osteoprotegerin and Anorexia-Nervosa

Topics: Anorexia Nervosa; Biomarkers; Cardiovascular Diseases; Diabetes Mellitus; Enzyme-Linked Immunosorbent Assay; Female; Glycoproteins; Humans; Kidney Diseases; Male; Multiple Myeloma; Osteitis Deformans; Osteoprotegerin; Prostatic Neoplasms; Reagent Kits, Diagnostic; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Reference Values; Specimen Handling; Urinary Bladder Neoplasms

The aim of this study was to determine whether girls with anorexia nervosa (AN) exhibited any relationships between serum levels of LP, ADIPO, RES, VISF, APE-36, APE-12, and bone markers, OPG and sRANKL.. Serum levels of selected adipose tissue hormones, OC, CTx, OPG and sRANKL were assessed using ELISA in 86 study participants suffering from AN and 21 healthy controls, all aged 13 to 18 years.. Girls with AN showed a significant reduction in body mass, BMI, serum concentrations of LP, RES, VISF, APE-36, APE-12, OC, CTx and increased ADIPO concentration. These changes were associated with significant increases in OPG and sRANKL and a decrease in the OPG/sRANKL ratio. Significant positive correlations were revealed between BMI and LP, APE-36, CTx, OPG/sRANKL ratio; OC and VISF; OPG and ADIPO; OPG/sRANKL ratio and LP, APE-36, APE-12. Significant negative correlations were revealed between CTx, sRANKL and RES, APE-36; OPG and APE-36, APE-12; OPG/sRANKL ratio and ADIPO. VISF was shown to be an independent predictor of OC. APE-36 and RES turned out to be independent predictors of CTx, and sRANKL, APE-36 and ADIPO were independent predictors of OPG while APE-36, LP and ADIPO were independent predictors of the OPG/sRANKL ratio.. Changes in bone markers, OPG, sRANKL and/or the OPG/sRANKL ratio exhibited by girls with AN have been found to be associated with changes in the levels of the selected adipose tissue hormones. Abnormal relationships between bone metabolism and LP, ADIPO, RES, VISF and APE might adversely affect the balance of the OPG/sRANKL system and thus potentially compromise the mechanism which compensates for bone remodelling disturbances.

Topics: Adiponectin; Adipose Tissue; Adolescent; Anorexia Nervosa; Apelin; Biomarkers; Bone and Bones; Female; Humans; Intercellular Signaling Peptides and Proteins; Leptin; Osteoprotegerin; RANK Ligand; Resistin

Low bone mineral density (BMD) in adolescents with anorexia nervosa (AN) is associated with a low bone turnover state. Osteoprotegerin (OPG), a cytokine that acts as a decoy receptor for receptor activator of nuclear factor-kappaB ligand, decreases bone resorption by inhibiting differentiation of osteoclast precursors and activation of mature osteoclasts, and by stimulating osteoclast apoptosis. We compared OPG levels in 43 adolescent girls with AN with 38 controls and examined bone density, bone turnover, and hormonal parameters. Girls with AN had lower fat mass, lean body mass, lumbar BMD z-scores, and lumbar bone mineral apparent density than controls. OPG levels were higher in girls with AN than in controls (44.5 +/- 22.5 pg/ml vs. 34.5 +/- 12.7 pg/ml, P = 0.02). Osteocalcin, deoxypyridinoline, estradiol, free testosterone, IGF-I, and leptin were lower in AN than in healthy adolescents. OPG values correlated negatively with body mass index (r = -0.27, P = 0.02), percent fat mass (r = -0.35, P = 0.0002), leptin (r = -0.28, P = 0.02), lumbar BMD z-scores (r = -0.25, P = 0.03), and lumbar bone mineral apparent density (r = -0.26, P = 0.03). In conclusion, adolescent girls with AN have higher serum OPG values than controls. OPG values correlate negatively with markers of nutritional status and lumbar bone density z-scores and may be a compensatory response to the bone loss seen in this population.

