Association of the apoptotic markers Apo1/Fas and cCK-18 and the adhesion molecule ICAM-1 with Type 1 diabetes mellitus in children and adolescents.

BACKGROUND: Type 1 diabetes mellitus (T1DM) is characterized by immune and metabolic dysregulation. Apo1/Fas is implicated in maintaining homeostasis of the immune system. Cytokeratin-18 (cCK-18) is a predictive marker of liver disorders in T2DM. Intercellular adhesion molecule-1 (ICAM-1) is considered to increase susceptibility to diabetes mellitus. All three markers are associated with endothelial function, apoptosis and diabetes-related complications. The possible role of Apo1/Fas, cCK-18 and ICAM-1 was investigated in children and adolescents with T1DM. METHOD: Forty-nine (49) children and adolescents with T1DM and 49 controls were included in the study. Somatometric measurements were obtained and the Body Mass Index (BMI) of the participants was calculated. Biochemical parameters were measured by standard laboratory methods and Apo1/Fas, cCK-18 and ICAM-1 were measured using appropriate ELISA kits. The statistical analysis was performed using the IBM SPSS Statistics 23 program. RESULTS: Apo1/Fas (p = 0.001), cCK-18 (p < 0.001) and ICAM-1 (p < 0.001) were higher in patients with T1DM compared to the controls. Apo1Fas was negatively correlated with glucose (p = 0.042), uric acid (p = 0.026), creatinine (p = 0.022), total cholesterol (p = 0.023) and LDL (p = 0.005) in the controls. In children and adolescents with T1DM, Apo1/Fas was positively correlated with total cholesterol (p = 0.013) and LDL (p = 0.003). ICAM-1 was negatively correlated with creatinine (p = 0.019) in the controls, whereas in patients with T1DM it was negatively correlated with HbA1c (p = 0.05). CONCLUSIONS: Apo1/Fas, cCK-18 and ICAM-1 may be useful as serological markers for immune and metabolic dysregulation in children and adolescents with T1DM. Also, Apo1/Fas may have a protective role against metabolic complications in healthy children.

Diagnosis of Thyroid Nodules in Children and Adolescents with Subclinical Hypothyroidism and Their Outcomes after Early Thyroxine Treatment-A Longitudinal Study.

Pediatric thyroid nodules (TNs) present a higher malignancy rate compared to adults. We sought to diagnose the frequency and characteristics of TNs in children and adolescents with subclinical hypothyroidism (SH) and their outcomes after levothyroxine (LT4) therapy. A total of 256 children with TNs and SH were followed every semester from 2006 to 2018. All patients were treated with LT4. Clinical and radiologic findings, such as the size and texture of the nodules, were documented. Analysis included one-way ANOVA, Kruskal-Wallis, Chi-square, and Fisher's exact tests. After initial LT4 therapy, TNs disappeared in 85.5% and did not reappear throughout follow-up. In 14.5%, TNs remained the same or increased in size, but they decreased after subsequent LT4 administration with an increased dose. Thyroid disease family history (FHTD) was documented in 77.0%. In total, 64.5% developed a goiter, 46.0% exhibited thyroid heterogeneity on ultrasound, 23.4% had positive Anti-Tg, and 25.4% had positive anti-TPO autoantibodies. Our findings support the possible premise that early pharmacologic intervention with LT4 may be beneficial in children and adolescents with TNs and SH. The increased frequency of FHTD, goiter, thyroid heterogeneity, and Hashimoto in our patients emphasizes that thyroid ultrasounds may be warranted in children and adolescents with these characteristics in order to rule out the presence of TNs.

Association of antimullerian hormone with the size of the appendix testis, the androgen and estrogen receptors and their expression in the appendix testis, in congenital cryptorchidism.

