TRI-PONDERAL MASS INDEX IS USEFUL FOR SCREENING CHILDREN AND ADOLESCENTS WITH INSULIN RESISTANCE

Triponderal mass index and markers of metabolic risk in children and adolescents with obesity

BACKGROUND AND OBJECTIVE

Triponderal mass index (TMI) would estimate excess adiposity better than body mass index (BMI), maintaining stable values during childhood. This work aims to determine the correlation between TMI and markers of metabolic risk as well as set values of TMI that are related to an increase of metabolic risk.

MATERIAL AND METHODS

Multicenter, observational, cross-sectional and prospective study in children under 14 years of age with obesity.

VARIABLES

age, sex, pubertal stage, weight, height, abdominal circumference, BMI, TMI, basal glucose and insulin, HOMA index, blood pressure, lipoprotein profile, transaminases and uric acid. BMI and TMI were expressed according to the values of the Barcelona longitudinal study. Statistical analysis was performed with the SPSS* program.

RESULTS

One hundred and ninety-nine patients (50.3% male), age 11.08 (2.48) years, TMI 19.68 (2.36)kg/m³. Correlation between TMI and abdominal circumference (r=0.571; p=0), insulin (r=0.198; p=0.005), HOMA index (r=0.189; p=0.008) and HDL-c (r=-0.188; p=0.008) was observed. IMT>20.15kg/m³ was associated with insulin≥15mIU/ml (p=0.029) and IMT>20.36kg/m³ with HDL-c<40mg/dl (p=0.023).

CONCLUSIONS

TMI was correlated with increase of abdominal circumference, insulin and HOMA index and decrease of HDL-c. IMT>20kg/m³ can be associated with increased insulin and decreased HDL-c. Therefore, the IMT seems to be a useful parameter in the assessment of pediatric patients with obesity.

Triponderal mass index is as strong as body mass index in the determination of obesity and adiposity

OBJECTIVE

In determining obesity and body adiposity, triponderal mass index (TMI) is as strong an anthropometric measurement as body mass index (BMI). The aim of this study was to develop TMI reference values for Turkish children and adolescents and compare TMI with BMI according to body adiposity and obesity indices.

METHODS

Data from the DAMTCA-II (Determination of Anthropometric Measurements of Turkish Children and Adolescents II) study were used in this cross-sectional study. Data from 4330 children (1931 boys, 2399 girls) ages 6 to 17 y were evaluated, and the TMI percentile values were produced. The predictive power of TMI and BMI for obesity and overweight were done for waist circumference, waist/height ratio, body fat percentage, and upper arm fat area, which are different parameters used to determine body adiposity.

RESULTS

The 3rd, 5th, 10th, 25th, 50th, 75th, 85th, 90th, 95th, and 97th TMI percentiles and mean values were calculated for all children's age and sex. TMI cutoff values were calculated by receiver operating characteristic analysis regarding waist/height ratio 0.5, waist circumference ≥90 percentile, arm fat area ≥85 percentile, and body fat percentage ≥85. TMI and BMI area under the curve values were similar for each of these four measurements. TMI was as robust an index as BMI in demonstrating obesity and adiposity for all age groups in boys and girls. It was concluded that the values >90th percentile (median 15.8 kg/m³) in girls aged ≤10 y, 95th percentile (median 16.2 kg/m³) in girls aged >10 y, >85th percentile (median 14.9 kg/m³) in boys aged ≤12 y and 75th percentile (median value 14.5 kg/m³) in boys aged >12 y are critical values for TMI when evaluating adiposity and obesity.

CONCLUSIONS

We considered that TMI is as effective as BMI in terms of waist/height ratio, waist circumference, arm fat area, and body fat percentage in determining overweight and obesity in children. The ages at which TMI showed distinct variation were determined for both sexes.

