Ovarian dysfunction in peripubertal hyperinsulinemia

Expression pattern of RAGE and IGF-1 in the human fetal ovary and ovarian serous carcinoma

The expression pattern of RAGE and IGF-1 proteins in different ovarian cell lineages was histologically analyzed in six fetal, nine adult human ovaries, and nine serous ovarian carcinomas (OSC) using immunohistochemical methods. Mild expression of IGF-1 in ovarian surface epithelium (Ose) and oocytes in the 15-week human ovaries increased to moderate or strong in the stromal cells, oocytes and follicular cells in week 22. Occasional mild RAGE expression was observed in Ose during week 15, while strong expression characterized primordial follicles in week 22. In the reproductive human ovary, IGF-1 was mildly to moderately expressed in all ovarian cell lineages except in theca cells of the tertiary follicle where IGF-1 was negative. RAGE was strongly positive in the granulosa cells and some theca cells of the tertiary follicle, while negative to mildly positive in all cells of the secondary follicle. In the postmenopausal human ovary IGF-1 and RAGE were mildly expressed in Ose and stroma. In OSC, cells were strongly positive to IGF-1 and RAGE, except for some negative stromal cells. Different levels of IGF-1 and RAGE co-expression characterized fetal ovarian cells during development. In reproductive ovaries, IGF-1 and RAGE were co-localized in the granulosa and theca interna cells of tertiary follicles, while in postmenopausal ovaries and OSC, IGF-1 and RAGE were co-localized in Ose and OSC cells respectively. Our results indicate that intracellular levels of IGF-1 and RAGE protein might regulate the final destiny of the ovarian cell populations prior and during folliculogenesis, possibly controlling the metastatic potential of OSC as well.

Association of plasma GDF-9 or GDF-15 levels with bone parameters in polycystic ovary syndrome

We aimed to determine plasma levels of growth and differentiation factor (GDF)-9 and GDF-15, and their possible association with bone turnover parameters and bone mineral density (BMD), in patients with polycystic ovary syndrome (PCOS). Forty-two obese PCOS women aged 25-35 years, 23 women with idiopathic hirsutism (IH) and 20 healthy controls matched for age and body mass index were enrolled. Anthropometric, metabolic and hormonal patterns, plasma GDF-9 and GDF-15 concentrations, bone turnover markers and BMD were measured. No significant differences were observed in bone turnover markers, BMD measurements, plasma GDF-9 and GDF-15 levels in subjects with PCOS compared with the other two groups. In the combined population of all three groups, GDF-15 concentrations were negatively correlated with osteocalcin (r = -0.317, p < 0.01). Analysis of PCOS patients showed a significant correlation of GDF-15 concentrations with age and homeostasis model assessment index (r = 0.319, p < 0.05, and r = 0.312, p < 0.05, respectively). In addition, GDF-15 concentrations were negatively correlated with osteocalcin (r = -0.395, p < 0.01) and positively correlated with urine deoxypyridinoline (r = 0.353, p < 0.05). GDF-9 did not correlate with bone markers and BMD measurements. In conclusion, plasma GDF-9 and GDF-15 levels as well as bone turnover markers and BMD measurements in subjects with PCOS (25-35 years of age) were comparable with those either in subjects with IH or in healthy controls with similar anthropometric and metabolic profiles. GDF-15 might be a marker of a crossregulation between bone and energy metabolism.

Childhood obesity and its impact on the development of adolescent PCOS

Obesity exacerbates the reproductive and metabolic manifestations of polycystic ovary syndrome (PCOS). The symptoms of PCOS often begin in adolescence, and the rising prevalence of peripubertal obesity has prompted concern that the prevalence and severity of adolescent PCOS is increasing in parallel. Recent data have disclosed a high prevalence of hyperandrogenemia among peripubertal adolescents with obesity, suggesting that such girls are indeed at risk for developing PCOS. Obesity may impact the risk of PCOS via insulin resistance and compensatory hyperinsulinemia, which augments ovarian/adrenal androgen production and suppresses sex hormone-binding globulin (SHBG), thereby increasing androgen bioavailability. Altered luteinizing hormone (LH) secretion plays an important role in the pathophysiology of PCOS, and although obesity is generally associated with relative reductions of LH, higher LH appears to be the best predictor of increased free testosterone among peripubertal girls with obesity. Other potential mechanisms of obesity-associated hyperandrogenemia include enhanced androgen production in an expanded fat mass and potential effects of abnormal adipokine/cytokine levels. Adolescents with PCOS are at risk for comorbidities such as metabolic syndrome and impaired glucose tolerance, and concomitant obesity compounds these risks. For all of these reasons, weight loss represents an important therapeutic target in obese adolescents with PCOS.