Topics: Adolescent; Anorexia Nervosa; Anthropometry; Body Composition; Bone and Bones; Bone Density; Bone Diseases, Metabolic; Child; Female; Glycoproteins; Hormones; Humans; Organ Size; Osteoprotegerin; Puberty; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor

Based on recent studies in humans, chemerin has been classified as an adipokine that might be associated with osteoporosis and BMD. Bone loss is common in adolescents with anorexia nervosa (AN). Moreover, dysfunction in the production of chemerin has also been shown. Therefore, we carried out a comparative analysis between chemerin, bone metabolism, the RANKL/RANK/OPG system, and BMD in girls with AN.. Plasma chemerin, OC, CTx, OPG, and sRANKL were determined by ELISA in 75 girls with AN aged 12.6-17.8 years. BMD was assessed by DXA and expressed as Z-score according to the lumbar spine (s) and total body (TB) sites. According to the s-BMD- and TB-BMD Z-score, girls with AN were divided into two subgroups with parallel analyses used: normal (Z-score > -2.0) and low (Z-score ≤ -2.0) s-BMD, and normal (Z-score > -2.0) and low (Z-score ≤ -2.0) TB-BMD.. Mean OC and the OPG/sRANKL ratio were markedly lower in the low s-BMD subgroup compared to the normal s-BMD subgroup. The s-Z-score values (both low and normal) correlated significantly and positively with the OPG/sRANKL ratio. Only in the low s-BMD subgroup did chemerin correlate significantly and positively with all nutritional indices and the OPG/sRANKL ratio. In the low TB-BMD subgroup the mean OC and the OPG/sRANKL ratio were lower than in the normal TB-BMD subgroup. The TB-Z-score values (both normal and low) correlated significantly and positively with all nutritional indices and the OPG/sRANKL ratio. The low TB-Z-score values correlated significantly and positively also with chemerin. In the low TB-BMD subgroup chemerin correlated significantly and positively with weight and BMI (expressed as absolute values), Cole index, the duration of the disease, and OPG/sRANKL ratio while its correlation with age was negative.. Undernutrition and associated deficit of adipose tissue may result in inadequate chemerin production and skeletal disorders in girls with AN. Chemerin acts as a coordinator of the dynamic balance between bone metabolism and the OPG/RANK/RANKL system and, in turn, may contribute to the loss of bone mass in girls with AN. The cortical bone site seems to be more severely responsive to chemerin actions than the trabecular bone site.

Topics: Adolescent; Anorexia Nervosa; Bone and Bones; Bone Density; Chemokines; Child; Female; Humans; Osteoporosis; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Numerous investigations, and especially in vitro studies, indicate that TGF-β1 may act as an important regulator of bone remodelling. Thus, it could be expected that disturbances of this cytokine production observed by several researchers might play a role in the mechanism leading to the development of osteoporosis in girls with anorexia nervosa (AN). The aim of the study was to determine whether 1) girls with AN exhibited a relationship between TGF-β1 and bone metabolism (as assessed based on serum OC and CTx concentrations) and 2) whether OPG and sRANKL might modify the possible relationship between TGF-β1 and bone metabolism.. Serum concentrations of TGF-β, OC, CTx, OPG, and its soluble ligand sRANKL were determined by ELISA in 60 girls with AN and in 20 healthy controls (C). All study participants were aged 13 to 17 years.. Body weight, BMI, BMI-SDS and the Cole index, serum TGF-β1, OC, CTx, and the OPG/sRANKL ratio were significantly reduced, while OPG and sRANKL levels were significantly increased, in girls with AN compared to healthy participants. BMI and the Cole index correlated negatively and significantly with serum CTx and OPG (AN group) or CTx only (groups C and C + AN). Girls with AN showed a positive and significant correlation between the Cole index and serum TGF-β1. The combination group (C + AN) showed a positive and significant correlation between BMI, the Cole index, and the OPG/sRANKL ratio and TGF-β1 concentration, while TGF-β1 correlated positively and significantly with OC concentrations and the OPG/sRANKL ratio. The Cole index and BMI were identified to be significant and independent predictors of CTx (C, AN, and C+AN groups) and OPG (AN group); the Cole index, BMI, and TGF-β1 independently predicted the OPG/sRANKL ratio (C, AN, and C + AN groups); TGF-β1 was found to be an independent predictor of OC (C + AN group).. Changes in bone markers, OPG, and/or OPG/sRANKL ratio observed in girls with AN are associated with changes in serum TGF-β1 concentrations. TGF-β1 suppression in girls with AN might lead to disturbances in the relationship between bone metabolism and the OPG/sRANKL system, which, in turn, might compromise the mechanism compensating for bone remodelling disturbances. (Endokrynol Pol 2016; 67 (5): 493-500).

