Elevated serum levels of tumor necrosis factor alpha in normal-weight women with polycystic ovary syndrome

Since an increase in tumor necrosis factor alpha (TNFalpha) expression has been associated with insulin resistance, this study was undertaken to determine the status of circulating TNFalpha and the relationship of TNFalpha with insulin levels, body weight, or both in women with polycystic ovary syndrome (PCOS). Fasting serum samples were analyzed in 34 subjects with PCOS, of whom 22 were obese (body mass index [BMI]>27 kg/m2), and in 40 normal control women, of whom 20 were obese. Women with PCOS exhibited a significantly (P<.02) higher mean serum TNFalpha concentration compared with the controls. The serum TNFalpha level and BMI were directly correlated in women with PCOS (r=.48, P<.005) and highly correlated in controls (r=.78, P<.001). When subjects were classified by body weight, the mean serum TNFalpha concentration was significantly (P<.001) elevated in normal-weight women with PCOS compared with normal-weight controls. On the other hand, mean serum TNFalpha concentrations in obese women with PCOS and obese controls were similar and significantly (P<.02) higher than in normal-weight women with PCOS. A direct correlation between serum fasting insulin and TNFalpha was evident in controls (r=.35, P<.03), but not in women with PCOS. However, in the subgroup of obese women with PCOS, fasting insulin directly correlated (r=.49, P<.03) with TNFalpha and the median fasting serum insulin concentration was significantly (P<.05) higher compared with the level in normal-weight women with PCOS and all controls. Fasting insulin and TNFalpha were no longer correlated in controls as a group and in obese women with PCOS when controlling for body weight. Serum TNFalpha did not correlate with luteinizing hormone (LH), testosterone (T), or dehydroepiandrosterone sulfate (DHEAS) in women with PCOS. However, serum insulin was significantly correlated (r=.49, P<.0004) with T and the BMI exhibited a trend for correlation with serum T (r=.33, P=.05) in women with PCOS. Finally, the mean serum LH concentration was significantly (P<.02) higher in normal-weight women with PCOS versus obese women with PCOS, and serum LH levels exhibited a trend for an inverse correlation with the BMI (r=.31, P=.09) in women with PCOS. We conclude that (1) serum TNFalpha is increased in normal-weight women with PCOS and is even higher in obese individuals regardless of whether they have PCOS; (2) factors other than obesity are the cause of elevated serum TNFalpha in normal-weight women with PCOS; and (3) whereas increased circulating TNFalpha may mediate insulin resistance in obesity, which may in turn promote hyperandrogenism in obese women with PCOS, it remains to be demonstrated whether this is also the case in normal-weight women with PCOS.     

Polymorphism of glycogen synthetase gene in polycystic ovary syndrome

OBJECTIVE Polycystic ovary syndrome is a heterogeneous disorder associated with a moderate degree of insulin resistance and a higher risk of developing NIDDM. The exact mechanism of insulin resistance is unclear. This study examines the frequency of an Xbal polymorphism of the glycogen synthetase gene (A2 allele) as a marker of insulin resistance and seeks to relate the presence of the A2 allele to indices of insulin sensitivity in women with polycystic ovary syndrome (PCOS). METHODS Insulin sensitivity was assessed by fasting insulin measurements, as well as following oral glucose tolerance test. An i.v. insulin tolerance test was performed to measure the rate of endogenous blood glucose disposal following an i.v. bolus of insulin. Restriction fragment length polymorphism was performed with Xbal digestion of PCR amplified product to detect the presence of A1 and A2 allele. PATIENTS Seventy-one obese (BMI > 25.1) and 19 non-obese (BMI < 25) women with PCOS, and 62 controls (33 obese and 29 non-obese) participated in the study. RESULTS Obese PCOS had significantly higher fasting insulin ( P = 0.002) compared to obese controls. There was no difference between non-obese PCOS and controls. Twenty per cent of obese PCOS had impaired glucose tolerance. The A1A2 genotype was detected in 16 of the 150 (10.7%) subjects examined. Of these, 11/88 (12.5%) were PCOS and 5/62 (8%) were controls. The A2A2 genotype was not present in any of the subjects. The A1A2 genotype was not detected in any of the subjects with impaired glucose tolerance. There was no significant difference in the incidence of the A1A2 genotype between PCOS and controls or between the individual groups. There was no association between the presence of the A1A2 genotype and indices of insulin sensitivity. CONCLUSION The Xbal polymorphism (A2 allele) of the glycogen synthetase gene was not over represented in the PCOS subject and did not relate to the indices of insulin sensitivity or glucose intolerance.     

