Accuracy of prediction equations to assess percentage of body fat in children and adolescents with Down syndrome compared to air displacement plethysmography

Swim, Strength, or Combined Programs: Effect on Health-Related Physical Fitness in Adolescents With Down Syndrome

The adolescent population with Down syndrome (DS) appears to show higher levels of body fat and lower levels of cardiorespiratory fitness or muscle strength than their peers without disabilities. There is a need to create physical activity programs to improve these data. The aim of this research was to determine the effects of a 16-week swimming program, strength program, and combined program (swimming and strength training) on body composition and health-related physical fitness on adolescents with DS and to assess whether there are differences in the results of the different training programs. Forty-five adolescents (17 female and 28 male; average age 15.5 [1.53] years) with DS were recruited and randomized to three groups (swim [n = 15], strength [n = 15], and combined [n = 15]). Results showed that the swim group had significant improvements in all health-related physical fitness variables and there was an improvement in some body-composition variables (p < .05). The strength and combined groups obtained minor improvements in the variables analyzed. In summary, a 16-week swim program consisting of three sessions of 60 min is able to improve levels of body composition and health-related physical fitness in adolescents with DS. The swim training program seems to be more effective in improving body composition and health-related physical fitness than the strength or combined program. These findings could be useful in different special-education centers due to the predisposition shown by the population with DS to this sport modality.

Serum apelin-12 and obesity-related markers in Egyptian children with Down syndrome

Children with Down syndrome (DS) exhibit higher overweight/obesity rates than their typically developing peers. Apelin-12 is a bioactive adipokine that exerts vital roles in obesity-related cardiometabolic comorbidities. To date, apelin-12 has not been investigated in obese-DS. This study aimed to explore the possible association between serum apelin-12 and obesity-related markers and to evaluate the efficiency of apelin-12 in the prediction of metabolic syndrome (MetS) in obese-DS compared to BMI Z-score matched obese-control. The cross-sectional study included 150 prepubertal children classified into three groups; obese-DS (n = 50), obese-control (n = 50), and normal-weight-control (n = 50). Anthropometric parameters, body adiposity, fasting serum levels of blood glucose (FBG), insulin, lipid profile, and apelin-12 were evaluated. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated from FBG and insulin. MetS was defined using Adult Treatment Panel III criteria modified for the pediatric age group. ROC curves were analyzed to evaluate the efficiency of apelin-12 in predicting MetS in obesity groups. Obese-DS exhibited higher body adiposity with marked central fat distribution, atherogenic lipid profile, and higher HOMA-IR compared to obese-control. Apelin-12 was significantly higher in obese-DS and obese-DS with MetS compared to obese-control and obese-control with MetS respectively (p < 0.001). The increase in apelin-12 with higher obesity grades was pronounced in obese-DS. Apelin-12 strongly correlated with body adiposity, several MetS risk factors, and HOMA-IR in obese-DS. Significantly higher AUC for apelin-12 in the diagnosis of MetS among obese-DS than obese-control (AUC = 0.948 vs. AUC = 0.807; p = 0.04).

CONCLUSIONS

 The current study supports the crucial role of apelin-12 in obesity-related clinical and biochemical markers and in MetS in obese-DS and obese-control. Serum apelin-12 is a potential diagnostic biomarker for MetS with greater performance in obese-DS than obese-control raising its potential for clinical and therapeutic applications.

WHAT IS KNOWN

• Obese-DS children displayed excess body adiposity, Pronounced central fat distribution, atherogenic lipid profile, higher HOMA-IR, and higher prevalence of MetS than obese-control.

WHAT IS NEW

• Higher serum apelin-12 was observed in obese-DS and obese-DS with MetS than obese-control and obese-control with MetS respectively. The increase in apelin-12 level with increasing obesity grades was more pronounced in obese-DS. • Apelin-12 strongly correlated with obesity-related markers and MetS components in obese-DS. Apelin-12 performed better as a diagnostic biomarker for MetS in obese-DS than obese-control.