Topics: Adolescent; Anorexia Nervosa; Bone and Bones; Bone Remodeling; Female; Humans; Osteoporosis; Osteoprotegerin; Receptor Activator of Nuclear Factor-kappa B; Transforming Growth Factor beta1

It has been indicated that disturbances in the production of certain pro-inflammatory cytokines might contribute to the development of osteoporosis in girls with anorexia nervosa (AN). The aim of the study was to determine whether girls with AN exhibited a relationship between IL-1β, IL-6, TNF-α, bone turnover markers (OC and CTx), OPG, sRANKL, and the OPG/sRANKL ratio.. Serum IL-1β, IL-6, TNF-α, OC, CTx, OPG, and sRANKL were determined by ELISA in 59 girls with AN and in 17 healthy counterparts, aged 13 to 17 years.. Girls with AN showed significant reduction in body weight, BMI, BMI-SDS, and Cole index compared to the controls. These changes were associated with a significant increase in IL-1β, IL-6, TNF-α, OPG, and sRANKL concentrations and a decrease in bone markers and the OPG/sRANKL ratio. Significant negative correlations were found between BMI, the Cole index and CTx, OPG (girls with AN); between BMI and OC, CTx as well as the Cole index and CTx (the control group - C); between BMI, the Cole index and IL-β1, IL-6, TNF-α, CTx in all study participants (group AN+C). The combined group AN+C also exhibited positive correlation between BMI, the Cole index, and the OPG/sRANKL ratio. Girls with AN showed positive correlations between IL-1β, IL-6, and CTx as well as between TNF-α and sRANKL whereas the correlation between TNF-α and the OPG/sRANKL ratio was negative (IL-6 and IL-1β were identified to be independent predictors of CTx, TNF-α and IL-6 independently predicted sRANKL while TNF-α, IL-6, and IL-1β were independent predictors of the OPG/sRANKL ratio). The control participants exhibited negative correlations between IL-1β and OPG and positive correlations between IL-1β and sRANKL (IL-1β was found to be an independent predictor of OPG and sRANKL). In the AN+C group, IL-1β correlated negatively with OC and OPG and positively with sRANKL, while IL-6 and TNF-α positively correlated with CTx (IL-6 and TNF-α turned out to be independent predictors of CTx, IL-1β of OPG while IL-6, TNF-α, and IL-1β were independent predictors of sRANKL and the OPG/sRANKL ratio).. The relationship between the nutritional status and IL-1β, IL-6, and TNF-α concentrations as well as bone status indicators seems to indicate that abnormalities observed regarding the concentrations of pro-inflammatory cytokines and bone remodelling in girls with AN might result from malnutrition. Correlations between IL-1β, IL-6, TNF-α, bone markers, OPG, its ligand sRANKL, and/or the OPG/sRANKL ratio suggest potential involvement of these cytokines in the mechanism underlying the lack of the expected bone mineral density increase in adolescent girls.

Topics: Adolescent; Anorexia Nervosa; Bone and Bones; Bone Density; Bone Remodeling; Cytokines; Female; Humans; Osteoprotegerin; RANK Ligand

