Evaluation of the hypothalamic-pituitary-adrenal axis and its relationship with central respiratory dysfunction in children with Prader-Willi syndrome.
BACKGROUND
Children with Prader-Willi Syndrome (PWS) have been considered at risk for central adrenal insufficiency (CAI). Hypothalamic dysregulation has been proposed as a common mechanism underlying both stress-induced CAI and central respiratory dysfunction during sleep.


OBJECTIVE
To evaluate CAI and sleep-related breathing disorders in PWS children.


METHODS
Retrospective study of cortisol response following either insulin tolerance test (ITT) or glucagon test (GT) in 20 PWS children, and comparison with 33 non- Growth Hormone deficient (GHD) controls. Correlation between sleep related breathing disorders and cortisol response in 11 PWS children who received both investigations.


RESULTS
In PWS children, the cortisol peak value showed a significant, inverse correlation with age (Kendall's τ = -0.411; p = 0.012). A similar though non-significant correlation was present between cortisol increase and age (τ = -0.232; p = 0.16). Similar correlations were found in controls. In only 1 of 20 PWS children (5 %), ITT was suggestive of CAI. Four patients had an elevated central apnea index but they all exhibited a normal cortisol response. No relationship was found between peak cortisol or cortisol increase and central apnea index (respectively p = 0.94 and p = 0.14) or the other studied polysomnography (PSG) parameters.


CONCLUSIONS
CAI assessed by ITT/GT is rare in PWS children. Our data do not support a link between CAI and central respiratory dysregulation.
Unité d'Endocrinologie pédiatrique, Cliniques Universitaires Saint-Luc, Université catholique de Louvain, avenue Hippocrate 10/1300, Brussels, B-1200, Belgium. veronique.beauloye@uclouvain.be.
Veronique
V
Beauloye
Department of Pediatrics, Division of Child Neurology and Metabolism, Pediatric sleep center, Ghent University Hospital, Ghent, Belgium. karlien.dhondt@uzgent.be.
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K
Dhondt
Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University Hospital and Ghent University, Ghent, Belgium. wesley.buysse@gmail.com.
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W
Buysse
Unité d'Endocrinologie pédiatrique, Cliniques Universitaires Saint-Luc, Université catholique de Louvain, avenue Hippocrate 10/1300, Brussels, B-1200, Belgium. adolphe.nyakasane@gmail.com.
A
A
Nyakasane
IREC, Université Catholique de Louvain, Brussels, Belgium. francis.zech@uclouvain.be.
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F
Zech
Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University Hospital and Ghent University, Ghent, Belgium. jean.deschepper@uzbrussel.be.|Department of Pediatrics, Division of Ped Endocrinology, UZ Brussel, Brussels, Belgium. jean.deschepper@uzbrussel.be.
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J
De Schepper
Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University Hospital and Ghent University, Ghent, Belgium. sara.vanaken@uzgent.be.
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S
Van Aken
Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University Hospital and Ghent University, Ghent, Belgium. kathleen.dewaele@uzgent.be.
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K
De Waele
Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University Hospital and Ghent University, Ghent, Belgium. margarita.craen@uzgent.be.
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M
Craen
Department of Pediatrics, Division of Ped Endocrinology, UZ Brussel, Brussels, Belgium. inge.gies@uzbrussel.be.
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I
Gies
Department of Pediatrics, Division of Ped Endocrinology, KULeuven, Leuven, Belgium. inge.francois@uzleuven.be.
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I
Francois
Department of Pediatrics, Division of Ped Endocrinology, KULeuven, Leuven, Belgium. dominique.beckers@uclouvain.be.|Department of Pediatrics, Division of Ped Endocrinology, CHU Mont-Godinne-Dinant, Université Catholique de Louvain, Yvoir, Belgium. dominique.beckers@uclouvain.be.
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D
Beckers
Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University Hospital and Ghent University, Ghent, Belgium. an.desloovere@uzgent.be.
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A
Desloovere
Unité de sommeil, Cliniques Universitaires Saint-Luc, Université catholique de Louvain, Brussels, Belgium. genevieve.francois@uclouvain.be.
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G
Francois
Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University Hospital and Ghent University, Ghent, Belgium. martine.cools@uzgent.be.
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Cools
D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005934:Glucagon / Q000008:administration & dosage; D013006:Growth Hormone / Q000008:administration & dosage; D006801:Humans; D006854:Hydrocortisone / Q000008:administration & dosage / Q000097:blood; D007030:Hypothalamo-Hypophyseal System; D007223:Infant; D007328:Insulin / Q000008:administration & dosage; D010913:Pituitary-Adrenal System; D011218:Prader-Willi Syndrome / Q000503:physiopathology*; D012119:Respiration; D012189:Retrospective Studies
D007328:Insulin; D013006:Growth Hormone; D005934:Glucagon; D006854:Hydrocortisone