The counterregulatory response to hypoglycaemia in women with the polycystic ovary syndrome

OBJECTIVE The pathogenetic mechanisms behind insulin resistance in polycystic ovary syndrome (PCOS) are far from fully elucidated. Aberrant counterregulatory responses to hypoglycaemia have been reported in patients with insulin resistance, and recent reports suggest that plasma glucose may be regulated at lower levels in women with PCOS. In this study we investigated the complete hormonal counterregulatory response to hypoglycaemia in women with PCOS. DESIGN Prospective cross-sectional study. PATIENTS Eight obese (BMI 25) and 10 non-obese (BMI < 25) women with PCOS, diagnosed by means of ultrasonography and clinical signs of chronic anovulation. Eight obese and 9 non-obese controls. MEASUREMENTS Hypoglycaemia was induced by an intravenous bolus of soluble insulin (0.15 IU/kg body weight). The counterregulatory responses of cortisol, GH, catecholamines, glucagon, chromogranin A (CGA), and neuropeptide Y (NPY) were studied together with symptoms of hypoglycaemia. RESULTS The obese women with PCOS had a more pronounced truncal-abdominal body fat distribution (waist hip ratio, WHR) and were hyperinsulinaemic, compared with the obese controls. All the women exhibited blood glucose levels (< 2 mmol/l) well below the threshold for the hormonal counterregulatory response and for the appearance of clinical symptoms. The non-obese women with PCOS showed a greater increase in serum concentrations of GH than the lean controls. The obese women with PCOS exhibited blunted responses of noradrenaline and NPY, but similar increases of adrenaline and CGA, compared with the obese controls. They also showed a lower symptom score during hypoglycaemia. The response of noradrenaline to hypoglycaemia correlated inversely with fasting insulin levels in the women with PCOS. Among all the obese women (PCOS and controls pooled) basal levels of noradrenaline correlated inversely with the WHR. CONCLUSIONS All the women with PCOS, independent of BMI, body fat distribution and insulin levels, showed preserved counterregulatory responses to hypoglycaemia. The reduced plasma levels of noradrenaline and the lower perception of hypoglycaemic symptoms in the obese women with PCOS could both reflect a lower activation of the sympathetic nervous system. This aberration seems related to truncal-abdominal obesity and hyperinsulinaemia. The finding of an increased response of GH in the lean women with PCOS could support previous suggestions of an altered activity of the GH/IGF-I system in these women.     

A new contributing factor to polycystic ovary syndrome: the genetic variant of luteinizing hormone.

Although the etiology of polycystic ovary syndrome (PCOS) is still unclear, LH is considered to play a central role in its pathogenesis. An immunologically anomalous form of LH, with two point mutations in the LHbeta gene, has been recently described. This genetic variant of LH (v-LH), of wide geographic distribution, is functionally different from wild-type (wt) LH. To assess the role of the v-LH in PCOS, we analyzed its frequency in groups of PCOS patients from Finland, The Netherlands, the United Kingdom, and the United States. The LH status was determined by two immunofluorometric assays from a total of 1466 subjects. The carrier frequency of the v-LH allele in the whole study population was 18.5%, being highest (28.9%) in Finland and lowest (11.2%) in The Netherlands. In the individual countries, the frequency of v-LH was similar in obese and nonobese controls, but in The Netherlands and Finland, it was 5- to 7-fold lower in obese PCOS subjects compared with that in the other groups (2-4.5% vs. 10.3-33.3%; P < 0.05). A similar tendency was found in the United States (5.7% vs. 11.1-25.0%), but not in the United Kingdom. The overall high prevalence of v-LH in healthy women and women with PCOS suggests that it is compatible with fertility. The similar frequency of v-LH in healthy nonobese and obese women indicates that obesity per se is not related to the variant. In contrast, the lower frequency of v-LH in obese PCOS patients suggests that v-LH somehow protects obese women from developing symptomatic PCOS. However, the regional differences in this finding between patients with apparently similar diagnostic criteria emphasizes the multifactorial nature of this syndrome, and that its pathogenesis may vary according to the genetic background. Although the definitive role of v-LH in PCOS remains to be proven, its determination may improve the prediction of risk of PCOS, especially in obese women.     

Tryptophan 64 --> arginine polymorphism of beta-3-adrenergic receptor in Chilean women with polycystic ovary syndrome