It has been suggested that disturbances in melatonin (MEL) secretion might play a role in osteoporosis development in females with anorexia nervosa (AN). It might be hypothesized that changes in the levels of hormones of the pituitary-ovarian, -thyroid and -adrenocortical axes might mediate the potential relationship between MEL and bone tissue.. We investigated whether a relationship existed between MEL and LH, FSH-E2, TSH-FT3, FT4 and ACTH-cortisol axes in girls with AN. We also aimed to establish whether such a relationship might adversely affect the balance of the OPG/sRANKL system.. Eighty-six girls with AN and 21 healthy subjects aged 12.6 to 18.2 years participated in the study. The serum levels of hormones as well as OPG and sRANKL were determined by radioimmunoassay (RIA), immunoradiometric assay (IRMA) or enzyme-linked immunosorbent assay (ELISA) methods.. Our study participants with AN showed a significant reduction in body mass and body mass index (BMI), a decrease in LH, E2 and FT3 concentrations, increased MEL concentration at 02.00 hours and increased amplitude between its nocturnal and morning levels (Δ MEL2.00/9.00) as well as an increase in cortisol concentration. These changes were associated with a significant increase of OPG and sRANKL levels and a decrease in the OPG/sRANKL ratio. BMI values correlated positively with LH, FSH, E2, FT3 and the OPG/sRANKL ratio while the correlation between BMI and cortisol was negative. Δ MEL2.00/9.00 correlated positively with cortisol and negatively with LH, FSH, E2, FT3 concentrations and the OPG/sRANKL ratio. A positive correlation was observed between LH, E2 and the OPG/sRANKL ratio as well as between cortisol and sRANKL while the correlation between LH and OPG as well as between cortisol and the OPG/sRANKL ratio was negative. E2 and LH were shown to be significant and independent predictors of Δ MEL2.00/9.00. LH turned out to be a significant and independent predictor of OPG, cortisol and FT3 were significant and independent predictors of sRANKL, while LH, E2, Δ MEL2.00/9.00 and FT3 were significant predictors of the OPG/sRANKL ratio.. Alterations in OPG and sRANKL levels observed in girls with AN are associated with changes in nocturnal MEL secretion, the circadian rhythm of MEL, and LH, E2, FT3 and cortisol levels. Dysregulation of the relationships between MEL and LH, E2, FT3 and cortisol found in girls with AN might affect the balance of the OPG/sRANKL system. Low values of the OPG/sRANKL ratio associated with high OPG and sRANKL levels suggest some defect in the mechanism compensating for bone remodeling disturbances.

Topics: Adolescent; Anorexia Nervosa; Body Mass Index; Bone and Bones; Bone Remodeling; Child; Enzyme-Linked Immunosorbent Assay; Female; Hormones; Humans; Hydrocortisone; Melatonin; Osteoprotegerin; Peptide Hormones; Pituitary Gland; RANK Ligand; Reference Values; Thyroid Gland

Minimal data exist concerning the relationship between osteokines of the RANKL/RANK/OPG system, especially RANKL, and bone status in females with anorexia nervosa (AN). For this reason we investigated the relationship between bone metabolism (as assessed based on serum levels of OC and CTx), and OPG and sRANKL concentrations in females with AN. Ninety-one female patients with AN and 29 healthy female subjects aged 13 to 18 years of age participated in the study. Serum OC, CTx, OPG and sRANKL were measured by ELISA. The female patients with AN demonstrated an essential suppression of OC and CTx, increased OPG and sRANKL levels, and a reduced OPG/sRANKL ratio. OC, CTx and the OPG/sRANKL ratio correlated positively with body mass and BMI in these patients, whereas in the case of OPG and sRANKL the relationship was negative. A significant positive correlation was observed between OPG and sRANKL and also between bone markers and the OPG/sRANKL ratio, and negative between CTx and sRANKL. In female patients with AN, the OPG/RANKL ratio was a significant and independent predictor of osteocalcin, a bone formation marker - OC (R(2)=0.065, p=0.012) whereas the OPG/sRANKL ratio and BMI were significant and independent predictors of a bone resorption marker - CTx (R(2)=0.095; p=0.012). In conclusion, the body mass, BMI values, and bone markers suppression observed in female patients with AN might be associated with an increase in OPG and sRANKL levels and a significant decrease of the OPG/sRANKL ratio. Although higher OPG levels may compensate for excessive bone resorption in female patients with AN, the lower OPG/sRANKL ratio seems to indicate that some inadequacies exist regarding this compensation effect, which might contribute to low bone density in these patients. The OPG/sRANKL ratio might prove a more relevant marker to predict bone metabolism in female patients with AN than sRANKL and/or OPG alone.

