Flavia Tosi

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.

Flutamide in the treatment of hirsutism: long-term clinical effects, endocrine changes, and androgen receptor behavior *

OBJECTIVE To investigate the long-term effects of treatment with low doses of flutamide on clinical and hormonal parameters, as well as on the androgen receptor status, in hirsute women. DESIGN Eighteen hirsute patients with regular menses were studied basally and during treatment with 125 mg flutamide, three times per day for 12 months. Barrier or intrauterine contraception was used during the study in sexually active women. Safety parameters were assessed throughout the study. Hirsutism, graded by the modified Ferriman-Gallwey score, and hormonal parameters were evaluated basally and at 4-month intervals during treatment. Gonadotropin-releasing hormone and ACTH stimulation tests were performed before and after 3 to 4 months of therapy. In addition, the concentration of androgen receptors in mononuclear leukocytes was measured, in both the follicular and luteal phases of the menstrual cycle, basally and after 4 months of flutamide treatment. RESULTS Flutamide was well tolerated in all women, with the noticeable exception of one patient who presented increased serum transaminase after 8 months of therapy. Hirsutism markedly improved in all women during the treatment (Ferriman-Gallwey score after 1 year: 4.1 +/- 0.5 versus 14.1 +/- 0.9). A reduction of serum androgens was found, whereas no change was observed in either basal or GnRH-stimulated gonadotropins or in the cortisol and 17 alpha-hydroxyprogesterone response to ACTH. Cycles remained ovulatory. Before treatment, the number of androgen receptors was higher in the luteal than in the follicular phase. This rhythmic differentiation disappeared after the patients had been given the antiandrogen drug. CONCLUSIONS Flutamide is effective in the treatment of hirsutism but requires constant surveillance of liver function. Androgen receptor blockade might be potentiated by a reduction of serum androgens. Flutamide affects androgen receptor behavior during the menstrual cycle. The meaning of this finding remains to be elucidated.

Outcome of long-term treatment with the 5α-reductase inhibitor finasteride in idiopathic hirsutism: clinical and hormonal effects during a 1-year course of therapy and 1-year follow-up *

OBJECTIVE To evaluate the long-term efficacy of the 5 alpha-reductase inhibitor finasteride in idiopathic hirsutism. DESIGN Prospective clinical study. SETTING Outpatients in a university hospital. PATIENT(S) Fourteen young women with idiopathic hirsutism. INTERVENTION(S) Finasteride, 5 mg once daily, was given for 12 months. MAIN OUTCOME MEASURE(S) Degree of hirsutism, graded by a modified Ferriman and Gallwey score, serum sex hormones, and serum and urinary markers of 5 alpha-reductase activity. Clinical outcome was evaluated up to and including the 1-year post-treatment period. RESULT(S) The Ferriman and Gallwey score showed a remarkable reduction after 12 months of finasteride treatment (4.4 +/- 0.7 versus 11.8 +/- 1.0; mean +/- SEM). Serum levels of the two 5 alpha-reductase activity markers, dihydrotestosterone and 3 alpha-androstanediol glucuronide, decreased, and urinary C19 and C21 5 beta:5 alpha steroid metabolite ratios consistently increased during finasteride administration. These changes were reversed readily after cessation of treatment. No significant adverse effect was reported. Nine of 14 women completed the 1-year post-treatment follow-up. Their hirsutism scores were increased substantially as compared with values recorded at the end of therapy, but still were lower than baseline values. CONCLUSION(S) The 5 alpha-reductase inhibitor finasteride is effective and well tolerated in longterm treatment of women with idiopathic hirsutism. Post-treatment follow-up suggests that drug effects on hair growth are sustained in the majority of subjects with this disorder.

Effect of hyperandrogenism and menstrual cycle abnormalities on bone mass and bone turnover in young women

Prolonged periods of amenorrhoea are regarded as a risk factor for the appearance of osteoporosis. Amenorrhoea is a feature of different pathological conditions with heterogeneous endocrine profiles. We evaluated bone mineral metabolism in patients with polycystic ovary syndrome (PCOS), hypothalamic amenorrhoea and idiopathic hirsutism in order to establish the relative importance for the maintenance of normal bone mass of ovulatory cycles and androgen and oestrogen production.