Effectiveness of exergames programme to modify body composition and health-related physical fitness in adolescents with down syndrome after COVID-19 quarantine

AIMS

to determine the effect of a 20-week exergame program on different indicators of body composition and components of health-related physical fitness in adolescents with Down syndrome. Methods and Procedures Outcomes: 49 adolescents (19 female and 30 males; average age, 14.19 ± 2.06 years) with Down syndrome were recruited and randomized to two groups (control group vs. intervention group). Adolescents allocated in the control group carried out a physical activity program three times a week for 20 weeks meanwhile adolescents allocated in the exercise group performed an exergame program three times a week for 20 weeks.

RESULTS

The exercise group had significant improvements in all health-related physical fitness variables and there is an improvement in some body composition variables (p < 0.05).

CONCLUSIONS AND IMPLICATIONS

20 week exergame program consisting of 3 sessions of 60 minutes is able to improve levels of body composition and health-related physical fitness in adolescents with Down syndrome.Highlights Research in body composition and health-related physical fitness of people with Down syndrome has revealed that an exergame programme increases levels of health-related physical fitness in adolescents with Down syndromeAn exergame programme can improve differences in markers of body composition between the control group and the intervention groupThe intervention group that performed the exergame programme showed increases in health-related physical fitness levels after 20 weeks of intervention.The control group that performed a based on developing motor behaviour programme did not show differences in body composition or health-related physical fitness after 20 weeks of intervention.

Evaluation of Skinfold Techniques in People with Down Syndrome: Development of a New Equation

The primary aim of this study was to evaluate the accuracy of skinfold thickness (SFT) measurements for the estimation of %Fat when compared to dual energy X-ray absorptiometry (DXA) in individuals with Down syndrome (DS). The secondary aim was to develop a new SFT-based body fat equation (SFT_NICKERSON). SFT-based %Fat was estimated using a body fat equation from González-Agüero (SFT_G-A) and body density conversion formulas from Siri (SFT_SIRI) and Brozek (SFT_BROZEK). Criterion %Fat was measured via DXA. SFT_G-A, SFT_SIRI, and SFT_BROZEK were significantly lower than DXA (mean differences ranged from -7.59 to -13.51%; all p < 0.001). The SEE values ranged from 3.47% (SFT_BROZEK) to 8.60% (SFT_G-A). The 95% limits of agreement were greater than ±10% for all comparisons. Mid-axilla and suprailium were significant predictors of %Fat (both p < 0.05). %Fat SFT_NICKERSON = 10.323 + (0.661 × mid-axilla) + (0.712 × suprailium). Age and all other skinfold sites were not statically significant in the regression model (all p > 0.05). Current findings indicate that SFT_G-A, SFT_SIRI, and SFT_BROZEK erroneously place an individual with excessive adiposity in a normal healthy range. Accordingly, the current study developed a new equation (SFT_NICKERSON) that can easily be administered in people with DS in a quick and efficient time frame. However, further research is warranted in this area.

Serum adiponectin, body adiposity and metabolic parameters in obese Egyptian children with Down syndrome

OBJECTIVES

Children with Down syndrome (DS) have a higher risk for obesity. Adiponectin plays a crucial role in obesity-related cardiometabolic comorbidities. The study aimed to explore whether body adiposity indicators, the frequency of metabolic syndrome (MetS) and its components, serum adiponectin and insulin resistance indices as well as the validity of serum adiponectin as a biomarker for MetS are different in prepubertal obese-DS children compared to matched obese-controls.

METHODS

Cross-sectional study included 150 prepubertal children classfied into three groups; obese-DS (n=50), obese-control (n=50) and normal-weight-control (n=50). Participants were evaluated for waist-circumference (WC), body adiposity, serum triglycerides, HDL-C, adiponectin and Homeostasis-Model-Assessment of Insulin-Resistance (HOMA-IR). MetS was defined using modified Adult Treatment Panel III-criteria.