Topics: Adolescent; Anorexia Nervosa; Biomarkers; Body Mass Index; Bone and Bones; Bone Density; Female; Humans; Osteocalcin; Osteoprotegerin; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Only scarce data exist concerning the relationship between dehydroepiandrosterone (DHEA) and/or its sulfate form DHEAS and bone status in adolescents with anorexia nervosa (AN).. We investigated whether a relationship existed between DHEAS and bone metabolism (as assessed based on serum osteocalcin [OC], and collagen type I cross-linked carboxy-terminal telopeptide [CTx]). We also aimed to establish whether the above mentioned relationship might be affected by osteoprotegerin (OPG) and its soluble ligand sRANKL.. Fifty-six female patients with AN and 21 healthy female subjects aged 13 to 16 years participated in the study. Serum DHEAS, OC, CTx, OPG and sRANKL were measured by ELISA.. Our female patients with AN demonstrated significant suppression of DHEAS and bone markers, an increase in OPG and sRANKL levels, and a reduction of the OPG/sRANKL ratio. DHEAS, CTx and the OPG/sRANKL ratio correlated positively with BMI. A significant positive correlation was also observed between DHEAS and the OPG/sRANKL ratio, OC and the OPG/sRANKL ratio, and CTx and sRANKL. The correlation was negative in the case of DHEAS and CTx, DHEAS and sRANKL, CTx and the OPG/sRANKL ratio, and sRANKL and the OPG/sRANKL ratio.. DHEAS suppression in girls with anorexia nervosa was associated with a decrease in the levels of bone markers, an increase in OPG and sRANKL concentrations and a significant decrease in the OPG/sRANKL ratio. DHEAS suppression in girls with anorexia nervosa might have a harmful effect on their bone tissue, probably via a shift in the OPG/RANKL ratio toward a functional excess of sRANKL.

Topics: Adolescent; Anorexia Nervosa; Biomarkers; Bone and Bones; Collagen Type I; Dehydroepiandrosterone; Dehydroepiandrosterone Sulfate; Female; Humans; Osteocalcin; Osteoprotegerin; RANK Ligand; Reference Values

Low fat mass and hormonal or nutritional deficiencies are often incriminated in bone loss related to thinness. Constitutional thinness has been described in young women with low body mass index (BMI) but close-to-normal body composition, physiological menstruation, no hormonal abnormalities, and no anorexia nervosa (AN) psychological profile.. Our objective was to determine whether constitutional thinness is associated with impaired bone quality.. This was an observational, cross-sectional study on 25 constitutionally thin and 44 AN young women with similar low BMI (<16.5 kg/m2) and 28 age-matched controls.. Femoral and lumbar spine bone mineral density by dual-energy x-ray absorptiometry, distal tibia and radius bone architecture and breaking strength by three-dimensional peripheral quantitative computed tomography, and bone turnover markers were determined.. Constitutionally thin subjects displayed a higher percentage of fat mass than AN subjects but had similar lumbar and femoral bone mineral density, which were significantly lower than in controls (P < 0.001). Constitutionally thin subjects displayed more markedly impaired trabecular and cortical bone parameters in the distal tibia than in the radius. AN bone structure was impaired only in subjects with a long history of disease. Calculated breaking strength was decreased in constitutional thinness and long-standing AN in both the radius and the tibia. Bone markers in constitutionally thin subjects were similar to those of controls. Osteoprotegerin to receptor activator of nuclear factor kappa B ligand ratio was higher in constitutionally thin subjects than in controls or AN women.. Young women with constitutional thinness present an unexpectedly high prevalence of low bone mass (44%) associated with small bone size, overall diminished breaking strength, but normal bone turnover. Mechanisms related to insufficient skeletal load and/or genetics are proposed to explain this new phenotype of impaired bone quality.

Topics: Absorptiometry, Photon; Acid Phosphatase; Adolescent; Adult; Alkaline Phosphatase; Anorexia Nervosa; Body Composition; Body Mass Index; Bone and Bones; Bone Density; Collagen Type I; Cross-Sectional Studies; Female; Humans; Isoenzymes; Osteocalcin; Osteoprotegerin; Peptides; Principal Component Analysis; RANK Ligand; Tartrate-Resistant Acid Phosphatase; Thinness

