Clinical Value of Serum Levels of 11-Oxygenated Metabolites of Testosterone in Women With Polycystic Ovary Syndrome.

CONTEXT: Recent data suggested that 11-oxygenated androgens may be the preponderant circulating androgens in women with PCOS. However, the pathophysiological significance of these hormones remains unclear. OBJECTIVE: The aim of this study was to evaluate the relationships between serum 11-OH testosterone (11-OHT) and 11-keto testosterone (11-KetoT) and clinical and biochemical hyperandrogenism, as well as the metabolic parameters, in women with PCOS. METHODS: The main classic and 11-oxygenated androgens were measured by LC-MS/MS and direct equilibrium dialysis in 123 women with PCOS, diagnosed according to the Rotterdam criteria, and 38 healthy controls. Insulin sensitivity was assessed by hyperinsulinemic euglycemic clamp. RESULTS: Serum 11-oxygenated androgens were higher in women with PCOS than in controls. Elevated levels of 11-OHT and 11-KetoT were found in 28.5% and 30.1% of PCOS women, respectively, whereas free testosterone (FT) was increased in 61.0% of them. Serum 11-oxygenated androgens showed a limited performance in recognizing women with classically defined hyperandrogenism. Unlike FT, 11-oxygenated androgens did not show significant relationships with anthropometric and metabolic parameters, except for a direct association with insulin sensitivity. In multivariable analysis, 11-OHT and 11-KetoT, directly, and FT, inversely, remained significant independent predictors of insulin sensitivity. CONCLUSIONS: Serum levels of 11-oxygenated androgens are higher in women with PCOS than in controls. However, these hormones show a poor performance in recognizing women with hyperandrogenism, as currently defined. The relationships of these androgens with insulin sensitivity strongly differ from that of FT, suggesting a different role of classic and 11-oxygenated androgens in the pathophysiology of PCOS.

Insulin-Mediated Substrate Use in Women With Different Phenotypes of PCOS: the Role of Androgens.

CONTEXT: Few studies have explored in vivo insulin action on substrate use in women with PCOS. In particular, no data are available in women with different PCOS phenotypes. OBJECTIVE: The aim of the study was to evaluate insulin action on glucose (Gox) and lipid (Lox) oxidation, nonoxidative glucose metabolism (Gnonox), and serum free fatty acids (FFAs) in different PCOS phenotypes. METHODS: Participants included 187 nondiabetic women with PCOS diagnosed according to the Rotterdam criteria. Data from a historical sample of 20 healthy women were used as reference values. Whole-body substrate use data were obtained by the hyperinsulinemic euglycemic clamp associated with indirect calorimetry. Serum androgens were assessed by liquid chromatography-mass spectrometry and equilibrium dialysis. RESULTS: During hyperinsulinemia, the increase of Gox (ΔGox), Gnonox, as well as the suppression of Lox (ΔLox) and serum FFA (Δ% FFA) were altered in each PCOS phenotype. Moreover, Gnonox and Δ% FFA were lower in women with the classic phenotype than in those with the ovulatory or the normoandrogenic phenotypes, and ΔGox was lower in women with the classic than in those with the ovulatory phenotype. In multivariable analysis fat mass and free testosterone were independent predictors of ΔGox, Gnonox, and Δ% FFA, whereas only fat mass predicted ΔLox. CONCLUSION: In women with PCOS, regardless of phenotype, insulin-mediated substrate use is impaired. This phenomenon is greater in individuals with the classic phenotype. Free testosterone plays an independent role in insulin action abnormalities in glucose and lipid metabolism.

Current treatment for polycystic ovary syndrome: focus on adolescence.

Polycystic ovary syndrome (PCOS) is the most frequent endocrine disorder in women and it is associated with an increased rate of infertility. Its etiology remains largely unknown, although both genetic and environmental factors play a role. PCOS is characterized by insulin resistance, metabolic disorders and low-grade chronic inflammation. To date, the treatment of PCOS is mainly symptomatic and aimed at reducing clinical signs of hyperandrogenism (hirsutism and acne), at improving menstrual cyclicity and at favoring ovulation. Since PCOS pathophysiology is still largely unknown, the therapeutic interventions currently in place are rarely cause-specific. In such cases, the therapy is mainly directed at improving hormonal and metabolic dysregulations typical of this condition. Diet and exercise represent the main environmental factors influencing PCOS. Thus, therapeutic lifestyle changes represent the first line of intervention, which, in combination with oral contraceptives, represent the customary treatment. Insulin resistance is becoming an increasingly studied target for therapy, most evidence stemming from the time-honored metformin use. Relatively novel strategies also include the use of thiazolidinediones and GLP1-receptor agonists. In recent years, a nutraceutical approach has been added to the therapeutic toolkit targeting insulin resistance. Indeed, emerging data support inositol and alpha-lipoic acid as alternative compounds, alone or in combination with the aforementioned strategies, with favorable effects on ovulation, insulin resistance and inflammation. Nevertheless, additional studies are required in adolescents, in order to assess the effectiveness of diet supplements in preventing negative impacts of PCOS on fertility in adult age. This review focuses on the main therapeutic options for PCOS to date.

