Anti-Müllerian hormone levels in peripubertal daughters of women with polycystic ovary syndrome

CONTEXT: We have previously observed increased anti-Müllerian hormone (AMH) levels in prepubertal daughters of polycystic ovary syndrome (PCOS) women, suggesting that these girls may have an altered follicular development. However, it is not known whether AMH levels remain increased during puberty. OBJECTIVE: The aim was to establish whether the increased AMH levels observed in prepubertal daughters of PCOS women persist during the peripubertal period, a stage during which the gonadal axis is activated and PCOS may become clinically manifested. DESIGN: We studied 28 daughters (8-16 yr old) of PCOS women (PCOSd) and 33 daughters (8-16 yr old) of control women (Cd). In both groups, an oral glucose tolerance test was performed. Gonadotropins, sex hormones, and AMH were determined in a fasting sample. RESULTS: Both groups were comparable in age, body mass index, and breast Tanner stage. Free androgen index, testosterone, AMH (Cd 14.4 +/- 8.0 pM vs. PCOSd 24.0 +/- 19.0 pM; P = 0.012), and 2-h insulin levels were significantly higher in the PCOSd group compared with the control group. The average ovarian volume was significantly higher in the PCOSd group. In both groups a positive correlation between 2-h insulin and AMH concentrations was observed (PCOSd: r = 0.530, P = 0.007; Cd: r =0.561, P = 0.008). CONCLUSIONS: AMH concentrations are increased in peripubertal PCOSd. These findings, along with the results of our previous study, suggest that PCOSd appear to show an increased follicular mass that is established during early development, and persists during puberty.     

Adiponectin before and after weight loss in obese children

Adiponectin is decreased in obesity and seems to be involved in insulin resistance. The influences of age, gender, puberty, and weight loss on adiponectin have not been studied in obese children. We measured body fat mass based on skinfold thickness, age, pubertal stage, gender, adiponectin, and insulin resistance (homeostasis model assessment) in 42 obese children. We analyzed adiponectin and homeostasis model assessment 1 yr later in these obese children and separated them into two groups according to degree of weight loss (decrease in sd score for body mass index, >or=0.5 vs. <0.5). Adiponectin was negatively correlated to percentage body fat (r = -0.44; P = 0.002), insulin resistance (r = -0.33; P = 0.016), and age (r = -0.41; P = 0.003). Adiponectin levels were significantly (P = 0.017) higher in pubertal girls compared with boys, but there was no significant difference in prepubertal children in respect to gender (P = 0.833). Adiponectin was significantly (P < 0.001) lower in pubertal compared with prepubertal children. The significant weight loss in 16 children was associated with a significant increase in adiponectin (P = 0.010) and a decrease in insulin resistance (P = 0.013), whereas there were no changes in the 26 children without significant weight loss. Adiponectin levels in obese children were negatively correlated to age, body fat, and insulin resistance and were decreased in puberty. Significant weight loss led to an increase in adiponectin levels and an improvement of insulin resistance.     

Increased anti-Müllerian hormone serum concentrations in prepubertal daughters of women with polycystic ovary syndrome

CONTEXT: Anti-Müllerian hormone (AMH) is produced by the granulosa cells and reflects follicular development. Adult women with polycystic ovary syndrome (PCOS) have increased levels of AMH associated with an excessive number of growing follicles. However, it is not known whether these abnormalities are present before the clinical onset of PCOS. OBJECTIVE: Our objective was to investigate whether prepubertal daughters of women with PCOS have increased AMH levels. DESIGN: Fourteen female infants (2-3 months old) and 25 prepubertal girls (4-7 yr old) born to PCOS mothers were studied. As a control group, we studied 21 female infants and 24 prepubertal girls born to mothers with regular menses and without hyperandrogenism. The group with PCOS mothers and the control group had normal birth weight and were born from spontaneous singleton pregnancies. Circulating concentrations of gonadotropins, testosterone, androstenedione, estradiol, 17-OH-progesterone, SHBG, inhibin B, and AMH were determined by specific assays. RESULTS: Serum concentrations of AMH were significantly higher in the PCOS group compared with the control group during early infancy (20.4 +/- 15.6 vs. 9.16 +/- 8.6 pmol/liter; P = 0.024) and during childhood (14.8 +/- 7.7 vs. 9.61 +/- 4.4 pmol/liter; P = 0.007). Gonadotropin and serum sex steroid concentrations were similar in both groups during the two study periods, except for FSH, which was lower during childhood in girls born to PCOS mothers. CONCLUSIONS: We conclude that serum AMH concentrations are increased in prepubertal daughters of PCOS women, suggesting that these girls appear to show evidence of an altered follicular development during infancy and childhood.     

