Resting energy expenditure in women with polycystic ovary syndrome.

STUDY QUESTION: Is resting energy expenditure (REE) altered in women with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER: Women with PCOS have a reduction in REE, when corrected for fat-free mass, independent of PCOS clinical phenotypes and BMI categories. WHAT IS KNOWN ALREADY: Obesity is an important issue in women with PCOS, in terms of frequency and pathophysiological implications. It has been hypothesized that obesity may be favoured by alterations in REE, but the studies have been limited and conflicting. STUDY DESIGN, SIZE, DURATION: This case-control study was a comparison of 266 women with PCOS and 51 healthy controls, recruited in the Verona 3P study from 2010 to 2021. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women with PCOS diagnosed by the Rotterdam criteria, with normal thyroid function and no interfering medications, were referred to the outpatient clinic of a tertiary care centre of endocrinology and metabolism for a measurement of REE. Healthy controls were recruited in the same period and submitted to the same procedure. In all subjects, REE was measured by indirect calorimetry and serum androgens were measured by LC-MS/MS. In women with PCOS, insulin sensitivity was assessed using the hyperinsulinemic-euglycemic clamp. MAIN RESULTS AND THE ROLE OF CHANCE: REE was similar in women with PCOS and controls. However, REE corrected for fat-free mass (REE/FFM) was significantly lower in women with PCOS than in controls (31.8 ± 4.0 vs 35.4 ± 3.9 kcal/kgFFM·day, P < 0.001). REE/FFM did not differ between normal-weight, overweight, or obese women with PCOS, and each of these subgroups showed lower REE/FFM values than controls. Reduced REE/FFM values were found in each phenotype of the syndrome. In multiple regression analysis, REE/FFM was independently associated with age and PCOS status, but not with fat mass. In PCOS women, REE/FFM was independently and directly associated with ovarian follicle number. LIMITATIONS, REASONS FOR CAUTION: Limitations of the study are the cross-sectional design, which limits the causal inference of the results, and the unavailability of precise information about lifestyle factors, which may be potential confounders. Further prospective studies are needed to establish the importance of this phenomenon in contributing to the weight excess of PCOS. WIDER IMPLICATIONS OF THE FINDINGS: A reduction of REE could potentially favour weight gain in women with PCOS and possibly contribute to the altered metabolic profile typical of this condition, even counteracting the therapeutic strategies aimed to reduce excess body fat in these women. Nevertheless, the presence of this abnormality in both obese/overweight and normal-weight patients suggests that other factors must play a role in this phenomenon. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by academic grants to PM from the University of Verona (FUR 2010-2022). All authors declare no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

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.

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.

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.

Physical Activity Patterns in Normal-Weight and Overweight/Obese Pregnant Women.

The aims of the present study were to assess the volume of physical activity (PA) throughout pregnancy in normal-weight vs overweight/obese women, and to investigate which factors may predict compliance to PA recommendations in these women throughout gestation. In 236 pregnant women, 177 normal-weight and 59 overweight/obese (median[IQR] BMI 21.2[19.9-22.8] vs 26.5[25.5-29.0] kg/m2, respectively), medical history, anthropometry and clinical data, including glucose tolerance, were recorded. In addition, pre-pregnancy PA was estimated by the Kaiser questionnaire, while total, walking and fitness/sport PA during pregnancy were assessed by the Physical Activity Scale for the Elderly (PASE) modified questionnaire, at 14-16, 24-28 and 30-32 weeks of gestation. PA volume was very low in the first trimester of pregnancy in both groups of women. However, it increased in the second and third trimester in normal-weight, but not in overweight/obese subjects. Higher pre-pregnancy PA was a statistically significant predictor of being physically active (>150 minutes of PA per week) during all trimesters of gestation. In conclusion, physical activity volume is low in pregnant women, especially in overweight/obese subjects. PA volume increases during pregnancy only in normal-weight women. Pre-pregnancy PA is an independent predictor of achieving a PA volume of at least 150 min per week during pregnancy.

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.

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.

Clustering of cardiovascular risk factors associated with the insulin resistance syndrome: assessment by principal component analysis in young hyperandrogenic women.

OBJECTIVE: Hyperinsulinemia is often associated with several metabolic abnormalities and increased blood pressure, which are risk factors for cardiovascular disease. It has been hypothesized that insulin resistance may underlie all these features. However, recent data suggest that some links between insulin resistance and these alterations may be indirect. The aim of our study was to further investigate this issue in a sample of young hyperandrogenic women, who often show insulin resistance and other metabolic abnormalities typical of the insulin resistance syndrome. RESEARCH DESIGN AND METHODS: We tested the hypothesis of a single factor underlying these features by principal component analysis, which should recognize one component if a single mechanism explains this association. The analysis was carried out in a sample of 255 young nondiabetic hyperandrogenic women. Variables selected for this analysis included the basic features of the insulin resistance syndrome and some endocrine parameters related to hyperandrogenism. RESULTS: Principal component analysis identified four separate factors, explaining 64.5% of the total variance in the data: the first included fasting and postchallenge insulin levels, BMI, triglycerides, HDL cholesterol, and uric acid; the second, BMI, blood pressure, and serum free testosterone; the third, fasting plasma glucose, postchallenge glucose and insulin levels, serum triglycerides, and free testosterone; and the fourth, postchallenge plasma insulin, serum free testosterone, and gonadotropin-releasing hormone agonist-stimulated 17-hydroxyprogesterone. CONCLUSIONS: These results support the hypothesis of multiple determinants in the clustering of abnormalities in the so-called insulin resistance syndrome.

Selective venous sampling in diagnosing ACTH-dependent hypercortisolism.

PURPOSE: To evaluate the sensitivity of selective sampling from the inferior petrosal sinuses in the differential diagnosis of ACTH-dependent hypercortisolism with non-diagnostic pituitary imaging. MATERIALS AND METHODS: Between 1987 and 2001, 17 patients (14 women and 3 men, aged 18-63 years) with ACTH-dependent hypercortisolism and negative X-ray of the sellar region, underwent simultaneous bilateral sampling from the inferior petrosal sinuses with ACTH measurement, at baseline and after stimulation with CRH (100 micro i.v.). Baseline samplings were also carried out at the level of the infrarenal and suprarenal inferior vena cava, of the adrenal and suprahepatic veins, of the superior vena cava, of the jugular veins, and of a peripheral vein. A central/peripheral gradient >2 at baseline and/or one >3 after stimulation with CRH was considered indicative of the pituitary origin of ACTH. Bilateral femoral venous catheterization was performed in an angiographic room using 5-French introducers after local anaesthesia. Selective catheterization of the inferior petrosal sinuses was achieved with 100 cm-long, steam-bent (45 degrees) 5-French catheters, without lateral holes. RESULTS: Twelve patients exhibited ACTH central/ peripheral gradients indicating the pituitary origin of the hormonal hyperincretion; this was confirmed by surgical exploration of the hypophysis in 10 patients, whereas 2 refused surgery and were therefore "lost". Of the five patients without ACTH central/peripheral gradients, one had an adrenal metastasis from ACTH-secreting lung neoplasia (with ACTH gradient in the blood flowing back from the adrenal gland), one had a hepatic CRHoma (with high levels of CRH in the suprahepatic veins), whereas the origin of the hyperincretion remained indeterminate in three. CONCLUSIONS: Bilateral simultaneous selective sampling from the inferior petrosal sinuses for ACTH measurements proved to be highly sensitive and free of complications in the differential diagnosis of ACTH-dependent forms of hypercortisolism.

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.