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.

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.

Combination treatment with metformin and glibenclamide versus single-drug therapies in type 2 diabetes mellitus: a randomized, double-blind, comparative study

To compare efficacy and tolerability of combination treatment with metformin and sulfonylurea with each of these drugs alone in the treatment of type 2 diabetes, 88 type 2 diabetic subjects (hemoglobin A1c [HbA1c] levels, 8.0%+/-1.0%; age, 57.3+/-7.1 years; body mass index [BMI]. 27.0+/-2.6 kg/m2; diabetes duration, 9.8+/-8.2 years; means +/- SD) were randomly assigned to double-blind treatment with metformin (500 to 3,000 mg/d), glibenclamide (5 to 15 mg/d), or their combination (metformin 400 to 2,400 mg/d + glibenclamide 2.5 to 15 mg/d) for 6 months. Thereafter, groups were crossed over for the following 6 months. Thus, each patient received metformin or glibenclamide alone, and the combination treatment. Doses were titrated to obtain HbA1c levels < or = 6.0% and fasting plasma glucose levels less than 140 mg/dL. Eighty patients concluded both treatment periods and were included in the analysis of treatment efficacy. In patients receiving metformin or glibenclamide alone, the maximal dose was reached in 21 and 25 patients, respectively; 8 and 15 of these subjects, respectively, required the maximal dose when they were on the combination treatment. During the study, 4 (10.0%) subjects receiving metformin, 7 (17.1%) receiving glibenclamide, and 31 (39.2%) receiving the combination treatment reached HbA1c levels < or = 6.0%. Moreover, when efficacy of the combination treatment on glycemic control was compared with that of single-drug therapies in each individual patient, the combination was significantly more effective than either metformin or glibenclamide (HbA1c after treatment, 6.1%+/-1.1% v 7.3%+/-1.4%, and 6.5%+/-0.7% v 7.6%+/-1.5%, respectively, both P<.0001). In conclusion, combination treatment with metformin and sulfonylurea is more effective than these drugs alone in improving glycemic control in type 2 diabetes, while also allowing a reduction of the dosage of each drug.

Acute Effect of Insulin on Autonomic Regulation of the Cardiovascular System: A Study by Heart Rate Spectral Analysis

Insulin is suggested to have direct effects on the cardiovascular system but these are not well described. We assessed the possible influence of insulin on autonomic control of heart function. A 2‐h hyperinsulinaemic euglycaemic clamp was performed in 10 healthy women (mean age 21.7 ± 1.3 years), at two different insulin infusion rates: 80 mU m−2 and 400 mU m−2 min−1, in 7 and 3 subjects, respectively. Saline alone was infused in 4 controls. Power spectral analysis (PSA) of heart rate was recorded before and after 90–120 min of insulin infusion, as were blood pressure and heart rate. Although there were no significant changes in heart rate or blood pressure, PSA showed marked reductions of high frequency (HF) bands after insulin (2.60 ± 0.12 vs 2.09 ± 0.16 log ms2, p < 0.005), as at both low and high infusion rates (2.46 ± 0.13 to 2.14 ± 0.23 log ms2, p < 0.05, and 2.92 ± 0.18 to 1.98 ± 0.06 log ms2, p < 0.01, respectively). There were no significant changes of low frequency (LF) bands. Densities at LF and HF did not change significantly in control studies. As HF and LF are considered to reflect parasympathetic and mainly sympathetic control respectively, our observation of an increased LF/HF ratio (0.13 ± 0.10 vs 0.63 ± 0.13, p < 0.005) may be considered an index of relative sympathetic predominance induced by insulin infusion. We conclude that insulin affects the cardiovascular system, reducing vagal influence on the heart and inducing a relative hypersympathetic tone.

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.

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.