Vitamin D status and premature adrenarche.

BACKGROUND: Vitamin D, an important factor in calcium-phosphate homeostasis, has recently been suggested to play an important role in the pathogenesis of numerous chronic conditions such as hyperandrogenism. The aim of this study was to investigate the relationship between vitamin D status and premature adrenarche (PA). METHODS: A total of 71 girls with PA and 52 healthy girls, as the control group, were recruited. Axillary and/or pubic hair development before the age of 8 years was defined as PA. Bone age and anthropometric measures including height, weight, and body mass index (BMI) were obtained. 25-Hydroxyvitamin D (25(OH)D), fasting plasma glucose and insulin were measured. Vitamin D insufficiency was defined as <20 ng/mL. RESULTS: The PA patients had older bone age, higher BMI standard deviation score, homeostasis model of assessment-insulin resistance (HOMA-IR), and androgen but lower 25(OH)D than the control group. HOMA-IR and dehydroepiandrosterone sulfate were also higher in PA patients with vitamin D insufficiency compared with those with normal vitamin D. There was a negative correlation between 25(OH)D and HOMA-IR. CONCLUSION: Low vitamin D is associated with PA; and insulin resistance may be a factor in this association.

Penile anthropometry of normal prepubertal boys in Turkey.

AIM: The age-related values of penile length must be known to determine abnormal penis sizes and to follow the treatment of underlying diseases. The aim of this study is to evaluate abnormal penile length in Turkish children by establishing novel reference values for Turkish population and to compare the mean penile length and other parameters with alternates from different ethnic populations and geography. METHODS: This cross-sectional study was conducted on a voluntary basis between November 2008 and November 2009 from four centres in Turkey and comprised of 1278 healthy volunteered prepubertal children. Complete stretched penile length and penis circumference measurements were used for penile length and penis circumference evaluations, respectively. All measurements were taken twice by only one investigator, and mean values were recorded. RESULTS: Penile length and penis circumference for every age group were obtained, percentile curves were established and these findings were compared with the results of previous studies. Significant differences were found between penile length of Turkish children and recently used reference values. CONCLUSION: With this study, novel reference values for penile length in prepubertal children were presented to the literature.

Vitamin D status in children with Hashimoto thyroiditis.

OBJECTIVE: To investigate vitamin D status in children with Hashimoto thyroiditis. SUBJECTS AND METHODS: The study group consisted of 78 children recently diagnosed as Hashimoto thyroiditis and 74 subjects as the control group. Parameters of calcium metabolism, thyroid function tests, and 25-hydroxyvitamin D [25(OH)D] levels were measured. RESULTS: Vitamin D deficiency rate was significantly higher in the Hashimoto group compared with the control subjects (73.1% vs. 17.6%, p < 0.0001). In the Hashimoto group, mean 25(OH)D levels were significantly lower compared with the control group (31.2 +/- 11.5 versus 57.9 +/- 19.7 nmol/L, p < 0.001) and was inversely correlated with the anti-thyroid peroxidase (anti-TPO) levels (r = -0.30, p = 0.007). CONCLUSION: The higher vitamin D deficiency rates besides lower vitamin D levels in the Hashimoto group together with the inverse correlation between vitamin D and anti-TPO suggest that vitamin D deficiency may have a role in the autoimmune process in Hashimoto thyroiditis in children.

The effects of oxcarbazepine and valproate therapies on growth in children with epilepsy.

AIM: This study aimed to evaluate the effects of monotherapy with valproate or oxcarbazepine on the linear growth of children with idiopathic epilepsy. METHODS: Antiepileptic treatment with valproate or oxcarbazepine was initiated in 76 patients. These were evaluated at baseline and at 6 and 18 months after commencement of therapy to determine height standard deviations (height z-scores). Serum ghrelin, insulin-like growth factor-1, and insulin-like growth factor-binding protein-3 levels were measured. RESULTS: In prepubertal patients receiving oxcarbazepine, height z-scores were elevated after 6 and 18 months of therapy (p = 0.008 and p = 0.001, respectively); in pubertal patients, a significant increase was noted at the 18th month of therapy (p = 0.004). In prepubertal patients receiving oxcarbazepine, serum standardized insulin-like growth factor-1 and insulin-like growth factor-binding protein-3 levels were significantly higher at the 18th month of therapy compared with baseline (p = 0.005 and p = 0.004, respectively). In puber-tal patients receiving valproate, serum ghrelin levels were significantly decreased at the 18th month of therapy compared with baseline (p = 0.006). CONCLUSION: Exposure to oxcarbazepine stimulated linear growth in epileptic patients through mechanisms involving the release of insulin-like growth factor-1 and insulin-like growth factor-binding protein-3. In contrast, expo-sure to valproate did not affect linear growth, but did lead to a decrease in serum ghrelin levels.