RESULTS

Obese-DS had significantly higher WC, %body fat, total-fat mass, trunk-fat mass, trunk/appendicular-fat mass ratio, triglycerides, insulin and HOMA-IR and significantly lower HDL-C values compared to obese-control. Higher prevalence of MetS and its components were observed in obese-DS that was evident at younger age. Adiponectin was significantly lower in obese-DS compared with obese-control and in obese-DS children with MetS compared to obesecontrol with MetS. The decrease in adiponectin with increasing grades of obesity was pronounced in obese-DS. Adiponectin exhibited strong correlations with body adiposity, several MetS components and HOMA-IR in obese-DS. Adiponectin performed better as a biomarker for MetS among obese-DS (AUC=0.808) than obese-control (AUC=0.674).

CONCLUSIONS

Prepubertal obese-DS displayed excess body adiposity with pronounced central fat distribution, atherogenic lipid profile and higher insulin resistance compared to matched obese-control. Adiponectin performed better as potential biomarker of MetS in obese-DS than obese-control.

Bidirectional longitudinal associations of fatness with physical fitness in adolescents with Down syndrome. The UP&DOWN Longitudinal study

BACKGROUND

The aim of this study was to examine the bidirectional longitudinal associations of several markers of fatness and physical fitness in adolescents with Down syndrome.

METHODS

This study comprised a total of 111 adolescents (41 females), aged from 11 to 20 years with complete data at the baseline. We had a drop-out of <10% from the baseline to the 2-year follow-up. The ALPHA health-related fitness test battery for youth was used.

RESULTS

Our results show that all fatness variables at the baseline were associated with a 2-year change in cardiorespiratory fitness (β ranging from -0.32 to -0.38; all p < .05), but not with muscular and motor fitness (p > .05). However, no associations were found between physical fitness components as predictors and fatness indicators (p > .05).

CONCLUSIONS

Results suggest that reducing fatness during adolescence might represent a modifiable factor to improve cardiorespiratory fitness at the 2-year follow-up, but not vice versa since associations were not bidirectional.

Down Syndrome Is a Metabolic Disease: Altered Insulin Signaling Mediates Peripheral and Brain Dysfunctions

Down syndrome (DS) is the most frequent chromosomal abnormality that causes intellectual disability, resulting from the presence of an extra complete or segment of chromosome 21 (HSA21). In addition, trisomy of HSA21 contributes to altered energy metabolism that appears to be a strong determinant in the development of pathological phenotypes associated with DS. Alterations include, among others, mitochondrial defects, increased oxidative stress levels, impaired glucose, and lipid metabolism, finally resulting in reduced energy production and cellular dysfunctions. These molecular defects seem to account for a high incidence of metabolic disorders, i.e., diabetes and/or obesity, as well as a higher risk of developing Alzheimer’s disease (AD) in DS. A dysregulation of the insulin signaling with reduced downstream pathways represents a common pathophysiological aspect in the development of both peripheral and central alterations leading to diabetes/obesity and AD. This is further strengthened by evidence showing that the molecular mechanisms responsible for such alterations appear to be similar between peripheral organs and brain. Considering that DS subjects are at high risk to develop either peripheral or brain metabolic defects, this review will discuss current knowledge about the link between trisomy of HSA21 and defects of insulin and insulin-related pathways in DS. Drawing the molecular signature underlying these processes in DS is a key challenge to identify novel drug targets and set up new prevention strategies aimed to reduce the impact of metabolic disorders and cognitive decline.

The effect of swimming program on body composition levels in adolescents with Down syndrome

BACKGROUND

Down syndrome has been associated with more than 80 clinical characteristics such as diabetes, cardiovascular problems or obesity.

AIMS

The current study determined the effect of a 36 weeks swimming program on different indicators of body composition in adolescents with Down syndrome.

METHODS AND PROCEDURES OUTCOMES

45 adolescents with Down syndrome were recruited and randomized to two groups (control group vs. exercise group). Adolescents allocated in the control group carried out a recreational swimming program twice a week during 36 weeks meanwhile adolescents allocated in the exercise group did exercise three time a week during 36 weeks. BMI, Waist circumference, waist-to-height ratio, triceps, subscapular, suprailiac and thigh skinfold were measured.