OBJECTIVE: To establish the frequency of the Trp64Arg polymorphism of the beta3 adrenergic receptor (ADRB3) in women with polycystic ovary syndrome (PCOS) from a Chilean population, focusing particularly on the interaction with body weight. In addition, we evaluated the relationship of the Trp64Arg variant with other metabolic components of this syndrome. PATIENTS AND DESIGN: In a case-control design study, a total of 106 women with clinical and hormonal evidence of PCOS and 82 healthy women (HW) were evaluated. MEASUREMENTS: An oral glucose tolerance test (OGTT) was performed and serum glucose and insulin were measured before the glucose load and 30, 60, 90 and 120 min after. Lipid profile was determined in the basal sample. Insulin resistance was assessed by the homeostatic model assessment (HOMA(IR)) and insulin sensitivity index (ISI) composite. A polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis was performed to determine the Trp64Arg polymorphism of ADRB3. RESULTS: The frequency of the heterozygous condition was similar between PCOS and HW (39%vs. 35%). Only two subjects were homozygous for arginine, both belonging to the PCOS group and having a body mass index (BMI) > 30 kg/m2. In the crude analysis, hypothesis tests and odds ratios show that there is no evidence of association between the ADRB3 Trp64Arg variant and PCOS (P = 0.47). Moreover, when data were stratified by BMI categories, the statistical test for interaction between Trp64 carrier status and obesity was not significant (P = 0.29). This variant was present in 52% of the obese PCOS patients and 40% of the obese HW. In normal weight and obese PCOS carriers, the presence of the Trp64Arg variant was associated with high triglyceride (TG) levels. A major effect of the Trp64Arg variant on insulin resistance parameters could not be demonstrated. CONCLUSIONS: The frequency of the Trp64Arg polymorphism was similar in healthy women and PCOS women, and a possible interaction between the effect of this variant and obesity in PCOS could not be demonstrated. However, our results showed an association between triglyceride levels and the presence of this genetic variant in PCOS women.     

DIFFERENCES IN CLINICAL AND ENDOCRINE FEATURES BETWEEN OBESE AND NON-OBESE SUBJECTS WITH POLYCYSTIC OVARY SYNDROME: AN ANALYSIS OF 263 CONSECUTIVE CASES

Two hundred and sixty-three women with ultrasound-diagnosed polycystic ovary syndrome were studied of whom 91 (35%) were obese (BMI greater than 25 kg/m2). Obese women with PCOS had a greater prevalence of hirsutism (73% compared with 56%) and menstrual disorders than non-obese subjects. Total testosterone and androstenedione concentrations in serum were similar in the two subgroups but SHBG concentrations were significantly lower, and free testosterone levels higher, in obese compared with lean subjects. In addition, concentrations of androsterone glucuronide, a marker of peripheral 5 alpha-reductase activity, were higher in obese than in non-obese women with PCOS. There were no significant correlations of either SHBG or free testosterone with androsterone glucuronide suggesting that obesity has independent effects on transport and on metabolism of androgen. There were no significant differences between the subgroups in either baseline gonadotrophin concentrations or the pulsatile pattern of LH and FSH secretion studied over an 8-h period. There was, however, an inverse correlation of FSH with BMI, but only in the obese subgroup. In conclusion, the increased frequency of hirsutism in obese compared with lean women with PCOS is associated with increased bio-availability of androgens to peripheral tissues and enhanced activity of 5 alpha-reductase in obese subjects. The mechanism underlying the higher prevalence of anovulation in obese women remains unexplained.     

Incretin hormone secretion in women with polycystic ovary syndrome: roles of obesity, insulin sensitivity, and treatment with metformin

In normal subjects, the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are responsible for 70% of the insulin response during a meal; but in diabetic subjects and other insulin-resistant conditions, the incretin effect is impaired. Polycystic ovary syndrome (PCOS) is associated with insulin resistance, and the pathophysiologic mechanisms behind PCOS resemble those of type 2 diabetes mellitus; therefore, women with PCOS may have alterations in the incretin hormone response. Metformin is widely used in the treatment of both type 2 diabetes mellitus and PCOS. Metformin may exert some of its effect on glucose metabolism by increasing GLP-1 biosynthesis and secretion and thereby increasing the incretin effect. The objective of the study was to measure incretin hormone secretion in women with PCOS and to evaluate the effect of metformin treatment. Cross-sectional comparison of 40 women with PCOS (19 lean and 21 obese) and 26 healthy control women (9 lean and 17 obese) and longitudinal evaluation of the effects of 8 months of metformin 1000 mg twice daily in women with PCOS were performed. Plasma concentrations of GIP and GLP-1 were determined frequently during a 75-g glucose tolerance test, and insulin sensitivity was evaluated by the euglycemic hyperinsulinemic clamp. The incretin hormone response did not differ between subjects with and without PCOS. Subgroup analysis showed lower GIP (area under the curve [AUC]) levels in obese women with PCOS compared with obese control women (P < .05) and compared with lean women with PCOS (P < .05). Metformin increased GIP (AUC) and GLP-1 (AUC) in lean women with PCOS (P < .05), and a similar trend was seen in the obese women (P = .07). The GIP secretion is attenuated in obese women with PCOS, whereas treatment with metformin increases the levels of both GIP and GLP-1 in women with PCOS.     

