Serum visfatin in relation to insulin resistance and markers of hyperandrogenism in lean and obese women with polycystic ovary syndrome.
(57/197)
BACKGROUND: Visfatin, a protein secreted by adipose tissue, is suggested to play a role in pathogenesis of insulin resistance. In polycystic ovary syndrome (PCOS), insulin resistance might be involved in the development of endocrine and metabolic abnormalities. The aim of the study was to asses the relation between serum visfatin concentration and insulin sensitivity and markers of hyperandrogenism in lean and obese PCOS patients. METHODS: The study group consisted of 70 women with PCOS (23 lean and 47 obese) and 45 healthy women (25 lean and 20 obese). Euglycemic hyperinsulinemic clamp and the measurements of serum visfatin, sex hormones were performed. RESULTS: The PCOS group had lower insulin sensitivity (P=0.00049) and higher serum visfatin (P=0.047) in comparison to the control group. The decrease in insulin sensitivity was present in both the lean (P=0.019) and obese (P=0.0077) PCOS subjects, whereas increase in serum visfatin was observed only in lean PCOS subjects (P=0.012). In the whole group, serum visfatin was negatively correlated with insulin sensitivity (r=-0.27, P=0.004). This relationship was also observed in the subgroup of lean (r=-0.30, P=0.038), but not obese women. Additionally, in lean women, visfatin was associated with serum testosterone (r=0.47, P=0.002) and free androgen index (r=0.48, P=0.002), independently of other potential confounding factors. CONCLUSIONS: Visfatin is associated with insulin resistance and markers of hyperandrogenism in lean PCOS patients. (+info)
Ultrasound in polycystic ovary syndrome--the measuring of ovarian stroma and relationship with circulating androgens: results of a multicentric study.
(58/197)
BACKGROUND: The introduction of transvaginal approach in ultrasound (US) has enabled the accurate evaluation of the structure of the ovary and stroma. Stroma represents an acknowledged US marker for polycystic ovary syndrome (PCOS). The proportion revealed between the stroma and the ovary surface in the median section (S/A ratio) had been indicated as a reliable marker for hyperandrogenism. In order to verify the feasibility of this determination in routine use and to confirm the efficacy of S/A ratio in predicting hyperandrogenism in PCOS, a multicentric study was performed in association with five Italian research groups. METHODS: A total of 418 subjects of fertile age presenting oligomenorrhoea or secondary amenorrhoea, enlarged ovaries measuring >10 cm(3) and/or >12 follicles measuring 2-9 mm in diameter took part in the study. Clinical, US and hormonal evaluations were performed in the early follicular phase or on random days in amenorrhoeic subjects. US assessment included ovarian volume, follicle number, ovarian and stroma area in median section. The hormonal study included a baseline plasma determination of LH, FSH, estradiol (E(2)), androstenedione (A), testosterone (T), dehydroepiandrosteronesulphate, 17-hydroxy-progesterone, sex hormone-binding globulin and prolactin. Correlations and receiver operator curves were used in statistical analysis of data. RESULTS: S/A was found to be the best significant predictor of elevated A and T levels. In order to ascertain significant cut-off values in relation to A and T levels Youden indexes were calculated and indicated 0.32 as the best cut-off for the S/A ratio. CONCLUSIONS: This work underlines the importance of stroma measure in improving US diagnosis of PCOS and suggest that this parameter may be used in routine clinical practice. In fact, multicentre study demonstrated the easy feasibility of such procedure without need of sophisticated machines or intensive training for operators. (+info)
Adipocyte fatty acid-binding protein is associated with markers of obesity, but is an unlikely link between obesity, insulin resistance, and hyperandrogenism in polycystic ovary syndrome women.