Update on statural growth and pubertal development in obese children

Childhood obesity is a growing and alarming problem, associated with several short-term and long-term metabolic and cardiovascular complications. In addition, it has also been suggested that excess adiposity during childhood influences growth and pubertal development. Several studies have shown that during pre-pubertal years, obese patients present higher growth velocity and that this pre-pubertal advantage tends to gradually decrease during puberty, leading to similar final heights between obese and non-obese children. Excess body weight might also influence pubertal onset, leading to earlier timing of puberty in girls. In addition, obese girls are at increased risk of hyperandrogenism and polycystic ovary syndrome. In boys, a clear evidence does not exist: some studies suggesting an earlier puberty associated with the obesity status, whereas other have found a delayed pubertal onset. Overall, the existing evidence of an association between obesity and modification of growth and pubertal patterns underlines a further reason for fighting the epidemics of childhood obesity.

Obesity and the pubertal transition in girls and boys

Childhood obesity has become a major health concern in recent decades, especially with regard to metabolic abnormalities that impart a high risk for future cardiovascular disease. Recent data suggest that excess adiposity during childhood may influence pubertal development as well. In particular, excess adiposity during childhood may advance puberty in girls and delay puberty in boys. Obesity in peripubertal girls may also be associated with hyperandrogenemia and a high risk of adolescent polycystic ovary syndrome. How obesity may perturb various hormonal aspects of pubertal development remains unclear, but potential mechanisms are discussed herein. Insulin resistance and compensatory hyperinsulinemia may represent a common thread contributing to many of the pubertal changes reported to occur with childhood obesity. Our understanding of obesity's impact on pubertal development is in its infancy, and more research into pathophysiological mechanisms and longer-term sequelae is important.

Identification of novel missense mutations of GDF9 in Chinese women with polycystic ovary syndrome

The gene for growth differentiation factor 9 (GDF9) is expressed in human oocytes and has an important function in regulating early follicle growth and fertility. Polycystic ovary syndrome (PCOS) is one of the common defects that causes ovary dysfunction and is linked to aberrant processes in folliculogenesis. Previous studies have discovered several mutations in the screening of GDF9 in premature ovarian failure but none in PCOS. This current study focused on the mutational analysis of the coding region of GDF9 among 216 Chinese PCOS patients. Of the 10 different variants found in this study, five novel missense mutations in GDF9 were discovered namely c.15C>G, c.118T>G, c.133A>G, c.1025A>T and c.1275C>A. The above-mentioned mutations indicate GDF9 may be potentially associated with PCOS patients. As far as is known, this study is the first to provide evidence for such an association.

Androgen receptor antagonism and an insulin sensitizer block the advancement of vaginal opening by high-fat diet in mice

Reduced hypothalamic sensitivity to steroid negative feedback may contribute to the onset of puberty. In high fat-fed rodents, the timing of vaginal opening (VO) is advanced, suggesting that puberty begins earlier. Because obesity can increase androgens, which interfere with normal steroid feedback in adult females, we hypothesized that androgens reduce hypothalamic sensitivity to negative feedback during puberty and that blocking androgen action would prevent advanced VO in high fat-fed mice. Age at VO was examined in mice fed high-fat or low-fat diets from weaning and treated with the androgen receptor antagonist flutamide or vehicle (controls). VO was advanced in high-fat vs. low-fat controls, and flutamide blocked this advancement. VO was also delayed in low fat-fed flutamide-treated females, suggesting involvement of androgens in the timing of normal puberty. We next investigated if high-fat diet-induced insulin resistance contributes to early VO, as elevated insulin can stimulate androgen production. VO was examined in mice on either diet treated with the insulin sensitizer metformin. Metformin blocked high-fat advancement of VO but did not alter the timing of VO in low fat-fed mice. Insulin was elevated in high fat-fed females that had undergone VO compared with age-matched low fat-fed or metformin-treated animals on either diet that had not undergone VO. Together, these data suggest a model in which metabolic changes induced by high-fat diet, including transient increased circulating insulin, act in part by increasing androgen action to influence the timing of puberty in females.