Normative data for adiponectin, resistin, interleukin 6, and leptin/receptor ratio in a healthy Spanish pediatric population: relationship with sex steroids

OBJECTIVES: To investigate the circulating levels of adiponectin, resistin, interleukin 6 (IL-6), and leptin/receptor ratio in healthy Spanish children throughout the different stages of pubertal development. To analyze the relationship between adipokines and sex steroid level changes during puberty. STUDY DESIGN: Serum adiponectin, resistin, IL-6 levels, and leptin/receptor ratio were studied in 160 healthy Spanish children grouped according to their pubertal stage (Tanner I, 23 girls and 22 boys; Tanner II, 19 girls and 16 boys; Tanners III and IV, 21 girls and 20 boys; and Tanner V, 20 girls and 19 boys). In addition, circulating levels of sex hormone-binding globulin (SHBG) were determined in every subject, and testosterone and estradiol levels in boys and girls respectively. RESULTS: Adiponectin levels decreased in boys from mid puberty (P < 0.05) to become significantly lower than in girls (P < 0.001), whereas IL-6 decreased in both sexes (P < 0.05). Resistin levels and leptin/receptor ratio showed no differences between sexes or according to pubertal stage, except in adult females, who had the highest levels of both parameters (P < 0.001). Serum IL-6 levels correlated significantly (P < 0.05) with testosterone and estradiol levels (r=-0.37 and -0.42 respectively), whereas estradiol, but not testosterone, correlated with leptin/receptor ratio (r=0.59; P < 0.001). Furthermore, a positive relationship was found between SHBG and adiponectin and IL-6 (P < 0.001 and P < 0.05 respectively). In addition, a direct correlation between leptin/receptor and body mass index was found in both sexes (P < 0.001). CONCLUSION: Variations in adipokine profiles throughout pubertal development appear to be related with progression of gonadal function.     

Metabolic profile in sons of women with polycystic ovary syndrome

CONTEXT: Polycystic ovary syndrome (PCOS) is a common endocrine-metabolic disorder with strong familial aggregation. It has been demonstrated that parents and brothers of PCOS women exhibit insulin resistance and related metabolic defects. However, metabolic phenotypes in sons of PCOS women have not been described. OBJECTIVE: Our objective was to assess the metabolic profiles in sons of women with PCOS during different stages of life: early infancy, childhood, and adulthood. DESIGN: Eighty sons of women with PCOS (PCOS(S)) and 56 sons of control women without hyperandrogenism (C(S)), matched for age, were studied. In early infancy, glucose and insulin were determined in the basal sample. In children and adults, a 2-h oral glucose tolerance test was performed with measurements of glucose and insulin. Adiponectin, leptin, C-reactive protein, SHBG, and serum lipids were determined in the basal sample during the three periods. RESULTS: During early infancy, PCOS(S) showed higher weight (P = 0.038) and weight sd score (P = 0.031) than C(S). During childhood, weight (P = 0.003), body mass index (BMI) (P < 0.001), BMI sd score (P < 0.001), waist circumference (P = 0.001), total cholesterol (P = 0.007), and low-density lipoprotein cholesterol (P = 0.022) were higher in PCOS(S) compared with C(S), but after adjusting for BMI, these differences were nonsignificant. During adulthood, PCOS(S) exhibited higher weight (P = 0.022), BMI (P = 0.046), and waist circumference (P = 0.028) than C(S). Fasting insulin (P = 0.030), homeostasis model assessment for insulin resistance (P = 0.034), total cholesterol (P = 0.043), low-density lipoprotein cholesterol (P = 0.034), and 2-h insulin (P = 0.006) were also significantly higher and insulin sensitivity index composite significantly lower in PCOS(S) than in C(S) (P = 0.003). After adjusting for BMI, only 2-h insulin and insulin sensitivity index composite remained significantly different. CONCLUSIONS: This study indicates that sons of PCOS women exhibit higher body weight from early infancy. In addition, insulin resistance became evident as the subjects got older, which may place them at risk for the development of type 2 diabetes and cardiovascular disease.     

Hyperandrogenism and hyperinsulinism in children of women with polycystic ovary syndrome: a controlled study

OBJECTIVE: Hyperandrogenia and insulin resistance are heritable family traits, likely to cluster in children of polycystic ovary syndrome (PCOS) mothers. DESIGN: We performed a case control study of PCOS children (n = 32) compared with children from control women (n = 38) for reproductive and metabolic abnormalities, stratifying results by three Tanner stage groupings. The children underwent history and physical examinations, a 3-h timed urine collection, a 2-h oral glucose tolerance test, and abdominal ultrasound examination (females only). Serum was obtained in older children (age > 8 yr) who consented. RESULTS: Urine LH levels were significantly lower in the Tanner IV-V PCOS girls compared with controls (P = 0.04). Urine testosterone levels were significantly elevated in Tanner II-III PCOS boys compared with controls (P = 0.007). There were no significant differences in dehydroepiandrosterone levels. We validated the correlation between salivary and serum levels of insulin (insulin areas under the curve) in an adult population [n =30, Pearson correlation coefficient (r) = 0.67; P < 0.0001], which also replicated in the children (2-h insulin r = 0.57; P = 0.0004). Mean area under the curve salivary insulin levels were significantly higher in the Tanner IV-V PCOS girls in the later stages of puberty when compared with controls (3625 +/- 1372 vs. 1766 +/- 621 min x muU/ml, 95% confidence interval 475-3242; P < 0.02). CONCLUSIONS: Hyperinsulinism may be a familial characteristic of PCOS children (or at least girls) but does not appear until the later stages of puberty. Other reproductive abnormalities that characterize PCOS may develop later.     