OBJECTIVES: Antimullerian hormone (AMH) causes regression of the mullerian ducts in the male fetus. The appendix testis (AT) is a vestigial remnant of mullerian duct origin, containing both androgen (AR) and estrogen (ER) receptors. The role of both AMH and AT in testicular descent is yet to be studied. We investigated the possible association of AMH with AT size, the AR and ER, and their expression in the AT, in congenital cryptorchidism. METHODS: A total of 26 patients with congenital unilateral cryptorchidism and 26 controls with orthotopic testes were investigated, and 21 ATs were identified in each group. AMH and insulin-like three hormone (INSL3) concentrations were measured with spectrophotometry. AR and ER receptor expression was assessed with immunohistochemistry using monoclonal antibodies R441 for AR and MAB463 for ER. For the estimation of receptor expression, the Allred Score method was used. RESULTS: AMH concentrations did not present significant differences between patients with congenital cryptorchidism and the controls. Also, no correlation was found between AMH, INSL3, and AT length. Allred scores did not present significant differences. However, expression percentiles and intensity for both receptors presented significant differences. Three children with cryptorchidism and the highest AMH levels also had the highest estrogen receptor scores in the AT. CONCLUSIONS: No association was found between AMH and the studied major parameters. However, higher AMH concentrations, in combination with higher estrogen receptor scores in the AT, may play a role in cryptorchidism in some children. Larger population samples are needed to verify this observation.

Association of the apoptotic marker APO1/Fas with children's predisposing factors for metabolic syndrome and with mean platelet volume.

BACKGROUND: Apoptosis antigen 1/FAS receptor (APO1/Fas) signaling in endothelial cells plays a significant role in angiogenesis while increased mean platelet volume (MPV) is an important marker for platelet activation. We investigated the possible correlation between APO1/Fas and both metabolic parameters and platelet activity (indicated by the MPV) in a healthy pediatric population. METHODS: One hundred and eighty-five children, aged 5-17 years old, were enrolled in the study. The participants were divided into subgroups according to their age and body mass index percentile (BMI%). APO1/Fas was measured by enzyme-linked immunosorbent assay (ELISA) and MPV by the MEK-6410K. RESULTS: Eighty-one children (43.8%) had excess weight, which was more prevalent in children ≤9 years of age. Sixty-five children (35.1%) exhibited a predisposition for metabolic syndrome. A negative correlation was found between APO1/Fas and predisposing factors for metabolic syndrome: Glucose, cholesterol, uric acid, low-density lipoprotein (LDL), and triglycerides. In contrast, a positive correlation was found between APO1/Fas and C-reactive protein (CRP). Receiver operating characteristic (ROC) analysis showed a predisposition to metabolic syndrome when APO1/Fas was <78.46 pg/mL. A negative correlation was also observed between APO1/Fas and MPV. MPV was also positively correlated with predisposing factors for metabolic syndrome: BMI%, glucose, cholesterol, uric acid, LDL, and negatively with high-density lipoprotein. CONCLUSIONS: APO1/Fas expression is associated with a lower predisposition to metabolic syndrome may be through endothelial homeostasis, the induction of apoptosis of cells involved in atherosclerosis, and platelet activity. It may also enhance CRP-mediated noninflammatory clearance of apoptotic cells. Early monitoring of all the components of metabolic syndrome in overweight children is important in order to prevent metabolic and cardiovascular complications.

Genetics of primary congenital hypothyroidism-a review.

PURPOSE: Congenital primary hypothyroidism (CH) is a state of inadequate thyroid hormone production detected at birth, caused either by absent, underdeveloped or ectopic thyroid gland (dysgenesis), or by defected thyroid hormone biosynthesis (dyshormonogenesis). A genetic component has been identified in many cases of CH. This review summarizes the clinical and biochemical features of the genetic causes of primary CH. METHODS: A literature review was conducted of gene defects causing congenital hypothyroidism. RESULTS: Mutations in five genes have predominantly been implicated in thyroid dysgenesis (TSHR, FOXE1, NKX2-1, PAX8, and NKX2-5), the primary cause of CH (85%), and mutations in seven genes in thyroid dyshormonogenesis (SLC5A5, TPO, DUOX2, DUOXA2, SLC6A4, Tg, and DEHAL1). These genes encode for proteins that regulate genes expressed during the differentiation of the thyroid, such as TPO and Tg genes, or genes that regulate iodide organification, thyroglobulin synthesis, iodide transport, and iodotyrosine deiodination. Besides thyroid dysgenesis and dyshormonogenesis, additional causes of congenital hypothyroidism, such as iodothyronine transporter defects and resistance to thyroid hormones, have also been associated with genetic mutations. CONCLUSION: The identification of the underlying genetic defects of CH is important for genetic counseling of families with an affected member, for identifying additional clinical characteristics or the risk for thyroid neoplasia and for diagnostic and management purposes.

