Open Access

ARTICLE

Prevalence and risk factors for low bone density in adults with a Fontan circulation

Paolo D’Ambrosio^1,2, Derek Tran^1,2, Charlotte E. Verrall^3,4, Chantal Attard⁵, Maria Fiatarone Singh^6,7, Julian Ayer^3,4,8, Yves d’Udekem^5,9,10, Stephen Twigg^2,11, David S. Celermajer^1,2,12, Rachael Cordina^1,2,5

1 Department of Cardiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
2 Faculty of Medicine and Health Sciences, University of Sydney, Sydney, New South Wales, Australia
3 The Heart Centre for Children, The Children’s Hospital at Westmead, Sydney, New South Wales, Australia
4 Discipline of Child and Adolescent Health, Sydney Medical School, Faculty of Health and Medicine, University of Sydney, Sydney, New South Wales, Australia
5 Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne, Victoria, Australia
6 Physical Activity, Lifestyle, Ageing and Wellbeing Faculty Research Group, Sydney Medical School, Faculty of Health Sciences, The University of Sydney, Sydney, New South Wales, Australia
7 Hebrew SeniorLife and Jean Mayer USDA Human Nutrition Research Center on Ageing, Tufts University, Boston, Massachusetts
8 Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
9 Department of Cardiothoracic Surgery, Royal Children’s Hospital, Melbourne, Victoria, Australia
10 Department of Pediatrics, University of Melbourne, Melbourne, Victoria, Australia
11 Department of Endocrinology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
12 Heart Research Institute, Sydney, New South Wales, Australia

* Corresponding Author: Dr Rachael Cordina, Department of Cardiology, Royal Prince Alfred Hospital, 50 Missenden Road, Camperdown, NSW 2050. Email:

Congenital Heart Disease 2019, 14(6), 987-995. https://doi.org/10.1111/chd.12836

Abstract

Objective and Patients: This study aimed to characterize bone mineral density abnormalities and pathophysiological associations in young adults living with a Fontan circulation.
Design: Participants underwent bone mineral density measurement using dual‐energy X‐ray absorptiometry and serum biochemical analysis, cardiopulmonary exercise and strength testing and transthoracic echocardiography.
Results: In our cohort (n = 28), 29% had osteopenic‐range bone mineral density and one patient was osteoporotic (average hip t score: −0.6 ± 1.1; spine t score: −0.6 ± 0.9). Four patients (14%) had z scores < −2.0. Parathyroid hormone levels were increased compared with laboratory median (6.1 ± 3.5 vs 4 pmol/L, P = .01) and 27% had 25‐ hydroxy‐vitamin D < 50 nmol/L. 25‐hydroxy‐vitamin D negatively correlated with parathyroid hormone (ρ = −0.53, P = .01) suggesting secondary hyperparathyroidism. Atrioventricular valve systolic to diastolic duration ratio, an echocardiographic measure of diastolic dysfunction, inversely correlated with hip t and z scores (P < .01). Hipt scores were positively associated with oxygen saturations (ρ = 0.45, P = .05) and tended to be inversely associated with parathyroid hormone levels (ρ = −0.44, P = .07) and N‐Terminal pro b‐type natriuretic peptide (ρ = −0.42, P = .08).
Conclusions: Many young adults with a Fontan circulation have abnormal bone mineral density. The underlying pathophysiology is likely multifactorial. Possible contributors include secondary hyperparathyroidism, hypoxemia, diastolic cardiac dysfunction and neurohormonal activation. As low bone mineral density is clinically relevant and potentially treatable, assessment of bone mineral density should be part of routine care in this cohort.

---

Keywords

---