Adiponectin is independently associated with insulin sensitivity in women with polycystic ovary syndrome

OBJECTIVE: The polycystic ovary syndrome (PCOS) is associated with obesity and insulin resistance predisposing to diabetes mellitus type 2 and atherosclerosis. Adiponectin is a recently discovered adipocytokine with insulin-sensitizing and putative antiatherosclerotic properties. The aim of the study was to elucidate determinants of circulating adiponectin levels and to investigate the potential role of adiponectin in insulin resistance in PCOS women. PATIENTS AND MEASUREMENTS: Plasma adiponectin and parameters of obesity, insulin resistance and hyperandrogenism were measured In 62 women with PCOS and in 35 healthy female controls. RESULTS: Both in PCOS and controls, adiponectin levels were lower in overweight or obese women than in normal-weight women, without any difference between PCOS and controls after adjustment for body mass index (BMI). In PCOS and in controls there was a significant correlation of adiponectin with BMI (r = -0.516, P < 0.001), fasting insulin (r = -0.404, P < 0.001), homeostasis model sensitivity (HOMA %S) (r = -0.424, P < 0.001) and testosterone (r = -0.279, P < 0.01), but no correlation with androstenedione (r = -0.112, P = 0.325), 17-OH-progesterone (r =-0.031, P = 0.784) or the LH/FSH ratio (r =-0.033, P = 0.753). Multiple linear regression analysis revealed that BMI and HOMA %S but not testosterone were independently associated with adiponectin plasma levels, explaining 16% (BMI) and 13% (HOMA %S) of the variability of adiponectin, respectively. In PCOS patients insulin sensitivity, as indicated by continuous infusion of glucose with model assessment (CIGMA %S) was significantly correlated with adiponectin (r = 0.55; P < 0.001), BMI (r =-0.575; P < 0.001), waist-to-hip ratio (WHR) (r =-0.48; P = 0.001), body fat mass assessed by dual-energy X-ray-absorptiometry (DEXA) [Dexa-fat (total) (r = -0.61; P < 0.001) and Dexa-fat (trunk) (r = -0.59; P < 0.001)] and with testosterone (r = -0.42; P = 0.001). Multiple linear regression analysis demonstrated that markers of obesity such as BMI, total or truncal fat mass, age and adiponectin were independently associated with CIGMA %S, and that circulating adiponectin accounted for about 18% of the degree of insulin resistance in PCOS. By contrast, testosterone was not a significant factor, suggesting that PCOS per se did not affect insulin sensitivity independent from obesity, age and adiponectin. Metformin treatment for 6 months in insulin-resistant PCOS women (n = 9) had no effect on plasma adiponectin (P = 0.59) despite significant loss of weight and fat mass and improvement in hyperandrogenaemia. CONCLUSIONS: PCOS per se is not associated with decreased levels of plasma adiponectin. However, circulating adiponectin is independently associated with the degree of insulin resistance in PCOS women and may contribute to the development and/or maintenance of insulin resistance independent from adiposity.     

Insulin sensitization for girls with precocious pubarche and with risk for polycystic ovary syndrome: effects of prepubertal initiation and postpubertal discontinuation of metformin treatment

Among girls with precocious pubarche (PP), those with low birth weight (LBW) are, even if nonobese, at risk for progression to polycystic ovary syndrome (PCOS) including hyperinsulinemic hyperandrogenism, dyslipidemia, dysadipocytokinemia, and central fat excess. Recently, we disclosed the efficacy of insulin sensitization with metformin to disrupt progression from PP to PCOS in formerly LBW girls who were postmenarche. In LBW-PP girls, we have now extended the exploration of early insulin sensitization therapy in two directions: 1) metformin therapy was started before puberty; and 2) we assessed the effects of metformin discontinuation in girls who had started metformin treatment after menarche. Prepubertal LBW-PP girls (n = 33; mean age, 8.0 yr; body mass index, 18.5 kg/m(2)) were randomly assigned to remain untreated or to receive metformin (425 mg/d) for 6 months. Postpubertal LBW-PP girls (n = 24; age, 12.4 yr; body mass index, 21.0 kg/m(2)) had been randomized (at -12 months) to remain untreated or to receive metformin (850 mg/d) for 12 months, at which time (0 month) a treatment cross-over was performed for 6 months. Fasting blood glucose and serum insulin, SHBG, dehydroepiandrosterone sulfate, androstenedione, testosterone, lipid profile, IL-6, and adiponectin were assessed at 0 and 6 months, as was body composition (by dual x-ray absorptiometry). In the prepubertal study (group A), comparisons of untreated vs. treated girls disclosed normalizing effects of metformin on SHBG, androstenedione, dehydroepiandrosterone sulfate, low and high density lipoprotein cholesterol, triglycerides, IL-6, adiponectin, total and abdominal fat mass, and lean body mass. In the postpubertal study (group B), treatment cross-over at 0 month was in each subgroup followed by a striking reversal in the course of the endocrine-metabolic state, adipocytokinemia, and body composition; all changes pointed to normalizing effects of metformin treatment. In conclusion, these two studies provide the first evidence that 1) prepubertal metformin therapy has normalizing effects on PCOS features in high risk girls with a combined history of LBW and PP; and 2) in adolescence, metformin's normalizing effects are reversed as soon as metformin therapy is discontinued.     