Insulin-resistance in paediatric age: Its magnitude and implications

Insulin resistance (IR) is insulin failure in normal plasma levels to adequately stimulate glucose uptake by the peripheral tissues. IR is becoming more common in children and adolescents than before. There is a strong association between obesity in children and adolescents, IR, and the metabolic syndrome components. IR shows marked variation among different races, crucial to understanding the possible cardiovascular risk, specifically in high-risk races or ethnic groups. Genetic causes of IR include insulin receptor mutations, mutations that stimulate autoantibody production against insulin receptors, or mutations that induce the formation of abnormal glucose transporter 4 molecules or plasma cell membrane glycoprotein-1 molecules; all induce abnormal energy pathways and end with the development of IR. The parallel increase of IR syndrome with the dramatic increase in the rate of obesity among children in the last few decades indicates the importance of environmental factors in increasing the rate of IR. Most patients with IR do not develop diabetes mellitus (DM) type-II. However, IR is a crucial risk factor to develop DM type-II in children. Diagnostic standards for IR in children are not yet established due to various causes. Direct measures of insulin sensitivity include the hyperinsulinemia euglycemic glucose clamp and the insulin-suppression test. Minimal model analysis of frequently sampled intravenous glucose tolerance test and oral glucose tolerance test provide an indirect estimate of metabolic insulin sensitivity/resistance. The main aim of the treatment of IR in children is to prevent the progression of compensated IR to decompensated IR, enhance insulin sensitivity, and treat possible complications. There are three main lines for treatment: Lifestyle and behavior modification, pharmacotherapy, and surgery. This review will discuss the magnitude, implications, diagnosis, and treatment of IR in children.

The triponderal mass index as a measure of adiposity in pediatric survivors of acute lymphoblastic leukemia: a cross-sectional study

Acute lymphoblastic leukemia (ALL) is the most common type of childhood cancer. Treatments of ALL predispose survivors to obesity, which increases the risk of cardiovascular disease and diabetes. The hallmark of obesity is excess fat mass, and adiposity is a superior predictor of cardiometabolic risk when compared to Body Mass Index (BMI), yet clinical measures of adiposity in children are lacking. The Tri-Ponderal Mass Index (TMI) (kg/m³) is a more accurate adiposity measure compared to BMI z-score in the general pediatric population. This cross-sectional study aimed to validate TMI as an adiposity measure against DEXA scan-derived adiposity, and to compare it to BMI z-score, in pediatric ALL survivors. This study was a retrospective chart review of pediatric ALL survivors diagnosed between 2004 and 2015 at McMaster Children’s Hospital, a tertiary pediatric center in Ontario, Canada. One hundred and thirteen patients (Female n = 55, 48.70%) were included, and adiposity was measured using DEXA scans. Exploratory partial correlations and linear regression analyses were adjusted for age, sex, ethnicity, and ALL risk status. Both TMI and BMI z-score correlated with the DEXA-measured fat mass percentage (FM%) (partial correlation TMI versus FM% r = 0.56; p value < 0.0001; BMI z-score versus FM% r = 0.55; p value < 0.0001). In regression analyses, the association of TMI was not inferior to BMI z-score in assessing adiposity (TMI versus FM% estimated unstandardized B 0.80, 95% CI 0.56, 1.02; p value < 0.0001; BMI z-score versus FM% (unstandardized B 0.37, 95% CI 0.26, 0.49; p value < 0.0001). The TMI is a useful clinical adiposity-specific measure in survivors of pediatric ALL.

Excess adiposity and low physical fitness hamper Supine-to-Stand test performance among sedentary adolescents

OBJECTIVE

The aim of this study was to analyze the relationship between body adiposity and physical fitness with performance in the Supine-to-Stand test (STS-test) in sedentary adolescents.

