Elsevier

Research in Developmental Disabilities

Volume 32, Issue 5, September–October 2011, Pages 1685-1693
Research in Developmental Disabilities

Fat and lean masses in youths with Down syndrome: Gender differences

https://doi.org/10.1016/j.ridd.2011.02.023Get rights and content

Abstract

The present study aimed at comparing fat and lean masses between children and adolescents with and without Down syndrome (DS) and evaluating the presence of sexual dimorphism. Total and regional fat and lean masses were assessed by dual energy X-ray absorptiometry (DXA) and the percentage of body fat (%BF) by air-displacement plethysmography (ADP) in 31 participants with DS and 32 controls. Waist circumference (WC) was also measured. Analysis of covariance and the Student's t-test were used to compare variables between groups and between sexes within the same group. There were no significant differences in %BF, WC or body mass index (BMI) between groups. Females with DS showed higher fat and lean masses in the trunk, and lower fat and lean masses in the lower limbs compared with females without DS (all p  0.05). Males with DS showed higher fat masses in the whole body and upper limbs, and lower lean masses in the whole body and lower limbs compared with males without DS (all p  0.05). Females in both groups showed higher levels of fat, and lower levels of lean than did their respective males (all p  0.05). Youths with DS showed higher fat and lower lean than their non-DS peers. The increased truncal fat in females with DS might indicate a higher risk of metabolic syndrome in this group. Sexual dimorphism in youths with and without DS was very similar. BMI, WC and %BF were not effective indicators of increased risk in youths with DS.

Highlights

► Youths with Down syndrome have different fat and lean distributions than controls. ► Their sexual dimorphism looks similar than the observed in controls. ► Youths with DS could be at higher risk of metabolic syndrome.

Introduction

Increased adiposity characterized by a higher percentage of body fat (%BF) during childhood and adolescence is related to a greater risk of premature illnesses, death from coronary heart disease, hypertension and type 2 diabetes mellitus later in life (Dietz, 1998, Ebbeling et al., 2002, Maffeis and Tato, 2001). Low lean mass is associated with decreased skeletal muscle tissue (Calbet et al., 2008), which that in turn, reduces the functional capacity and the maximum oxygen consumption that is a marker of health in youth and is also associated with increased cardiovascular health later in life (Ortega et al., 2005, Ortega et al., 2008). Although certain clinical studies indicate that a common characteristic of youths with Down syndrome (DS) is to have light to moderate obesity (Chumlea and Cronk, 1981, Cronk et al., 1985, Hawn et al., 2009, Rubin et al., 1998), and that no difference in fat-free mass can be found when compared with youths without DS (Luke, Sutton, Schoeller, & Roizen, 1996), soft-tissue body composition in children and adolescents with DS has not been sufficiently studied (González-Agüero et al., 2010).

Although cardiovascular disease is not one of the most common disorder related to mortality in this population (Coppus et al., 2008, Prasher, 1993, Thase, 1982) and despite the fact that persons with DS may have fewer atherosclerotic risk factors than others with intellectual disability without DS (Draheim, McCubbin, & Williams, 2002), the continuous increase in life expectancy in the DS population (from 9 to 55 years and older during the last 70 years) (Bittles and Glasson, 2004, Glasson et al., 2002, Smith, 2001) together with high levels of adipose tissue (especially in the trunk) (Dietz, 1998, Ebbeling et al., 2002, Maffeis and Tato, 2001, Ortega et al., 2005, Ortega et al., 2008) might be a future health issue.

In this regard, Bronks and Parker (1985) described that although the %BF assessed with anthropometry in participants with DS did not significantly change with age, it was consistently high at all ages, suggesting that fat mass accumulation occurs prior to adulthood.

In adults, studies assessing the %BF by dual energy X-ray absorptiometry (DXA) showed higher levels of fat mass and lower levels of lean mass in participants with DS compared with age- and sex-matched controls without DS (Baptista et al., 2005, Guijarro et al., 2008).

Air-displacement plethysmography (ADP) has been used to assess body composition in children and adolescents because of its accuracy and validity of estimation at the individual level (Fields and Goran, 2000, Parker et al., 2003). However, to our knowledge only one study assessed DS adults with ADP (Usera, Foley, & Yun, 2005). In addition, DXA offers the possibility of performing regional analyses (trunk, upper and lower limbs) of fat and lean masses.

On the other hand, due to the high cost and large dimensions of those two methods, a limited number of studies have been performed on DS populations (Angelopoulou et al., 1999, Baptista et al., 2005, Guijarro et al., 2008).