Glucose-to-insulin ratio rather than sex hormone-binding globulin and adiponectin levels is the best predictor of insulin resistance in nonobese women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), the main androgen disorder in women, has been suggested to be associated with a high risk of developing cardiovascular disease and type 2 diabetes. In many PCOS patients, overweight or central obesity is generally associated with increases in fasting insulin levels, insulin resistance, and glucose intolerance, and has been identified as a target for new therapeutic strategy, including early change in lifestyle. Early biochemical marker(s) for identifying at-risk patients will be useful for prevention studies. The main goal of the present study was to search for such tool(s). We investigated 16 nonobese PCOS women by performing euglycemic hyperinsulinemic clamp and measuring insulin levels during fasting and oral glucose tolerance test, as well as the serum concentrations of SHBG, leptin, and adiponectin, the newly identified adipose factors. Eight of the 16 patients had a steady-state glucose disposal rate less than 8.5 mg/kg.min, the lowest normal value for nonobese control women. These insulin-resistant patients had significant higher body mass index (BMI) and waist-to-hip ratio (WHR), and lower high-density lipoprotein cholesterol and SHBG levels. As expected, glucose disposal correlated negatively with BMI (P = 0.01), WHR (P = 0.01), and fasting insulin level (P = 0.003). On stepwise regression analysis, however, the glucose-to-insulin ratio (GIR) emerged as the strongest independent parameter to appraise insulin resistance (R(2) = 0.61). SHBG level correlated positively with GIR (P < 0.001) and negatively with BMI (P = 0.003) but did not correlate with either insulin response during the glucose tolerance test or plasma leptin and/or adiponectin levels. In contrast, BMI was the only independent predictive parameter of SHBG (P = 0.003, R(2) = 0.73). Interestingly, plasma adiponectin levels were positively associated with glucose disposal rate (P = 0.043) and negatively with WHR (P = 0.024), waist circumference being the best predictor of adiponectin level (P < 0.01). Leptin level correlated only with BMI (r = 0.62, P = 0.01). This study confirmed that insulin resistance, despite the lack of obesity as such, is clearly present in many PCOS women, and demonstrated that GIR is the best predictor for insulin resistance. It was also shown that adiponectin level is a good indicator of abdominal fat mass and is associated to insulin resistance. Finally, low SHBG levels in PCOS are intimately associated with BMI, suggesting that some signal(s) from the adipose tissue, independent of adiponectin and leptin, may regulate liver production of SHBG.     

Effect of the insulin sensitizer pioglitazone on insulin resistance, hyperandrogenism, and ovulatory dysfunction in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism, chronic anovulation, and insulin resistance; long-term consequences include diabetes mellitus type 2. The aim of this randomized, double-blind, controlled trial was to investigate whether the thiazolidinedione derivative pioglitazone diminishes insulin resistance and hyperandrogenism and enhances ovulation rates in women with PCOS. Forty premenopausal women with PCOS were randomly allocated to treatment with either pioglitazone (30 mg/d) or placebo for periods of 3 months. Administration of pioglitazone resulted in a remarkable decline in both fasting serum insulin levels (P < 0.02) and the area under the insulin response curve after an oral glucose load (P < 0.02). This represented an increase in insulin sensitivity and a decrease in insulin secretion (P < 0.05). Furthermore, pioglitazone increased serum SHBG (P < 0.05), resulting in a significant decrease in the free androgen index (P < 0.05 compared with placebo). Treatment with pioglitazone was also associated with higher ovulation rates (P < 0.02). Thus, pioglitazone significantly improved insulin sensitivity, hyperandrogenism, and ovulation rates in women with PCOS, thereby providing both metabolic and reproductive benefits.     