Plasma visfatin levels in normal weight women with polycystic ovary syndrome

BACKGROUND: The present study was designed to measure plasma visfatin levels in normal weight women with polycystic ovary syndrome (PCOS) and to assess possible correlations between visfatin and the hormonal or metabolic parameters of the syndrome. METHODS: Twenty-five normal weight [body mass index (BMI)<25 kg/m(2)] women with PCOS, 24 obese and overweight (BMI>25 kg/m(2)) controls (ovulating women without clinical or biochemical hyperandrogenism), and 24 normal weight controls were studied. Blood samples were collected between the 3rd and the 7th days of a menstrual cycle in the control groups and during a spontaneous bleeding episode in the PCOS groups at 9:00 A.M., after an overnight fast. Circulating levels of LH, FSH, prolactin (PRL), testosterone (T), Delta(4)-androstenedione (Delta(4)-Alpha), dehydroepiandrosterone sulfate (DHEA-S), 17alpha-OH-progesterone (17OH-P), sex hormone-binding globulin (SHBG), insulin, glucose, and visfatin were measured. RESULTS: Plasma visfatin levels and the visfatin-to-insulin ratio were significantly lower in normal weight controls than in both normal weight women with PCOS and overweight or obese controls. The visfatin-to-insulin ratio was significantly higher in normal weight women with PCOS than in overweight or obese controls. Plasma visfatin levels were found to be positively correlated with LH and Delta(4)A levels, as well as with free androgen index (FAI) values, and negatively correlated with SHBG. LH and SHBG levels were found to be the only independent significant determinants of circulating visfatin. In the control groups, plasma visfatin levels were significantly correlated with BMI, waist (W) measurement, and waist-to-hip ratio (WHR). CONCLUSIONS: Visfatin levels are positively associated with obesity in healthy women of reproductive age. Moreover, the present study indicates, for the first time, a possible involvement of increased visfatin levels in PCOS-associated metabolic and hormonal disturbances.     

Roles of LH and insulin resistance in lean and obese polycystic ovary syndrome

OBJECTIVE The relationship between insulin resistance and hyperandrogenism led us to study insulin resistance in polycystic ovary syndrome (PCOS) in order to determine its prevalence and pathogenesis. DESIGN Blood samples were taken on the 8th day after menses commenced. PATIENTS Sixty-one women with PCOS, 30 with normal weight (BMK25 kg/m²) (group 1) and 31 with obesity (BMI<26 kg/m₂) (group 2) were studied. They were divided also according to LH level: group A, low or normal LH (n==23) and group B, high LH (n= 38). Twenty lean control women and 16 obese control women were studied. MEASUREMENTS Serum LH, testosterone, free testosterone, dehydroepiandrosterone, sex-hormone binding globulin, androstenedione, and fasting insulin were measured. Insulin sensitivity was explored by the insulin tolerance test (ITT). ITT was performed by bolus i.v. insulin of 0 1 IU/kg. Blood glucose was measured before (– 5, 0) and after injection (3, 5, 7, 10, 15 minutes). Insulin sensitivity was given by the ratio of glycaemic variation to initial blood glucose (AG/G index). RESULTS ΔG/G was correlated with other insulin resistance parameters, particularly fasting insulin r=–0.40, P<0.01. The PCOS groups had the following insulin resistances (mean ± SEM) compared to matched groups: ΔG/G lean PCOS vs lead controls: 0.45 ± 0.02 vs 0.61 ± 0.01, P< 0.001; ΔG/G obese PCOS vs obese controls: 0.32 ± 0.02 vs 0.40 ± 0.01, P<0.02. Insulin resistance was higher in group A than in group B: ΔG/G 0 29 ± 002 vs 0 45 ± 0 02, P < 0.001. The prevalence of insulin resistance was 63% in lean PCOS and 51% in obese PCOS. Positive correlations between AG/G index and LH were found in group 1 and 2, respectively r= 0.45, P<0.01 and r= 0.55, P<0.01. CONCLUSION PCOS was associated with a significant decrease of insulin sensitivity, independent of obesity. The correlation between LH and insulin sensitivity suggests a complementary action in PCOS.     

The correlation of plasma omentin-1 with insulin resistance in non-obese polycystic ovary syndrome

ObjectivesAberrant circulating adipokines are considered to be related to the pathological mechanism of polycystic ovary syndrome (PCOS). This study aims to evaluate the relationship between plasma omentin-1 levels, metabolic and hormonal parameters in the setting of non-obese Chinese women with PCOS.Material and methodsThis was a case-controlled, cross-sectional study of 153 non-obese (BMI < 25 kg/m²) PCOS and 114 age-matched healthy non-obese control individuals. Levels of plasma omentin-1, fasting blood glucose, insulin and sexual hormones and ovary volume were analyzed in all subjects.ResultsPlasma omentin-1 levels of non-obese PCOS individuals were significantly lower than in healthy non-obese controls. Body Mass Index (BMI), homeostasis model of assessment for insulin resistance index (HOMA-IR), levels of testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), LH/FSH ratio and ovary volume (OV) were significantly higher in subjects with PCOS than controls. In the HOMA-IR stratified subgroups, PCOS individuals with insulin resistance had lower omentin-1 than those without insulin resistance after BMI adjustment. Omentin-1 was negatively correlated with BMI, HOMA-IR and fasting insulin. Multiple linear regressions revealed that BMI contributed to omentin-1 levels. Ovary volume was negatively correlated to HOMA-IR but had no correlation with omentin-1.ConclusionsPlasma omentin-1 concentrations were decreased in the non-obese PCOS group. Insulin resistance could further decrease plasma omentin-1 in non-obese individuals with PCOS independent of BMI status.     

