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

Abstract

Background Adults with a Fontan circulation tend to have myopenia and elevated adiposity when measured by dual energy x‐ray absorptiometry. Bioelectrical impedance analysis is an alternative validated approach to assess body composition. We used bioelectrical impedance analysis to compare body composition between pediatric patients with a Fontan circulation and control individuals without heart disease. Methods and Results A retrospective chart review identified all patients aged <22 years with a Fontan circulation who presented for cardiopulmonary exercise testing and bioelectrical impedance analysis from April 2019 to January 2020. Data were compared with control subjects tested during the same period. We studied 47 patients with a Fontan circulation (53% boys; 15±3.1 years) and 165 controls (48% boys; 14.4±2.5 years). Fontan status was associated with shorter height, but similar age, sex, and overall body mass. Patients with Fontan had lower lean body mass (−12.0±22%, Z‐score −0.5±1, P =0.005), skeletal muscle mass (−13.6±1.4%; Z‐score, −0.5±1; P =0.004), skeletal muscle indexed to height (−10.3±13.3%; Z‐score, −0.5±1; P =0.005), and higher percent body fat (+13.8±18.6%; Z‐score, 0.4±1.2; P =0.03). Greater skeletal muscle mass was associated with higher peak oxygen consumption ( r 2 =0.52, P <0.0001) and oxygen pulse ( r 2 =0.68, P <0.0001). Patients who had suffered a late complication (ie, heart transplant referral or evidence of extracardiac organ dysfunction) of the Fontan operation (13 of 47, 27.7%) had lower skeletal muscle mass ( P =0.048) and higher body fat percentage ( P =0.003). Conclusions The Fontan circulation is associated with marked myopenia and increased adiposity. Higher muscle mass was associated with better exercise capacity. Fontan complications are associated with lower muscle mass and increased adiposity.

Overweight and Obesity in Patients with Congenital Heart Disease: A Systematic Review

“…Twenty-six of the included studies were cross-sectional studies that examined the prevalence of overweight and obesity in patients with CHD [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ], and four were cohort studies that investigated the longitudinal change of the prevalence across the lifespan [ 10 , 43 , 44 , 45 ]. The body composition of patients with CHD was compared to a healthy reference cohort in 13 of the included studies [ 20 , 21 , 22 , 23 , 24 , 28 , 29 , 30 , 33 , 35 , 40 , 41 , 45 ], whereas 9 studies merely investigated the prevalence of overweight and obesity in patients with CHD [ 10 , 17 , 18 , 19 , 24 , 32 , 36 ,…”

“…All included studies assessed overweight and obesity with the body mass index (BMI), while two studies additionally performed dual x-ray absorptiometry [ 18 , 20 ], one study performed impedance measurement [ 35 ], and one study assessed waist circumference [ 20 ]. Based on the BMI, patients were classified as underweight (<18.5 kg/m 2 ), normal weight (18.5–24.9 kg/m 2 ), overweight (25–29.9 kg/m 2 ), obese (≥30 kg/m 2 ) and severe obese (≥35 kg/m 2 ).…”

“…Various contributing factors have an impact on weight status and should therefore be considered when investigating the prevalence of overweight and obesity. The included studies in this review controlled for age [ 21 , 24 , 35 , 37 , 39 ], age and lesion severity [ 27 ], age and sex [ 10 , 17 , 18 , 20 , 23 , 28 , 31 , 33 , 36 , 38 , 40 , 41 , 43 , 44 ], race/ethnicity [ 29 , 45 ], family history, parent’s nutritional status [ 19 ], marital status, educational level, and geographic region [ 34 ]. Six studies did not take confounders into account and were therefore rated as “poor” [ 8 , 22 , 25 , 26 , 37 , 42 ].…”

“…In children with CHD, the prevalence of overweight ranged from 9.5% [ 36 ] to 31.5% [ 39 ] and the prevalence of obesity ranged from 9.5% [ 19 ] to 26.2% [ 36 ]. Studies comparing children with CHD to healthy controls reported similar overweight and obesity prevalence in both groups [ 18 , 20 , 21 , 24 , 33 , 35 , 40 , 41 , 45 ], whereby controls were age-matched [ 21 , 35 ], age and sex matched [ 20 ], and age, sex and race/ethnicity matched [ 45 ].…”

“…Patients with Transposition of the Great Arteries and Coarctation of the Aorta showed significantly higher BMI compared with norm data and other cardiac diagnoses [ 38 , 44 ]. Studies on Fontan children reported a lower prevalence of overweight and obesity at the time of Fontan procedure, which increased to 30% five years post-surgery [ 10 ], but showed no significant difference to healthy controls [ 35 ].…”