METHODS

Sixty-two adolescents, of both sexes, between 10 and 16 years old, participated in the study. Body mass (BM), height, waist circumference (WC), fat mass (FM), fat-free mass (FFM), right and left handgrip strength (HGS-right, HGS-left), abdominal resistance (ABDO), flexibility (FLEX), and cardiorespiratory fitness (VO_2peak) were measured. Body mass index (BMI), z-score BMI (BMI-z), tri-ponderal mass index (TMI) and waist-to-height ratio (WHtR) were calculated. The STS-test was applied to evaluate the STS-MC by the movement patterns in the execution of the test. The STS-time in seconds (s) was categorized into terciles: fast (FG < 2.0 s), intermediate (IG = 2.0-2.6 s) and slow (SG > 2.6 s). One-way ANOVA, Chi-square, Spearman's correlation coefficient as well as non-parametric tests were used, with significance p ≤ 0.05.

RESULTS

The SG presented higher BMI, BMI-z, TMI, WHtR, FM, %FM, as well as lower averages for %FFM, HGS-right, HGS-left, FLEX, ABDO, VO_2peak, VO_2peak relative to BM (VO_2peakBM) in relation to GF. The BMI, BMI-z, TMI, WC, WHtR and FM showed moderate and direct correlations with STS-time and inverse with STS-MC (p < 0.01). HGS-right, HGS-left, ABDO, and VO_2peakBM showed moderate and an inverse correlation with STS-time (p < 0.05). The VO_2peakBM was moderate and with direct correlations to STS-MC (p < 0.01).

CONCLUSION

It is concluded that excess fat and low physical fitness hamper STS-test performance. Therefore, the STS-test can be used for screening students to assess MC.

Evaluation of clinical, endocrine and metabolic findings in obese children with and without hepatosteatosis

OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) is a common obesity-related comorbidity in childhood. In this study, we aimed to evaluate predictors of NAFLD by comparing clinical, endocrine and metabolic findings in obese children with and without hepatosteatosis.

METHODS

Two hundred and eight obese children aged 6-18 years were included. The patients were divided into group 1 (patients with NAFLD, n=94) and group 2 (patients without NAFLD, n=114). Anthropometric measurements, pubertal stage, lipid profiles, fasting glucose and insulin, homeostatic model of assessment for insulin resistance (HOMA-IR), uric acid, total bilirubin, alanine aminotransferase (ALT), blood urea nitrogen, thyroid-stimulating hormone and free thyroxine parameters were compared retrospectively.

RESULTS

The mean body weight, body mass index (BMI), height, tri-ponderal mass index (TMI), insulin, HOMA-IR, triglyceride, ALT and uric acid values were significantly higher, while high-density lipoprotein-cholesterol (HDL-C) values were significantly lower in group 1. The 70.7% of obese children with hepatosteatosis and 83.9% of those without hepatosteatosis were correctly estimated by parameters including age, gender, ALT, HDL-C, fasting insulin and uric acid values.

CONCLUSIONS

Since obesity-associated hepatosteatosis induces various long-term metabolic impacts in children, early detection is of critical importance. Age, gender, TMI, BMI, ALT, HDL-C, fasting insulin and uric acid values may help to predict the risk of hepatosteatosis. Besides, we assessed whether TMI compared to BMI does not have a better utility in estimating obesity-induced hepatosteatosis in children. This is the first study to show the association between TMI and hepatosteatosis in children.

Adolescent Tri-ponderal Mass Index Growth Trajectories and Incident Diabetes Mellitus in Early Adulthood

PURPOSE

Studies have reported the influence of adolescent obesity on development of adult diabetes, but the effect of the growth pattern during this period has rarely been explored. Also, the tri-ponderal mass index (TMI) was thought to be a better estimation of adolescent body fat levels than the body mass index (BMI), so we sought to investigate whether growth trajectories derived by these two indices could predict incident diabetes.

METHODS

We conducted a study by using the Taipei City Hospital Radiation Building Database, a longitudinal cohort established in 1996. Physical exam results including blood test results were collected annually and the BMI z-score/TMI growth trajectory groups during 13 to 18 years of age were identified using growth mixture modeling. A Cox proportional hazard model for incident diabetes was used to examine the risk of baseline obese status and different BMI/TMI growth trajectories.

