PED/PEA-15 Protein, PCOS, Obesity, Insulin Sensitivity Indexes, Metformin, Oral Contraceptives

Effects of Metformin Versus Oral Contraceptives on PED/PEA-15 Protein Expression in Obese Women With Polycystic Ovary Syndrome

Insulin-resistance plays an important role in polycystic ovary syndrome (PCOS) physiopathology. The phosphoprotein enriched in the diabetes (PED/PEA-15), a 15 kDa protein related to insulin sensitivity, is over-expressed in type 2 diabetic patients and in PCOS women, independently of obesity. The effectiveness of oral contraceptives pills (OCP) or metformin (MET) in PCOS management is still uncertain. Aim of this pilot clinical study was to compare the effects of OCPs or MET on the expression of PED/PEA-15 in association with insulin sensitivity in obese PCOS women. Outcome measures: PED/PEA-15, BMI, plasma glucose and insulin, 1/HOMA-IR, homeostasis model assessment of insulin resistance; QUICKI, quantitative insulin sensitivity check index; ISI: whole-body insulin sensitivity index. Study design: twenty obese PCOS women (age: 24.7±18 yr; BMI: 30±2.4 kg/m2) were randomized according to insulin sensitivity to receive 30 µg ethinylestradiol plus 30 mg drospirenone 21 day/month or MET 1250 mg three times daily for 6 months. Results: At baseline, age and BMI were not different in the two groups; PED/PEA-15 protein expression was higher in MET than in OCP group (p=0.011), along with higher 1/HOMA-IR (p=0.004), and lower QUICKI and ISI (p=0.003 and p<0.001, respectively). After treatment, independently of body weight, only in MET group PED/PEA-15 decreased (p=0.004), along with insulin and 1/HOMA-IR (p<0.001), and QUICKI and ISI increased (p<0.001). Insulin sensitivity indexes improvement correlated significantly with PED/PEA-15 protein expression, but not with BMI. Conclusions: PED/PEA-15 protein over-expression in obese PCOS women with IR reduced after a six month treatment with MET, while remained unchanged in the OCP group. The reduction was independent of body weight, and correlated with insulin sensitivity indexes. This effect further supported MET as a more effective therapy than OCPs for obese PCOS women with IR, also when fertility is not required.

Study Overview

• Status: Completed
• Conditions: Polycystic Ovarian Syndrome; Insulin Sensitivity
• Intervention / Treatment: Drug: Metformin; Drug: oral contraceptive

Detailed Description

Subjects:

Twenty obese PCOS women (age: 24.7±18 yr; BMI: 30±2.4 kg/m2) were consecutively admitted to the Endocrinology Unit of the Department of Molecular and Clinical Endocrinology and Oncology of the Federico II University of Naples, and were enrolled in this clinical study. The diagnosis of PCOS was made according to the diagnostic criteria for PCOS At study entry the patients were randomized in two groups of treatment, according to insulin sensitivity. OCP group, 10 patients (BMI 29.7± 1.5 kg/m2) received 30 µg ethinylestradiol plus 30 mg drospirenone 21 day/month. MET group, 10 patients (BMI 30.4± 3.1 kg/m2), received metformin 1250 mg three times daily. The duration of follow-up was 6 months. The control group consisted of 10 healthy female volunteers, who were age matched.

Methods:

As all PCOS women were anovulatory, they underwent a progesterone challenge test (100 mg natural progesterone i.m.; Prontogest, Amsa, Rome, Italy), which induced uterine bleeding in all PCOS women. To exclude the presence of type 2 diabetes or abnormal glucose tolerance, the oral glucose tolerance test (OGTT) was performed and the normal glucose response to the OGTT was defined according to the 'Report of the Expert Committee on the diagnosis and classification of diabetes mellitus'.

All anthropometric measurements were taken with subjects wearing only light clothes and without shoes. In each woman, weight and height were measured to calculate the BMI [weight (kg) divided by height squared (m2), kg/m2]. Height was measured to the nearest cm using a wall-mounted stadiometer. Body weight (BW) was determined to the nearest 50 g using a calibrated balance beam scale.

Patients were given a standardized interview to obtain information about the duration of obesity, eating patterns, smok¬ing habits and physical exercise. In particular, subjects were also asked to make a daily record of the amount of physical activity (no exercise; ≤2-3 h/week; ≥2-3 h/week). Preadmission food intake and dietary history were assessed by a skilled dietitian who used a computer-assisted interview (Winfood 1.5, Medimatica srl, Martinsicuro, Italy). All PCOS women received a normo-caloric diet.

Assays:

Blood samples were obtained between 08.00 h and 09.00 h from an antecubital vein after an overnight fast, with the patient in the resting position. The OGTT was performed using 75 g dextrose. Blood samples were obtained at 0, 30, 60, 90, 120, min for plasma glucose and insulin measurements. Fasting plasma glucose (FPG) levels were determined by the glucose oxidase method immediately after the OGTT. Fasting plasma insulin (FPI) samples were promptly centrifuged, plasma was separated and stored at -20°C until assay. FPI was measured by a solid-phase chemiluminescent enzyme immunoassay using commercially available kits (Immunolite Diagnostic Products Co, Los Angeles, CA). 1/HOMA-IR, QUICKI and ISI were calculated.