Prevalence and characteristics of the metabolic syndrome in women with polycystic ovary syndrome

The polycystic ovary syndrome (PCOS) is characterized by insulin resistance with compensatory hyperinsulinemia. Insulin resistance also plays a role in the metabolic syndrome (MBS). We hypothesized that the MBS is prevalent in PCOS and that women with both conditions would present with more hyperandrogenism and menstrual cycle irregularity than women with PCOS only. We conducted a retrospective chart review of all women with PCOS seen over a 3-yr period at an endocrinology clinic. Of the 161 PCOS cases reviewed, 106 met the inclusion criteria. The women were divided into two groups: 1) women with PCOS and the MBS (n = 46); and 2) women with PCOS lacking the MBS (n = 60). Prevalence of the MBS was 43%, nearly 2-fold higher than that reported for age-matched women in the general population. Women with PCOS had persistently higher prevalence rates of the MBS than women in the general population, regardless of matched age and body mass index ranges. Acanthosis nigricans was more frequent in women with PCOS and the MBS. Women with PCOS and the MBS had significantly higher levels of serum free testosterone (P = 0.002) and lower levels of serum SHBG (P = 0.001) than women with PCOS without the MBS. No differences in total testosterone were observed between the groups. We conclude that the MBS and its components are common in women with PCOS, placing them at increased risk for cardiovascular disease. Women with PCOS and the MBS differ from their counterparts lacking the MBS in terms of increased hyperandrogenemia, lower serum SHBG, and higher prevalence of acanthosis nigricans, all features that may reflect more severe insulin resistance.     

Gender differences of adiponectin levels develop during the progression of puberty and are related to serum androgen levels

Adiponectin is an adipocytokine with profound antidiabetic and antiatherogenic effects that is decreased in obesity. With the increasing prevalence of obesity and the emergence of related disorders, including type 2 diabetes in children, the regulation of adiponectin and its relationship to childhood obesity is of great interest. In this study we aimed to elucidate the impact of gender, pubertal development, and obesity on adiponectin levels in children. We investigated two phenotypically characterized cohorts of 200 normal weight and 135 obese children and adolescents covering a wide range of age (3.4-17.9 yr) and body mass index (-2.1 to +4.8 sd score). In healthy lean boys, adiponectin levels significantly declined in parallel with physical and pubertal development, subsequently leading to significantly reduced adiponectin levels in adolescent boys compared with girls (5.6 +/- 0.5 vs. 7.1 +/- 0.5 mg/liter; P = 0.03). This decline was inversely related to testosterone (r = -0.42; P < 0.0001) and dehydroepiandrosterone sulfate (r = -0.20; P = 0.0068) serum concentrations and may account for the gender differences seen in adults. Using a stepwise forward multiple regression model, pubertal stage was the strongest independent predictor of adiponectin (r(2) = 0.206; P < 0.0001), with additional influences of body mass index sd score and testosterone. Adiponectin levels were decreased in obese children and adolescents compared with lean peers of corresponding age and pubertal stage (5.18 vs. 7.13 mg/liter; P = 0.015). In obese children, adiponectin levels were closely associated with parameters related to the metabolic syndrome, such as insulin resistance, hyperinsulinemia, blood pressure, and uric acid, in univariate and multivariate analyses, with the insulin sensitivity index being the strongest independent parameter identified by stepwise forward multiple regression (r(2) = 0.226; P < 0.0001). Hence, there is a strong association of adiponectin serum concentrations with obesity, pubertal development, and metabolic parameters in children indicating epidemiological and pathophysiological relevance already in childhood.     

Ovarian function during puberty in girls with type 1 diabetes mellitus: response to leuprolide

CONTEXT: An increased prevalence of polycystic ovary syndrome (PCOS) has been reported in adult women with type 1 diabetes mellitus (DM1). We investigated whether these hormonal abnormalities begin during puberty by evaluating the ovarian steroidogenic response to leuprolide acetate. METHODS: We studied 56 adolescent girls with DM1 (aged 12.3 +/- 0.2 yr) and 64 healthy girls (C) (aged 11.9 +/- 0.2 yr) up to 2 yr post menarche, matched by age, body mass index, and pubertal development. We evaluated anthropometrical data and Ferriman-Gallway score and performed a leuprolide test (500 microg sc) to study ovarian function. Ovarian volume was determined by transabdominal ultrasonography. RESULTS: We found five DM1 but no C girls with abnormally located terminal hair (Fisher's exact, P < 0.05). Free androgen index increased throughout puberty in girls with DM1 (ANOVA, P < 0.0001), which was associated with a decrease in SHBG levels in girls with DM1 (ANOVA, P < 0.0001). Stimulated 17OH progesterone (17OHProg) increased throughout puberty only in girls with DM1 (ANOVA, P < 0.01). Girls with DM1 at Tanner stage 5 had higher stimulated LH to FSH ratio, testosterone, and 17OHProg levels than girls at Tanner stage 4. In contrast, in C girls the stimulated testosterone, 17OHProg, and LH to FSH ratio were similar at Tanner stages 4 and 5. Ovarian volumes and uterine length were larger in girls with DM1 (analysis of covariance, P < 0.05). CONCLUSIONS: These data suggest that patients with DM1 have differences in ovarian steroidogenic response to leuprolide, compared with C girls during puberty. Future studies in young women should clarify whether these findings are related to the pathogenesis of hyperandrogenism later in life.     