Correlation between insulin-like peptide 3 and appendix testis length in congenital cryptorchidism.

AIM: The appendix testis (AT) is a vestigial remnant of Müller's paramesonephric duct. Insulin-like 3 hormone (INSL3) is produced in the Leydig cells of the testis. We investigated the possible correlation between AT length and plasma INSL3 concentrations in patients with congenital cryptorchidism (CCO) and patients with hydrocele, who served as controls. METHODS: A total of 40 patients with CCO and 34 patients with hydrocele and orthotopic testes were investigated. Sixteen patients presented high cryptorchidism and 24 low cryptorchidism. During surgery, AT was identified in 34 patients with CCO (high cryptorchidism:15, low cryptorchidism:19) and 28 controls. Plasma INSL3 levels were measured with a spectrophotometry enzyme immunoassay Elisa sandwich technique. RESULTS: AT was present in 85.0% of the boys with CCO and 82.4% of the controls. A significant positive correlation was found between the AT length and INSL3 concentrations in CCO patients. CONCLUSIONS: A longer AT may reflect better testicular function in boys with CCO, since it is correlated with higher INSL3 concentrations.

Polycystic ovary Syndrome in Adolescents: Pitfalls in Diagnosis and Management.

PURPOSE OF REVIEW: Polycystic ovary syndrome (PCOS) is the commonest endocrine disorder during a woman's reproductive lifespan, with well-documented diagnostic criteria and therapeutic strategies in adults; the same is not necessarily true for adolescents. The purpose of this review was to identify frequent pitfalls in PCOS diagnosis and management during adolescence. RECENT FINDINGS: Although there is no global consensus on the definition, most experts converge to the presence of both oligo/amenorrhea and (clinical and/or biochemical) hyperandrogenism, as a prerequisite for diagnosis in adolescents. The former criterion includes: (a) consecutive menstrual intervals > 90 days even in the first year after menarche; (b) menstrual intervals persistently < 21 or > 45 days for ≥ 2 years after menarche; or (c) lack of menses by the age of 15 or 2-3 years after pubarche. However, these menstrual irregularity patterns may overlap with other common entities in adolescents, such as frequent or infrequent uterine bleeding or anovulation due to immaturity of the hypothalamic-pituitary-ovarian axis. Clinical signs of hyperandrogenism are obscure, without well-validated criteria. Finally, the criterion of polycystic morphology cannot be safely used in adolescents, mostly due to technical limitations of the transabdominal ultrasound. Except for the efficacy of lifestyle intervention in overweight and obese adolescents with PCOS, limited and low-quality data exist regarding the available medications, such as oral contraceptives, metformin, and anti-androgens. Individualized management, guided by clinical experience and research data and close monitoring appear the most effective approach in this PCOS population for optimal control of its reproductive and metabolic outcomes. Research focusing on PCOS genetic and molecular mechanisms may elucidate what diagnostic and therapeutic strategies will be most appropriate in adolescents with PCOS in the future.

Investigation of the role of ß-TrCP in growth hormone transduction defect (GHTD).