Serum Androgens Are Independent Predictors of Insulin Clearance but Not of Insulin Secretion in Women With PCOS.

CONTEXT/OBJECTIVE: In insulin-resistant individuals, hyperinsulinemia is a key compensatory mechanism, aimed at maintaining glucose homeostasis. Increased secretion and reduced clearance of insulin may both potentially contribute to this phenomenon. Insulin resistance and hyperinsulinemia are common findings in women with polycystic ovary syndrome (PCOS). While there is some information on insulin secretion, very few studies have investigated metabolic clearance rate of insulin (MCRI) in these women. Moreover, there is paucity of data on the relationships between MCRI and the pathophysiological characteristics of PCOS. The aim of the study was to explore these issues. PATIENTS: One hundred ninety women with PCOS, diagnosed according to the Rotterdam criteria, with normal glucose tolerance. DESIGN: Assessment of MCRI and clinical, hormonal, and metabolic characteristics of subjects. MCRI and insulin sensitivity were measured by the hyperinsulinemic euglycemic clamp. Serum androgens were assessed by liquid chromatography-mass spectrometry and equilibrium dialysis. A historical sample of healthy women was used to define the corresponding reference intervals. RESULTS: MCRI was impaired in about two-thirds of women with PCOS. Subjects with low MCRI differed from those with normal MCRI for a number of anthropometric, metabolic, and endocrine features. In multivariate analysis, the degree of adiposity, estimates of insulin secretion, and serum androgen concentrations were independent predictors of MCRI. Conversely, age, adiposity, MCRI, and insulin sensitivity, but not serum androgens, were independent predictors of insulin secretion. CONCLUSIONS: In women with PCOS, metabolic clearance of insulin is reduced, contributing to generating hyperinsulinemia. Serum androgens are independent predictors of this phenomenon.

A Case Report of Insulinoma Relapse on Background Nesidioblastosis: A Rare Cause of Adult Hypoglycemia.

Context: Nesidioblastosis is a rare cause of adult hypoglycemia. Current medical therapy can mitigate disease symptoms. However, side effects and limited efficacy may prevent long-term disease management. Case Description: A 63-year-old white woman presented at our institution on April 2017 with a history of distal spleno-pancreatectomy for well-differentiated insulinoma in 2013. Hypoglycemic events did not resolve after surgery, and residual nesidioblastosis near the pancreatic resection margins was identified. Hypoglycemic episodes increased in frequency and severity despite high-dose diazoxide (DZX) therapy. On April 2016, octreotide was introduced but soon discontinued for inefficacy. When the patient arrived at our attention, add-on pasireotide was started and glucose levels monitored by subcutaneous sensor. Compared with DZX, 225 mg/d alone, sensor glucose during pasireotide + DZX 75 mg/d showed occurrence of severe hypoglycemia. Pasireotide was discontinued, and the instrumental workup (68Ga-DOTATOC CT/positron emission tomography, 99mTc-nanocolloid scintigraphy and echo-endoscopy + fine-needle aspiration biopsy) identified an insulinoma relapse. Subtotal pancreatectomy was performed without further recurrence of hypoglycemia over 9 months of follow-up. Conclusions: Although insulinoma relapses on background nesidioblastosis rarely occur, they should be considered as an alternate diagnosis when medical therapy fails to prevent hypoglycemia. Further studies are warranted to test whether the immunophenotypic signature of nesidioblastosis/insulinoma may provide insights for a tailored use of pasireotide.

Reassessing Free-Testosterone Calculation by Liquid Chromatography-Tandem Mass Spectrometry Direct Equilibrium Dialysis.