Clinical significance of serum vascular endothelial growth factor, endostatin, and leptin levels in children with lymphoma.

BACKGROUND: A number of clinical studies conducted in adults have demonstrated the prognostic significance of angiogenic factors in malignancies, however, only a limited number of studies have been conducted in children. The aim of this study was to determine serum vascular endothelial growth factor (VEGF), endostatin, and leptin levels in children with lymphoma and to investigate whether these factors provide prognostic information. PROCEDURE: Serum samples from 36 children with lymphoma (non-Hodgkin lymphoma (NHL) N = 21, Hodgkin lymphoma (HL) N = 15) were collected at diagnosis and during remission. Serum samples were also collected from 18 healthy children as the control group. Serum VEGF and endostatin levels were quantified by using enzyme-linked immunosorbent assay (ELISA) and serum leptin by immunoradiometric assay. RESULTS: The serum VEGF levels were found elevated in patients compared to controls (P = 0.033), while endostatin and leptin levels were lower in patients than in controls (endostatin, 43.9 ± 5.8 ng/ml vs. 123.6 ± 13.5 ng/ml, P < 0.001; leptin, 5 ± 1.5 ng/ml vs. 6.7 ± 1.2 ng/ml, P = 0.013). VEGF levels declined (pre, 151.6 ± 55.9 pg/ml vs. post, 16.2 ± 7.9 pg/ml, P = 0.041), while endostatin and leptin levels increased in patients who achieved remission (33 of 36 patients) when compared to pre-treatment levels (endostatin pre, 43.1 ± 5.9 ng/ml vs. post, 65.9 ± 6.8 ng/ml, P = 0.047; leptin, pre, 5.3 ± 1.6 ng/ml vs. post, 9.8 ± 2.7 ng/ml, P = 0.012). Serum VEGF, endostatin, and leptin levels were not predictive of survival. CONCLUSION: Serial measurement of serum VEGF, endostatin, and leptin levels could potentially be used to predict response to treatment or progressive disease in children with lymphoma.

Diagnostic value of urinary luteinizing hormone levels in the monitoring of precocious puberty treatment.

Objective To determine whether first-voided urinary LH (FV-ULH) - level measurement can adequately assess pubertal suppression as much as standard tests can. Subjects and methods The study group included patients with central precocious puberty and rapidly progressing early puberty who received up to 3 - 4 doses of GnRHa therapy monthly and did not have adequate hormonal suppression after GnRH stimulation (90-minute LH level > 4 IU/L). Design: All of the participants underwent an LHRH test just after admission to the study. According to the stimulated peak LH levels, the patients were divided into 2 groups and followed until the end of the first year of treatment. The concordance between FV-ULH and stimulated LH levels was assessed. Results The FV-ULH levels in patients with inadequate hormonal suppression were significantly high compared to patients with adequate hormonal suppression. FV-ULH levels were very strongly correlated with stimulated LH levels (r = 0.91). Its correlation with basal LH levels was significant (r = 0.65). However, this positive correlation was modestly weakened after the first year of treatment. The cutoff value for FV-ULH of 1.01 mIU/mL had the highest sensitivity (92.3%) and specificity (100%). Conclusion FV-ULH levels, using more reliable and sensitive assay methods, can be used to monitor the adequacy of GnRHa therapy.

The effect of beta-glucan supplementation on glycemic control and variability in adolescents with type 1 diabetes mellitus.