PED/PEA-15 protein was measured in white-blood cells (WBC) lysates obtained from 10 to 12 ml of freshly collected uncoagulated whole blood, after separation with dextran 6%, using Western blot analysis. For Western blot analysis WBC were solubilized at 4°C in TAT buffer, centrifuged at 500g for 20 min, and supernatant fractions were stored at -20°C until used. The amount of 50 μg of lysate proteins were heated at 100°C in Laemmli buffer. Proteins were separated by 15% SDS-PAGE and then transferred to 0•45-mm Immobilon-P membranes (Millipore, Bedfort, MA). Filters were probed with PED/PEA-15 antiserum at 1:2000 dilution, revealed by enhanced chemiluminescence and autoradiography. The protein bands were quantified by laser densitometry and expressed as percentage of pixels (arbitrary units).

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Phase 3

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 28 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• female
• premenopausal
• obesity
• PCOS.

Exclusion Criteria:

• pregnancy
• type 2 diabetes or impaired glucose tolerance
• hypothyroidism
• hyperprolactinaemia
• Cushing's syndrome
• nonclassical congenital adrenal hyperplasia
• previous (within the last 6 months) use of oral contraceptives
• glucocorticoids
• antiandrogens
• ovulation induction agents
• antidiabetic and antiobesity drugs, or other hormonal drugs.

None of the subjects was affected by any neoplastic, metabolic, hepatic, and cardiovascular disorder or other concurrent medical illness (i.e. diabetes, renal disease, and malabsorptive disorders),acute and chronic inflammations based on medical history, physical examination, and routine laboratory tests, including measurement of oral temperature, white blood cell count and urinalysis.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: metformin	Drug: Metformin; metformin 1250 mg three times daily; Other Names: Biguanides
Active Comparator: oral contraceptive	Drug: oral contraceptive; 30 µg ethinylestradiol plus 30 mg drospirenone 21 day/month.; Other Names: estroprogestins

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
PED/PEA-15 protein expression	6 months

Secondary Outcome Measures

Outcome Measure	Time Frame
BMI, plasma glucose, plasma insulin, insulin sensitivity indexes (1/HOMA-IR, homeostasis model assessment of insulin resistance; QUICKI, quantitative insulin sensitivity check index; ISI, whole-body insulin sensitivity index).	6 months

Collaborators and Investigators

• Sponsor: Federico II University
• Investigators: Principal Investigator: Annamaria Colao, MD PhD, Department of Molecular and Clinical Endocrinology and Oncology Federico II University of Naples

Publications and helpful links

General Publications

• Savastano S, Di Somma C, Pizza G, De Rosa A, Nedi V, Rossi A, Orio F, Lombardi G, Colao A, Tarantino G. Liver-spleen axis, insulin-like growth factor-(IGF)-I axis and fat mass in overweight/obese females. J Transl Med. 2011 Aug 16;9:136. doi: 10.1186/1479-5876-9-136.
• Savastano S, Valentino R, Pizza G, De Rosa A, Orio F, Passaretti F, Formisano P, Lombardi G, Beguinot F, Colao A. Preliminary data on effects of metformin on PED/PEA-15 cellular levels in obese women with polycystic ovary syndrome. J Endocrinol Invest. 2010 Jul-Aug;33(7):446-50. doi: 10.1007/BF03346622.

Study record dates

Study Major Dates

• Study Start: December 1, 2006
• Primary Completion (Actual): December 1, 2006
• Study Completion (Actual): January 1, 2009

Study Registration Dates

• First Submitted: July 24, 2009
• First Submitted That Met QC Criteria: July 28, 2009
• First Posted (Estimate): July 29, 2009

Study Record Updates

• Last Update Posted (Estimate): October 14, 2009
• Last Update Submitted That Met QC Criteria: October 13, 2009
• Last Verified: October 1, 2009

More Information

Terms related to this study

• Keywords: PCOS; metformin; OCP; Oral Contraceptive; IR; PED/PEA-15 protein
• Additional Relevant MeSH Terms: Pathologic Processes; Glucose Metabolism Disorders; Metabolic Diseases; Immune System Diseases; Neoplasms; Endocrine System Diseases; Disease; Ovarian Cysts; Cysts; Ovarian Diseases; Adnexal Diseases; Gonadal Disorders; Hyperinsulinism; Hypersensitivity; Polycystic Ovary Syndrome; Syndrome; Insulin Resistance; Hypoglycemic Agents; Physiological Effects of Drugs; Reproductive Control Agents; Contraceptive Agents, Female; Metformin; Contraceptive Agents; Contraceptives, Oral; Biguanides
• Other Study ID Numbers: NeuroendoUnit-11