Context: Assessment of free testosterone (FT) might help evaluate androgen status in patients with borderline total testosterone (T) and/or altered sex hormone-binding globulin (SHBG) levels. However, the validity of different methods to measure FT is debatable. Methods: Serum from 183 women and 146 men was analyzed using equilibrium dialysis (ED), with FT directly measured by liquid chromatography-tandem mass spectrometry. FT calculation was re-evaluated for the mass action law-based equation according to Vermeulen (cFT-V), empirical equations according to Ly (cFT-L), and a proposed calculation based on a multistep, dynamic, allosteric model according to Zakharov (cFT-Z). Results: FT level analyzed by ED [median,13 pmol/L (1.2% of T) in women; 248 pmol/L (1.5% of T) in men] was strongly inversely correlated to SHBG level, significantly to albumin level in women, and only weakly to SHBG level in men. The median [percentile (p) range, 2.5 to 97.5] ratios of calculated FT (cFT) over ED-FT (from European Male Aging Study samples) were 1.19 (0.9 to 1.47), 1.00 (0.69 to 1.42), and 2.05 (1.26 to 3.26) for cFT-V, cFT-L, and cFT-Z, respectively. The ratio for cFT-V was not significantly affected by SHBG, T, or albumin levels (ρ range, 0.17 to -0.01); ratios for cFT-L and cFT-Z were affected (P < 0.05 and P < 0.001, respectively) and strongly correlated with SHBG levels (ρ = 0.72 and 0.75, respectively). Rank correlations between cFT% and ED-FT% (for men) were 0.62, 0.74, and 0.89 for cFT-Z, cFT-L, and cFT-V, respectively. Conclusion: FT results by direct ED confirm prior FT data from indirect ED and ultrafiltration methodologies. Calculations have inherent limitations, with clinically important differences among evaluated equations: cFT-V, although overestimating FT level, appears the most robust approximation, largely independent of SHBG, albumin, and T levels.

The free androgen index is inaccurate in women when the SHBG concentration is low.

OBJECTIVE/CONTEXT: The free androgen index (FAI) is known to give erroneous results in men, but it is still a commonly used test for the investigation of hyperandrogenism in women. This study aimed to compare the results of the FAI with the gold standard equilibrium dialysis method for free testosterone in women. DESIGN/PATIENTS: Free serum testosterone T (ED-T) and total serum T (T) were measured by equilibrium dialysis and LC-MS/MS in patients with polycystic ovarian syndrome (n = 130), normal female controls (n = 53) and normal males (n = 120). Calculated free T (cFT) and free androgen index (FAI) were also measured in these patients. In addition, cFT was retrospectively calculated in 4223 female patients with a normal T (<1.6 nmol/L) routinely investigated for hyperandrogenism. RESULTS: The cFT showed good agreement with measured ED-T, and the ratio cFT/ED-T was stable across all SHBG concentrations. In contrast, the FAI/ED-T ratio and the FAI/cFT ratio increased when the concentration of SHBG fell below 30 nmol/L. CONCLUSIONS: The FAI is not a reliable indicator of free T when the SHBG concentration is low and would give misleading information in a large number of women being investigated for hyperandrogenism.

Insulin resistance in a large cohort of women with polycystic ovary syndrome: a comparison between euglycaemic-hyperinsulinaemic clamp and surrogate indexes.

STUDY QUESTION: Could surrogate indexes identify insulin resistant individuals among women with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER: Surrogate indexes may be able to rule in, but not rule out, insulin resistance in women with PCOS. WHAT IS KNOWN ALREADY: Insulin resistance is a typical finding of women with PCOS and most clinical information on this issue is based upon surrogate indexes of insulin resistance. However, data on the performance of these indexes in PCOS women are very limited. STUDY DESIGN SIZE, DURATION: A retrospective analysis of 406 women referred to our outpatient clinic for hyperandrogenism and/or menstrual dysfunction and submitted to hyperinsulinemic euglycaemic clamp between 1998 and 2015. PARTICIPANTS/MATERIALS, SETTING, METHODS: In total, 375 of these women had PCOS by the Rotterdam criteria and were included in the study. Six surrogate indexes of insulin sensitivity were calculated from glucose and insulin levels, either at fasting (homeostasis model assessment (HOMA), glucose/insulin (G/I) ratio and quantitative insulin sensitivity check index (QUICKI)) or after oral glucose load (Gutt, Stumvoll0-120 and Matsuda). MAIN RESULTS AND THE ROLE OF CHANCE: Overall, insulin resistance, as identified by the M-clamp value, was found in 74.9% of these women. The percentage was 59.3% in normal-weight vs 77.5% in overweight and 93.9% in obese subjects. All surrogate indexes were highly correlated with the M-clamp values. However, their ability to identify insulin resistant individuals was limited, in terms of sensitivity and especially in normal-weight subjects. ROC analysis showed similar performances of these indexes (AUC values 0.782-0.817). LIMITATIONS REASONS FOR CAUTION: Potential referral bias of PCOS patients may have caused overestimation of the prevalence of insulin resistance in these women. WIDER IMPLICATIONS OF THE FINDINGS: By using surrogate indexes many subjects with PCOS may be erroneously diagnosed as insulin sensitive, especially among normal-weight women. These indexes can be used to rule in, but not rule out, insulin resistance in PCOS. STUDY FUNDING/COMPETING INTEREST(S): Academic grants to P. Moghetti from the University of Verona. All authors declare no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