Serum lipoprotein lipid profile in women with the polycystic ovary syndrome: relation to anthropometric, endocrine and metabolic variables

OBJECTIVE Although often associated with insulin resistance and glucose intolerance, various lipoprotein abnormalities have been found in polycystic ovary syndrome (PCOS) but not Invariably so when the degree of obesity is taken into account. We have therefore Investigated the serum lipid profile in a group of women with polycystic ovary syndrome with and without obesity. DESIGN Cross-sectional study of serum lipoprotein lipids and plasma free fatty acids in relation to anthropometric, metabolic and hormonal variables in women with PCOS and weight-matched controls. PATIENTS Twenty-four obese (Pob, mean BMI ± SD 30·6±3·3kg/m²) and 25 non-obese (Pnob, 22·2 ±2·3kg/m²) women with PCOS. Twenty obese (Cob, 30·2 ± 3·5 kg/m²) and 20 non-obese (Cnob, 21·4 ± 1·5 kg/m²) controls. MEASUREMENTS Fasting concentrations of plasma free fatty acids, serum cholesterol and triglycerides in high density lipoproteins (HDL), low density lipoproteins (LDL) and very low density lipoproteins (VLDL) In relation to insulin sensitivity index (M/I; assessed with the euglycaemic insulin clamp), glucose tolerance (k-value; intravenous glucose tolerance test), basal serum hormone concentrations, and body fat distribution (skinfolds and waist hip ratio). RESULTS Plasma concentrations of free fatty acids were markedly higher in Pob than in the other groups (all P < 0 001). The lipoprotein lipids did not differ between Pob and Cob, or between the non-obese groups, whereas both obese groups had higher serum concentrations of triglycerides, totally and in VLDL, and lower HDL-cholesterol than their non-obese counterparts. Pob also had higher serum levels of total and LDL-cholesterol than Pnob. Pob had a more pronounced subcutaneous truncal-abdominal adiposity, higher fasting insulin levels and lower M/I than the other groups, and a lower k-value than Cob. Cob had higher levels of fasting insulin than Cnob. Free fatty acid levels correlated with the k-value (inversely) in both women with PCOS and controls, and with M/I (inversely), age and testosterone levels in PCOS. Step-wise regression analysis for the total population, comparing endocrine, anthropometric and metabolic explanatory variables, showed that the serum levels of HDL-cholesterol and triglycerides were mainly correlated with body fat distribution (both) and fasting insulin levels (triglycerides), and levels of total and LDL-cholesterol with BMI and age. CONCLUSIONS Plasma free fatty acid correlations were markedly increased In obese women with PCOS, closely associated with the lower insulin sensitivity and lower glucose tolerance in these women. In spite of these profound metabolic aberrations, the lipoprotein lipid profile was not significantly more abnormal in obese women with PCOS than in their weight-matched controls.     

Positive relationship between androgen and the endocrine disruptor, bisphenol A, in normal women and women with ovarian dysfunction

This study was performed to investigate the serum levels of bisphenol A (BPA), an endocrine disruptor, in women with ovarian dysfunction and obesity. Fasting serum samples were obtained from 19 non-obese and 7 obese women with normal menstrual cycles: 7 patients with hyperprolactinemia, 21 patients with hypothalamic amenorrhea, and 13 non-obese and 6 obese patients with polycystic ovary syndrome (PCOS). BPA was measured by an enzyme-linked immunosorbent assay. BPA was detected in all human sera. Serum BPA concentrations were significantly higher in both non-obese and obese women with polycystic ovary syndrome (1.05 +/- 0.10 ng/ml, 1.17 +/- 0.16 ng/ml; p<0.05, respectively) and obese normal women (1.04 +/- 0.09 ng/ml, p<0.05) compared with those in non-obese normal women (0.71 +/- 0.09 ng/ml). There was no difference among women with hyperprolactinemia, women with hypothalamic amenorrhea, and non-obese normal women. There were significant positive correlations between serum BPA and total testosterone (r = 0.391, p<0.001), free testosterone (r = 0.504, p<0.001), androstenedione (r = 0.684, p<0.001), and DHEAS (r = 0.514, p<0.001) concentrations in all subjects. These findings show that there is a strong relationship between serum BPA and androgen concentrations, speculatively due to the effect of androgen on the metabolism of BPA.     

