Effect of the Glycemic Index of Diet on Metabolic and Reproductive Parameters in Overweight and Obese Infertile Women
Condition: Female Infertility; Obesity
MeSH terms: Infertility; Infertility, Female; Overweight
Study type: Interventional

Summary: 
      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.
    

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.
    

Intervention name(s): Low Glycemic Index Diet Group; Conventional Diet Group
Intervention type(s): Other; Other
Intervention description(s): This diet will be designed as a moderate reduced-energy, moderate-to-high ﬁber, low glycemic index/load diet.; This diet will be designed as a moderate reduced-energy, moderate-to-high ﬁber, high glycemic index/load diet.
Allocation: Randomized
Intervention model: Factorial Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: female infertility; glycemic index; leptin; ghrelin; overweight; obesity; in vitro fertilization