RESULTS

ANCOVA tests were used to evaluate differences between groups in post-test intervention. Repeated measures of ANOVA were performed in order to assess differences in pre-test intervention in each group. t test were carried out to compare the pre-post-intervention differences in physical characteristics and body composition within each group. The exercise group had significant improvements in all variables of body composition (p < 0.05) except in subscapular and thigh skinfold.

CONCLUSIONS AND IMPLICATIONS

The results suggest that a 36 weeks swimming program consisting of 3 sessions of 50 minutes is able to decrease levels of body composition in a sample of adolescents with Down syndrome. The findings indicate that it would be important to generate high intensity sports programs in sports associations in order to obtain positive impact on body composition levels within this population.

Inflammation and fatness in adolescents with and without Down syndrome: UP & DOWN study

BACKGROUND

The main objective of this study was to describe the inflammatory status of adolescents with Down syndrome (DS) and their relationship with adiposity.

METHODS

Ninety-five adolescents with DS (44.2% girls) and a control group of 113 adolescents (47.8% girls), aged between 11 and 18 years old, from the UP & DOWN study were included in this substudy. Serum C-reactive protein, C3 and C4 complement factors, total proteins, interleukin-6, tumour necrosis factor-α, insulin, cortisol, leptin, adiponectin, galactin-3 and visfatin were analysed; homeostatic model assessment index was calculated. In order to evaluate adiposity, we measured the following body fat variables: weight, height, waist circumference and skinfold thicknesses. Birth weight was obtained by questionnaire. In addition, body mass index, waist-to-height ratio (WHtR) and body fat percentage (BF%) were calculated.

RESULTS

Down syndrome group showed higher levels of body mass index, WHtR, waist circumference, BF% and lower birth weight than controls (P < 0.001). In the general linear model in the total sample, WHtR was positively associated with C3 and C4 (P < 0.001) as well as with leptin levels (P = 0.015). BF% was positively associated with total proteins (P = 0.093) and leptin levels (P < 0.001). DS was positively associated with total proteins (P < 0.001), C3 (P = 0.047) and C4 (P = 0.019). Despite the higher levels of adiposity found in DS group, no direct association was found between BF% and leptin levels, comparing with the control group.

CONCLUSIONS

These findings suggest that abdominal obesity should be controlled in adolescents because of its relationship with acute phase-inflammatory biomarkers but especially in DS adolescents who may show a peculiar metabolic status according to their relationship between adiposity and inflammatory biomarkers.

Agreement Between 2 Segmental Bioimpedance Devices, BOD POD, and DXA in Obese Adults

This study examined the agreement between 2 segmental bioimpedance analysis (BIA) devices, air displacement plethysmography (BOD POD), and dual energy X-ray absorptiometry (DXA) for estimating body composition in obese adults. Fifty obese adults (25 men and 25 women; age = 34.20 ± 11.19 years; BMI = 36.14 ± 5.33 kg/m²) had their body fat percentage (BF%) and fat-free mass (FFM) evaluated with 2 segmental BIA devices (InBody 230 and InBody 720), BOD POD, and DXA (Lunar iDXA). Body composition via the BOD POD was determined using the Siri equation whereas manufacturer-based equations generated metrics (ie, BF% and FFM) for the InBody devices. The effect size of the mean differences for all BF% and FFM comparisons were trivial (Cohen's d < 0.20). The standard error of estimate (SEE), total error (TE), and 95% limits of agreement (LOAs) were low for both segmental BIA devices when compared to DXA (SEE < 2.26% and 2.35 kg; TE < 2.58% and 2.66 kg; 95% LOAs < ± 4.94% and 4.86kg). The error for BOD POD was also low when compared to DXA (SEE = 2.39% and 2.57 kg; TE = 2.34% and 2.56 kg; 95% LOAs = 4.63% and 5.06 kg). Validity statistics were slightly higher, but considered acceptable, when comparing the segmental BIA devices against BOD POD (SEE < 3.37% and 3.63 kg; TE < 3.44% and 3.79 kg; 95% LOAs < ± 6.62% and 7.19 kg). Lastly, the 2 segmental BIA devices produced nearly identical validity statistics when compared to each other. However, both BIA devices revealed proportional bias for BF% and FFM when compared to the BOD POD and DXA (all p < 0.05). The current study's findings indicate the InBody 230 is interchangeable with the InBody 720 in obese adults. Also, the trivial effect size, when compared against the BOD POD and DXA, suggest the InBody devices could be used for estimating group BF% and FFM. In contrast, the significant proportional bias demonstrates the BIA devices are not acceptable for individual estimates of body composition in an obese clinical population.