(59/197)
OBJECTIVE: Many polycystic ovary syndrome (PCOS) women suffer from adiposity and insulin resistance (IR), which play an important role in the development and maintenance of PCOS. Adipocyte fatty acid-binding protein (A-FABP) is mainly expressed in adipocytes, and circulating A-FABP has been associated with markers of obesity and IR. Thus, as observed with other adipose tissue derived factors, secreted A-FABP might be involved in the pathogenesis of obesity-associated disorders such as PCOS. DESIGN: Plasma A-FABP concentrations were measured in 102 non-diabetic PCOS women, and associations with markers of obesity, IR, inflammation, and hyperandrogenism were investigated by correlation and multiple linear regression analyses. The effect of lifestyle intervention on A-FABP was studied in a second cohort of 17 obese PCOS women. RESULTS: A-FABP correlated with body mass index (BMI; R = 0.694, P < 0.001), dual-energy X-ray-absorptiometry (DEXA) fat mass (R = 0.729, P < 0.001), DEXA lean body mass (R = 0.399, P = 0.001), HOMA %S (R = -0.435, P < 0.001), hsCRP (R = 0.355, P = 0.001), and free testosterone (fT; R = 0.230, P = 0.02). Adjusted for age, smoking, and glucose metabolism the association of A-FABP with HOMA %S was still significant (P < 0.001), whereas the associations with fT (P = 0.09) and hsCRP (P = 0.25) were not. Inclusion of BMI into the model abolished the impact of A-FABP on HOMA %S. In BMI-matched PCOS women (n = 20 pairs), neither HOMA %S (P = 0.3) nor fT (P = 0.6) were different despite different A-FABP levels (P < 0.001), and in 17 obese PCOS women undergoing a lifestyle intervention, changes in IR were not paralleled by changes in A-FABP. CONCLUSIONS: Circulating A-FABP was correlated with markers of obesity, but had no major impact on IR, inflammation, or hyperandrogenemia in PCOS women. (+info)
Low sex hormone-binding globulin as a predictive marker for insulin resistance in women with hyperandrogenic syndrome.
(60/197)
BACKGROUND: The aim of the present study is to assess insulin resistance (IR) in women with hyperandrogenic syndrome, which was suggested to replace the term polycystic ovary syndrome by the Androgen Excess Society, and to evaluate whether sex hormone-binding globulin (SHBG) can be used as a predictive marker of IR in hyperandrogenic women. METHODS: Clinical, metabolic, and endocrine parameters were measured, and an oral glucose tolerance test was carried out. The women were classified as IR group or non-IR group, in accordance with defined cutoff points for the homeostatic model assessment of IR (HOMA-IR) at > or =2.5, the quantitative insulin sensitivity check index at < or = 0.33, and the Matsuda insulin sensitivity index (ISI) at < or = 5. RESULTS: The women classified as having IR had a significantly higher body mass index (BMI) and free androgen index (FAI) and showed significantly lower SHBG and high-density lipoprotein (HDL) levels, regardless of the indices used. However, with the Matsuda ISI, generally more women were diagnosed as having IR, and this group had significantly higher total testosterone and triglyceride values, as well as a higher incidence of hirsutism. CONCLUSIONS: Women who were classified as being insulin resistant using insulin sensitivity indices showed significantly higher BMI and FAI values and lower SHBG and HDL levels. However, the Matsuda ISI may be more favorable for identifying IR in hyperandrogenic women. SHBG may serve as a predictive marker of IR in these women, particularly in those who are obese. (+info)
Evidence of subpopulations with different levels of insulin resistance in women with polycystic ovary syndrome.