Insulin Resistance and Polycystic Ovary Syndrome.

BACKGROUND: Insulin resistance and the associated compensatory hyperinsulinemia are common findings in women with PCOS, and may play a key role in this condition. METHODS: In this article, we focused on the significance of insulin resistance in PCOS, reviewing the available literature on epidemiology, pathogenesis, pathophysiology and treatment of this condition. RESULTS: It has been estimated that approximately 70% of these women are insulin resistant, but this figure is affected by frequent referral bias. In addition, there is metabolic heterogeneity between clinical phenotypes of PCOS. A fundamental issue is the role that hyperinsulinemia plays in androgen overproduction, which is enhanced by bidirectional links between insulin resistance and hyperandrogenism. Available data suggest that women with PCOS may have insulin action alterations of heterogeneous origins, which induce specific abnormalities in these subjects due to the presence of intrinsic defects. Obesity is a common finding in these patients and contributes to the association between PCOS and insulin resistance, combining with the effect of PCOS per se. Insulin sensitization shows several beneficial effects in the treatment of this condition. However, clinical response is heterogeneous. CONCLUSION: Insulin resistance is a common feature of women with PCOS, although it is not universal and differ between clinical phenotypes of PCOS. Insulin resistance and hyperandrogenism appear to be interrelated key factors in the pathogenesis of PCOS. We hypothesize that PCOS might represent a common end-stage clinical phenotype of different processes, in which there are impaired insulin action and hyperandrogenism, probably favoured by specific, intrinsic abnormalities of these women.

Implications of Androgen Assay Accuracy in the Phenotyping of Women With Polycystic Ovary Syndrome.

CONTEXT/OBJECTIVE: Hyperandrogenism is a common feature of women with polycystic ovary syndrome (PCOS) and is considered a cardinal element for the diagnosis and phenotyping of this condition. Unfortunately, routinely available methods for measuring serum androgens suffer from major limitations. No data are available on the impact of androgen assay quality on the assignment of PCOS women to the different clinical phenotypes of PCOS, when defined according to the Rotterdam criteria for diagnosis. PATIENTS: Two hundred four consecutive Caucasian women with PCOS, diagnosed by the Rotterdam criteria participated in the study. DESIGN: Assessment of total T (TT), free T (FT), and androstenedione (A) by both a chemiluminescent assay, routinely available in our hospital, and gold standard methodology, ie, liquid chromatography-mass spectrometry and equilibrium dialysis, was performed. The results were compared and the associations of these data with clinical and metabolic features of PCOS women were analyzed. RESULTS: By using gold standard assays, TT was high in 36.3% of women, whereas A only marginally contributed to identifying hyperandrogenemic patients. However, gold standard FT measurement was elevated in 70.6% of the PCOS patients, identifying them as hyperandrogenemic. Routine TT and A assays, and the derived calculated FT, were strikingly inaccurate, with substantial overestimation. These assays erroneously classified 60 patients (29.4%), 32 as false hyperandrogenemic, and 28 as false normoandrogenemic, with incorrect assignment of many patients to the clinical phenotypes of PCOS and inappropriate estimation of their metabolic risk. In particular, women misclassified as normoandrogenic had a more severe metabolic profile than true normoandrogenic subjects. CONCLUSIONS: FT alone, as measured by equilibrium dialysis or calculated by using the Vermeulen formula, provided that TT is assayed by gold standard methodology, can be used to identify hyperandrogenemic PCOS subjects. The use of routine androgen assays may misclassify the phenotype of many PCOS women, with errors in the estimation of individual metabolic risk.

Serum testosterone predicts cardiorespiratory fitness impairment in normal-weight women with polycystic ovary syndrome.