AIMS: This study aimed to investigate whether supplemental soluble fiber, oat ß-glucan, has any effect on glycemic control and variability of adolescents with type 1 diabetes mellitus. METHODS: This study was conducted in 30 adolescents with type 1 diabetes mellitus and it consisted of three phases lasting one week. At Phase I, all subjects followed a standard diet program. For Phase II and Phase III, the subjects continued their standard diet program and added natural oat flakes containing 3 g/day and 6 g/day ß-glucan, respectively. Glucose levels were monitored by continuous glucose monitoring (CGM). The maximal, minimal, mean and daytime and night blood glucose levels, percentages of glucose values in a target range and below and above a target values were calculated for each of the phases. Premeal, postmeal, peak blood glucose values and peak times of meals were evaluated for each of the phases. Glycemic variability was measured via SD, CV, MAGE, IQR, MODD, LBGI, HBGI, and CONGA parameters. RESULTS: The maximal, mean and daytime and night blood glucose levels were the lowest at Phase III (p < 0.05). Minimal blood glucose levels were the highest at Phase III (p < 0.05). Phase I, II, and III showed similar durations elapsed for Level 2 and Level 1 hypoglycemia, euglycemia, Level 1 and Level 2 hyperglycemia (p > 0.05). Premeal and postmeal blood glucose levels were lowest at Phase III for breakfast, lunch, and overall (p < 0.05). The lowest peak blood glucose levels were detected at Phase III for breakfast, lunch, dinner and overall (p < 0.05). Phase III also showed delayed peaks for all time-points (p < 0.05 for each) compared to other phases. Phase III had significantly lower levels of SD, CV, LBGI, and CONGA levels than those in either Phase I or Phase II (p < 0.05 for each). CONCLUSION: 6 g/day oat ß-glucan have favorable outcomes in glycemic control and variability in adolescents with type 1 diabetes mellitus.

Dyskeratosis congenita with corneal limbal insufficiency.

We describe a newly diagnosed Turkish adolescent female with Dyskeratosis congenita along with the novel ocular finding of corneal limbal insufficiency. Corneal limbal insufficiency was suggested to be a premature aging sign resulting from a deficiency in corneal stem cell activity, a biological process caused by underlying telomeric defect in this disease.

Plant growth regulator (4-chlorophenoxy acetic acid) increases apoptosis in gonads of rats without changing hormonal levels.

BACKGROUND/AIMS: Plant growth regulators are considered to leave minimal amounts of remnants and therefore cause no significant side effects in humans. In this study, we aimed to investigate the hormonal and histopathological effects of 4-chlorophenoxy acetic acid (4-CPA), a commonly used plant growth regulator, on the gonadal functions of rats. METHODS: The study was implemented on 64 Wistar albino rats (20 days old). Forty-eight rats received 4-CPA every day until 50 days of age. The rats were randomized into 4 groups (a control group and three 4-CPA groups with doses of 25, 50 and 100 mg/kg/day); each group was further divided into males and females, making a total of 8 groups. The levels of FSH, LH, testosterone, estradiol, leptin, inhibin-B and neuropeptide-Y were measured. Histopathological examination of the testes and ductus deferens in male rats, and ovaries and uterus of female rats (caspase-3 and -9 immunoreactivity) was performed. RESULTS: Although hormone levels were similar between the groups, rats that received 4-CPA showed significantly higher degrees of apoptosis compared to the control group (p < 0.001) and increased doses of 4-CPA were directly correlated with the amount of apoptosis (p < 0.001). CONCLUSION: 4-CPA induced apoptosis in the gonads of rats without concurrent changes in plasma hormone levels.

Genetic polymorphisms of FSHR, CYP17, CYP1A1, CAPN10, INSR, SERPINE1 genes in adolescent girls with polycystic ovary syndrome.

BACKGROUND: Polycystic ovary syndrome (PCOS), whose genetic basis is not completely well understood, is the most common endocrine disorder in women and it typically develops during adolescence. The aim of this study is to investigate the possible association between single nucleotide polymorphisms (SNPs) of FSHR, CYP17, CYP1A1, CAPN10, INSR, SERPINE1 genes and PCOS in adolescent girls. METHODS: DNA samples from forty-four adolescent girls with PCOS and 50 healthy controls were analyzed by PCR-RFLP and direct DNA sequencing to determine the genotypic frequency of 17 different polymorphic loci on the FSHR (A307T, N680S), CYP17 (-34 T/C), CYP1A1 (T6235C), CAPN10 (44, 43, 19, 63), INSR (exon 17 C/T), SERPINE1 (4G/5G) genes. Genotyping of exon 12 (six polymorphisms) and intron 12 (one polymorphism) of INSR gene by direct DNA sequencing was performed for the first time in this study. RESULTS: No significant differences were observed in the genotype and allele distributions of above mentioned polymorphisms between cases and control groups. CONCLUSION: Our data does not support an association between SNPs of FSHR, CYP17, CYP1A1, CAPN10, INSR, SERPINE1 genes and susceptibility to PCOS or related traits in Turkish adolescent girls.