Changes in Body Composition and Physical Fitness in Adolescents with Down Syndrome: The UP&DOWN Longitudinal Study

Background: Adolescents with Down syndrome (DS) demonstrate higher values of body composition and lower levels of physical fitness when compared with their peers with typically developing (TD) or their peers with intellectual disability but without DS. Objective: To examine, during a 2-year period, changes in indicators of body composition and physical fitness components in TD adolescents and adolescents with DS. Methods: Hundred adolescents with DS (64 males) aged 11-20 years old were matched by sex to 163 TD adolescents (108 males) aged 12-18. Indicators of body composition were determined by body mass index (BMI), waist circumference, waist-to-height ratio, skinfolds, and percentage of body fat (%BF). Components of physical fitness were assessed by the Assessing Level of Physical Activity (ALPHA) health-related fitness test battery for youth. Results: In the 2-year follow-up, significant (p < 0.05) decreases in BMI and increases in cardiorespiratory fitness and handgrip strength were seen for both groups; decreases in %BF were only seen for participants with DS; and increases in standing long jump were seen only for TD adolescents. Conclusions: Results indicate that during the 2-year study period, there were significant decreases in BMI and significant increases in handgrip strength and cardiorespiratory fitness in the TD group. For participants with DS, there was a significant decrease in %BF. However, participants with DS did not exhibit improvements in physical fitness.

The prevalence of obesity in children and young people with Down syndrome

BACKGROUND

Overweight and obesity is a growing concern among individuals with intellectual disabilities; however, little is known about the prevalence among children and youth with Down syndrome (CYDS). The purpose of this study was to determine the prevalence of overweight/obesity among CYDS in South West Ireland.

METHODS

This cross-sectional study measured height and weight of 61 CYDS aged 4-16 years. Body mass index (BMI) was calculated and percentage body fat (PBF) was measured using bio-electrical impendence analysis (BIA).

RESULTS

Using the International Obesity Task Force BMI cut-offs, 51.6% of males and 40% of females were overweight/obese compared to 32% and 14.8%, respectively, using PBF. The mean PBF for males was 18.76 versus females 22.38 (p < .05). There is a higher prevalence of overweight/obesity, particularly in males, compared to the general population of children.

CONCLUSIONS

The difference in estimation of overweight/obesity between BMI and BIA has implications for research and clinical practice.

Increased levels of inflammatory plasma markers and obesity risk in a mouse model of Down syndrome

Down syndrome (DS) is caused by the trisomy of human chromosome 21 and is the most common genetic cause of intellectual disability. In addition to the intellectual deficiencies and physical anomalies, DS individuals present a higher prevalence of obesity and subsequent metabolic disorders than healthy adults. There is increasing evidence from both clinical and experimental studies indicating the association of visceral obesity with a pro-inflammatory status and recent studies have reported that obese people with DS suffer from low-grade systemic inflammation. However, the link between adiposity and inflammation has not been explored in DS. Here we used Ts65Dn mice, a validated DS mouse model, for the study of obesity-related inflammatory markers. Ts65Dn mice presented increased energy intake, and a positive energy balance leading to increased adiposity (fat mass per body weight), but did not show overweight, which only was apparent upon high fat diet induced obesity. Trisomic mice also had fasting hyperglycemia and hypoinsulinemia, and normal incretin levels. Those trisomy-associated changes were accompanied by reduced ghrelin plasma levels and slightly but not significantly increased leptin levels. Upon a glucose load, Ts65Dn mice showed normal increase of incretins accompanied by over-responses of leptin and resistin, while maintaining the hyperglycemic and hypoinsulinemic phenotype. These changes in the adipoinsular axis were accompanied by increased plasma levels of inflammatory biomarkers previously correlated with obesity galectin-3 and HSP72, and reduced IL-6. Taken together, these results suggest that increased adiposity, and pro-inflammatory adipokines leading to low-grade inflammation are important players in the propensity to obesity in DS. We conclude that DS would be a case of impaired metabolic-inflammatory axis.