(61/197)
BACKGROUND: Polycystic ovary syndrome (PCOS) is non-uniformly associated with insulin resistance (IR). We examined IR in women with PCOS. METHODS: Sixty-nine PCOS women were subjected to the insulin suppression test (IST) to determine their steady-state plasma glucose (SSPG) as a direct measure of insulin sensitivity. RESULTS: SSPG exhibited a multimodal distribution suggesting the existence of subpopulations. The heterogeneous distribution of plasma glucose at 180 min (P = 0.011), with three modes, suggested differences in the plasma glucose level trajectories during the IST. Hence, the population was separated into three groups: (i) (n = 33), subjects with SSPG < or = 152.5 mg/dl, corresponding to the first to fifth deciles; (ii) (n = 29), subjects in the interval 152.5 mg/dl < SSPG < or = 300 mg/dl; (iii) (n = 7), subjects with SSPG > 300 mg/dl, corresponding to the tenth decile. Plasma glucose distributions at 180 min showed differences in their mean values and ranges among groups (P < 0.0001). The trajectories of the groups differed significantly during the IST (P < 0.0001). CONCLUSIONS: insulin sensitivity in our patients exhibited a discontinuous distribution, implying that PCOS is a heterogeneous disorder possessing subpopulations regarding IR. (+info)
Androgen excess is associated with the increased carotid intima-media thickness observed in young women with polycystic ovary syndrome.
(62/197)
BACKGROUND: We evaluated carotid intima-media thickness (CIMT) as an early marker of atherosclerosis, as well as its main determinants among androgen excess, obesity and insulin resistance, in patients with polycystic ovary syndrome (PCOS). METHODS: We selected 40 PCOS patients and 20 non-hyperandrogenic women who were similar in terms of age and grade of obesity. Complete clinical, metabolic and hormonal profiles and left common CIMT measurements were obtained. RESULTS: Patients with PCOS presented with increased mean CIMT values when compared with controls (F = 8.575; P = 0.005), and this was independent of obesity. Five PCOS patients but no controls had increased CIMT values. CIMT correlated directly with serum total and free testosterone, androstenedione and dehydroepiandrosterone-sulfate levels and mean 24-h heart rate (HR), and inversely with the insulin sensitivity index (ISI), but no correlation was observed with the body mass index (BMI). Multiple stepwise linear regression models showed that in PCOS patients, the main determinants of CIMT were serum total testosterone or androstenedione concentrations, with no influence of ISI or the mean 24-h HR. CONCLUSIONS: Compared with control women, PCOS patients present with an increased CIMT, independent of obesity and related directly to androgen excess; this suggests that hyperandrogenism is associated with atherosclerosis and cardiovascular risk in these women. (+info)
Flutamide metformin for post-menarcheal girls with preclinical ovarian androgen excess: evidence for differential response by androgen receptor genotype.
(63/197)
OBJECTIVE: Addition of androgen receptor (AR) blockade (flutamide) to insulin-sensitising therapy (metformin) may confer synergistic benefits in girls with hyperinsulinaemic androgen excess. We hypothesised that girls with shorter AR gene CAG repeat alleles, and thus greater receptor sensitivity, might benefit more from the addition of low-dose flutamide. DESIGN: Open randomised crossover study. METHODS: In this study, 32 post-menarcheal girls (mean age 12.1 years) with a history of low birth weight and precocious pubarche were subgrouped by CAG genotype ('short': CAG mean length 20, n=14; 'long': CAG >20, n=18). Within each subgroup, girls were 1:1 randomised to metformin alone (850 mg/day) or in combination with flutamide (62.5 mg/day) for 12 months. To allow comparisons with no treatment, long-CAG girls randomised to flutamide-metformin, and short-CAG girls randomised to metformin alone were observed for 12 months before treatment. Body composition by absorptiometry, fasting lipid profiles and levels of insulin, glucose and androgens were measured during the first 12 months on each treatment. RESULTS: In all girls, 12 months flutamide-metformin lowered body fat and improved lipid profiles when compared with no treatment. Compared with metformin alone, flutamide-metformin achieved greater reductions in the percentage of body fat and abdominal fat mass in the short-CAG subgroup (P=0.001 to P<0.0001). In contrast, in the long-CAG subgroup, flutamide-metformin produced no further improvements when compared with metformin alone. CONCLUSIONS: In young post-menarcheal girls with preclinical androgen excess, low-dose flutamide-metformin improved body composition and key endocrine-metabolic abnormalities. However, only those girls with genetic markers of greater AR sensitivity may benefit from the addition of flutamide above metformin alone. (+info)
A floxed allele of the androgen receptor gene causes hyperandrogenization in male mice.
(64/197)