Osteoprotegerin (OPG) and receptor activator of nuclear factor-kappaB ligand (RANKL) are key factors in bone remodeling in patients with anorexia nervosa (AN) and osteopenia. The purpose of this study was to investigate basal serum levels of OPG, RANKL and leptin, as well as bone mineral density (BMD) measured by DEXA at lumbar vertebrae L1-L4, and their evolution during one year in two groups of patients with AN.. Group I included 10 adolescent girls suffering from malnutrition and secondary amenorrhea with an evolution of more than one year at the beginning of the study who received oral estrogen treatment throughout the follow-up period. Group II comprised 10 girls with malnutrition and secondary amenorrhea with an evolution of less than one year who received nutritional treatment only. All parameters were compared with those of a control group of 19 healthy, age-matched girls with normal BMI and regular menstrual cycles.. The OPG/RANKL ratio was significantly decreased (p<0.05) after 1 year in group I, a fact that was due to an increase (p<0.05) in serum RANKL values. A correlation between OPG/RANKL and BMD was found in group I at the beginning of the study (r = 0.95; p<0.001). Patients in this group showed lower BMD values (p<0.01), both at diagnosis and at the end of the study, than those of group II patients, who showed normal BMD values.. The decrease in the OPG/RANKL ratio in girls with AN could partly explain the increase in bone loss that occurs in these patients.

Topics: Absorptiometry, Photon; Adolescent; Amenorrhea; Anorexia Nervosa; Biomarkers; Bone Density; Bone Diseases, Metabolic; Bone Remodeling; Bone Resorption; Enzyme-Linked Immunosorbent Assay; Estradiol; Female; Follow-Up Studies; Humans; Leptin; Lumbar Vertebrae; Malnutrition; Osteoprotegerin; Radioimmunoassay; RANK Ligand; Receptors, Leptin; Reference Values; Treatment Outcome

Osteoporosis is one of the major complications in anorexia nervosa (AN) patients. Receptor activator of nuclear factor kappaB ligand (RANKL) and osteoprotegerin (OPG) have been identified as important regulators of bone turnover. The objective of this study was to clarify the role of RANK-RANKL-OPG system, and their relationship with other regulators for bone metabolism in AN patients. We investigated serum levels of RANKL, OPG, and bone turnover markers of 26 Japanese young female AN patients and 7 age-matched healthy women. We measured serum levels of estradiol (E2), insulin like growth factor-I (IGF-I) and triiodothyronin (T3) from the same samples and studied their relationship with RANKL or OPG. Mean serum levels of E2, IGF-I, T3 and leptin in AN patients were significantly lower than those of controls (p<0.05). Serum levels of OPG in AN patients were significantly higher than those in controls and negatively correlated with body mass index (BMI), E2, IGF-I or leptin. Serum levels of free RANKL could not be detected except for only one healthy control in both groups. These results suggest that serum OPG levels may be increased by a compensatory mechanism for malnutrition and estrogen deficiency which induces an increase in bone resorption.

Topics: Adolescent; Adult; Alkaline Phosphatase; Anorexia Nervosa; Bone and Bones; Bone Density; Calcium; Collagen Type I; Estradiol; Female; Humans; Insulin-Like Growth Factor I; Leptin; Osteoprotegerin; Parathyroid Hormone; Peptides; Phosphates; RANK Ligand; Statistics, Nonparametric; Triiodothyronine

Low bone mineral density (BMD) is a frequent, often persistent complication in patients with major depressive disorder (MDD) and anorexia nervosa (AN) that increases the risk of pathologic fractures. The pathogenetic process underlying osteopenia in MDD and AN is still unclear, although several factors, including a dysbalance of cytokines, are associated with loss of bone mass. Alterations in the serum levels of cytokines have been observed in patients with MDD, AN, and other psychiatric disorders. Therefore, we examined serum levels of cytokines, markers of bone turnover, and BMD in 13 patients with MDD and a lifetime history of AN. Bone turnover markers (osteocalcin and C-terminal degradation products of type I collagen) and tumor necrosis factor alpha (TNF-alpha) in patients were significantly increased compared with those of the control group. Osteoprotegerin (OPG) in patients was significantly decreased. Eight of 13 patients (62%) displayed osteopenia at the lumbar spine. TNF-alpha correlated significantly with C-terminal degradation products of type I collagen, an osteoclastic marker, but significantly negatively with OPG. Our data suggest that TNF-alpha and OPG may play a role in the pathogenetic process underlying osteopenia in these patients.

Topics: Adolescent; Adult; Anorexia Nervosa; Bone Density; Bone Diseases, Metabolic; Cytokines; Depressive Disorder, Major; Female; Glycoproteins; Hormones; Humans; Lumbar Vertebrae; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Tumor Necrosis Factor-alpha