Altered thyrotropic and lactotropic axes regulation in Huntington's disease
Résumé
Background: Recently a loss of hypothalamic dopamine D2 receptors was demonstrated in Huntington's disease. Activation of dopamine D2 receptors is known to inhibit both thyrotropic and lactotropic axes function. Objective: To assess whether thyrotropic and lactotropic axes activity are disturbed in HD patients, contributing to symptoms such as unintended weight loss. Participants & methods: In nine early-stage, medication-free HD patients (6 males, 3 females) and nine age-, sex- and body mass index-matched controls, we measured serum levels of thyroid-stimulating hormone (TSH) and prolactin (males only) every 10 min for 24 h. Multi-parameter auto-deconvolution and approximate entropy analysis were applied to quantify basal, pulsatile and total TSH and prolactin secretion rates as well as the regularity of hormone release. Results: Compared with controls, TSH and prolactin secretion tended to be slightly, but not significantly, higher in HD patients (TSH: 1.13±0.14 vs. 0.91±0.19 mU/L, p=0.40; prolactin: 4.91±0.42 vs. 4.83±0.26 μg/L, p=0.87). However, in HD patients total T3 levels were significantly higher (1.60±0.05 vs. 1.35±0.09, p=0.045), while T4 levels tended to be higher as well (91.9±3.9 vs. 81.3±3.1, p=0.085). Prolactin secretion was significantly more irregular in HD patients (ApEn: 1.06 ± 0.08 vs. 0.80 ± 0.09, p=0.037). Total T3 levels were negatively associated with motor impairment (r=-0.72, p=0.030), whereas increasing free T4 levels were associated with a larger mutant CAG repeat size (r=+0.68, p=0.044). Conclusion: Our findings indicate a mild hyperactivity of the thyrotropic axis and a disturbed regulation of the lactotropic axis in early stage HD patients.
Fichier principal
PEER_stage2_10.1111%2Fj.1365-2265.2010.03836.x.pdf (1.33 Mo)
Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...