Background Growth hormone(GH) and epidermal growth factor (EGF) stimulate cell growth and differentiation, and crosstalking between their signaling pathways is important for normal cellular development. Growth hormone transduction defect (GHTD) is characterized by excessive GH receptor (GHR) degradation, due to over-expression of the E3 ubiquitin ligase, cytokine inducible SH2-containing protein (CIS). GH induction of GHTD fibroblasts after silencing of messenger RNA (mRNA) CIS (siCIS) or with higher doses of GH restores normal GH signaling. ß-Transducing-repeat-containing protein (ß-TrCP), another E3 ubiquitin ligase, also plays a role in GHR endocytosis. We studied the role of ß-TrCP in the regulation of the GH/GHR and EGF/EGF receptor (EGFR) pathways in normal and GHTD fibroblasts. Materials and methods Fibroblast cultures were developed from gingival biopsies of a GHTD (P) and a control child (C). Protein expression and cellular localization of ß-TrCP were studied by Western immunoblotting and immunofluorescence, respectively, after: (1) GH 200 µg/L human GH (hGH) induction, either with or without silence CIS (siCIS), and (2) inductions with 200 µg/L GH or 1000 µg/L GH or 50 ng/mL EGF. Results After induction with: (1) GH200/siCIS, the protein expression and cytoplasmic-membrane localization of ß-TrCP were increased in the patient, (2) GH200 in the control and GH1000 in the patient, the protein and cytoplasmic-membrane localization of ß-TrCP were increased and (3) EGF, the protein expression and cytoplasmic-membrane localization of ß-TrCP were increased in both the control and the patient. Conclusions (1) ß-TrCP appears to be part of the negative regulatory mechanism of the GH/GHR and EGF/EGFR pathways. (2) There appears to be a negative correlation between ß-TrCP and CIS. (3) In the control and GHTD patient, ß-TrCP increases when CIS is suppressed, possibly as a compensatory inhibitor of the GH/GHR pathway.

New insights into the expression of androgen and estrogen receptors of the appendix testis in congenital cryptorchidism.

Background The appendix testis (AT) is the most common vestigial remnant of the human testis. Variations in the presence and expression of AT androgen receptor (AR) and estrogen receptor (ER) have been reported in cryptorchidism. We studied the possible association of AR and ER expression of the AT with cryptorchidism. Methods ATs were resected from 40 boys who underwent inguinoscrotal surgery, (20 patients with congenital unilateral cryptorchidism [UC] and 20 controls with orthotopic testes and hydrocele). AR and ER expression was evaluated with immunohistochemistry, and the percentage and intensity of AR and ER expression were evaluated by the Allred scoring method. AT length was compared between the two groups. Correlation of AR and ER expression was evaluated independently in patients and controls. Results The Allred score for AR trended toward lower values in UC compared to controls (p = 0.193), while ER scores presented statistically significant lower values in UC compared to controls (p = 0.017). No significant difference or trend was found in the expression of both receptors between high and low cryptorchidism (p = 0.981 for AR, p = 0.824 for ER) and for the appendiceal length between UC and controls (p = 0.369). Conclusions The findings of a trend for lower AR expression and a statistically significant lower expression of ER in UC may suggest an association of AR and ER with cryptorchidism and may provide an insight into the process of testicular descent.

Epidermal growth factor receptor (EGFR) involvement in successful growth hormone (GH) signaling in GH transduction defect.

BACKGROUND: Growth hormone (GH) transduction defect (GHTD) is a growth disorder with impaired signal transducer and activator of transcription 3 (STAT3) phosphorylation mediated by overexpression of cytokine-inducible SH2-containing protein (CIS), which causes increased growth hormone receptor (GHR) degradation. This study investigated the role of epidermal growth factor (EGF) in the restoration of normal GH signaling in GHTD. METHODS: Protein expression, cellular localization and physical contact of proteins of the GH and EGF signaling pathways were studied by Western immunoblotting, immunofluorescence and co-immunoprecipitation, respectively. These were performed in fibroblasts of one GHTD patient (P) and one control child (C) at the basal state and after induction with human GH (hGH) 200 µg/L (GH200), either with or without silencing of CIS mRNA, and after induction with hGH 1000 µg/L (GH1000) or 50 ng/mL EGF. RESULTS: The membrane availability of the EGF receptor (EGFR) and the activated EGFR (pEGFR) was increased in P only after simultaneous GH200 and silencing of CIS mRNA or with GH1000, whereas this occurred in C after GH200 alone. After EGF induction, the membrane localization of GHR, STAT3 and that of EGFR were increased in P more than in C. CONCLUSIONS: In conclusion, in GHTD, the EGFR seems to participate in successful GH signaling, but induction of GHTD fibroblasts with a higher dose of hGH is needed. The EGF/EGFR pathway, in contrast to the GH/GHR pathway, seems to function normally in P and is more primed compared to C. The involvement of the EGFR in successful GH signaling may explain the catch-up growth seen in the Ps when exogenous hGH is administered.