OBJECTIVE: Limited literature has shown that maximal oxygen consumption (V'O2max), that is the maximal capacity of an individual to perform aerobic work, may be lowered in overweight/obese women with polycystic ovary syndrome (PCOS). However, it remains unclear whether this impairment is associated with PCOS per se or is entirely due to body fat excess. Our objective was to assess whether cardiorespiratory fitness is altered in normal-weight PCOS women and to investigate which factors are associated with this phenomenon. SUBJECTS: Fifteen normal-weight PCOS women and 15 age- and BMI-matched healthy controls. Fourteen subjects in each group completed the protocol. MEASUREMENTS: V'O2max and ventilatory thresholds (maximal incremental cycle ergometer test with breath-by-breath analysis of gas exchange), insulin sensitivity (hyperinsulinaemic euglycaemic clamp) and androgenaemia (serum total and free testosterone, measured by liquid chromatography mass spectrometry and equilibrium dialysis) were accurately assessed. RESULTS: Maximal V'O2 and power were strikingly impaired in normal-weight PCOS individuals, as compared with healthy controls (29·4 ± 1·5 vs 35·8 ± 1·6 ml O2/kg/min, P = 0·008; 138 ± 6 vs 170 ± 10 W, P = 0·011, respectively). Similarly, oxygen consumption and power at both the first and second ventilatory thresholds were significantly lower in PCOS subjects than in healthy women. In multiple regression analysis, V'O2max was negatively predicted by serum-free testosterone levels, but not by body fat mass and glucose disposal rate (R(2) = 0·45 P = 0·013). CONCLUSIONS: Cardiorespiratory fitness is impaired in normal-weight PCOS women. Androgen excess but not insulin sensitivity is associated with this alteration.

Total body fat and central fat mass independently predict insulin resistance but not hyperandrogenemia in women with polycystic ovary syndrome.

CONTEXT/OBJECTIVE: Obesity is a common feature of women with polycystic ovary syndrome (PCOS). The aim of this study was to assess the role of body fat on insulin resistance and androgen excess in these subjects. PATIENTS/DESIGN: One hundred sixteen consecutive Caucasian women with PCOS, diagnosed by the Rotterdam criteria, underwent accurate assessment of clinical, anthropometric, hormonal, and metabolic features. In particular, total fat mass and fat distribution were assessed by dual-energy x-ray absorptiometry, serum-free T by liquid chromatography mass spectrometry and equilibrium dialysis and insulin sensitivity by the glucose clamp technique. RESULTS: Total fat mass and truncal fat were significantly higher in insulin-resistant than in insulin-sensitive PCOS subjects (+89% and +127%, respectively, both P < .001), and both tended to be higher in hyperandrogenemic than in normoandrogenemic women (+22% and +28%, respectively, P = .087 and P = .090). All parameters of adiposity correlated inversely with insulin sensitivity (P < .001) and directly with serum-free T (P ≤ .001). A statistically significant inverse relationship was observed between insulin sensitivity and serum-free T concentrations (r = -0.527, P < .001). In a multiple regression analysis, either total fat mass or truncal fat, in addition to serum-free T and age, were independent predictors of insulin sensitivity. However, insulin sensitivity, but not total fat mass or truncal fat, was an independent predictor of free T concentrations. CONCLUSIONS: These data suggest that body fat contributes to determining insulin resistance in PCOS women. However, the association between body fat and hyperandrogenism seems to be to a large extent explained by insulin resistance.

Hemostatic and fibrinolytic abnormalities in polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is the most common form of anovulatory infertility, affecting up to 10% of women of reproductive age. This syndrome was first described in 1935 when American gynecologists Stein and Leventhal associated the presence of ovarian cysts with anovulation, obesity, and hirsutism. For many years, the effects of PCOS on coagulation and fibrinolysis have remained largely unexplored. This review summarizes current knowledge of the effects of PCOS on coagulation and fibrinolysis, and the putative mechanisms by which PCOS may contribute to the development of coagulation and fibrinolytic disorders. To date, there is relatively strong evidence suggesting that PCOS is associated with increased platelet aggregation and decreased plasma fibrinolytic activity. However, whether these hemostatic disorders are linked to the abnormal hormonal system in PCOS remains to be elucidated. Moreover, it should be emphasized that PCOS is a heterogeneous endocrine condition, and that the number of published studies is limited, the sample size of most of these studies is relatively small, and the selection of control subjects has not been always appropriate. Furthermore, well-designed studies on larger cohorts of carefully characterized PCOS patients are needed to provide more comprehensive information on this issue.

