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

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
45

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
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

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
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

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hospital de Clinicas de Porto Alegre

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.
Conselho Nacional de Desenvolvimento Científico e Tecnológico

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • 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

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2012

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 1, 2013

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2013

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 7, 2015

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 14, 2015

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 15, 2015

Study Record Updates

Last Update Posted (Estimate)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 15, 2015

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 14, 2015

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 11-0326

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