Osteoprotegerin, RANKL, ADMA, and Fetuin-A serum levels in children with type I diabetes mellitus.

INTRODUCTION: Patients with type I diabetes mellitus (T1DM) have increased incidence of atherosclerosis and cardiovascular disease. Although these complications are unusual in children with T1DM, prevention, and early intervention could decrease morbidity and mortality. Osteoprotegerin (OPG), asymmetric dimethylarginine (ADMA), and Fetuin-A have been associated with increased cardiovascular risk (CVR). Increased OPG and ADMA, and decreased or increased Fetuin-A serum levels have been associated with increased CVR. AIM: Because patients with T1DM have higher CVR we investigated OPG, ADMA, and Fetuin-A, in children with T1DM. METHODS: We determined the serum levels of OPG, receptor activator of nuclear factor-κB ligand (RANKL), ADMA, and Fetuin-A by enzyme-linked immunosorbent assay (ELISA) in 56 children with T1DM aged 12.1 ± 3.4 yr and in 46 normal control children, (C) aged 11.3 ± 3.0 yr. RESULTS: Serum OPG levels were significantly increased in patients with T1DM (3.352 ± 0.73 pmol/L) compared with C (2.75 ± 0.67 pmol/L, p < 0.0001) but RANKL did not change. ADMA was significantly decreased in T1DM compared with C (0.68 ± 0.13 µmol/L versus 0.82 ± 0.18 µmol/L, p < 0.0001). Fetuin-A was similar in T1DM (0.551 ± 0.13 g/L) and C (0.540 ± 0.11 g/L) subjects. OPG was positively associated with glycosylated hemoglobin A1c (p < 0.001) and negatively associated with BMI (p < 0.01). ADMA and Fetuin-A were not associated with A1c and ADMA was only negatively associated with age (p < 0.05). CONCLUSION: OPG is increased, ADMA is decreased, but RANKL and Fetuin-A are unchanged in T1DM children. Whereas increased OPG has been firmly related to increased CVR, more studies, especially longitudinal studies, are needed to delineate the role and clinical significance of decreased ADMA and if Fetuin-A has any role in T1DM.

Bridging the gap: metabolic and endocrine care of patients during transition.

OBJECTIVE: Seamless transition of endocrine patients from the paediatric to adult setting is still suboptimal, especially in patients with complex disorders, i.e., small for gestational age, Turner or Prader-Willi syndromes; Childhood Cancer Survivors, and those with childhood-onset growth hormone deficiency. METHODS: An expert panel meeting comprised of European paediatric and adult endocrinologists was convened to explore the current gaps in managing the healthcare of patients with endocrine diseases during transition from paediatric to adult care settings. RESULTS: While a consensus was reached that a team approach is best, discussions revealed that a 'one size fits all' model for transition is largely unsuccessful in these patients. They need more tailored care during adolescence to prevent complications like failure to achieve target adult height, reduced bone mineral density, morbid obesity, metabolic perturbations (obesity and body composition), inappropriate/inadequate puberty, compromised fertility, diminished quality of life and failure to adapt to the demands of adult life. Sometimes it is difficult for young people to detach emotionally from their paediatric endocrinologist and/or the abrupt change from an environment of parental responsibility to one of autonomy. Discussions about impending transition and healthcare autonomy should begin in early adolescence and continue throughout young adulthood to ensure seamless continuum of care and optimal treatment outcomes. CONCLUSIONS: Even amongst a group of healthcare professionals with a great interest in improving transition services for patients with endocrine diseases, there is still much work to be done to improve the quality of healthcare for transition patients.

Recombinant human growth hormone in the treatment of Turner syndrome.

