6448 Metabolic Profile and Adipose Tissue Distribution of Young Individuals with Turner Syndrome
Authors: Thomas Varsha M , Backeljauw Philippe Ferdinand , Shah Amy , Gutmark-Little Iris 
Published: October 2024

Abstract
Disclosure: V.M. Thomas: None. P.F. Backeljauw: Consulting Fee; Self; Novo Nordisk, Ascendis, Biomarin, Cavalry Biosciences, Upsher-Smith Laboratories, Tolmar. Speaker; Self; BioMarin, Ascendis.. A. Shah: None. I. Gutmark-Little: Research Investigator; Self; Novo Nordisk, Ascendis, OPKO.
Introduction: Turner syndrome (TS) is the most common sex chromosome abnormality in females. Incidence of type 2 diabetes mellitus, hypertension, and dyslipidemia is high in TS. Current practice is to employ BMI as a proxy for adiposity. However, BMI is not an optimal tool due to the short stature observed in TS. Alternate methods such as the dual-energy x-ray absorptiometry (DXA) scan and bioelectrical impedance (BI) may provide more information about body composition. Objectives: The objective of this study is to assess alternative outpatient methods for body composition assessment, including adiposity in pediatric patients with TS. The secondary goal is to characterize the metabolic profile of pediatric subjects with TS compared to obese (BMI ≥95 th%ile) and lean controls (BMI: 5-85th%ile). Methods: This is a cross-sectional study. TS patients are on ≥50mcg transdermal estradiol equivalent replacement OR are self-menstruating. BI, DXA, metabolic markers, interleukin-6 (IL-6) & C-reactive protein (CRP) were obtained in all 3 groups. Statistical analysis was conducted using SPSS software. Results: We present preliminary data on 15 TS, 12 obese, and 15 lean youth, aged 13-19 years. TS youth averages: Age 16.5±1.3 years; BMI 29.3±8.5 kg/m2 (z-score: 1.21±1.27). DXA visceral adiposity (DXA VA): 392±257 g; BI visceral fat (BI VF): 1300±750 cm². Elevated LDL-C&gt;100 mg/dL was noted in n=5 (102-166). Elevated AST &/or ALT &gt;40 unit/L were found in 6 TS. 6 TS had elevated BI VF and DXA VA (&gt;250g) with BMI z-score &lt;2.0. Increased CRP &/or IL-6 levels were noted in 4 TS (BMI z-score: 1.29-2.54), all of whom had primary ovarian failure. These 4 also had increased DXA VA (358-887 g), and BI VF (1500-2500 cm²) compared to the rest of the group. Obese youth averages: Age 16.7±1.83 years; BMI 38 kg/m2 (z-score: 2.26±0.3); DXA VA 674±226 g; BI VF 2300±390 cm². LDL-C&gt;100 mg/dL noted in n=5 (102-121). AST&ALT&lt;35 units/L for all. Increased CRP &/or IL-6 were noted in 4 study subjects (DXA VA: 474-718 g). All 4 had normal A1c, lipid, and liver profiles. Lean youth averages: Age 16.4±2.4 years, BMI 21.6 kg/m2 (z-score: 0.32±0.7); DXA VA 162±68 g; BI VF: 580±370 cm². LDL-C &gt;100 mg/dL noted in n=3 (106-120); 1 subject had increased AST&ALT &gt;40 unit/L. All others had AST & ALT&lt;26 units/L. Elevated CRP/IL-6 was noted in 4 subjects, 1 of whom had increased DXA VA (367g). All subjects had normal HgA1c (≤5.6). Total mass, lean mass, and fat % from DXA and BI were compared (correlation analysis) for each subject and showed agreement throughout. Conclusion: Based on these preliminary data, BI may be a convenient and noninvasive tool to assess adiposity in the outpatient setting in TS. BI and DXA both detected increased visceral fat in TS subjects with normal BMI. BI could potentially identify TS individuals at risk for metabolic dysfunction. Further studies on larger patient numbers will be needed to confirm these preliminary findings.
Presentation: 6/2/2024