Plasma levels of pentraxin-3, an inflammatory protein involved in fertility, are reduced in women with polycystic ovary syndrome.

OBJECTIVE: Pentraxin-3 (PTX3), like C-reactive protein (CRP), is an acute-phase protein that belongs to the pentraxin superfamily. Moreover, it is expressed in the cumulus oophorus and appears to be involved in female fertility. The aim of the present study was to assess whether PTX3 levels are altered in polycystic ovary syndrome (PCOS) women and whether they show any relationship with the main features of these subjects. DESIGN: A cross-sectional study was conducted at the outpatient clinic of an academic centre. METHODS: A total of 66 women affected with PCOS and 51 healthy controls were studied. Plasma PTX3 and serum CRP were measured by ELISA. Androgens were measured by liquid chromatography-mass spectrometry and free testosterone was measured by equilibrium dialysis. In PCOS women, insulin sensitivity was assessed by the glucose clamp technique. RESULTS: Adjusting for age and BMI, plasma PTX3 was reduced in PCOS women (P=0.036), in contrast with serum CRP, which was increased (P=0.004). In multiple regression analysis, serum androgens and other endocrine and ovarian features of PCOS were predictors of PTX3 levels, whereas body fat was the main independent predictor of CRP concentrations. CONCLUSIONS: Plasma PTX3 levels were reduced in PCOS women and independently associated with hyperandrogenism and other endocrine and ovarian features of PCOS.

Metabolic inflexibility is a feature of women with polycystic ovary syndrome and is associated with both insulin resistance and hyperandrogenism.

CONTEXT: Metabolic inflexibility, ie, the impaired ability of the body to switch from fat to carbohydrate oxidation under insulin-stimulated conditions, is associated with insulin resistance. This alteration in metabolic plasticity can lead to organ dysfunction and is considered a key issue among the abnormalities of the metabolic syndrome. It is still unknown whether this phenomenon occurs in women with polycystic ovary syndrome (PCOS). OBJECTIVE: Our objective was to examine whether metabolic inflexibility is a feature of PCOS women and whether hyperandrogenism may contribute to this phenomenon. DESIGN AND PATIENTS: Eighty-nine Caucasian women with PCOS were submitted to hyperinsulinemic-euglycemic clamp. Respiratory exchange ratios were evaluated at baseline and during hyperinsulinemia by indirect calorimetry to quantify substrate oxidative metabolism. Total testosterone was measured by liquid chromatography mass spectrometry and free testosterone by equilibrium dialysis. SETTING: Outpatients were seen in a tertiary care academic center. MAIN OUTCOME MEASURE: Metabolic flexibility was assessed by the change in respiratory quotient upon insulin stimulation. RESULTS: Sixty-five of the 89 PCOS women (73%) had increased serum free testosterone, 68 (76%) were insulin resistant, and 62 (70%) had an impaired metabolic flexibility. Comparison of hyperandrogenemic and normoandrogenemic women showed that the 2 subgroups were of similar age but differed in terms of several anthropometric and metabolic features. In particular, hyperandrogenemic women had greater body mass index (32.9 ± 1.0 vs 24.7 ± 0.9 kg/m(2), P < .001) and lower glucose utilization during the clamp (9.2 ± 0.4 vs 10.9 ± 0.7 mg/kg fat-free mass · min, P = .023) and metabolic flexibility (0.09 ± 0.06 vs 0.12 ± 0.01, P = .014). In univariate analysis, metabolic flexibility was associated with several anthropometric, endocrine, and metabolic features. In multivariate analysis, this feature was directly associated with baseline respiratory quotient and insulin sensitivity and inversely with free testosterone and free fatty acids concentrations under insulin suppression (R(2) = 0.634, P < .001). CONCLUSIONS: Metabolic inflexibility is a feature of PCOS women. Both insulin resistance and androgen excess might contribute to this abnormality.

Divergences in insulin resistance between the different phenotypes of the polycystic ovary syndrome.

