Effect of the Glycemic Index of Diet on Metabolic and Reproductive Parameters in Overweight and Obese Infertile Women

April 14, 2015 updated by: Hospital de Clinicas de Porto Alegre

Effect of a Hypocaloric Diet With Different Glycemic Indexes on Ghrelin and Leptin Levels, Metabolic Parameters, and Reproductive Outcomes in Overweight and Obese Infertile Women: A Randomized Clinical Trial

Infertility has been currently recognized as a disorder related to obesity. Among several metabolic changes associated with obesity, insulin resistance appears to be linked to hormonal disorders that affect reproductive system. Leptin and ghrelin are hormones involved in energy balance regulation and are also associated with reproductive system regulation, but its relationship with infertility is scarce. The aim of this study is to determine the effect of a hypocaloric diet with different glycemic indexes on ghrelin and leptin levels, hormonal, metabolic and reproductive parameters in infertile overweight or obese women candidates to in vitro fertilization. The patients who meet the inclusion criteria and accept to participate in the study, will be allocated in one of the following groups: Hypocaloric Low Glycemic Index diet group; Hypocaloric Conventional diet group or Control group (maintenance of usual diet) and follow the study protocol for 12 week. Immediately after the end of the diet protocol, the patients will be submitted to the in vitro fertilization treatment.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Infertility has been currently recognized as a disorder related to obesity. Among several metabolic changes associated with obesity, insulin resistance appears to be linked to hormonal disorders that affect reproductive system. Leptin and ghrelin are hormones involved in energy balance regulation and are also associated with reproductive system regulation, but its relationship with infertility is scarce. The aim of this study is to determine the effect of a hypocaloric diet with different glycemic indexes on ghrelin and leptin levels, hormonal, metabolic and reproductive parameters in infertile overweight or obese women candidates to in vitro fertilization. Infertile women with grade I and II obesity, or pre-obesity with increased waist circumference will be recruited. Patients will be assigned to Hypocaloric Low Glycemic Index diet group; Hypocaloric Conventional diet group or Control group (maintenance of usual diet), and will follow the protocol for 12 weeks. The two intervention diets will be similar in terms of caloric intake and macronutrient distribution and different in terms of carbohydrates quality (index and glycemic load). Immediately after the end of the diet protocol, the patients will be submitted to the in vitro fertilization treatment. Before and after the intervention anthropometric measurements (weight, height, body mass index, waist and hip circumference) and body composition (body fat percentage determined by the measurement of seven skinfolds) will be evaluated as well as biochemical parameters: leptin, acylated ghrelin, glucose, insulin, serum lipids (total cholesterol and lipoproteins, and triglycerides), sex hormones - follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, progesterone, prolactin, testosterone and sex hormone binding globulin (SHBG). Primary outcome: clinical pregnancy rate. Secondary outcomes: HOMA-IR (Homeostasis Model Assessment), acylated ghrelin and leptin levels, body fat percentage, number of oocytes retrieved, percentage of fertilized oocytes and embryo quality.

Study Type

Interventional

Enrollment (Actual)

45

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Brazil
    • RS
      • Porto Alegre, RS, Brazil
        • Hospital de Clinicas de Porto Alegre

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 35 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • Diagnose of female infertility and indication for treatment with in vitro fertilization
  • Body Mass Index (BMI) equal or greater than 30 kg/m² or BMI > 25 kg/m² with increased waist circumference (> 80 cm);
  • Being not treated (diet) for weight loss/gain and maintaining stable body weight in the three months prior to the study;
  • Not having stomach/digestive problems
  • Not having the knowledge of cardiovascular disease history;
  • Non-smokers;
  • Not using any medication.

