Hyperinsulinism and polycystic ovary syndrome (PCOS): role of insulin clearance

PURPOSE

Insulin resistance and compensatory hyperinsulinism are the predominant metabolic defects in polycystic ovary syndrome (PCOS). However, hyperinsulinism, as well as being compensatory, can also express a condition of reduced insulin clearance. Our aim was to evaluate the differences in insulin action and metabolism between women with PCOS (with normal glucose tolerance) and age- and BMI-matched women with prediabetes (without hyperandrogenism and ovulatory disorders).

METHODS

22 women with PCOS and 21 age/BMI-matched women with prediabetes were subjected to a Hyperinsulinemic-euglycemic clamp and an Oral Glucose tolerance Test (OGTT). Insulin sensitivity was assessed by the glucose infusion rate during clamp (M value); insulin secretion by Insulinogenic index, Oral Disposition Index (DIo) and AUC(2h-insulin) during OGTT; and insulin clearance by the metabolic clearance rate of insulin (MCRI) during clamp.

RESULTS

Women with PCOS showed significantly higher levels of AUC(2h-insulin) (p < 0.011), Insulinogenic Index (p < 0.001), DIo (p = 0.002) and significantly lower levels of AUC(2h-glucos)e (p = 0.001). No difference was found between the two groups regarding insulin sensitivity (M value). Lower levels of MCRI were found in women with PCOS [420 (IQR 227-588) vs. 743 (IQR 597-888) ml m(-2) min(-1): p < 0.001]. Furthermore, in the PCOS group, a strong independent inverse correlation was only observed between MCRI and AUC(2h-insulin) (PCOS: β:-0.878; p < 0.001; Prediabetes: β:-0.501; p = 0.019).

CONCLUSIONS

Our study suggests that in normoglycemic women with PCOS there is peripheral insulin sensitivity similar to that of women with prediabetes. What sets PCOS apart is the hyperinsulinism, today still simplistically defined "compensatory"; actually this is mainly related to decreased insulin clearance whose specific causes and dynamics have yet to be clarified.

Visceral adiposity index and DHEAS are useful markers of diabetes risk in women with polycystic ovary syndrome

OBJECTIVE

On the basis of the known diabetes risk in polycystic ovary syndrome (PCOS), recent guidelines of the Endocrine Society recommend the use of an oral glucose tolerance test (OGTT) to screen for impaired glucose tolerance (IGT) and type 2 diabetes (T2DM) in all women with PCOS. However, given the high prevalence of PCOS, OGTT would have a high cost-benefit ratio. In this study, we identified, through a receiver operating characteristic analysis, simple predictive markers of the composite endpoint (impaired fasting glucose (IFG) or IGT or IFG+IGT or T2DM) in women with PCOS according to the Rotterdam criteria.

DESIGN

We conducted a cross-sectional study of 241 women with PCOS in a university hospital setting.

METHODS

Clinical, anthropometric, and metabolic (including OGTT) parameters were evaluated. The homeostasis model assessment of insulin resistance (HOMA2-IR), the Matsuda index of insulin sensitivity, and the oral dispositional index and visceral adiposity index (VAI) were determined.

RESULTS

Out of 241 women included in this study, 28 (11.6%) had an IFG, 13 (5.4%) had IGT, four (1.7%) had IFG+IGT, and four (1.7%) had T2DM. Among the anthropometric variables examined, the VAI had a significantly higher C-statistic compared with BMI (0.760 (95% CI: 0.70-0.81) vs 0.613 (95% CI: 0.54-0.67); P=0.014) and waist circumference (0.760 (95% CI: 0.70-0.81) vs 0.619 (95% CI: 0.55-0.68); P=0.028). Among all the hormonal and metabolic serum variables examined, DHEAS showed the highest C-statistic (0.720 (95% CI: 0.65-0.77); P<0.001).

CONCLUSIONS

In addition to fasting glucose, the VAI and DHEAS may be considered useful tools for prescreening in all women with PCOS without the classical risk factors for diabetes.

Student teacher anxieties related to class management, pedagogy, evaluation, and staff relations

BACKGROUND

Anxiety is an important consideration in teaching, with implications for classroom success.

AIMS

We investigated the nature of anxiety in student teachers.

SAMPLES

Approximately 1000 student teachers in Canada were involved in four studies to explore education-related anxieties.

METHODS

Incorporating a cross-cultural focus, student teachers were tested on an anxiety measure designed for British student teachers, then examined for (1) the impact of practice teaching, (2) the value of instructional preparation, (3) demographic variables, and (4) models that predict anxiety.

RESULTS

Anxiety factors (i.e., evaluation, pedagogical, class management, and staff relations), similar to those for British participants, emerged with evaluation anxiety being highest. A practice teaching experience generated reduced anxiety for both sexes, but more so for females, with the greatest reductions for evaluation and pedagogical anxiety. In one study, participants reported anxieties prior to instruction (PRETEST), following instruction (POST-INSTR) and following practice teaching (POST-TEACH). Females showed higher anxiety ratings than males (PRETEST and POST-INSTR) but were comparable to males after practice teaching. Females in the lower grades division showed higher anxiety scores. Anxiety decreased between PRE-TEST and POST-INSTR for all four scales, and between POST-INSTR and POST-TEACH for evaluation, pedagogy and staff relations; however, class management anxiety did not decrease after practice teaching. Also, anxiety increased as placement grade level decreased. All models (demographic, experiential, and dispositional) were predictive but the best predictor was the psychological disposition to feel overwhelmed.

CONCLUSIONS

Student-teacher anxieties are related to demographic variables, experiential variables, and dispositional variables.

The resistant ovary syndrome la sindrome da ovaio resistente

After briefly recapitulating present-day knowledge on this recently identified syndrome with its polymorphic clinical and laboratory pattern, the authors describe three cases that have come to their attention. The most interesting was case III which was successfully treated on the basis of analogous reports found in the literature, with large doses of HMG-HCG in spite of the apparent "physiological absurdity" of this treatment. The authors stress the discrepancy frequently observed between functional diagnosis and histological findings; they suggest some possible explanations but stress the need for further research in order to clarify the nature of the functional damage in these patients and the level at which it is situated.