Comparison of bioelectrical impedance and DXA for measuring body composition among adults with Down syndrome

BACKGROUND

Individuals with Down syndrome (DS) have been shown to display high levels of adiposity and a unique body shape. Laboratory methods used to evaluate body composition might be too cumbersome for this special population. Therefore, field methods are desired due to their non-invasive nature.

OBJECTIVE

to determine the agreement between dual energy x-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA) for measuring body fat percentage BF% and fat-free mass (FFM) among adults with DS.

METHODS

Twenty-one adults (male: n = 10; female: n = 11) with DS participated in this study. BF% and FFM were determined by DXA and BIA.

RESULTS

There was a significant mean difference between DXA and BIA for BF% (41.33 ± 8.98% and 34.23 ± 9.22%, respectively) and FFM (41.80 ± 8.74 kg and 46.95 ± 9.92 kg, respectively). The correlation between the two devices for BF% and FFM were significant (r = 0.89 and r = 0.94, respectively, p < 0.001 for both). The standard error of estimate and total error values were 4.38% and 8.27%, respectively, for BF% and 3.04 kg and 6.13 kg, respectively, for FFM. The 95% limits of agreement ranged from -15.64% below to 1.46% above the constant error (CE) of -7.09% for BF% and from -1.52 kg below to 11.83 kg above the CE of 5.15 kg for FFM.

CONCLUSIONS

The significant mean differences and large amount of individual error suggest that BIA may not be an appropriate surrogate body composition measure compared to DXA in adults with DS.

Comparison of body adiposity index (BAI) and air displacement plethysmograph with estimations of % body fat in adults with Down's syndrome

BACKGROUND/OBJECTIVES

The aim of this study was to verify the agreement between body fat percentage (%BF) values evaluated by air displacement plethysmograph (ADP) and body adiposity index (BAI) in adults with Down's syndrome (DS).

SUBJECTS/METHODS

Forty-five adults with DS volunteered to participate in this study (19 women; age 28.7±8.5 years and 26 men; age 29.1±8.8 years). The %BF was measured by ADP (%BF_ADP) and estimated by anthropometric measures [%BF=(hip circumference/height)^1.5-18] (%BF_BAI). Agreement between methods was evaluated by paired t-test, Pearson's correlation coefficient and Bland-Altman analysis.

RESULTS

Although high correlation coefficients were found between %BF_ADP and %BF_BAI for women (r=0.78, P<0.05) and men (r=0.87, P<0.05), significant differences were observed between methods for both sexes (38.9±8.9 vs 42.5±8.5% for women, and 25.8±11.3 vs 32.6±5.4% for men in %BF_ADP and %BF_BAI, respectively). Moreover, Bland-Altman analysis showed that the mean error estimate was +3.6 (95%CI, -7.59 to 14.79) in women and +6.74 (95%CI, -7.25 to 20.72) in men.

CONCLUSIONS

The results indicate that BAI seems to be a limited method to evaluate %BF in women and in men with DS.

Systematic review of field-based physical fitness tests for children and adolescents with intellectual disabilities

BACKGROUND

Testing physical fitness in children and adolescents with intellectual disabilities (ID) can be challenging. This review provides an overview on psychometric properties of field-based physical fitness tests studied in children and adolescents with ID.