Assessment of growth hormone secretion in normal stature children using 24-hour integrated concentration of GH and pharmacological stimulation

The integrated concentration of serum GH (IC-GH) is used for the assessment of spontaneous GH secretion. In order to use the IC-GH as a diagnostic tool a normative reference range needs to be established. We determined the IC-GH by continuous blood withdrawal in 119 children of normal height, weight and growth rate. Although the mean IC-GH increased with pubertal status, 4.4 +/- 1.2 micrograms/L at Tanner I (n = 36), 5.5 +/- 2.1 micrograms/L at Tanner II-III (n = 43), and 5.8 +/- 1.6 at Tanner IV-V (n = 40) (P less than 0.03), there was a considerable overlap of individual IC-GH levels between the pubertal groups. Gender affected the mean IC-GH level slightly, but not the range. Although the mean IC-GH of girls tended to be higher than that of boys this difference was not statistically significant. Ninety five percent of the IC-GH values were above the 3.2 micrograms/L level. The response to pharmacological stimulation (clonidine, insulin, or arginine) was also evaluated in 68 of the subjects. The peak GH response to pharmacological stimulation (micrograms/L) with clonidine 21.0 +/- 10.7 (n = 66) was significantly higher than to either arginine 13.1 +/- 6.1 (n = 23) or insulin 14.2 +/- 6.3 (n = 19) (P less than 0.01). The peak response to clonidine increased significantly with pubertal status (P less than 0.001) and there was an interactive effect of gender and pubertal stage where the GH response of prepubertal boys exceeded that of prepubertal girls but the response of pubertal girls exceeded that of pubertal boys (P less than 0.02). The peak stimulated GH levels was correlated with IC-GH in this subgroup r = 0.52, P less than 0.0001). This study provides a large normative data base for IC-GH and the GH provocative tests in normally growing children of varying pubertal status.     

The roles of insulin sensitivity, insulin-like growth factor I (IGF-I), and IGF-binding protein-1 and -3 in the hyperandrogenism of African-American and Caribbean Hispanic girls with premature adrenarche.

Recent reports indicate that girls with premature adrenarche are at risk of developing functional ovarian hyperandrogenism and polycystic ovarian syndrome (PCOS). As insulin and insulin-like growth factors (IGFs) have been implicated in the pathogenesis of PCOS, we hypothesize that they may also have a role in the hyperandrogenism of premature adrenarche. Thirty-five prepubertal girls (23 Caribbean Hispanics and 12 Black African-Americans) underwent a 60-min ACTH and LH-releasing hormone test. Insulin sensitivity (S(I)) was assessed using the frequently sampled i.v. glucose tolerance test with tolbutamide. Fasting levels of IGF-I, IGF-binding protein-1 (IGFBP-1), IGFBP-3, sex hormone-binding globulin, and free testosterone (T) were also obtained. The mean age of the patients was 6.8 yr, and bone age was 8.0 yr. Twenty-five patients had a family history of noninsulin-dependent diabetes mellitus and 19 patients had acanthosis nigricans. The mean S(I) for the entire group was 6.78 +/- 5.21 x 10(-4) min/microU x mL (normal prepubertal S(I), 6.5 +/- 0.54 x 10(-4) min(-1) x microU(-1) x mL(-1)). However, 15 of the 35 girls had an S(I) that was more than 2 SD below the mean reported for normal prepubertal children. Of these 15 patients, 13 were obese, and 14 had acanthosis nigricans. For the entire group of girls, the mean ACTH-stimulated levels of 17-hydroxypregnenolone (17OHPreg), dehydroepiandrosterone (DHEA), androstenedione (AS), 17-hydroxyprogesterone (17OHP), and T and the ACTH-stimulated ratios of 17OHPreg/17OHP, 17OHPreg/DHEA, 17OHP/AS, and DHEA/AS did not differ from the levels reported for Tanner stage II-III pubertal girls. The girls were divided into two groups based on their S(I) (group I, S(I) >2 SD below the mean for age; group II, normal S(I)). The group I girls with a reduced S(I) had significantly higher ACTH-stimulated levels of 17OHPreg (group I, 760 +/- 87.84 ng/dL; group II, 428.9 +/- 46.28 ng/dL; P = 0.002), 17OHPreg/17OHP ratio (group I, 3.95 +/- 0.36; group II, 2.96 +/- 0.35; P = 0.05), 17OHPreg/DHEA (group I, 2.06 +/- 0.21; group II, 1.4 +/- 0.13; P = 0.01), and free T (group I, 1 +/- 0.23 ng/dL; group II, 0.49 +/- 0.19 ng/dL; P = 0.014). Levels of sex hormone-binding globulin were lower in the group I girls. Furthermore, for the entire group of girls, the S(I) correlated inversely with ACTH-stimulated levels of 17OHPreg, DHEA, and AS and the ACTH-stimulated ratio of 17OHPreg/17OHP. IGF-I correlated inversely with S(I) (r = -0.94; P < 0.001) and correlated directly with the ACTH-stimulated levels of 17OHPreg (r = 0.8; P < 0.001) and AS (r = 0.63; P < 0.05). IGF-I also correlated with the ACTH-stimulated ratios of 17OHPreg/17OHP (r = 0.61; P < 0.05), 17OHPreg/DHEA (r = 0.9; P < 0.001), 17OHP/AS (r = 0.79; P < 0.001), and DHEA/AS (r = 0.96; P < 0.001). IGFBP-1 correlated inversely with the ACTH-stimulated levels of 17OHPreg (r = -0.38; P < 0.05) and DHEA (r = -0.36; P < 0.05). To summarize, the ACTH-stimulated delta5-steroid levels were higher in prepubertal girls with premature adrenarche and reduced S(I). There was a significant inverse correlation among ACTH-stimulated hormone levels, S(I), and IGFBP-1, whereas IGF-I correlated directly with ACTH-stimulated androgens. These findings support the hypothesis that insulin and IGFs may have a role in the hyperandrogenism of premature adrenarche just as they do in PCOS. Hence, in certain girls with premature adrenarche, hyperandrogenism may be the first presentation of PCOS and/or insulin resistance.     

