AUTHOR=Eriksson Robert , Broberg Brian V. , Ishøy Pelle L. , Bak Nikolaj , Andersen Ulrik B. , Jørgensen Niklas R. , Knop Filip K. , Ebdrup Bjørn H. 

TITLE=Bone Status in Obese, Non-diabetic, Antipsychotic-Treated Patients, and Effects of the Glucagon-Like Peptide-1 Receptor Agonist Exenatide on Bone Turnover Markers and Bone Mineral Density

JOURNAL=Frontiers in Psychiatry

VOLUME=Volume 9 - 2018

YEAR=2019

URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2018.00781

DOI=10.3389/fpsyt.2018.00781

ISSN=1664-0640

ABSTRACT=Background: Low bone mineral density (BMD) may constitute an underestimated comorbidity in schizophrenia patients undergoing long-term antipsychotic treatment. Glucagon-like peptide 1 (GLP-1) receptor agonists are antidiabetic drugs, which may also affect bone turnover.

Methods: In planned secondary analyses of a three-month, double-blind, randomized, placebo-controlled trial (n=45), we explored effects of the GLP-1 receptor agonist exenatide 2 mg once-weekly (n=23), or placebo (n=22) on bone turnover markers (BTMs) and bone mineral density (BMD) in chronic, obese, antipsychotic-treated patients with schizophrenia spectrum disorder. Baseline BTMs were compared to sex- and age-adjusted reference values from a Danish population cohort, and T- and Z-scores were calculated for BMD.

Results: In women (n=24), all baseline BTM measurements of procollagen type I N-terminal propeptide (PINP) and C-terminal cross-linking telopeptide of type I collagen (CTX) were within reference values. In men (n=21), 5% displayed lower PINP and 14% displayed lower CTX. One patient displayed BMD Z-score <-2, and 23% of patients (17% of women and 29% of men) displayed -2.5<T-scores<-1 indicating osteopenia, but none had osteoporosis. After treatment, PINP decreased at trend level significance (P=0.05), and BMD increased for L2–L4 (P=0.016). No changes in bone markers were significant after correction for mean prolactin levels.

Conclusions: Sex- and age-adjusted measures of bone status in chronic, obese, antipsychotic-treated patients appeared comparable to the reference population. Subtle changes in bone markers during three-month exenatide treatment may suggest beneficial effects of GLP-1 receptor agonists on bone status in antipsychotic-treated patients, and further studies should consider the potential influence of prolactin.