METHODS

A literature search was performed in March 2014. Studies were included if they evaluated feasibility, reliability and/or validity of a field-based physical fitness test in children and adolescents with ID.

RESULTS

Twenty-six papers met the inclusion criteria and described 18 tests on body composition (4), muscular strength (4), muscular endurance (6), and cardiorespiratory fitness (4). Best results on feasibility, reliability and/or validity were found for bioelectric impedance analysis, body mass index, grip strength, arm hang and distance run/walk tests. These results were mainly found in adolescents with mild to moderate ID.

CONCLUSION

Some tests were found feasible, reliable and/or valid in subgroups of children and adolescents with ID, but not in children and adolescents with all ages and levels of ID. Further assessment is needed before wider application in all children and adolescents with ID.

The Accuracy of Anthropometric Equations to Assess Body Fat in Adults with Down Syndrome

BACKGROUND

The aim of this study was to verify the accuracy of anthropometric equations to estimate the body density (BD) of adults with Down syndrome (DS), and propose new regression equations.

MATERIALS AND METHODS

Twenty-one males (30.5 ± 9.4 years) and 17 females (27.3 ± 7.7 years) with DS participated in this study. The reference method for BD was air displacement plethysmography (ADP). Also, the BD was estimated by anthropometric equations. The body fat percentage (BF %) was estimated by the Siri equation.

RESULTS

For females, the Durnin and Womersley equation showed no difference from the ADP, but a trend of underestimation was observed. For males, all equations were significantly different for the BF % from ADP. The equations developed in this study showed a high correlation and acceptable agreement with BF % from ADP in both genders.

CONCLUSION

All equations are not valid for DS adults. The new equations developed here were accurate in estimating the BF %.

Percentage of body fat in adolescents with Down syndrome: Estimation from skinfolds

BACKGROUND

Adolescents with Down syndrome (DS) have a unique morphology and body shape, and this needs to be taken into account when assessing body fat percentage (BF%).

OBJECTIVE

To develop a predictive equation from anthropometric variables (skinfolds) for estimating BF% in adolescents with DS.

METHODS

Twenty-three adolescents with DS (7 girls, 16 boys) participated in the study; seven skinfold measurements were taken (biceps, triceps, subscapular, supraspinale, abdominal, front thigh, and medial calf), circumferences and diameters were measured following ISAK recommendations. Total body volume (and then body density) was measured with air displacement plethysmography (ADP); BF% was then calculated. Correlation between anthropometry data and BF% by ADP, and stepwise regression analyses were applied to develop a specific prediction equation.

RESULTS

All the skinfolds, BMI, hip, waist and thigh circumferences correlated with BF% and were included in the regression analysis; sex and triceps were added into the model (R² = 0.89, p < 0.05). Therefore the proposed equation computed as follows: BF% = (0.97 TR) - (8.869·SEX) + 15.6 where TR is triceps skinfolds (mm) and SEX is equal to 0 for female and 1 for male.

CONCLUSIONS

The proposed prediction equation is recommended for the assessment of BF% in adolescents with DS as it is the only one specifically developed and validated in this unique population. It is a cheap, reliable and accessible method that removes the need for use of expensive equipment.

The role of fatness on physical fitness in adolescents with and without Down syndrome: The UP&DOWN study

BACKGROUND/OBJECTIVES

Adolescents with Down syndrome (DS) exhibit higher levels of fatness and low levels of physical fitness compared with those without DS. In adolescents without DS, fatness is tightly associated with physical fitness, but this association is unclear in adolescents with DS. The aim of this study was to examine the association between several markers of fatness and physical fitness in a relative large sample of adolescents with and without DS.

SUBJECTS/METHODS

A total of 111 adolescents with DS (41 females) aged 11-20 years participated in this cross-sectional study. We also included a sex-matched control group (ratio 1:2) of 222 adolescents without DS aged 12-18 years, participating in the UP&DOWN Study. The Assessing Level of Physical Activity (ALPHA) health-related fitness test battery for adolescents was used to assess fatness and physical fitness.

