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Basic and Meal Stimulated Plasma GIP Levels are Higher in Lean PCOS Women with FAI over 5. Milewicz T et al. (2016) Glucose dependent insulinotropic peptide (GIP) belongs to the incretins which are responsible for 70% of the insulin release after oral glucose intake. Its impaired secretion was noted in several conditions involving insulin resistance, including polycystic ovary syndrome (PCOS), known as the state with increased testosterone level. This paper considers a possible relationship between the free androgen index (FAI) and basal as well as meal stimulated level of GIP in lean women affected by PCOS. To our knowledge, no previous study has evaluated the matter so far. cross-sectional study 50 age-matched lean women (BMI=20.76±1.83) were enrolled to the study and divided into 2 groups. Patients with phenotype with FAI<5 were classified as group 1, PCOS patients with FAI>5 formed group 2. All subjects underwent standard meal test. Serum GIP concentration was determined both at fasting and at 60 min of the test. Calculations were carried out using Statistica 10. Mann-Whitney test indicated a statistically significant difference in medians values of GIP plasma levels between groups on fasting (36.4 pg/ml vs. 59.6 pg/ml; p=0.0007) and at 60 min after meal test (50.1 pg/ml vs. 72.5 pg/ml; p=0.006). Spearman test indicated significant positive correlation between FAI and GIP levels at 0' and 60' in total study population (0':R=0.37;p=0.008; 60':R=0.28; p=0.049). Excess androgen activity might be a factor contributing to alter secretion of incretins in lean PCOS women. However it could not be ruled out that it is also possible that increased GIP levels might induce hyperandrogenemia in PCOS. An increased GIP levels may induce hyperinsulinemia and play an additive to insulin resistance role in progression to diabetes mellitus type 2 (DMT2).//////////////////
Circulating irisin and GIP are associated with the development of polycystic ovary syndrome. Chang CL 2014 et al.
Context: Polycystic ovary syndrome (PCOS) is characterized by oligo- or anovulation, polycystic ovary, and/or hyperandrogenism. In addition, many PCOS patients present with dyslipidemia, insulin resistance, and obesity. Due to the complexity of this disorder, the causes of PCOS remain to be identified. Objectives: Because many PCOS patients have a propensity to develop dyslipidemia, we hypothesized that the brown adipose-differentiation factor, irisin, and the glucose-dependent insulinotropic peptide (GIP) play a role in the development of PCOS. Design and Setting: Serum hormone levels in 202 PCOS patients and 47 healthy women were investigated. Patients or Other Participants: Patients were stratified based on the presence/absence of metabolic syndrome risk factors, as defined by the National Cholesterol Education Program's Adult Treatment Panel III report (ATPIII [+] and ATPIII [-]), or BMI (healthy-weight and overweight). Main Outcome Measures: We measured serum irisin, GIP, luteinizing hormone (LH), anti-Mullerian hormone (AMH), and androgens as well as metabolic indices including HOMA-IR, ISI Matsuda, and QUICKI. Results: PCOS patients exhibited hyperandrogenism, dyslipidemia, and hyperinsulinism as well as elevated LH and AMH levels. In addition, fasting irisin level (p < .001) and glucose-induced GIP response (p = .013) in PCOS patients were significantly elevated as compared to those of control women. Remarkably, levels of fasting irisin and glucose-induced GIP response remained significantly elevated in ATP III [-] PCOS and healthy-weight PCOS patients when compared to matched controls. Analysis of the effect size indicated that both fasting irisin and glucose-induced GIP response are significant risk factors for PCOS with odds ratios of 6.63 and 4.21, respectively. Conclusion: Although there is as yet no evidence for a causal link between irisin and/or GIP and PCOS, it is conceivable that irisin and GIP might contribute to the the develpment of PCOS and may also represent novel PCOS biomarkers.
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