title: C-Peptide, Baseline and Postprandial Insulin Resistance after a Carbohydrate-Rich Test Meal - Evidence for an Increased Insulin Clearance in PCOS Patients?
abstract: IntroductionKnown characteristics of patients with PCOS include infertility, menstrual disorders, hirsutism and also often insulin resistance. These symptoms increase with increasing body weight. In the LIPCOS study (LifestyleIntervention for Patients with Polycystic Ovary Syndrome [PCOS]) long-term changes of the PCOS in dependence on pregnancy and parenthood were systematically assessed. In the framework of the LIPCOS study, PCOS patients were given a standardised carbohydrate-rich test meal in order to examine glucose homeostasis and insulin secretion. The results were compared with those of a eumenorrhoeic control group who all had corresponding BMI values and corresponding ages.Methods and Patients41 PCOS patients (without diabetes) and 68 controls received a standardised carbohydrate-rich test meal (260 kcal, 62 % carbohydrates, 32 % fat, 6 % proteins) in order to generate a submaximal insulin and glucose stimulation. The values were determined at baseline and postprandial after 60, 120 and 180 minutes. In addition, the corresponding C-peptide levels were recorded.ResultsIn the PCOS patients (n = 41), the insulin secretion test after a standardised test meal showed almost identical baseline and postprandial insulin levels when compared with those of the age- and BMI-matched eumenorrhoeic controls (n = 68). In the PCOS patients, the baseline and postprandial glucose levels were significantly elevated (92.88 ± 10.28 [PCOS] vs. 85.07 ± 9.42 mg/dL [controls]; p < 0.001) so was C-peptide (p < 0.025).ConclusionsIn the present study we have shown for the first time that, after consumption of a standardised test meal, PCOS patients formally exhibit a higher fasting insulin resistance than controls. In spite of the higher stimulated C-peptide levels, the insulin levels did not increase more strongly with increasing glucose levels than in controls which may be indicative of a higher insulin clearance in PCOS patients.
authors.affiliation: Frauenklinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Stassek
authors.affiliation: Hochschule Weihenstephan-Triesdorf, Weidenbach, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Erdmann
authors.affiliation: Frauenklinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Ohnolz
authors.affiliation: Gemeinschaftspraxis Prof. Berg und Dr. Lesoine, München, Germany.
authors.forename: F D
authors.initials: FD
authors.lastname: Berg
authors.affiliation: Frauenklinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kiechle
authors.affiliation: Frauenklinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Seifert-Klauss
keywords: C-peptide; impaired glucose tolerance; insulin; polycystic ovarian syndrome