Low serum 25-hydroxyvitamin D levels and secondary hyperparathyroidism in Fontan patients.
BACKGROUND
Limited data exist on the vitamin D status in Fontan patients. We determined the prevalence and potential risk factors of vitamin D deficiency in this patient subset. Methods and results Data were collected from 27 Fontan patients (55.6% male, mean age 8.1±5.3 years). Protein-losing enteropathy was diagnosed in six patients (22.2%). Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D level of <20 ng/ml. The neutrophil-to-lymphocyte ratio, a marker of systemic inflammation, was calculated. Associations between laboratory measurements and patient characteristics were explored. Mean serum 25-hydroxyvitamin D level was 14.1±10.4 ng/ml. Vitamin D deficiency was found in 19/27 patients (70.3%). Only skin type was associated with vitamin D deficiency (p=0.04). Hyperparathyroidism was present in 5/21 (23.8%) patients, and was more prevalent in patients with protein-losing enteropathy (p<0.001). Parathyroid hormone levels correlated with parameters of systemic inflammation (neutrophil-to-lymphocyte ratio: r=0.484, p=0.026; relative lymphocyte count: r=-0.635, p=0.002). Vitamin D supplementation significantly increased serum 25-hydroxyvitamin D levels (p<0.0001), and was accompanied by a reduction in parathyroid hormone concentrations (p=0.032).


CONCLUSIONS
A high prevalence of vitamin D deficiency was found among Fontan patients, independent of age, time after Fontan procedure, ventricular morphology, and presence of protein-losing enteropathy. A potentially important link between parathyroid hormone levels and systemic inflammation is suggested.
1Department of Paediatric Cardiology,Heart Centre Cologne,University Hospital of Cologne,Cologne,Germany.
Finn
F
Holler
1Department of Paediatric Cardiology,Heart Centre Cologne,University Hospital of Cologne,Cologne,Germany.
Tobias
T
Hannes
1Department of Paediatric Cardiology,Heart Centre Cologne,University Hospital of Cologne,Cologne,Germany.
Ingo
I
Germund
1Department of Paediatric Cardiology,Heart Centre Cologne,University Hospital of Cologne,Cologne,Germany.
Mathias
M
Emmel
2Department of Paediatrics,Children's Hospital,University of Cologne,Cologne,Germany.
Heike
H
Hoyer-Kuhn
3Paediatric Heart Centre,Justus-Liebig University,Giessen,Germany.
Markus
M
Khalil
1Department of Paediatric Cardiology,Heart Centre Cologne,University Hospital of Cologne,Cologne,Germany.
Narayanswami
N
Sreeram
1Department of Paediatric Cardiology,Heart Centre Cologne,University Hospital of Cologne,Cologne,Germany.
Floris E A
FE
Udink Ten Cate
D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D002648:Child; D002675:Child, Preschool; D005260:Female; D018729:Fontan Procedure; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000453:epidemiology*; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D011504:Protein-Losing Enteropathies / Q000453:epidemiology*; D012189:Retrospective Studies; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*; D055815:Young Adult
D015415:Biomarkers; D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D
25-hydroxyvitamin D; Fontan; parathyroid hormone; protein-losing enteropathy; vitamin D deficiency