Zofia Ostrowska

RANKL/RANK/OPG system and bone status in females with anorexia nervosa

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.

Assessment of Serum Apelin Levels in Girls with Anorexia Nervosa

CONTEXT Pilot studies in rats have suggested that apelin (APE) is involved in the control of appetite and food intake. APE is secreted in the organs involved in the control of hunger and satiety: the stomach, hypothalamus, and fat tissue. Anorexia nervosa (AN) is an eating disorder that represents a good biological model of chronic fat tissue atrophy in humans. To date, there are no reports of APE expression in the fat tissue and its circulating concentrations in patients with AN. OBJECTIVE Our objective was to assess serum APE concentrations in girls with AN. DESIGN, PARTICIPANTS, AND SETTING APE-36 and APE-12 serum concentrations were evaluated in 87 Polish girls with restrictive AN, in 61 healthy (H) controls, 17 girls with no otherwise specified eating disorders (NOS), and 30 girls with simple obesity (OB). RESULTS Mean serum APE-36 and APE-12 concentrations in patients with AN and NOS were significantly lower than in the H and OB groups. However, no differences between AN, H, and NOS groups were observed when APE concentrations were calculated per body mass index (BMI). In participants with normal BMI, serum APE-36 (r = 0.35) and APE-12 (r = 0.37) concentrations correlated positively with BMI. CONCLUSIONS We conclude that compared with H controls, serum APE-36 and APE-12 concentrations decreased as a result of fat tissue depletion in patients with AN. Conversely, obese adolescents had elevated APE-36 and APE-12 due to excessive fat mass as well as increased APE production in adipose tissue.

Dehydroepiandrosterone sulfate, osteoprotegerin and its soluble ligand sRANKL and bone metabolism in girls with anorexia nervosa.

BACKGROUND 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). AIM 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. MATERIAL/METHODS 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. RESULTS 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. DISCUSSION/CONCLUSIONS 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.

Assessment of serum visfatin levels in girls with anorexia nervosa.

Objective  Visfatin (VISF) is a recently described peptide regulating the process of adipocyte differentiation. Only one pilot study of VISF expression in the fat tissue and its circulating concentrations in a small group of patients with anorexia nervosa (AN) have been published, yet.

Bone metabolism, osteoprotegerin, receptor activator of nuclear factor-kB ligand and selected adipose tissue hormones in girls with anorexia nervosa

INTRODUCTION 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. MATERIAL AND METHODS 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. RESULTS 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. CONCLUSIONS 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.

Functional polymorphism rs710218 in the gene coding GLUT1 protein is associated with in-stent restenosis

AIM To analyze the association between in-stent restenosis (ISR) and polymorphisms in genes coding IGF-1, IGFBP3, ITGB3 and GLUT1, which play an important role in the smooth muscle cell proliferation and extracellular matrix synthesis - the main components of neointima. MATERIALS & METHODS We analyzed 265 patients who underwent bare metal stent implantation. RESULTS The differences in the occurrence of ISR between genotypes of the analyzed polymorphisms in the IGF-1, IGFBP3 and ITGB3 were not statistically significant. The T/T genotype of the rs710218 polymorphism in the GLUT1 (SLC2A1) gene was more common in the ISR group compared with non-ISR patients (81.1 vs 64.8%; p = 0.02). In a multivariable model the A/A and A/T genotype remained correlated with lower occurrence of ISR (odds ratio: 0.45; 95% CI: 0.21-0.97; p = 0.03). CONCLUSION The rs710218 polymorphism in the gene coding GLUT1 protein is a novel risk factor for ISR.

Circadian concentrations of free testosterone, selected markers of bone metabolism, osteoprotegerin and its ligand sRANKL in obese postmenopausal women.

BACKGROUND It has been suggested that increased testosterone secretion in postmenopausal obese women might have some protective effect on bone tissue; the association might be significantly influenced by the RANKL/RANK/OPG system. AIM The aim of the study was to determine whether postmenopausal obese women showed any relationship between the pattern of adipose tissue distribution, circadian free testosterone (FT) concentrations and bone metabolism (as assessed based on circadian osteocalcin [OC] and C-terminal telopeptide [CTx] levels), and to establish whether osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) might play a role in the relationship. MATERIAL/METHODS FT, OC, CTx, OPG and soluble RANKL (sRANKL) levels were determined by ELISA in serum samples collected every three hours for 24 hours from 47 postmenopausal women (12 with gynoid obesity [GO], 17 with android obesity [AO], and 18 healthy individuals). RESULTS Obese women demonstrated an adipose tissue distribution-dependent increase in mean circadian FT levels and a decrease in mean circadian OC, CTx, OPG and sRANKL compared to control participants. In GO subjects, these changes were accompanied by smaller FT amplitudes, suppression of the circadian rhythms of bone markers and OPG, and a shift of sRANKL rhythm acrophase, whereas AO subjects showed a decrease in bone marker amplitudes and suppression of OPG and sRANKL rhythms. In comparison with the controls, significant adipose tissue distribution-dependent changes were found in the correlations between FT and bone markers, FT and OPG, OC and CTx, OPG and sRANKL, CTx and OPG, and CTx and sRANKL. Compared to GO participants, those with AO had higher coefficients of correlations between mean circadian FT and OC as well as between OC and CTx, and lower in the case of FT and sRANKL as well as CTx and OPG and CTx and sRANKL. DISCUSSION/CONCLUSIONS Postmenopausal obesity results in adipose tissue distribution-dependent alterations in circadian FT levels accompanied by suppression of bone metabolism and a decline in circadian variations of the osteokines under investigation, especially sRANKL. Increased FT secretion in postmenopausal women might exert a protective effect on bone tissue, most likely via a shift in the OPG/RANKL ratio that tilts the balance toward a functional excess of OPG.