Turner syndrome (TS) is a common chromosomal disorder in women that is associated with the absence of one of the X chromosomes. Severe short stature and a lack of pubertal development characterize TS girls, causing psychosocial problems and reduced bone mass. The growth impairment in TS seems to be due to multiple factors including an abnormal growth hormone (GH) - insulin-like growth factor (IGF) - IGF binding protein axis and haploinsufficiency of the short stature homeobox-containing gene. Growth hormone and sex steroid replacement therapy has enhanced growth, pubertal development, bone mass, and the quality of life of TS girls. Recombinant human GH (hGH) has improved the height potential of TS girls with varied results though, depending upon the dose of hGH and the age of induction of puberty. The best final adult height and peak bone mass achievement results seem to be achieved when hGH therapy is started early and puberty is induced at the normal age of puberty in a regimen mimicking physiologic puberty. The initiation of estradiol therapy at an age-appropriate time may also help the TS patients avoid osteoporosis during adulthood. Recombinant hGH therapy in TS seems to be safe. Studies so far show no adverse effects on cardiac function, glucose metabolism or any association with neoplasms but research is still in progress to provide conclusive data on long-term safety.

Renal dysgenesis and KAL1 gene defects in patients with sporadic Kallmann syndrome.

OBJECTIVE: To correlate the presence of renal agenesis/dysgenesis to the prevalence of KAL1 gene defects in patients with sporadic Kallmann syndrome (KS). DESIGN: Prospective assessment of renal structure and DNA sequence analysis of the KAL1 gene. SETTING: Outpatient clinics of the divisions of endocrinology of university hospitals. PATIENT(S): Sixteen male patients with sporadic KS. INTERVENTION(S): Assessment of renal structure by abdominal ultrasounds scans and DNA extraction, polymerase chain reaction amplification, and DNA sequence analysis of all 14 exons of the KAL1 gene. MAIN OUTCOME MEASURE(S): KAL 1 gene structure and presence of renal dysgenesis. RESULT(S): Renal dysgenesis was identified in only two of 16 KS patients. Genetic defects were found in only two patients with KS, that is, in those with the identified renal dysgenesis. The first gene defect was identified in a patient with associated right renal agenesis who had two point mutations in the KAL1 gene: the first was a G to A transition in exon 11, turning codon 514 encoding glutamic acid into lysine; and the second was a G to A transition in exon 13, turning codon 660 encoding alanine into threonine. The second gene defect was identified in a patient with ichthyosis, right renal agenesis, and mirror movements of the upper limbs (synkinesia) and comprised a deletion of exons 5-10 of the KAL1 gene and a complete deletion of the steroid sulphatase gene. CONCLUSION(S): The phenotype of renal agenesis/dysgenesis strongly indicates the existence of KAL1 gene defects in the genotype of patients with sporadic KS, providing evidence for the X-linked mode of inheritance and offering the opportunity for genetic counseling.

Combined effect of mutations of the GH1 gene and its proximal promoter region in a child with growth hormone neurosecretory dysfunction (GHND).

Mutational analysis of the growth hormone 1 (GH1) gene and its promoter in a patient with GH neurosecretory dysfunction (GHND) revealed a heterozygous new deletion of one base 7-bp downstream from the 3'-splice site of exon 4 (IVS4'del+7) of the GH1 gene and two new heterozygous mutations at sites -135 and -138 of the GH1 promoter. In addition, two polymorphisms at sites -301 and -308 of the GH1 promoter were observed. All other family members had either the -301/-308 polymorphisms or the IVS4'del+7 mutation, but none had both. The IVS4'del+7 mutation located close to the splice donor site possibly interferes with the success of the splicing process, or the mutant transcripts are highly unstable because of nonsense-mediated mRNA decay. The -135/-138 mutations, albeit in close proximity to a putative Pit-1 recognition site, do not seem to affect binding of this transcription factor. The combination of the two polymorphisms, -301/-308, results in significantly reduced DNA-binding activity as monitored by electrophoretic mobility-shift assay. Transcription factor recognition site analysis of the GH1 promoter (MatInspector) revealed that HES1, one of the effectors of the Notch signalling system, is the only transcription factor whose binding is expected to be disrupted by each haplotype or by their combination. We provide evidence that the combination of -301/-308 polymorphisms with the IVS4'del+7 mutation in a GHND patient probably accounts for the reduced amount of growth hormone spontaneously secreted from his pituitary gland and for the severe growth delay.