A novel mutation in the SLC19A2 gene in a Turkish female with thiamine-responsive megaloblastic anemia syndrome.

Reported here is a 2-year-old girl who was diagnosed to have thiamine-responsive megaloblastic anemia during evaluations for her bilateral neurosensorial deafness. Besides reporting a new mutation on the gene SLC19A2 for the first time in the literature, we highlight the recognition of this syndrome--when megaloblastic anemia and diabetes mellitus coexists--and the role of thiamine replacement for the treatment of both disorders.

Effect of Telehealth System on Glycemic Control in Children and Adolescents with Type 1 Diabetes

Objective: A close diabetes team-patient relationship is required for establishing satisfactory metabolic control. The purpose of this study was to investigate the effect of a telehealth system on diabetes control. Methods: The study was carried out between June 2015 and January 2016 at the Gazi University Faculty of Medicine, Pediatric Endocrinology Department. The telehealth system was developed by the diabetes team. The demographic characteristics, frequency of use and hemoglobin A1c (HbA1c) changes of type 1 diabetic (T1DM) patients using this communication network were analysed. Results: Eighty two patients [43 (52.4%) females, mean (±standard deviation) age 10.89±4 years] used the telehealth system. Fourteen (17.1%) of the cases were on pump therapy and 59 (72.0%) were counting carbohydrates. The individuals with diabetes or their families preferred WhatsApp communication. Whatsapp provided a means for instant messaging in most instances (57.3%), contact with diabetes education nurse (32.9%) and consultation with the diabetes team about insulin doses and blood glucose regulation (42.7%). HbA1c values after six months were significantly lower in patients/parents calling frequently (p<0.001) compared with HbA1c values recorded at the beginning of the study. Conclusion: Increase in frequency of counselling by the diabetes team led to improved blood glucose control in T1DM patients. A telehealth system is useful for early detection of the need for changes in treatment and for intervention. It also promoted better self care.

CTLA4 gene polymorphisms in children and adolescents with autoimmune thyroid diseases.

Two common forms of autoimmune thyroid diseases are Graves' disease and Hashimoto's thyroiditis. Cytotoxic T lymphocyte antigen 4 (CTLA4) encoded by the CTLA4 gene on chromosome 2q33 plays a role in susceptibility to Graves' disease and is probably important also for Hashimoto's thyroiditis as well as for the other endocrine autoimmune disorders. The CTLA4 locus is the only nonhuman leukocyte antigen locus that has been found in association with Graves' disease repeatedly. Particularly, association of three polymorphic markers of CTLA4 gene, namely, C(-318)T, A49G, and (AT)n dinucleotide repeat, with Graves' disease was demonstrated in most of the population-based investigations. On the other hand, there are few studies to reveal the association of these markers with Hashimoto's thyroiditis. A49G polymorphism was proposed to be associated with Hashimoto's thyroiditis, and C(-318)T was suggested to be not associated. The patient groups consisted of 88 patients (10 males and 78 females; mean age: 14.5 +/- 3.2 years [4.6-21.0 years]) with a previous diagnosis of Hashimoto's thyroiditis and 112 euthyroid volunteers (51 males and 61 females; mean age: 14.1 +/- 2.9 years [5.2-18 years]). The frequency of A/G (A49G) genotype was high and statistically significant in patients with Hashimoto's thyroiditis in comparison with the control group. Although the frequency of C/T [C(-318)T] genotype is not significantly high in children with Hashimoto's thyroiditis according to the control group, the risk of Hashimoto's thyroiditis in A/G genotype group was 4.66 times greater than the group with A/A genotype. In this study, we documented that the A49G polymorphism might increase the susceptibility for Hashimoto's thyroiditis.

Evaluation of bone turnover in epileptic children using oxcarbazepine.