Sex hormone binding globulin levels in adolescent subjects with diabetes mellitus.

In normal adolescents there is a pubertal fall in circulating levels of sex hormone binding globulin (SHBG) in both sexes which is not explained by classically accepted mechanisms of control of SHBG. Recent in vitro and in vivo evidence has suggested that SHBG is inversely regulated by insulin. In view of this we have compared SHBG levels in 80 adolescent subjects with Type 1 diabetes to those in 61 normal adolescents. In both normals and in Type 1 diabetic subjects there was a pubertal fall in SHBG levels. Contrary to expectations, SHBG levels were not elevated in those with diabetes, but prepubertally were significantly lower in both sexes (boys mean +/- SD, 70 +/- 28 nmol l-1, normals 130 +/- 52 nmol l-1, p less than 0.001; girls, 61 +/- 17 nmol l-1, normals 110 +/- 23 nmol l-1, p = 0.01). In pubertal subjects no differences in SHBG levels were seen between the two groups, or between either sex within any group. In subjects with Type 1 diabetes SHBG levels were unrelated to metabolic control as reflected by HbA1 but were inversely related to pubertal stage (r = 0.55, p less than 0.001). In prepubertal subjects with diabetes, in whom abnormal SHBG levels were found, these levels were weakly related to insulin dose (r = 0.33, p less than 0.05); no such relationship was found in the other groups. The significance of the abnormal SHBG levels in prepubertal children with diabetes and its relationship to any irregularities of their sexual development is unclear.     

Metabolic characteristics of women with polycystic ovaries and oligo-amenorrhoea but normal androgen levels: implications for the management of polycystic ovary syndrome

OBJECTIVE: Application of the newly introduced Rotterdam criteria for polycystic ovary syndrome (PCOS) generates four phenotypic subgroups, defined by the presence/absence of three diagnostic elements: polycystic ovarian (PCO) morphology (P); hyperandrogenism (H); and oligo-amenorrhoea (O). Whilst PCOS is associated with adverse metabolic features, the strength of the association within individual subgroups is not established. We characterized the metabolic and endocrine profiles of PCOS women who are oligomenorrhoeic but normoandrogenaemic, and compared these to other PCOS women and controls. DESIGN: Retrospective dataset analyses. PATIENTS: A total of 309 Europid PCOS women, all with PCO morphology, of whom 191 were also hyperandrogenaemic and oligomenorrhoeic (PHO), 76 hyperandrogenaemic with normal menses (PH) and 42 oligomenorrhoeic but normoandrogenaemic (PO); plus 76 Europid control women without PCOS. MEASUREMENTS: Metabolic parameters: fasting insulin, lipids, homeostasis model assessment (HOMA) measures of insulin sensitivity; endocrine variables: LH, FSH; prevalence of metabolic syndrome. RESULTS: Insulin sensitivity: PO women were indistinguishable from controls, and markedly less insulin-resistant than PHO women (vs. controls, P = 0.38 after adjustment for BMI and age; vs. PHO, P = 0.003). Metabolic syndrome: the prevalence in PO women (7.1%) was similar to that in controls (3.9%), and lower than in PHO women (29.3%, P < 0.0001). LH levels: PO women were intermediate between controls (vs. controls, P = 0.008) and PHO women (vs. PHO, P = 0.06). CONCLUSIONS: Normoandrogenaemic, oligomenorrhoeic women with PCOS are metabolically similar to control women with significantly fewer metabolic features than PCOS women who are also hyperandrogenaemic. However, higher than normal LH and lower sex hormone-binding globulin (SHBG) concentrations in the PO women support the view that they form part of the spectrum of PCOS.     