CONTEXT/OBJECTIVE: Current diagnostic criteria for polycystic ovary syndrome (PCOS) have generated distinct PCOS phenotypes, based on the different combinations of diagnostic features found in each patient. Our aim was to assess whether either each single diagnostic feature or their combinations into the PCOS phenotypes may predict insulin resistance in these women. PATIENTS/DESIGN: A total of 137 consecutive Caucasian women with PCOS, diagnosed by the Rotterdam criteria, underwent accurate assessment of diagnostic and metabolic features. Insulin sensitivity was measured by the glucose clamp technique. RESULTS: Among women with PCOS, 84.7% had hyperandrogenism, 84.7% had chronic oligoanovulation, and 89% had polycystic ovaries. According to the individual combinations of these features, 69.4% of women had the classic phenotype, 15.3% had the ovulatory phenotype, and 15.3% had the normoandrogenic phenotype. Most subjects (71.4%) were insulin resistant. However, insulin resistance frequency differed among phenotypes, being 80.4%, 65.0%, and 38.1%, respectively, in the 3 subgroups (P < .001). Although none of the PCOS diagnostic features per se was associated with the impairment in insulin action, after adjustment for covariates, the classic phenotype and, to a lesser extent, the ovulatory phenotype were independently associated with insulin resistance, whereas the normoandrogenic phenotype was not. Metabolic syndrome frequency was also different among phenotypes (P = .030). CONCLUSIONS: There is a scale of metabolic risk among women with PCOS. Although no single diagnostic features of PCOS are independently associated with insulin resistance, their combinations, which define PCOS phenotypes, may allow physicians to establish which women should undergo metabolic screening. In metabolic terms, women belonging to the normoandrogenic phenotype behave as a separate group.

Hyperinsulinemia amplifies GnRH agonist stimulated ovarian steroid secretion in women with polycystic ovary syndrome.

CONTEXT: In vitro data show that insulin may enhance basal and LH-stimulated ovarian androgen secretion, particularly in theca cells from women with polycystic ovary syndrome (PCOS). However, in vivo studies gave inconsistent results. OBJECTIVE: The objective of the study was to assess whether hyperinsulinemia affects in vivo ovarian steroid secretion and steroid metabolism. DESIGN AND SETTINGS: This was a controlled cross-sectional study, conducted in a tertiary care academic center. PARTICIPANTS: Nine young PCOS women participated in the study. INTERVENTION: Participants were submitted, in two separate days, to a GnRH agonist stimulation (buserelin 100 µg, s.c.), during a 17-h hyperinsulinemic (80 mU/m(2) · min) euglycemic clamp and, as a control, during saline infusion. Adrenal steroid secretion was suppressed by dexamethasone. MAIN MEASURES: During both protocols, before and after GnRH agonist stimulation, serum insulin, gonadotropins, cortisol, progesterone, 17-hydroxyprogesterone, androstenedione, testosterone, estradiol, and urinary androgen metabolites were measured. RESULTS: Insulin increased from 25.1 ± 13.3 to 341.5 ± 102.6 mU/liter during the clamp, whereas it did not significantly change during saline infusion. Baseline steroids and gonadotropins were similar in the two protocols. During hyperinsulinemia, GnRH agonist-stimulated serum progesterone and androstenedione were significantly higher than during saline infusion, and 17-hydroxyprogesterone was of borderline significance. Moreover, 24 h after GnRH agonist stimulation, testosterone was higher after hyperinsulinemia. Serum gonadotropins and estradiol response did not differ between the protocols. Urinary androgen metabolites excretion significantly increased after GnRH agonist stimulation, but the increase was similar during insulin and saline infusions. CONCLUSIONS: These in vivo data show that sustained hyperinsulinemia potentiates gonadotropin-stimulated ovarian androgen steroidogenesis. Insulin-induced increase in ovarian hormone secretion is not accompanied by an increased steroid metabolism.

Insulin enhances ACTH-stimulated androgen and glucocorticoid metabolism in hyperandrogenic women.

OBJECTIVE: In hyperandrogenic women, hyperinsulinaemia amplifies 17 α-hydroxycorticosteroid intermediate response to ACTH, without alterations in serum cortisol or androgen response to stimulation. The aim of the study is to assess whether acute hyperinsulinaemia determines absolute changes in either basal or ACTH-stimulated adrenal steroidogenesis in these subjects. DESIGN AND METHODS: Twelve young hyperandrogenic women were submitted in two separate days to an 8 h hyperinsulinaemic (80  mU/m² × min) euglycaemic clamp, and to an 8 h saline infusion. In the second half of both the protocols, a 4 h ACTH infusion (62.5  µg/h) was carried out. Serum cortisol, progesterone, 17 α-hydroxyprogesterone (17-OHP), 17 α-hydroxypregnenolone (17-OHPREG), DHEA and androstenedione were measured at basal level and during the protocols. Absolute adrenal hormone secretion was quantified by measuring C19 and C21 steroid metabolites in urine collected after the first 4 h of insulin or saline infusion, and subsequently after 4 h of concurrent ACTH infusion. RESULTS: During insulin infusion, ACTH-stimulated 17-OHPREG and 17-OHP were significantly higher than during saline infusion. No significant differences in cortisol and androgens response to ACTH were found between the protocols. Nevertheless, urinary excretion of ACTH-stimulated C19 and C21 steroid metabolites was significantly higher during hyperinsulinaemia than at basal insulin levels (both P < 0.005). Changes in steroid metabolites molar ratios suggested stimulation by insulin of 5 α-reductase activity. CONCLUSIONS: These in vivo data support the hypothesis that insulin acutely enhances ACTH effects on both the androgen and glucocorticoid pathways.

