Endocrine Abstracts

Objective: The purpose of the study was to investigate osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANK-L) levels in acromegaly patients with regard to the disease activity. The associations between OPG, RANK-L and random growth hormone (GH), insulin-like growth factor 1 (IGF-1), lumbar spine (LS) bone mineral density (BMD), femoral neck (FN) BMD were also evaluated.

Methods: A study group included 72 patients with acromegaly, and was divided into three subgroups: 9 active acromegaly (AA), 24 controlled acromegaly (CTA) and 39 cured acromegaly (CA). 54 age- and sex-matched healthy individuals were recruited to the control group (CG). Serum concentrations of OPG, RANK-L, GH and IGF-1 were measured. Dual-energy x-ray absorptiometry was performed at two sites: LS and hip.

Results: The patients with acromegaly had significantly higher OPG levels than CG (AA+CTA+CA vs CG; P<0.0001). There were no significant differences in RANK-L levels among the subgroups of patients, despite of subject classification. OPG correlated negatively with IGF-1, FN T-score, FN BMD in the groups AA+CTA+CA, CTA+CA and CTA (P<0.05). Positive correlations between RANK-L and IGF-1 were observed in the following groups: AA+CTA+CA, CTA+CA, AA and CA (P<0.05). There were also positive correlations between RANK-L and FN T-score, FN Z-score, FN BMD, LS BMD in the groups AA+CTA+CA and CTA+CA and between RANK-L and FN T-score, FN Z-score, FN BMD in the CTA and CA groups (P<0.05).

Conclusions: OPG/RANK-L system might play a role in bone remodeling in acromegaly.