This study evaluated the effects of oxcarbazepine monotherapy on bone turnover in prepubertal and pubertal children. Thirty-four newly diagnosed pediatric patients with normal bone mineral density, serum biochemical markers of bone formation, and hormonal markers participated. Levels of 25-hydroxyvitamin D were significantly decreased after therapy compared with baseline values. Levels of gamma-glutamyl transferase, phosphorus, alkaline phosphatase, osteocalcin, parathyroid hormone, and calcitonin had increased. However, only changes in osteocalcin and gamma-glutamyl transferase levels were statistically significant compared with baseline values. Drug-induced osteopenia was evident in 3 patients with z scores of bone-mineral density less than -2.0, whereas these patients had z scores of less than -1.5 before treatment. Although 18 months of oxcarbazepine treatment exerted slightly adverse effects on bone metabolism, the effect seems insignificant in children with normal bone-mineral density. Although alterations in bone metabolism do not always suffice to explain the decrease in bone-mineral metabolism, we think that patients with osteopenia before the initiation of oxcarbazepine therapy should be followed carefully, especially in long-term treatment.

A 46XX disorder of sex development with a prostate gland and increased level of prostate-specific antigen.

A 5-year-old child with precocious puberty and complete masculinization of the genitalia was diagnosed to have 21-hydroxylase deficiency. The patient was also found to have a prostate gland and increased prostate-specific antigen. The presence of a prostate and its relation to prostate-specific antigen and prostate adenocarcinoma are discussed in the light of the relevant literature.

Anxiety and depression states of adolescents with polycystic ovary syndrome

Background/aim: Various studies have shown that adult patients with polycystic ovary syndrome (PCOS) have higher levels of anxiety and depression compared to their normal counterparts. However, it is still unclear whether these mood disorders already exist in adolescents affected by PCOS. The aim of the present study is to assess differences in anxiety and depression levels between adolescents with PCOS and age- and body mass index (BMI)-matched controls and to determine the possible factor(s) impacting these psychological parameters in adolescents with PCOS. Materials and methods: The study included 80 adolescents with PCOS and 50 age- and BMI-matched controls. All participants completed standardized questionnaires assessing anxiety and depression. A multiple linear regression model was used to analyze the impact of potential variables on anxiety and depression scores of the adolescents with PCOS. Results: Significantly higher levels of anxiety, specifically generalized and social anxieties, as well as depression were found in adolescents with PCOS compared to controls. Higher BMI was found to be associated with higher levels of depression and generalized anxiety, and higher modified Ferriman-Gallwey score with higher level of panic disorder in adolescents affected by PCOS. Conclusion: Adolescents with PCOS experience significantly more emotional distress compared to adolescents without PCOS. This emotional distress may be related, at least in part, to certain clinical features of PCOS including obesity and hirsutism. PCOS in adolescents should be assessed not only for the gynecological and metabolic aspects but also for the emotional aspects of the disease.

Microdeletion and mutation analysis of the SHOX gene in patients with idiopathic short stature with FISH and sequencing

Background/aim: The aim of this study was to investigate the prevalence of the microdeletions and mutations of the SHOX gene in children with idiopathic short stature (ISS) by the usage of fluorescence in situ hybridization (FISH) and direct sequencing technique. Materials and methods: Thirty-seven children referred to our clinic because of short stature were classified as having ISS after clinical examination. Chromosome analyses, FISH analysis of the SHOX gene, and direct sequencing of the coding exons of SHOX , through the second to the sixth exon, in 24 of the 37 patients were also performed. Results: All children had normal karyotypes and the SHOX gene region was found to be intact in all. No mutation was detected in the exonic sequences and exon/intron boundaries of the SHOX gene in 24 children analyzed. Conclusion: No mutation was detected in the exonic sequences and exon/intron boundaries of the SHOX gene and this indicated that the prevalence of the SHOX mutations can differ according to the selection criteria, used methods, sample size, and population.

Relationship between obesity and iron deficiency anemia: is there a role of hepcidin?