Expression of growth differentiation factor-9 and bone morphogenetic protein-15 in oocytes and cumulus granulosa cells of patients with polycystic ovary syndrome

OBJECTIVE

To evaluate the effect of growth differentiation factor-9 (GDF-9) and bone morphogenetic protein-15 (BMP-15) on the development of follicles among patients with polycystic ovary syndrome (PCOS).

DESIGN

Case-control study.

SETTING

University Hospital.

PATIENT(S)

Twenty-two oocytes were obtained from 15 patients with PCOS and 67 oocytes from 58 controls. Cumulus granulosa cells (GC) were obtained from 16 patients with PCOS and controls treated with intracytoplasmic sperm injection.

INTERVENTION(S)

Immunofluorescence combined with laser scanning confocal microscopy and immunocytochemistry were used to analyze the expression of GDF-9 and BMP-15 in oocytes and cumulus GCs.

MAIN OUTCOME MEASURE(S)

To detect the protein expression levels.

RESULT(S)

No significant difference was found in the expression of GDF-9 and BMP-15 in the oocytes and BMP-15 in the cumulus GCs of patients with PCOS and controls. However, the expression of GDF-9 in cumulus GCs of patients with PCOS was decreased significantly compared with controls (8.88 +/- 1.52 vs. 5.01 +/- 0.83).

CONCLUSION(S)

The expression of GDF-9 and BMP-15 in the oocytes of patients with PCOS who received ovulation induction treatment was in the normal range, but the GDF-9 expression in cumulus GCs from patients with PCOS was significantly lower than the normal. Reduced GDF-9 expression in cumulus GCs of patients with PCOS appears to be associated with decreased long-term developmental potential of the oocytes of patients with PCOS.

Symptoms and treatments of polycystic ovary syndrome

Up to 10% of women may suffer from polycystic ovary syndrome (PCOS). The clinical symptoms may vary, so the biochemical profile and ultrasonography are used to predict an accurate diagnosis. Many studies have indicated that a relationship may exist between hyperinsulineamia and hyperandrogenism but the exact pathogenesis remains obscure. PCOS is treated by a combination of surgery or pharmacological management. Treatment is not always successful therefore women in these cases require support and care from nursing staff to help overcome the disappointment of treatment failure. To support women with PCOS, nurses need to be knowledgeable about the condition and its clinical manifestations and available treatment options. This article aims to examine the current aetiology, clinical manifestations, pathophysiology, diagnosis and treatment options available to women with a diagnosis of PCOS.

Effects of Thermal Stimulation, Applied to the Hindpaw via a Hot Water Bath, upon Ovarian Blood Flow in Anesthetized Nonpregnant Rats

The effects of thermal stimulation, applied to the hindpaw via a hot bath set to either 40 degrees C (non-noxious) or 49 degrees C (noxious), upon ovarian blood flow were examined in nonpregnant anesthetized rats. Ovarian blood flow was measured using a laser Doppler flowmeter. Blood pressure was markedly increased following 49 degrees C stimulation. Ovarian blood flow, however, showed no obvious change during stimulation, although a small increase was observed after stimulation. Ovarian blood flow and blood pressure responses to 49 degrees C stimulation were abolished after hindlimb somatic nerves proximal to the stimuli were cut. Heat stimulation (49 degrees C) resulted in remarkable increases in both ovarian blood flow and blood pressure in rats in which the sympathetic nerves supplying the ovary were cut but the hindlimb somatic nerves remained intact. The efferent activity of the ovarian plexus nerve was increased during stimulation at 49 degrees C. Stimulation at 40 degrees C had no effect upon ovarian blood flow, blood pressure or ovarian plexus nerve activity. Electrical stimulation of the distal part of the severed ovarian plexus nerve resulted in a decrease in both the diameter of ovarian arterioles, observed using a digital video microscope, and ovarian blood flow.The present results demonstrate that noxious heat, but not non-noxious warm, stimulation of the hindpaw skin in anesthetized rats influences ovarian blood flow in a manner that is attributed to reflex responses in ovarian sympathetic nerve activity and blood pressure.