A Reduced Carbohydrate Diet Intervention for Polycystic Ovary Syndrome (PCOS)
Condition: Polycystic Ovary Syndrome
MeSH terms: Polycystic Ovary Syndrome; Syndrome
Study type: Interventional

Summary: 
      Polycystic ovary syndrome (PCOS) affects 5-10% of women of reproductive age, and is
      associated with infertility, risk for obesity and type 2 diabetes, and impaired quality of
      life. The elevated insulin characteristic of PCOS is likely to play a major role in its
      symptoms. Manipulation of dietary carbohydrate quantity and quality (glycemic load; GL) may
      lower insulin and improve both reproductive and metabolic outcomes. The purpose of this study
      is to determine if a lower GL diet intervention is more effective than a standard (STD) diet
      in improving reproductive and metabolic outcomes of women with PCOS in the absence of weight
      loss.
    

Detailed description: 
      Polycystic ovary syndrome (PCOS) is a heterogeneous syndrome affecting 5-10% of women of
      reproductive age. It is characterized by elevated circulating insulin, reduced insulin
      sensitivity, infertility, hyperandrogenism, and a multitude of symptoms that result in a
      decreased quality of life. The elevated insulin characteristic of PCOS is likely to play a
      major role in its pathogenesis by reducing insulin sensitivity and stimulating testosterone
      (T) production and increasing its free fraction. Although many women with PCOS are
      overweight/obese (10-50%), those who are non-obese suffer from the same symptoms as their
      obese counterparts. Thus, it is likely that the metabolic disturbances associated with PCOS
      predispose to weight gain, which in turn exacerbates PCOS by worsening insulin resistance.
      Manipulation of dietary carbohydrate quantity and quality (glycemic load; GL) may lower
      insulin and improve both reproductive and metabolic outcomes. No study has tested the
      efficacy of a lower GL diet among non-obese women with PCOS.

      The Specific Aim of this proposal is to determine if a lower GL diet intervention is more
      effective than a standard (STD) diet in improving reproductive and metabolic outcomes of
      women with PCOS (both normal-weight and overweight/obese). We hypothesize that, in the
      absence of weight change, the lower GL diet will be more effective than the STD diet in
      decreasing insulin secretion, increasing insulin sensitivity, decreasing free T, decreasing
      fat from metabolically harmful sites, decreasing inflammation, and improving menstrual
      cyclicity and ovulation. Further, the lower GL diet will increase perceived fullness and
      decrease hunger, effects mediated via gut hormones.

      Development of a diet that optimizes reproductive and metabolic health among women with PCOS
      will reduce reliance on pharmacologic treatments and improve quality of life, even in the
      absence of weight loss. This project is novel in being the first to conduct a highly
      controlled nutrition intervention in non-obese women with PCOS under weight stable
      conditions, utilizing robust measures of insulin secretion and action, fat distribution,
      inflammation, hunger/fullness, the gut hormone profile, and reproductive function. The
      results from this study can be used as a starting point from which to explore optimal diets
      for overweight women with PCOS.
    

Intervention name(s): Reduced Glycemic Load Diet; Standard Diet
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): 36-40% fat; 40-42% carbohydrate; 18-22% protein
Glycemic Load <=46 per 1000 calories; 25-27% fat; 55-57% carbohydrate; 18-22% protein
Glycemic Load >=77 per 1000 calories
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Basic Science
Keywords: Polycystic Ovary Syndrome; Insulin; Diet; Glycemic Load