Fat distribution in non-obese girls with and without precocious pubarche: central adiposity related to insulinaemia and androgenaemia from prepuberty to postmenarche

OBJECTIVE: Precocious pubarche (PP) in girls is associated with hyperinsulinaemia and dyslipidaemia of prepubertal onset, and with ovarian hyperandrogenism and ovulatory dysfunction in adolescence, particularly if they also had prenatal growth restraint and postnatal growth acceleration. Hyperinsulinaemia may be the pathogenic key factor, possibly amplified by hyperandrogenaemia. While such PP girls do not have increased body mass index (BMI), we hypothesized that body fat mass and fat distribution may differ between PP girls and matched controls, and may relate to insulin and androgen levels. PATIENTS AND DESIGN: Sixty-seven PP girls (age range 6.0-18.0 years) and 65 control girls matched for age and pubertal stage (5.9-18.0 years) had height, weight, waist and hip circumferences measured, and dual-energy X-ray absorptiometry (DXA) assessment of total body fat mass, and fat mass in abdominal and truncal regions. All girls had fasting plasma glucose, serum insulin, lipids, testosterone and SHBG levels measured; PP girls also had a standard 2-h oral glucose tolerance test (oGTT). RESULTS: Despite no differences in BMI, PP girls had significantly larger waist circumference, waist-to-hip ratio, total fat mass, percentage fat mass, abdominal fat mass, and truncal fat mass vs. controls in each pubertal stage. Overall, fasting insulin levels, free androgen index (FAI) and blood lipid levels were more closely related to central fat than to total body fat mass. In a multiple regression analysis, truncal fat mass was independently related to both fasting insulin (P = 0.009) and FAI (P < 0.0001). Abdominal fat mass was inversely related to birthweight (r = -0.25, P = 0.001). In PP girls, central fat mass was positively related to insulin levels after oGTT (truncal fat vs. 30 min insulin; r = 0.46, P < 0.0005). CONCLUSIONS: Precocious pubarche girls had excess total body and central fat mass throughout all pubertal stages, and increased central fat was related to hyperinsulinaemia and hyperandrogenaemia. It remains to be verified whether body composition in PP girls can be normalized by insulin-sensitization and/or antiandrogen therapy.     

Adipose Tissue Dysfunction in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder among premenopausal women. In addition to infertility, PCOS is associated with insulin resistance, features of the metabolic syndrome, and an increased risk for diabetes. Similar to individuals with metabolic syndrome, many women with PCOS manifest abdominal obesity, suggesting adipose tissue dysfunction. The adipose tissue of women with PCOS is characterized by hypertrophic adipocytes and impairments in lipolysis and insulin action. The expression and secretion of a wide variety of adipokines implicated in insulin resistance, including adiponectin and others, are also altered in PCOS. Collectively, the available data indicate that adipose tissue dysfunction plays a central role in the metabolic abnormalities observed in PCOS. Whether these abnormalities are primary or secondary to hyperandrogenism or other abnormalities in PCOS is not yet known.     

Rosiglitazone treatment increases plasma levels of adiponectin and decreases levels of resistin in overweight women with PCOS: a randomized placebo-controlled study

OBJECTIVE: Abdominal obesity, insulin resistance and compensatory hyperinsulinaemia play a central role in the pathogenesis of the polycystic ovary syndrome (PCOS). Abdominal adipose tissue is a source of adipokines, such as adiponectin and resistin, both of which may be involved in the development of insulin resistance and chronic inflammation in PCOS. Ghrelin, an important regulatory peptide of food intake, may also play a role in metabolic disturbances related to PCOS. The aim of this study was to examine the effects of 4 months of treatment with the insulin sensitizer rosiglitazone on plasma adiponectin, resistin and ghrelin levels in overweight women with PCOS. DESIGN: A randomised placebo-controlled study. METHODS: Thirty overweight/obese women with PCOS (body mass index>25 kg/m(2), mean age 29.1+/- 1.2 (S.E.M.) years) were randomly allocated to either rosiglitazone (Avandia, 4 mg twice a day) or placebo treatment. Plasma levels of adiponectin, resistin and ghrelin and their correlation to serum levels of insulin, C-peptide and steroid hormones, and insulin sensitivity (euglycaemic hyperinsulinaemic clamp) were assessed. RESULTS: Adiponectin and ghrelin levels correlated significantly with most metabolic markers of insulin resistance and with serum levels of DHEA and 17-hydroxyprogesterone. Plasma levels of adiponectin increased from 9.26+/-0.90 (S.E.M.) to 22.22+/-3.66 microg/ml (P<0.001) and those of resistin decreased from 12.57+/-1.63 to 9.21+/-0.53 ng/ml (P=0.009) at 4 months of treatment, but plasma ghrelin levels did not change. CONCLUSIONS: Rosiglitazone had beneficial effects on serum levels of adiponectin and resistin, suggesting that these adipocytokines may contribute to the improvement in insulin sensitivity observed during the treatment.