Body composition parameters and sarcopenia in adults with Down syndrome: a case–control study

Background. Individuals with Down syndrome (DS) experience premature aging. Whether accelerated aging involves changes in body composition parameters and is associated with early development of sarcopenia is unclear. Aims. To compare parameters of body composition and the prevalence of sarcopenia between adults with DS and the general population. Methods. Body composition was assessed by whole-body dual-energy X-ray absorptiometry (DXA). Fat mass (FMI) and skeletal mass indices (SMI) were calculated as the ratio between total body fat mass and appendicular lean mass and the square of height, respectively. Fat mass distribution was assessed by the android/gynoid fat ratio (A/G). Sarcopenia was defined according to the criteria and cut-points recommended by the European Working Group on Sarcopenia in Older People 2 (EWGSOP2). Data on age- and sex-matched non-DS controls were retrieved from the 2001–2002 National Health and Nutrition Examination Survey (NHANES) population. Results. Sixty-four DS adults (mean age 37.2 ± 12.0 years, 20.3% women) were enrolled and compared with age- and sex-matched NHANES participants (n = 256), in a 1:4 ratio. FMI (7.96 ± 3.18 kg/m2 vs. 8.92 ± 4.83 kg/m2, p = 0.135), SMI (7.38 ± 1.01 kg/m2 vs. 7.46 ± 2.77 kg/m2, p = 0.825) and A/G (0.98 ± 0.17 vs. 1.01 ± 0.22, p = 0.115) were not significantly different between DS and control participants. When the sample was stratified by sex, women with DS had a higher FMI compared with their NHANES controls (10.16 ± 4.35 kg/m2 vs. 8.11 ± 4.29 kg/m2, p < 0.001), while men with DS had lower A/G ratio (1.04 ± 0.16 vs. 1.11 ± 0.22, p = 0.002). Sarcopenia was more frequent in individuals with DS than in controls (35.6% vs. 19.9%, p = 0.007). This association was stronger in men 40 years and older. Conclusions. Adults with DS have a higher prevalence of sarcopenia compared with the general population. This finding suggests that DS is associated with early muscle aging and calls for the design of interventions targeting the skeletal muscle to prevent or treat sarcopenia.