RESULTS

Our results show that fatness is not associated with low levels of physical fitness in adolescents with DS (that is, 3 of the 16 analyses identified differences in physical fitness variables by groups of fatness). In contrast, fatness, as expected, is associated with levels of physical fitness in adolescents without DS (that is, 13 of the 16 analyses identified differences in physical fitness variables by groups of fatness).

CONCLUSIONS

The present finding contributes to new knowledge by suggesting that the role of fatness on physical fitness is different in adolescents with and without DS, and consequently, the poor levels of physical fitness in adolescents with DS may be due to the syndrome rather than the high prevalence of obesity from this population.

Validity of the body adiposity index in adults with Down syndrome

The purpose of this investigation was to determine the agreement between the body adiposity index (BAI) and dual energy X-ray absorptiometry (DXA) for measuring BF% in adults with Down syndrome (DS). Twenty adults (male: n=10; female: n=10) with Down syndrome volunteered to participate in this study. Criterion BF% was determined by DXA and predicted BF% was estimated by the BAI method. There was a significant mean difference (p<0.001) between DXA BF% (39.94±10.80%) and the BAI BF% (42.60±8.19%). The correlation between the two BF% variables was large and significant (r=0.73, p<0.001). However, the standard error of the estimate and total error was 7.79% and 7.86%, respectively. Additionally, the 95% limits of agreement ranged from 12.21% below to 17.52% above the constant error of 2.65%. Our findings suggest that on average, the BAI significantly overestimated BF% when compared to DXA values. Though there was a strong correlation between both methods, the wide limits of agreement suggest there is large amount of individual error when estimating BF% via the BAI. Therefore, the use of the BAI for individuals with DS does not appear to be accurate for estimating BF%.

Measuring body composition in individuals with intellectual disability: a scoping review

BACKGROUND

Research shows obesity to be more prevalent amongst individuals with intellectual disability (ID) making correct measurement of body composition crucial. This study reviewed the validity and reliability of methods used for assessing body composition in individuals with ID.

METHODS

Authors conducted electronic searches through PubMed (1990 to present) and PsycINFO (1990 to present) and assessed relevant articles independently based on scoping review guidelines. Reviewers included primary research related to the validity and reliability of body composition measures on individuals with ID.

RESULTS

Searches identified six articles assessing body composition methods used on individuals with ID including body mass index (BMI), skinfold thickness, bioelectrical impedance analysis (BIA), waist circumference, tibia length, and anthropometric girth measurements. BMI and waist circumference appear suitable measures but skinfold thickness measurements may not be advisable due to participants' noncompliance resulting in a lack of precision and inaccurate results.

CONCLUSIONS

The current literature contains too few well-conducted studies to determine the precision and validity of body composition measures on individuals with ID. There may be a need to devise further regression equations that apply to individuals with specific types of ID in order to increase the reliability and validity of body composition measurements.

Bioelectrical impedance for measuring percentage body fat in young persons with Down syndrome: validation with dual-energy absorptiometry

AIM

Children with Down syndrome have an increased prevalence of obesity, although there is little work describing body composition in this population. The aims of this study were to accurately measure body fat in children with Down syndrome and to identify which existing algorithm best predicts percentage body fat in this population.

METHODS

Seventy children with Down syndrome had anthropometric, bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) data collected to calculate percentage body fat (PBF). Pearson correlations were carried out to assess the relationships of various methods for measuring body fat and Bland-Altman plots to assess systematic error.

RESULTS

Mean PBF was 30.5% for girls and 22.5% for boys. A total of 38% of girls and 23% of boys were obese according to international criteria. PBF as determined by DXA correlated well with PBF by BIA in both girls and boys (r = 0.91 and 0.89, respectively, p < 0.001).

CONCLUSION

There are high rates of obesity in children with Down syndrome. BIA can be used to accurately determine adiposity in this population. We recommend the use of the Schaeffer algorithm for calculation of PBF in children with Down syndrome.