Lean mass deficits, vitamin D status and exercise capacity in children and young adults after Fontan palliation.

We sought to evaluate body composition in children and young adults with Fontan physiology. Leg lean mass (LM) deficits correlate with diminished exercise capacity in other populations and may contribute to exercise limitations in this cohort. This cross-sectional study included whole body dual energy X-ray absorptiometry scans in 50 Fontan participants ≥5 years, and measures of peak oxygen consumption (VO2) in 28. Whole body and leg LM (a measure of skeletal muscle) were converted to sex- and race-specific Z-scores, relative to age and stature, based on 992 healthy reference participants. Median age was 11.5 (range 5.1-33.5) years at 9.3 (1.1-26.7) years from Fontan. Height Z-scores were lower in Fontan compared with reference participants (-0.47±1.08 vs 0.25±0.93, p<0.0001). Body mass index Z-scores were similar (0.15±0.98 vs 0.35±1.02, p=0.18). LM Z-scores were lower in Fontan compared with reference participants (whole body LM -0.33±0.77 vs 0.00±0.74, p=0.003; leg LM -0.89±0.91 vs 0.00±0.89, p<0.0001). LM Z-scores were not associated with age or Fontan characteristics. Leg LM Z-scores were lower in vitamin D deficient versus sufficient Fontan participants (-1.47±0.63 vs -0.71±0.92, p=0.01). Median per cent predicted peak VO2 was 81% (range 13%-113%) and was associated with leg LM Z-scores (r=0.54, p=0.003). Following Fontan, children and young adults are shorter than their peers and have significant LM deficits. Skeletal muscle deficits were associated with vitamin D deficiency and reduced exercise capacity. Future studies should examine the progression of these deficits to further understand the contribution of peripheral musculature to Fontan exercise capacity.

Avitabile CM ，Leonard MB ，Zemel BS ，Brodsky JL ，Lee D ，Dodds K ，Hayden-Rush C ，Whitehead KK ，Goldmuntz E ，Paridon SM ，Rychik J ，Goldberg DJ ... -  《-》

Body Composition and Exercise Performance in Youth With a Fontan Circulation: A Bio-Impedance Based Study.

Powell AW ，Wittekind SG ，Alsaied T ，Lubert AM ，Chin C ，Veldtman GR ，Cordina R ，Katz DA ，Mays WA ，Knecht SK ，Opotowsky AR ... -  《Journal of the American Heart Association》

Deficits in bone density and structure in children and young adults following Fontan palliation.

Survival of patients with congenital heart disease has improved such that there are now more adults than children living with these conditions. Complex single ventricle congenital heart disease requiring Fontan palliation is associated with multiple risk factors for impaired bone accrual. Bone density and structure have not been characterized in these patients. Tibia peripheral quantitative computed tomography (pQCT) was used to assess trabecular and cortical volumetric bone mineral density (vBMD), cortical dimensions, and calf muscle area in 43 Fontan participants (5-33 years old), a median of 10 years following Fontan palliation. pQCT outcomes were converted to sex- and race-specific Z-scores relative to age based on >700 healthy reference participants. Cortical dimensions and muscle area were further adjusted for tibia length. Height Z-scores were lower in Fontan compared to reference participants (mean ± SD: -0.29 ± 1.00 vs. 0.25 ± 0.93, p < 0.001); BMI Z-scores were similar (0.16 ± 0.88 vs. 0.35 ± 1.02, p = 0.1). Fontan participants had lower trabecular vBMD Z-scores (-0.85 ± 0.96 vs. 0.01 ± 1.02, p < 0.001); cortical vBMD Z-scores were similar (-0.17 ± 0.98 vs. 0.00 ± 1.00, p = 0.27). Cortical dimensions were reduced with lower cortical area (-0.59 ± 0.84 vs. 0.00 ± 0.88, p<0.001) and periosteal circumference (-0.50 ± 0.82 vs. 0.00 ± 0.84, p < 0.001) Z-scores, compared to reference participants. Calf muscle area Z-scores were lower in the Fontan participants (-0.45 ± 0.98 vs. 0.00 ± 0.96, p = 0.003) and lower calf muscle area Z-scores were associated with smaller periosteal circumference Z-scores (R = 0.62, p < 0.001). Musculoskeletal deficits were not associated with age, Fontan characteristics, parathyroid hormone or vitamin D levels. Children and young adults demonstrate low trabecular vBMD, cortical structure and muscle area following Fontan. Muscle deficits were associated with smaller periosteal dimensions. Future studies should determine the fracture implications of these deficits and identify interventions to promote musculoskeletal development.

Avitabile CM ，Goldberg DJ ，Zemel BS ，Brodsky JL ，Dodds K ，Hayden-Rush C ，Whitehead KK ，Goldmuntz E ，Rychik J ，Leonard MB ... -  《-》

Body Composition in Young Adults Living With a Fontan Circulation: The Myopenic Profile.

Tran D ，D'Ambrosio P ，Verrall CE ，Attard C ，Briody J ，D'Souza M ，Fiatarone Singh M ，Ayer J ，d'Udekem Y ，Twigg S ，Davis GM ，Celermajer DS ，Cordina R ... -  《Journal of the American Heart Association》

Skeletal muscle abnormalities and exercise capacity in adults with a Fontan circulation.

Cordina R ，O'Meagher S ，Gould H ，Rae C ，Kemp G ，Pasco JA ，Celermajer DS ，Singh N ... -  《-》