Body fat and insulin resistance independently predict increased serum C-reactive protein in hyperandrogenic women with polycystic ovary syndrome.

OBJECTIVE: Increased serum C-reactive protein (CRP), an independent predictor of coronary heart disease, was reported in women with polycystic ovary syndrome (PCOS). It remains unclear whether this finding is due to the association between PCOS and either insulin resistance, obesity, or androgen excess, which are all common features of this condition. The aims of this study were to assess whether increased serum CRP is a specific feature of PCOS and to investigate the mechanisms underlying this association. DESIGN AND METHODS: Serum high-sensitivity CRP (hs-CRP) was measured in 86 hyperandrogenic women (age 21.6+/-4.2 years, body mass index (BMI) 23.6+/-3.5 kg/m2), 50 with PCOS and 36 with idiopathic hyperandrogenism (HA). Thirty-five BMI-matched healthy women were also studied as controls. In these subjects, endocrine and metabolic profiles were assessed. In all hyperandrogenic subjects and 14 controls, insulin sensitivity was measured by the glucose clamp technique. Body fat was measured by bioelectrical impedance. RESULTS: Hs-CRP concentrations were higher in PCOS women (3.43+/-2.01 mg/l) than in HA subjects and healthy women (2.43+/-1.04, P<0.005; and 2.75+/-0.86 mg/l, P<0.05 respectively versus PCOS). In multiple regression analyses, increased serum hs-CRP was independently predicted by higher body fat and lower insulin sensitivity. However, in lean women, serum-free testosterone was an additional, negative, predictive variable. CONCLUSIONS: PCOS is accompanied by a low-grade chronic inflammation. Body fat appears the main determining factor of this finding, which is only partly explained by insulin resistance. At least in lean women, androgen excess per se seems to play an additional, possibly protective, role in this association.

Chromosome translocation frequency after radioiodine thyroid remnant ablation: a comparison between recombinant human thyrotropin stimulation and prolonged levothyroxine withdrawal.

BACKGROUND: Thyroid remnant ablation of differentiated thyroid carcinoma (DTC) patients is traditionally performed after levothyroxine withdrawal. Recombinant human TSH (rhTSH) administration increases serum TSH levels without inducing hypothyroidism. AIM: The aim of the study was to investigate the frequency of chromosome translocations in DTC patients after the first (131)I therapeutic dose and compare the frequency of translocations between DTC patients off levothyroxine and those receiving rhTSH. PATIENTS AND METHODS: A total of 20 DTC patients were randomly assigned to levothyroxine withdrawal [(30 d) group A; n=10, nine women; mean age 48.5+/- 19.2 yr] or rhTSH injections [(0.9 mg im per 2 consecutive days) group B; n=10, eight women; mean age 50.4+/- 18.8 yr] before undergoing (131)I activity (3.7 GBq). The frequency of translocations in peripheral lymphocytes was analyzed by tricolor fluorescence in situ hybridization with whole-chromosome-specific probes for chromosomes 1, 4, and 8. Lymphocytes were stained routinely (about 500 each time). RESULTS: The two groups showed similar baseline translocation frequency. After (131)I administration, the total chromosomal translocation rate was significantly lower in group B than group A (P = 0.02). The frequency of translocations increased significantly in group A only (P = 0.01 vs. baseline). Rearrangement specifically involved chromosomes 4 and 8 (P = 0.02 vs. baseline). CONCLUSIONS: Our preliminary data show that in hypothyroid status (131)I ablation therapy induces a higher translocation rate, especially in chromosomes 4 and 8. This finding, in agreement with previous dosimetric reports, suggests that whereas inducing a low extrathyroid exposure, rhTSH reduces the potential risk of chromosomal aberration associated with blood irradiation.