OBJECTIVES: Iron deficiency is common in obese children although the underlying mechanism is unclear. The aim of this study was to investigate the associations between iron parameters, leptin, hepcidin and adiponectin levels in obese children. METHODS: A total of 237 children, ranging in age from 5 to 18 years, 180 with primary obesity and 57 healthy children and adolescents, were enrolled. Complete blood count, serum iron levels, iron-binding capacity, ferritin levels, leptin, hepcidin and adiponectin levels were studied. RESULTS: White blood cell and platelet count, iron-binding capacity, high-sensitive C-reactive protein, leptin and hepcidin values in the obese group were higher than those of the control group (p < 0.001, p = 0.002, p < 0.001, p < 0.001, p < 0.001 and p < 0.001, respectively). However, mean corpuscular volume, adiponectin and transferrin saturation values in the obese group were lower than in the control group (p = 0.026, p = 0.003, and p < 0.001, respectively). No significant differences were found in terms of hemoglobin, serum ferritin, iron and IL-6 levels. CONCLUSIONS: Our study suggests that hepcidin levels do not contribute to the development of iron deficiency anemia in pediatric obese individuals.

Retinal Neural and Vascular Structure in Isolated Growth Hormone Deficiency Children and Evaluation of Growth Hormone Treatment Effect

OBJECTIVE: To evaluate neural and vascular retinal morphology of children with isolated growth hormone deficiency (GHD) and to determine any retinal changes due to GH treatment. METHODS: Twenty-eight children with isolated GHD and 53 age-, gender- and body mass index-matched healthy volunteers were enrolled in this prospective study. The retinal nerve fibre layer (RNFL) and macular thickness (MT) were measured, as well as intraocular pressure (IOP). The number of retinal vascular branching points were calculated. Effect of GH treatment on the retina and IOP was evaluated after one year of treatment. Measurements were also made in the control group at baseline and following the initial examination. Pre- and post-treatment changes were compared. The findings were also compared with those of the controls. The correlation between ocular dimensions and insulin-like growth factor-I (IGF-1) levels were also analysed. RESULTS: The number of branching points was significantly lower in GHD patients as compared with control subjects (15.11±2.67 and 19.70±3.37, respectively, p=0.05 for all comparisons). No statistically significant differences were found in mean RNFL, MT and IOP values between GHD patients and control subjects. GH treatment did not create any significant changes in the retinal vascularization or other retinal neural parameters and IOP either within the patient group or when compared with the control group. No correlations were observed between ocular dimensions and IGF-1 levels. CONCLUSION: Our findings suggest that isolated GHD may lead to decreased retinal vascularization. However, retinal neural growth and differentiation were not affected by GHD. These findings may be related to the fetal development process of pituitary somatotropic cells and the retina. Additionally, GH treatment did not cause any changes in retinal neural and vascular tissues.

Osteoprotegerin and RANKL serum levels and their relationship with serum ghrelin in children with chronic renal failure and on dialysis.

BACKGROUND: Osteoprotegerin (OPG) and receptor activator of the nuclear factor kappaB ligand (RANKL) constitute a complex system of mediators involved in the regulation of bone resorption process. Ghrelin, a growth hormone secretagogue, has been shown to modulate proliferation and differentiation of osteoblasts. The present study was carried out to evaluate the serum concentrations of OPG and sRANKL in children with chronic renal impairment (CRI) and on dialysis, and to establish a possible relationship between their serum levels and that of ghrelin. METHODS: 33 patients including 10 patients with CRI, 12 peritoneal dialysis (PD) and 11 hemodialysis (HD) patients and 22 healthy controls were enrolled into the study. OPG, sRANKL and ghrelin levels were studied with radioimmunoassay. RESULTS: Serum OPG levels in CRI, PD and HD groups were significantly higher than the healthy controls (p = 0.002, p < 0.001, p < 0.001, respectively) whereas sRANKL levels were significantly lower than the healthy controls (p = 0.03, p = 0.01, p = 0.001, respectively). Ghrelin levels were significantly higher in CRI, PD and HD groups compared to healthy controls (p = 0.001, p < 0.001, p < 0.001, respectively). We observed a negative correlation between the sRANKL and OPG levels (r = -0.27, p = 0.04) as well as between sRANKL and ghrelin levels (r = -0.31, p = 0.02). OPG levels showed a positive correlation with ghrelin levels (r = 0.63, p < 0.001). CONCLUSION: We found a lower RANKL bioactivity index in children with CRI and on dialysis. The mechanism and the role of elevated OPG and low sRANKL in uremia are unclear, but they might partly represent a compensatory mechanism to the negative balance of bone remodeling in renal bone disease in children. Additionally, we demonstrated for the first time that ghrelin and the RANKL/OPG system have a close relationship in CRF. Therefore, ghrelin may be of importance in mediating the effects of the RANKL/OPG system in renal bone disease.