composition is presented as lean and fat mass indices (LMI, FMI). Z-scores for lumbar spine areal BMD (LBMD), total body less head (TBLH), bone mineral content (BMC), LMI, and FMI were calculated using female normative data. Results are expressed as median and min, max.

RESULTS

Six females with genetically confirmed CAIS were identified-one with intact gonads and five with history of gonadectomy at 2-11 months. In the subject with intact gonads, LBMD-Z and TBLH BMC-Z were -1.56 and -1.26, respectively, at age 16 years. Among those with gonadectomy, LBMD-Z was -1.8 (-3.59 to 0.49) at age 15.6 years (12-16.8) and decreased in all three subjects who had longitudinal follow-up despite hormone replacement therapy (HRT). Adherence to HRT was intermittent. LMI-Z and FMI-Z were 0.1 (-1.39 to 0.7) and 1.0 (0.22 to 1.49), respectively.

CONCLUSIONS

These limited data indicate that adolescents with CAIS have bone mass deficit. Further studies are needed to understand the extent of BMD abnormalities and the effect of gonadectomy, especially early in childhood, and to establish the optimal HRT regimen for bone accrual. Data on lean mass are reassuring.

Association of Predicted Lean Body Mass and Fat Mass With Incident Diabetic Nephropathy in Participants With Type 2 Diabetes Mellitus: A Post Hoc Analysis of ACCORD Trial

BACKGROUND

Lean body mass (LBM) and fat mass (FM) have been shown to have different associations with several chronic diseases but little is known about the sex-specific association of LBM and FM with diabetic nephropathy (DN) risk among participants with diabetes.

METHODS

Participants from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study was used in a post hoc analysis to examine the association of predicted LBM index (LBMI) and FM index (FMI) with incident DN risk (defined as a composite outcome of three types of predefined DN). Because of sex differences in body composition, analyses were conducted separately using sex-specific quartiles of predicted LBMI and FMI.

RESULTS

Of the 9,022 participants with type 2 diabetes (5,575 men and 3,447 women) included in this study, 5,374 individuals developed DN (3,396 in men and 1,978 in women). Higher quartiles of LBMI were associated with a reduced risk of DN while higher quartiles of FMI were associated with an increased higher risk of DN among men but not women. Compared with the lowest quartile, the fully adjusted hazard ratios (HRs) and 95% confidence intervals (CIs)for the highest quartile of predicted LBMI and FMI were respectively 0.83 (95% CI 1.71 - 0.96) and 1.23 (95% CI 1.06-1.43) among men; and 0.92 (95% CI 0.63 - 1.33) and 1.14 (95% CI 0.79 - 1.63) among women.

CONCLUSIONS

Among participants with diabetes, predicted LBMI was inversely associated with risk of DN while predicted FMI was positively associated with an increased risk of incident DN among men but not women. Trial registration: ClinicalTrials.gov., no. NCT00000620.