Insulin, leptin, IGF-I and insulin-dependent protein concentrations after insulin-sensitizing therapy in obese women with polycystic ovary syndrome

OBJECTIVE: To determine the clinical, hormonal and biochemical effect of 4-5 months of insulin-sensitizing therapy (hypocaloric diet+metformin) in obese patients with polycystic ovary syndrome (PCOS). DESIGN: Prospective study. METHODS: Twenty-three obese patients with PCOS, 19 obese patients without menstrual disturbances and 11 healthy control women were recruited from the Department of Endocrinology and Endocrine Gynecology, Medical Academy, Bialystok, Poland. Obese patients received 500 mg metformin together with hypocaloric diet three times daily for 4-5 months, after baseline study. The clinical parameters, menstrual pattern and serum concentrations of insulin, leptin, IGF-I, insulin-dependent proteins (sex hormone-binding protein (SHBG), insulin-like growth factor-binding protein-1 (IGFBP-1)), gonadotropins and sex steroids were determined before and after treatment. RESULTS: In the baseline study, obese patients with PCOS had significantly higher insulin, testosterone and LH concentrations in comparison with the other groups. The serum leptin, IGF-I, IGFBP-1 and SHBG were not different between the two groups of obese patients, but there was a significant difference in comparison with the control group. After metformin therapy a significant reduction in BMI, % of body fat and leptin concentration were observed in both groups of obese patients. Fasting insulin, testosterone and LH concentrations decreased significantly only in the PCOS group. Six out of 11 patients in the PCOS group had more regular menstrual cycles; two patients conceived. CONCLUSIONS: Insulin-sensitizing therapy could be considered as an additional therapeutic option in obese women with PCOS.     

Dyslipidaemia is associated with insulin resistance in women with polycystic ovaries

OBJECTIVE Polycystic ovary syndrome (PCOS) is characterized by hyperinsulinaemia and insulin resistance. Previous reports of lipid abnormalities in the syndrome have produced conflicting results which may, in part, be related to the lack of appropriate controls for the obese women with PCOS. Only one study has related lipid levels to insulin sensitivity. The objective of this study was to assess lipids and lipoproteins in women with PCOS, to compare the results with weight matched controls, and to relate the findings to indices of insulin secretion and action, and to menstrual history. DESIGN A cross-sectional study of insulin sensitivity and lipids in a cohort of PCO subjects compared to weight and ethnic group matched controls. PATIENTS AND METHODS We have therefore investigated glucose tolerance, plasma lipids and lipoproteins in 19 lean (LP) and 55 obese (OP) patients with PCO and compared the results with those in 22 lean (LC) and 15 obese (OC) control women. Insulin sensitivity was measured in the same subjects with a short insulin (0.05 U/kg i.v. insulin) tolerance test (LP, n = 18; OP, n = 20; LC, n = 19; OC, n = 11). RESULTS Results are expressed as mean ± SEM or median (interquartile range). Fasting plasma glucose levels were similar in the four groups but the plasma glucose area was higher after oral glucose (75 g) in both the lean and obese PCOS groups than in their controls (LC 32.4 ± 0.7 vs LP 35.2 ± 1.2, P < 0.01; OC 34.7 ± l.8 vs OP 37.8 ± 1.5 mmol/l/3 h, P < 0.01). Insulin sensitivity was significantly reduced in obese PCOS women (LC 196 ± 9 vs LP 179 ± 9, NS; OC 168 ± 12 vs OP 133 ± 9 mmol/l/min, P < 0.01). Total serum cholesterol levels were similar in the four groups but HDL₂-cholesterol was reduced in both obese and lean PCOS (LC 0.42 (0.38–0.62), LP 0.31 (0.26–0.44), P < 0.05; OC 0.34 (0.21–0.47), OP 0.21 (0.12–0.32) mmol/l, P < 0.01). Total HDL-cholesterol was decreased significantly only in the obese PCOS group. Body mass index correlated significantly and negatively with total HDL-cholesterol and with HDL₂-cholesterol levels both within the PCOS group and the control women. Using multiple regression insulin insensitivity contributes significantly beyond BMI to the low HDL-cholesterol in women with polycystic ovaries. CONCLUSION Polycystic ovary syndrome is associated with biochemical risk factors for premature vascular disease, which cannot be explained by obesity alone.     

Combined βFSH and βLH response to TRH in patients with clinically non-functioning pituitary adenomas

OBJECTIVE‘Paradoxical’ responses of LH, FSH, α-subunits and βLH to TRH have previously been reported in individuals with clinically non-functioning pituitary tumours (NFT). The present study was designed to assess the in vivoin vitro responses of βFSH to TRH in NFT. We further examined the possibility that a TRH challenge with combined measurement of βFSH and βLH will identify a common anomalous secretory pattern in patients with NFT. DESIGN, PATIENTS AND MEASUREMENTSForty patients with NFT underwent a standard TRH test (400 μg intravenously). Blood samples for the determination of βFSH, βLH, FSH and LH were collected prior to TRH as well as 15, 30, 45, 60 and 90 minutes following injection. Additionally, cultured adenomatous cells from eight of these patients were exposed to TRH in the absence and presence of octreotide and gonadotropin subunits were determined. RESULTSTRH elicited a marked rise in circulating βFSH in 29 of 40 individuals and in βLH in 28 of 36 patients with NFT. In a subgroup of eight individuals whose tumours were harvested during surgery and cultured for 7–21 days, TRH increased βFSH or βLH and α-subunit release in cultured adenomatous cells in all cases, including tumours from subjects not responding to TRH in vivo. In this subgroup of patients octreotide inhibited basal βFSH secretion but not basal βLH secretion both in vivo and in primary cultures of NFT cells. Both the in vivoin vitroβFSH, βLH and α-subunit responses to TRH were entirely inhibited by octreotide. In all, 38 of the 40 subjects could be identified by either elevated basal βFSH or βLH levels and/or an abnormal rise in either βFSH or βLH in response to TRH. CONCLUSIONThe measurement of basal and TRH-stimulated β-FSH and β-LH levels identifies an abnormal hormonal secretory pattern in the vast majority (>90%) of patients with clinically nonfunctioning pituitary tumours.     

