Endocrine Abstracts

Introduction: Treatment with dopamine agonists in patients with PRL adenomas has been associated with weight loss in short-term studies. However, long-term studies on weight changes are lacking. Taq1A is a restriction fragment length polymorphism considered as a gene marker for the D2DR gene. The presence of at least one A1 allele is linked to reduced brain dopaminergic activity due to reduced receptor binding and lower density of the dopamine two receptor.

Objectives: We aimed at testing the hypothesis that the dopaminergic treatment in prolactinoma patients leads to sustained weight loss and that the presence of diminished weight loss response under dopamine agonists is associated with the minor A1 allele of Taq1A.

Materials and methods: We included n=44 patients (17 males and 27 females, 26 macroadenomas and 18 microadenomas) with PRL adenomas treated with dopamine agonists (cabergoline, bromocriptine, quinagolide, and metergoline) into this study. Outcome measures were weight and body mass index (BMI) change under dopaminergic treatment after 2 years with regard to Taq1A status.

Results: We observed that the dopaminergic treatment leads to a significant mean weight loss of 3.1±6.25 kg after 2 years. Regarding Taq1A polymorphisms, 21 patients were carriers of at least one A1 allele (genotype A1/A1 or A1/A2) and 23 patients had a genotype of A2/A2. However, the presence of the A1 allele was neither associated with the mean BMI at baseline nor with an altered weight loss response under dopamine agonist therapy.

Discussion: Our results implicate that the dopaminergic treatment leads to a sustained weight loss in patients with PRL adenomas after 2 years. However, there was no association to the A1 allele of Taq1A, observation that needs to be analysed in larger cohorts.