The difficult conditions of these two methods make them unsuitable for field and clinical use; therefore other methods such as anthropometry are also widely used. Waist circumference (WC) seems to be one of the best anthropometric indicator for increased risk of metabolic syndrome in healthy children (Moreno et al., 2002); however no data on populations with DS can be found on this regard. It is important to note that we used a combination of three methods (DXA, ADP and WC) in order to better evaluate the body composition of this population, and to assess the effectiveness of WC as a predictor of high adiposity levels in a population with DS.

Lastly, due to the lack of information related to body composition in youths with DS, it is still unknown whether the common sexual dimorphism presents in youths without DS is also present in children and adolescents with DS.

Thus the aims of the present study were: (1) to compare total and regional distributions of fat and lean masses between male and female children and adolescents with and without DS; (2) to investigate whether WC can accurately detect those individuals with an elevated level of adiposity; and (3) to evaluate the presence of sexual dimorphism in children and adolescents with DS.

Section snippets

Participants

A total sample of 31 children and adolescents with DS (14 females/17 males, aged 10–19 years) were recruited from different schools and institutions of Aragón (Spain). An age- and sex-matched control group composed of 32 participants (13 females/19 males) without DS was recruited from a public school also in Aragón. All participants without DS were healthy, without known illness and free of medication for at least 3 months before the beginning of the study.

Full clinical histories, including

Physical characteristics

Age and physical characteristics of the participants are summarized in Table 1. In general, participants with DS were lighter and smaller than those without DS (all p  0.05). No differences in age, BMI and WC were observed between groups or between genders within the same group.

Percentage of body fat

The %BF assessed by ADP and DXA is presented in Table 2. Females in both groups (with and without DS) had a higher %BF than the males from their respective groups (all p  0.05). No differences between groups were observed

Discussion

Although some previous studies have evaluated body composition in adults with DS using either DXA or ADP (Baptista et al., 2005, Usera et al., 2005), to our knowledge, this is the first study that includes body composition assessment in children and adolescents with DS using DXA, ADP and WC at the same time. The main finding of the present study is that, despite similar values of WC, BMI and %BF (both with DXA and ADP) between populations with and without DS, different distributions of fat and

Conclusions

The current investigation provides evidence that children and adolescents with DS have higher levels of total and regional fat mass than their counterparts without DS. Furthermore, BMI, WC and %BF seem not to be accurate enough to detect an excess of adiposity in this population. As a consequence, more precise studies of the body composition in this specific population are required, with particular attention being paid in evaluating regional adiposity levels and the implications for future

Acknowledgments

The authors want to thank all the children and their parents that participated in the study for their understanding and dedication to the project. Special thanks are given to Fundación Down Zaragoza and Special Olympics Aragon for their support. We also thank Scott G Mitchell from the University of Glasgow and Steven J James for his work of reviewing the English style and grammar, and Paula Velasco from the University of Zaragoza for her great technical assistance. This work was supported by

References (48)

  • F. Baptista et al.

    Bone mineral mass in males and females with and without Down syndrome

    Osteoporosis International

    (2005)
  • A.H. Bittles et al.

    Clinical, social, and ethical implications of changing life expectancy in Down syndrome

    Developmental Medicine & Child Neurology

    (2004)
  • J.M. Bland et al.

    Statistical methods for assessing agreement between two methods of clinical measurement

    Lancet

    (1986)
  • R. Bronks et al.

    Anthropometric observation of adults with Down syndrome

    American Journal of Mental Deficiency

    (1985)
  • J.A. Calbet et al.

    Look before you leap: On the issue of muscle mass assessment by dual-energy X-ray absorptiometry (reply to Jordan Robert Moon comments)

    European Journal of Applied Physiology

    (2008)
  • W.C. Chumlea et al.

    Overweight among children with trisomy

    Journal of Mental Deficiency Research

    (1981)
  • A.M. Coppus et al.

    Survival in elderly persons with Down syndrome

    Journal of the American Geriatric Society

    (2008)
  • C.E. Cronk et al.

    Assessment of overweight children with trisomy 21

    American Journal of Mental Deficiency

    (1985)
  • J.P. Despres et al.

    Abdominal obesity and metabolic syndrome

    Nature

    (2006)
  • W.H. Dietz

    Health consequences of obesity in youth: Childhood predictors of adult disease

    Pediatrics

    (1998)
  • C.C. Draheim et al.

    Differences in cardiovascular disease risk between nondiabetic adults with mental retardation with and without Down syndrome

    American Journal of Mental Retardation

    (2002)
  • D.A. Fields et al.

    Body composition techniques and the four-compartment model in children

    Journal of Applied Physiology

    (2000)
  • E.J. Glasson et al.

    The changing survival profile of people with Down's syndrome: Implications for genetic counselling

    Clinical Genetics

    (2002)
  • González-Agüero, A., Vicente-Rodriguez, G., Moreno, L. A., & Casajús, J. A. Bone mass in male and female children and...
  • Cited by (0)

    View full text