GH release after GHRH plus arginine administration in obese and overweight women with polycystic ovary syndrome

Few and unclear data are available in the literature about the relationship between impairment of GH/IGF-I axis and polycystic ovary syndrome (PCOS). This study was aimed to evaluate the basal GH and IGF- levels, and GH release after challenge test in obese and overweight women with PCOS. Thirty patients with PCOS and other 30 healthy women matched for age, body mass index (BMI) and waist-hip ratio (WHR) were studied. Serum follicle-stimulating hormone (FSH), LH, PRL, E2, P, 17OH-progesterone (17OH-P), total T, delta4, DHEA-S, SHBG, GH and IGF-I levels were evaluated in each subject. A GHRH plus arginine challenge test was performed in all subjects. After provocative test, in PCOS and control women the GH levels were significantly (p<0.05) higher in comparison to basal values from 30 min to 120 min. At the same times, a significant (p<0.05) difference was observed between women with PCOS in comparison to healthy women. The mean peak value of GH resulted significantly (p<0.05) lower in PCOS women in comparison to healthy women. The total GH response (area under curve, AUC) to GHRH plus arginine test resulted significantly (p<0.05) lower in PCOS than in healthy women. These findings were statistically significant (p<0.05) also considering the distinction in obese and overweight women. The AUC for GH secretion was significantly lower (p<0.05) in obese in comparison to overweight subjects in the control group, whereas no significant difference was detected between obese and overweight women in the PCOS group. In conclusion, in PCOS women there is a BMI-independent alteration of the GH levels. Further investigations will be necessary to establish the real cause of these data.     

多囊卵巢综合征患者血浆酰化刺激蛋白水平变化与血脂相关性研究

目的 探讨多囊卵巢综合征(PCOS)患者血浆中酰化刺激蛋白(ASP)、补体C3、C反应蛋白(CRP)与血脂紊乱的相关性.方法 34例PCOS患者分为肥胖组(15例)和非肥胖组(19例),41例年龄匹配月经正常的妇女分为单纯肥胖组(21例)和正常对照组(20名),测定血中ASP、C3、CRP、游离脂肪酸(FFA)、甘油三酯(TG)和总胆同醇(TC)水平.结果 肥胖PCOS组、非肥胖PCOS组及单纯肥胖组ASP水平均显著高于正常对照组[分别为(36.4±10.9,34,8±9.9,35.1±14.0,24.8±7.8)nmoL/L,均P<0.05].肥胖PCOS组及单纯肥胖组C3水平显著高于正常对照组[分别为(2.2±1.2,2.5±1.5,1.1±0.7)S/L,P<0.05].肥胖PCOS组、非肥胖PCOS组及单纯肥胖组CRP水平均显著高于正常对照组[分别为(32.1±29.2,30.0±24.8,23.8±5.5,7.5±4.8)ms/L,P<0.05].相关分析结果显示,ASP、C3与体重指数(BMI)、CRP、FFA、TG呈显著正相关.CRP与BMI、FFA、TG、Tc呈显著正相关.结论 PCOS患者存在ASP、C3和CRP水平的异常且与脂质代谢紊乱有关.ASP与C3不相关提示C3在向ASP转化中还受其他因素调节.     

Retinol-binding protein in nonobese women with polycystic ovary syndrome

Objective Although polycystic ovary syndrome (PCOS) is frequently associated with insulin resistance, cardiovascular disease and various metabolic diseases, the mechanisms linking PCOS to metabolic changes are not fully understood. Retinol‐binding protein (RBP) was recently reported as an adipocytokine that may link insulin resistance and lipid metabolism. The aim of this study was to investigate the potential role of RBP in women with PCOS. Research design and methods Fifty women with PCOS and 40 healthy women, all of whom were age‐ and weight‐matched, were studied. Blood was obtained to determine RBP levels as well as metabolic and hormonal parameters, and the homeostasis model assessment of insulin resistance (HOMA‐IR) was calculated for each subject. Results The RBP levels were higher (P < 0·01) in women with PCOS after adjusting for age, body mass index (BMI), mean blood pressure, triglyceride (TG), high density lipoprotein (HDL)‐cholesterol, low density lipoprotein (LDL)‐cholesterol, fasting glucose, fasting insulin, estimated glomerular filtration rate (GFR), LH/FSH, total testosterone and SHBG levels. PCOS status was the strongest predictor of elevated RBP levels. In both the PCOS and control groups, RBP levels were significantly correlated with HOMA‐IR (P = 0·03 in the PCOS group; P = 0·01 in controls). In addition, RBP levels were significantly correlated with total cholesterol, LDL‐cholesterol and TG levels in PCOS (P < 0·01, P < 0·01 and P = 0·01, respectively). Conclusions Higher RBP levels in the PCOS group, when compared to the non‐PCOS group, were observed, and this difference may play a role in the pathophysiology found in women with PCOS. Further studies are needed to clarify the role of RBP in these women.     

