The incretin effect and secretion in obese and lean women with polycystic ovary syndrome: a pilot study.

BACKGROUND: Insulin resistance is considered to play an important role in the pathogenesis of polycystic ovary syndrome (PCOS) and in the progression to type 2 diabetes. Recent reports concentrate on a possible relationship between incretin secretion and beta-cell function in PCOS. The aim of the present study is to investigate the incretin effect in obese and lean women with PCOS. METHODS: Twenty women with PCOS and ten age-matched healthy women were recruited in the study. The oral glucose tolerance test (OGTT) and isoglycemic test were carried out on each participant after an overnight fast at 2-weeks interval. Plasma levels of insulin, glucose, C-peptide, glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1) were assayed. RESULTS: Obese women with PCOS demonstrated lower GIP concentrations (area under the curve [AUC]) in response to OGTT compared to the control group. The incretin effect was found significantly augmented in the obese women with PCOS compared to controls. This finding remained robust in the subgroup analysis including only body mass index (BMI)-matched healthy women. CONCLUSIONS: Increased insulinotropic effect could counteract the blunted GIP response to OGTT in obese women with PCOS. It is suggested that the pathology of PCOS may also include impaired activity of the enteroinsular axis.

Effect of intracerebroventricular infusion of neurotensin in glucose-dependent insulinotropic peptide secretion in dogs.

UNLABELLED: GIP is a major physiological component of the enteroinsular axis. Several researchers have pointed to a neural regulation of GIP secretion. We have previously studied the effect of intracerebroventricular (icv) infusion of insulin, NPY and bombesin in the regulation of GIP secretion. The aim of the present study is to evaluate a possible role of neurotensin in neural regulation of GIP secretion. Thirty-two adult dogs were used in this study. In a dose-response study (experiment 1) we used 3 different doses of neurotensin (25, 50 and 100microg) in a bolus icv infusion. In experiment 2 the animals received a bolus icv infusion of 50microg neurotensin and an equivalent amount of artificial cerebrospinal fluid (aCSF) at 1-week interval. In experiment 3 the animals received a continuous icv infusion of neurotensin at a constant rate of 1microg/kg/h and aCSF over a 3-h period, at 1-week interval. In experiment 4 the experiment of group 3 was repeated with a simultaneous intraduodenal infusion of a glucose load through the Mann-Bollman fistula. Plasma levels of glucose, insulin and GIP were assayed. RESULTS: Bolus and continuous icv infusion of neurotensin produced a significant increase in glucose, GIP and insulin levels. In the 4th experiment icv infusion of neurotensin produced a more prominent increase of glucose and insulin levels compare to infusion of aCSF. GIP levels were lower after infusion of neurotensin compared to aCSF. CONCLUSIONS: Our data suggest a differential effect of neurotensin on GIP secretion, dependent on the energy load.

[Right and left ventricular ejection fraction evaluation in patients with chronic pulmonary disease. Comparison of nuclear medicine methods].

UNLABELLED: Our aim was to evaluate right ventricular ejection fraction (RVEF) and left ventricular ejection fraction (LVEF) in patients with chronic pulmonary disease (CPD) during a standard 99mTc-isonitrilium myocardial perfusion study. Forty patients (14 women and 26 men, mean age 67.7 +/- 7 years old) suffering from CPD enrolled in this study. Patients were consecutively submitted to: a) First pass (FP) angiocardiography with 99mTc (Tauc-FP). b) Multigated angiocardiography (MUGA). c) FP with 99mTc-sestamibi (MIBI-FP). d) Gated FP (MIBI-gFP) and GatedSPECT was performed in 23 patients. A simple SPECT study was performed to the rest of them. Our results showed: For the RV: RVEF measured by each method: Tauc-FP =49.09+/-8.4%, MUGA =48.51+/-10.6%, MIBI-FP =49.45+/-7.8 % and MIBI-gFP =52.49+/-6.05%. No difference among these methods was noted (P=0.674). MIBI-FP ejection fraction range was wider than MIBI-gFP and narrower than MUGA. A strong correlation (r=0.88 P<0.01) and good agreement was found between MIBI-gFP and MIBI-FP. Less strong correlation was estimated between not only Tc-FP and MUGA (r=0.76 P<0.01) but MIBI-FP and MUGA (r=0.68 P<0.01) as well with no sufficient agreement. For the LV: LVEF was also measured by each method: Tauc-FP=61,1+/-8,5%, MUGA=61,2+/-10%, MIBI-FP=61,8+/-6%,EF GSPECT=60,2+/-7%. There was a strong correlation (r=0.87 P<0.01) with good agreement between Tauc-FP and MUGA. For all patients, correlation between MIBI-FP and GSPECT was weak (r=0.62 P<0.01) but ameliorated by the exclusion of 4 patients with small end diastolic volumes (EDV) (r=0.82 P<0.01). The correlation between MUGA and GSPECT got stronger (r=0.85 P<0.01) by the same exclusion. Finally, a strong correlation (r=0.81 P<0.01) with sufficient agreement was noted between MIBI-FP and MUGA. IN CONCLUSION: For the RV: simple or gated FP are reliable with good agreement methods of RVEF evaluation in patients with CPD that can easily be performed during every radionuclide isonitrilium myocardial perfusion study. MUGA is proved to be comparative to the FP estimation of RV EF. The gFP affords the narrowest range of RVEF calculated, allowing the more accurate functional identification of RV borders. For the LV: FP (with 99mTc or with sestamibi-99mTc) is a reliable method of LVEF measurement in patients with CPD when compared with MUGA. MuIotaBetaIota-FP can evaluate LVEF during a standard myocardial perfusion study with radionuclide isonitrilium. GSPECT-EF correlation with EF measured by MUGA or FP is strongly affected by EDV.