osteoprotegerin and Acromegaly

This study aimed to assess bone mineral density (BMD) and trabecular bone score (TBS) in 61 patients from the acromegaly group (AG) with regard to the activity of the disease in comparison to 42 patients-control group (CG). We also analyzed selected bone markers and their association with BMD and TBS.. Lumbar spine and femoral neck BMD measurements were performed. TBS values were obtained. Serum concentrations of selected bone markers, including osteoprotegerin (OPG), were measured.. We revealed a difference in TBS values between the AG and CG as well as between the TCA (treatment-controlled acromegaly) vs. CG and TCA+CA (cured acromegaly) vs. CG. We did not observe any statistically significant difference in BMD. OPG had a lower concentration in the CG compared to the AG. TBS correlated negatively with OPG in the AG (r = -0.31, p = 0.01) and in the TCA+ CA group (r = -0.3, p = 0.01).. The acromegalic patients have altered bone microstructure as indicated by the decreased TBS regardless of the activity of the disease and BMD. OPG could be a marker of the destruction of the bone microstructure, but further studies are needed.

Topics: Absorptiometry, Photon; Acromegaly; Bone Density; Cancellous Bone; Humans; Osteoprotegerin

The objective of this study was to investigate the effect of hyperprolactinemia and high levels of insulin-like growth factor-I (IGF-I) on bone resorption and their relation with receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) in patients with prolactinoma and acromegaly. Thirty-one patients with acromegaly, 28 patients with prolactinoma, and 33 healthy individuals were included in the study. Serum concentrations of RANKL, OPG, bone alkaline phosphatase (bone ALP), osteocalcin (OC), C-terminal telopeptide of type 1 collagen (CTX), procollagen type 1 N-terminal propeptide (P1NP) and urine deoxypyridinoline (DPD) levels were detected and bone mineral density (BMD) was measured. Groups were not statistically different from each other with regard to serum levels of RANKL and OPG. The RANKL/OPG ratio was higher in the prolactinoma group than in the control group (p=0.046). A positive correlation between OPG and increasing age was detected in both the prolactinoma and control groups (r=0.524, p=0.004 and r=0.380, p=0.029, respectively). An inverse correlation was observed between IGF-I and OPG after excluding age in the prolactinoma group (r=-0.412, p=0.046). OC and bone ALP were negatively associated with RANKL in the acromegaly group (r=-0.384, p=0.036 and r=-0.528, p=0.003, respectively). There was an inverse correlation between OPG and BMD at the femoral neck in the acromegaly group (r=-0.422, p=0.02). The effect of IGF-I on bone remodeling may be partly mediated by RANKL and OPG. The RANKL/OPG ratio plays an important role in prolactinoma. A positive correlation of OPG with age and an inverse correlation with IGF-I favor the compensatory response of OPG against bone loss in the aging skeleton.

Topics: Acromegaly; Adolescent; Adult; Aged; Biomarkers; Bone Resorption; Case-Control Studies; Cross-Sectional Studies; Female; Humans; Male; Middle Aged; Osteoprotegerin; Prognosis; Prolactinoma; RANK Ligand; Young Adult

To investigate the possible role of osteoprotegerin (OPG) in bone metabolism in humans by measuring serum levels of OPG in five well-characterized patient populations with known or suspected pathology in bone homeostasis, but with differences in the pathogenesis of these disturbances.. The study comprised 34 patients with Cushing's syndrome (CS), 24 acromegalic patients, 16 patients with growth hormone deficiency (GHD), 29 HIV-infected patients, 25 patients with common variable immunodeficiency (CVI) and 59 age- and sex-matched healthy controls (CTR).. Serum levels of tumor necrosis factor (TNF)-alpha, OPG, C-terminal telopeptides of Type-I collagen (CTX-I) and osteocalcin were determined in all study subjects as well as cortisol (CS and CTR) and IGF-I (acromegaly, GHD and CTR).. OPG levels were significantly elevated in both CVI (median increase approximately 32%, P < 0.05) and HIV-infected patients with especially high levels in the latter group ( approximately 52%, P < 0.001), significantly correlated with increased TNFalpha levels (r = 0.47, P < 0.02). Also CS patients had elevated serum OPG ( approximately 24%, P < 0.01), significantly correlated with increased serum cortisol (r = 0.35, P < 0.05). In contrast, OPG levels in acromegalic and GHD patients were not different from healthy controls. No relationships were found between OPG levels and CTX-I or osteocalcin.. These findings suggest that enhanced OPG levels may be a compensatory response to enhanced osteoclast activity or negative bone remodeling balance in some conditions, but may also be a parameter of enhanced activity in the OPG system possibly correlated to enhanced activity of other members of the TNF family.

Topics: Acromegaly; Adult; Aged; Bone and Bones; Bone Remodeling; Common Variable Immunodeficiency; Cushing Syndrome; Female; Glucocorticoids; Glycoproteins; HIV Infections; Homeostasis; Human Growth Hormone; Humans; Hydrocortisone; Immunologic Deficiency Syndromes; Insulin-Like Growth Factor I; Male; Middle Aged; Osteocalcin; Osteoclasts; Osteoprotegerin; Peptide Fragments; Procollagen; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Tumor Necrosis Factor-alpha