RESULTS

Five growth trajectory groups were identified for the BMI z-score and the TMI. During approximately 20 400 person-years follow-up, 33 of 1387 participants developed diabetes. Baseline obesity defined by the BMI z-score and the TMI were both related to adult diabetes. The persistent increase TMI growth trajectory exhibited a significantly increased risk of diabetes after adjusting for baseline obese status and other correlated covariates (hazard ratio: 2.85, 95% confidence interval: 1.01-8.09). There was no association between BMI growth trajectory groups and incident diabetes.

CONCLUSIONS

A specific TMI growth trajectory pattern during adolescence might be critical for diabetes prevention efforts.

Validity and accuracy of body fat prediction equations using anthropometrics measurements in adolescents

BACKGROUND

The pediatric relative fat mass (RFM) has been recently presented and validated as an index for estimating percentage body fat (%BF) in North American children and adolescents. Similar to body mass index (BMI) and tri-ponderal mass index (TMI), RFM uses anthropometric measures (i.e., weight, height and waist circumference) to estimate body composition. The primary purpose of this study was to validate the newly developed RFM equation for %BF prediction in Southern Brazilian adolescents; as secondary objective, we compared %BF estimation from BMI- and TMI-derived equations.

METHODS

A total of 631 individuals (434 boys) aged 11 to 18 were analyzed. Bland-Altman analyses were used to determine concordance between predicted equations and %BF measured by DXA; results are presented using mean difference (i.e., bias) and standard deviation. Sensitivity and specificity were calculated for %BF percentile classifications.

RESULTS

RFM underestimated %BF in 65.2% of boys (- 4.3 ± 2.8%) and 84.8% of girls (- 5.3 ± 2.7%). In contrast, TMI overestimated %BF in 62.9% of boys (4.0 ± 2.9%) and 56.3% (3.5 ± 3.0%) of girls. The performance of BMI showed mixed results; %BF was overestimated in 68.4% of boys (5.0 ± 4.0%) and underestimated in 67.5% of girls (- 3.9 ± 2.6%), all p < 0.001. Although, RFM had the highest specificity for %BF percentile classifications, sensitivity was low and inferior to BMI and TMI.

CONCLUSION

TMI was superior to RFM and BMI in predicting %BF in Southern Brazilian adolescents. Using RFM, BMI or TMI equations for %BF prediction without a population-specific correction factor may lead to incorrect interpretations. We suggest that correction factors should be investigated to improve the accuracy of these surrogate indices for body composition assessment.

LEVEL OF EVIDENCE

Level V, cross sectional descriptive study.

Tri-Ponderal Mass Index as a Screening Tool for Identifying Body Fat and Cardiovascular Risk Factors in Children and Adolescents: A Systematic Review

Because of the limitation of body mass index (BMI) in distinguishing adipose mass from muscle, the tri-ponderal mass index (TMI) has been proposed as a new indicator for better assessing adiposity in children and adolescents. However, it remains unclear whether TMI performs better than BMI or other adiposity indices in predicting obesity status in childhood and obesity-related cardiovascular risk factors (CVRFs) in childhood or adulthood. We searched PubMed, Cochrane Library, and Web of Science for eligible publications until June 15, 2021. A total of 32 eligible studies were included in this systematic review. We found that TMI had a similar or better ability to predict body fat among children and adolescents than BMI. However, most of the included studies suggested that TMI was similar to BMI in identifying metabolic syndrome although TMI was suggested to be a useful tool when used in combination with other indicators (e.g., BMI and waist circumference). In addition, limited evidence showed that TMI did not perform better than BMI for identifying specific CVRFs, including insulin resistance, high blood pressure, dyslipidemia, and inflammation in children and adolescents, as well as CVRFs in adults.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero, CRD42021260356.