Plasma Osteoprotegerin Levels Before and After Treatment of Thyroid Dysfunctions

ABSTRACT

Purpose: Osteoprotegerin (OPG) is a soluble decoy receptor for the receptor activator of nuclear factor kappaB ligand, thereby inhibiting bone resorption. In this study, we aimed to evaluate plasma OPG levels in patients with thyroid dysfunctions and determine whether its levels change after restoration of euthyroidism.
Material and Method: OPG levels were studied at the time of diagnosis and after the restoration of euthyroidism at least for 8 weeks in patients diagnosed with overt thyrotoxicosis and hypothyroidism.
Results: Seventeen hypothyroid, 17 thyrotoxic patients and 17 age-, sex- and body mass index-matched healthy controls were analyzed. Mean basal plasma OPG levels were 5.42±2.66, 5.04±1.62 and 5.24±0.93 pmol/l in thyrotoxic, hypothyroid and healthy controls, respectively (p=0.844). After restoration of euthyroidism, OPG was 5.52±2.37 pmol/l in thyrotoxic and 4.33±1.37 pmol/l in hypothyroid patients, indicating no significant difference compared to baseline values (p=0.846 and p=0.109, respectively). We also did not observe any correlation between basal OPG levels and basal thyrotropin and thyroid hormone levels.
Discussion: Thyroid dysfunctions seem to affect bone functions by mechanisms other than OPG, however, more clinical studies with larger sample sizes are needed to clarify the underlying mechanisms of thyroid dysfunction-related changes in bone metabolism.