Exclusion Criteria:

  • Patients with BMI equal or higher than 40 kg/m² (morbid obesity)
  • Patients who are already receiving some type of nutritional intervention
  • Patients with co-morbidities that may interfere with reproductive capacity (genetic and/or endocrine disorders, diabetes mellitus, cancer, liver or kidney failure), alcoholics, individuals who have contact (work) with heavy metals or chemicals (exposure to solvents and pesticides)
  • Lack of adherence to the proposed dietary treatment

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Low Glycemic Index Diet Group
Patients will follow a treatment with a hypocaloric diet with low glycemic index/load for 12 weeks, immediately before the in vitro fertilization cycle.
Other: Low Glycemic Index Diet Group
This diet will be designed as a moderate reduced-energy, moderate-to-high fiber, low glycemic index/load diet.
Active Comparator: Conventional Diet Group
Patients will follow a treatment with a hypocaloric diet with high glycemic index/load for 12 weeks, immediately before the in vitro fertilization cycle.
Other: Conventional Diet Group
This diet will be designed as a moderate reduced-energy, moderate-to-high fiber, high glycemic index/load diet.
No Intervention: Control Group
Patients will follow their usual diet for 12 weeks, immediately before the in vitro fertilization cycle.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinical Pregnancy Rate
Time Frame: up to 18 weeks - in average, two weeks after the end of the in vitro fertilization cycle
Clinical Pregnancy will be considered as pregnancy diagnosed by ultrasound visualization of one or more gestational sacs or definitive clinical signs of pregnancy.
up to 18 weeks - in average, two weeks after the end of the in vitro fertilization cycle

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
HOMA-IR index (Homeostasis Model Assessment)
Time Frame: baseline and 12 weeks
The HOMA-IR index will be obtained by the following formula: fasting glucose (mg/dl/18) x fasting insulin (U/mL)/22.5.
baseline and 12 weeks
Acylated Ghrelin Levels (pg/dL)
Time Frame: baseline and 12 weeks
The levels of acylated ghrelin will be determined by enzyme immunoassay (SPI BIO, Montigny le Bretonneux, France) using a plate reader (Biochrom Anthos MultiRead 400, Biochrom Ltd., Cambridge, UK).
baseline and 12 weeks
Leptin Levels (ng/mL)
Time Frame: baseline and 12 weeks
The levels of leptin will be determined by enzyme immunoassay (SPI BIO, Montigny le Bretonneux, France) using a plate reader (Biochrom Anthos MultiRead 400, Biochrom Ltd., Cambridge, UK).
baseline and 12 weeks
Body Fat Percentage (%)
Time Frame: baseline and 12 weeks
The body fat percentage will be determined measuring the skinfolds at seven sites (triceps, subscapular, suprailiac, axillary, pectoral, abdomen and thigh) using a standardized technique of measurement and determination.
baseline and 12 weeks
Number of Oocytes Retrieved
Time Frame: between 12 and 16 weeks, during the in vitro fertilization cycle
Women will follow a pre-established protocol of ovarian stimulation as part of the preparation for the in vitro fertilization cycle. The evolution of oocytes development will be accompanied by the medical team using the ultrasound technique and when at least one oocyte reach the average size of 17 mm the puncture of oocytes by aspiration will be held.
between 12 and 16 weeks, during the in vitro fertilization cycle
Percentage of Fertilized Oocytes (%)
Time Frame: between 12 and 16 weeks, during the in vitro fertilization cycle
The percentage of fertilized oocytes will be obtained using the following formula: number of embryos/ total number of oocytes x 100.
between 12 and 16 weeks, during the in vitro fertilization cycle
Embryo Quality
Time Frame: between 12 and 16 weeks, during the in vitro fertilization cycle
Embryo quality will be determined by the Embryonic Score Calculation - ESC, where embryos with score 4, are considered the best quality.
between 12 and 16 weeks, during the in vitro fertilization cycle

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hospital de Clinicas de Porto Alegre

Collaborators

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.
Conselho Nacional de Desenvolvimento Científico e Tecnológico

Investigators

  • Principal Investigator: Cileide C Moulin, PhD, Ufrgs/Hcpa

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2012

Primary Completion (Actual)

December 1, 2013

Study Completion (Actual)

December 1, 2013

Study Registration Dates

First Submitted

April 7, 2015

First Submitted That Met QC Criteria

April 14, 2015

First Posted (Estimate)

April 15, 2015

Study Record Updates

Last Update Posted (Estimate)

April 15, 2015

Last Update Submitted That Met QC Criteria

April 14, 2015

Last Verified

April 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 11-0326

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Obesity

Clinical Trials on Low Glycemic Index Diet Group

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Mongolia

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

3
Subscribe