Growth and long-term hormonal therapy.

Sex hormone replacement therapy (HRT) in the female adolescent has the following goals: 1. to mimic physiologic puberty; 2. to enhance normal growth; 3. to induce and maintain normal menstruation, 4. to support normal bone maturation and calcification; 5. to initiate and maintain normal brain cell growth and brain plasticity; and 6. to preserve the woman's psycho-sexual well-being. A physiologic peak bone mass during puberty and young adulthood is achieved when HRT is started by the age of 12. Estrogen has a biphasic effect on longitudinal growth, stimulatory at low doses and inhibitory at high doses. Therefore HRT in the adolescent girl is initiated with low doses of estrogen which progressively increase during a two-year period. This facilitates normal longitudinal growth and normal growth of the uterus for normal menstruation and future pregnancy with a donor oocyte. Whether HRT will continue past the normal age of menopause is still controversial.

Alteration in serum leptin correlates with alterations in serum N-telopeptide of collagen type I and serum osteocalcin during the progression of osteoporosis in ovariectomized rats.

The role of leptin during the progression of osteoporosis was investigated in ovariectomized rats by correlation of serum leptin levels with N-telopeptide of collagen type I (NTx) and osteocalcin levels before ovariectomy and 20, 40 and 60 days after the operation. Furthermore, peripheral quantitative computed tomography was used to confirm the development of severe osteoporosis in rats on day 60. The levels of NTx and osteocalcin were significantly increased on day 20 [61.9+/-5.4 nM BCE (bone collagen equivalents) and 215.6+/-53.3 ng/mL, respectively] in comparison to those before ovariectomy (41.3+/-1.7 nM BCE and 60.4+/-10.9 ng/mL). Accordingly, leptin was significantly elevated on day 20 (3033+/-661 vs. 606+/-346 pg/mL before ovariectomy). Bone markers and leptin levels remained constant up to day 40, while a slight, but not statistically significant, decrease was noted for osteocalcin and leptin on day 60. Although leptin and bone markers did not correlate before ovariectomy (r=0.09 for NTx and r=-0.05 for osteocalcin), strong correlation was observed at all time points after ovariectomy. The data obtained suggest that the alterations in serum leptin levels during the progression of osteoporosis in ovariectomized rats follow the alterations in bone markers.

Growth hormone insufficiency and its impact on ovarian function.

Growth hormone (GH) and the insulin-like growth factor-I (IGF-I) play significant roles in pubertal development, menarche, the menstrual cycle, fertility, and reproduction. Growth hormone deficiency or insufficiency causes a delay in the onset of puberty and in its normal course unless treated with synthetic GH. It seems that GH affects the ovary during puberty both indirectly through the gonadotropins and IGF-I, and directly through its effect on steroidogenesis. The GH axis is activated by small increases in circulating estrogens, which initiate large increases in GH during puberty. The reproductive function of the female is also affected by GH. GH acts on the ovary affecting gametogenesis and steroidogenesis. GH receptor mRNA and protein have been found in ovarian cells, and this suggests that the direct action of GH provides an important modulatory effect on gonadotropin-dependent and -independent functions. It also affects the maturation of the follicle and gamete, and thereby plays a facilitatory role in fertility. The majority of women with GH-deficiency, but not all, require assisted reproductive technologies to induce ovulation. Many women with polycystic ovary syndrome (PCOS) have an impaired GH response to stimulation with Levo-Dopa and GH releasing hormone (GHRH). Hyperandrogenism in PCOS may contribute to the reduced GH secretion because testosterone directly stimulates somatostatin release. Reduction of the excessive androgens facilitates the dopaminergic control of GH. In conclusion, GH-insufficient states disrupt ovarian function, causing problems in sexual maturation, the menstrual cycle, and the reproductive ability of the female.