不同肥胖标准PCOS患者血清sICAM-1水平对比观察及意义

目的比较不同肥胖标准的多囊卵巢综合征(PCOS)患者血清可溶性细胞间黏附分子-1(sICAM-1)水平,并探讨其意义。方法选取PCOS患者54例,将体质量指数(BMI)≥24 kg/m~218例归为肥胖A组,<24 kg/m~2者36例归为非肥胖A组;腰臀比(WHR)≥0.8者29例归为肥胖B组,<0.8者25例归为非肥胖B组;WHR≥0.8且BMI≥24 kg/m~2的患者14例归为肥胖C组,BMI<24 kg/m~2且WHR<0.8的患者15例归为非肥胖C组。采用ELISA方法检测各组患者血清sICAM-1水平。结果肥胖A、B、C组血清sICAM-1水平分别高于非肥胖A、B、C组(P均<0.05);肥胖A、B、C组血清sICAM-1水平比较P均>0.05;非肥胖A组血清sICAM-1水平高于非肥胖B、C组(P均<0.05),非肥胖B、C组血清sICAM-1水平相比,P>0.05。患者血清sICAM-1水平与BMI、WHR均呈正相关(r=0.204,0.360,P均<0.05),sICAM-1与WHR的相关性高于sICAM-1与BMI的相关性(P<0.05)。结论 PCOS患者血清sICAM-1水平与BMI...     

The independent effects of polycystic ovary syndrome and obesity on serum concentrations of gonadotrophins and sex steroids in premenopausal women

OBJECTIVE To investigate the basal levels of gonadotrophins and sex steroids, with special reference to the effects of obesity and body fat distribution, In premenopausal women, both those with polycystic ovary syndrome (PCOS) and those with normal ovaries and regular menstrual cycles. DESIGN Cross-sectional study. The separate effects of obesity (and body fat distribution and fasting Insulin levels) and PCOS on endocrine variables were evaluated by means of analysis of covariance. PATIENTS Sixty-seven women with anovulatory menstrual cycles and polycystic ovaries according to ultrasonography and 59 women with normal ovaries and regular cycles, both groups covering a wide range of body mass index (BMI, PCOS, 17·6-37·4, mean 25·7 kg/m²; controls, 18·8-40·9, mean 25·1 kg/m²). MEASUREMENTS Serum levels of gonadotrophins, sex steroid hormones, prolactin and GH obtained in the early follicular phase in the controls, fasting insulin levels, anthropometric measures (BMI, skinfolds, waist hip ratio). RESULTS Mean serum concentrations of LH, andro-stenedione, testosterone, the free androgen index (FAI; all P < 0·0001) and DHEAS (P < 0·01) were higher, and serum FSH (P < 0·01) and serum SHBG levels lower (P < 0·0001), in the PCOS group than in the controls. Women with PCOS had a more pronounced upper body fat distribution and higher fasting insulin levels than the controls. Independent of PCOS, BMI was positlvely associated with serum levels of FSH (P < 0·001) and negatively with levels of LH (P < 0·05), LH/FSH ratio (P < 0·0001), SHBG (P < 0·0001) and androstenedione (P < 0·01), whereas for levels of testosterone, FAI and DHEAS the impact of obesity differed significantly between the groups. Thus, in the PCOS group, testosterone levels (P < 0·05) and the FAI (P < 0·001) were positively associated with BMI, whereas they were constant throughout the entire range of BMI in the controls. DHEAS levels were positively associated with BMI in the PCOS group (P < 0·05) and negatively in the controls (P < 0·01). Measures of upper body fat were related to testosterone and FAI levels, independent of BMI. CONCLUSIONS Lower FSH levels were found in women with PCOS than during the early follicular phase of normally ovulating women, suggesting a role in anovulation in PCOS. Obesity itself exerted effects on endocrine variables, with the net result of a reduced LHIFSH ratio and lower serum levels of androstenedione and SHBG in both groups; obesity was associated with increased levels of DHEAS, testosterone and FAI exclusively in the women with PCOS. The results underline the endocrine impact of obesity and body fat distribution and the necessity of applying reference values of BMI matched subjects when establishing the endocrine profile of women with PCOS.