Selected pro-inflammatory cytokines, bone metabolism, osteoprotegerin, and receptor activator of nuclear factor-kB ligand in girls with anorexia nervosa

INTRODUCTION 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. MATERIAL AND METHODS 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. RESULTS 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). CONCLUSIONS 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.

Growth hormone/insulin-like growth factor-1 axis, calciotropic hormones and bone mineral density in young patients with chronic viral hepatitis

INTRODUCTION Chronic liver disease caused by HBV and HCV infections, due to its great prevalence and serious medical consequences, is at the present time a significant clinical problem. An impaired liver function can provoke severe disturbances in calcium and phosphorus homeostasis, and consequently in the bone metabolism resulting in hepatic osteodystrophy. The aim of this study was to determine whether there are significant differences in bone mineral density (BMD) and/or circadian levels of hormones connected with bone metabolism and bone turnover markers in patients with chronic viral hepatitis. MATERIAL AND METHODS Circadian levels (AUC, area under the curve) of GH, IGF-I, IGFBP-3, osteocalcin (BGLAP), C-terminal telopeptide of type I collagen (ICTP), PTH, 25(OH)D, total calcium and total phosporus were measured in the blood of members of the study group (n = 80). BMD was assessed using the dual-energy X-ray absorptiometry method of the L2-L4 lumbar spine. Data was compared to that of healthy individuals (n = 40). RESULTS BMD (1.05 g/cm3 vs. 1.20 g/cm3), total calcium concentration (2.20 mmol/L vs. 2.45 mmol/L), total phosphorus concentration (1.06 mmol/L vs. 1.33 mmol/L), IGF-I (AUC 3,982.32 ng/mL vs. 5,167.61 ng/mL), IGFBP-3 (AUC 725.09 ng/L vs. 944.35 ng/L), 25(OH)D (AUC 356.35 ng/mL vs. 767.53 ng/mL) and BGLAP (AUC 161.39 ng/L vs. 298 ng/L) were lower in the study group. GH (AUC 88.3 ng/mL vs. 48.04 ng/mL), iPTH (AUC 1,201.94 pg/mL vs. 711.73 pg/mL) and ICTP (AUC 104.30 μg/L vs. 54.49 μg/L) were higher in patients with hepatitis. Positive correlations were noted between bone mineral density and IGF-I, IGFBP-3, and BGLAP levels. CONCLUSIONS Chronic viral hepatitis causes a decrease in bone mineral density. Impaired liver function disrupts homeostasis of the calcium- vitamin D-parathyroid hormone axis and provokes secondary hyperparathyroidism. Chronic viral hepatitis induces a decrease in the synthesis of IGF-I and IGFBP-3 and an increase in GH secretion. Hepatic osteodystrophy is probably caused by both changes in calciotropic hormones as well as in the somatotropin hormone axis.

Role of omentin and chemerin in metabolic syndrome and tumor diseases.

For the past few years adipokines have been a center of appreciation and interest. They are biologically active molecules causing pleiotropic effects. They assist in angiogenesis, adipose tissue metabolism and inflammation, and modulate tissue sensitivity for insulin. Adipokines are produced in adipose tissue, so an abnormal quantity of this tissue leads to impaired levels of these factors. Because of their different concentrations in various conditions, it would be plausible to use them as markers for individual conditions, such as obesity, type 2 diabetes mellitus, pancreatitis, gastric cancer, lung cancer or colon cancer. Such adipokines as leptin, resistin, visfatin, adiponectin, and apelin are subjects of research. In our study we focused on the function and significance of chemerin and omentin in metabolic syndrome and cancers. In type 2 diabetes mellitus, both chemerin and omentin enhance the body sensitivity to insulin, which results in increased glucose uptake. However, in diabetic patients, serum concentration of omentin decreases, while that of chemerin increases. A similar trend was observed in obese patients. As a cancer marker, chemerin turned out to be helpful in diagnosis of gastric cancer, mesothelioma, and polycystic ovary syndrome, which can lead to endometrial cancer. An elevated concentration of omentin was noted in colon cancer, and increased expression of the omentin gene was reported in nasal polyps and mesothelioma.