This is a randomized, single-blind, parallel 5 treatment group 24-week trial designed to directly compare the therapeutic effects of exenatide once weekly (EQW), dapagliflozin (DAPA), EQW plus DAPA, combined DAPA/metformin extended release (XR) and the weight loss medication, phentermine/topiramate extended release (PHEN/TPM ER) on metabolic and endocrinological parameters in overweight/obese non-diabetic women with PCOS. In this study, we will examine the efficacy of these therapies on metabolic parameters, body weight and body composition, anthropometric measurements, and reproductive function in a well-defined group of pre-menopausal overweight/obese, non-diabetic women with PCOS, focusing on their relationship to insulin resistance and obesity. We hope to determine which treatment(s) addressing the multifaceted disturbances of individual subgroups emerge as the preferable therapy.
Polycystic ovary syndrome is a heterogeneous condition characterized by disordered reproductive and metabolic function which accounts for the myriad of clinical features including androgen excess, chronic anovulation, insulin resistance adiposity, and dyslipidemia. This syndrome is highly prevalent, affecting between 8 and 18% of the female population, depending on the diagnostic criteria used. Hyperandrogenism, ovarian dysfunction and metabolic abnormalities - the main determinants of PCOS - all appear to be involved in a synergistic way in the pathophysiology of PCOS. Women with PCOS are more likely to be obese: between 38 and 88% of women with PCOS are overweight or obese, although PCOS can also manifest in lean women. Obesity, particularly abdominal obesity, plays a central role in the development of PCOS, and exacerbates the reproductive and metabolic dysfunction. Rather than absolute body weight, it is the distribution of fat that is important with central (visceral) adiposity being a risk factor. Visceral adipose tissue is more metabolically active than subcutaneous fat and the amount of visceral fat correlates with insulin resistance and hyperinsulinemia. Weight gain is also often an important pathogenic factor, with PCOS usually becoming clinically manifest in women with a presumable genetic predisposition for PCOS who subsequently gain weight. Therefore, environmental (particularly dietary) factors are important. However, BMI is also influenced by genetic factors such as the fat mass and obesity-associated protein, and obesity is a highly heritable condition. Therefore, the weight gain responsible for the manifestation of PCOS in many women with this condition is itself influenced by genetic factors. Ethnicity, genetic background, personal and family history, degree of obesity must all be taken into account because they might aggravate or even trigger metabolic disturbances women with PCOS. Moreover, the incidence of glucose intolerance, dyslipidemia, gestational diabetes, and type 2 diabetes (DM2) is increased in women with PCOS at all weight levels and at a young age. PCOS may be a more important risk factor than ethnicity or race for glucose intolerance in young women. The exact factors responsible for this excess risk in women with PCOS have not been identified; family history of DM 2, obesity, insulin resistance, beta cell (ß-cell) secretory dysfunction, and hyperandrogenism are possible candidates. With better understanding of its pathophysiology, the metabolic consequences of the syndrome are now evident. Therefore, these patients need to be followed up even after their presenting complaint has been adequately resolved. Lifestyle modification is a key component for the improvement of reproductive function for overweight, anovulatory women with PCOS. Even a modest weight loss 5% of total body weight can restore ovulation in overweight women with PCOS. Features of PCOS (e.g., hirsutism, testosterone levels, insulin resistance, menstrual cyclicity and ovulation) showed marked improvements, and PCOS frequently resolved after substantial weight loss induced by bariatric surgery. Recently a number of anti-diabetes medications have been approved which facilitate weight loss and improve the underlying insulin resistance. We reported that treatment with the glucagon like peptide -1 (GLP-1) agonist, exenatide for 24 weeks was superior to single agent metformin treatment in improving insulin action and reducing body weight and hyperandrogenism in obese women with PCOS. We further observed exenatide treatment significantly improved first-phase insulin responses to oral glucose administration. Since aberrant first-phase insulin secretion and impaired suppression of endogenous glucose production are major contributors to postprandial hyperglycemia and development of type 2 diabetes, the effects of exenatide once weekly \[EQW (2 mg)\] to target these defects, and normalize glucose excursions are likely to be clinically significant in obese patients with PCOS. Sodium/glucose cotransporter 2 (SGLT-2) inhibitors are the newest class of medications for diabetes management that have not been investigated for use in the women with PCOS. The SGLT2 inhibitor, dapagliflozin \[DAPA (10 mg/day)\] has an insulin-independent action, promotes weight loss, has a low incidence of hypoglycemia, and complements the action of other antidiabetic agents. The loss of glucose with attendant caloric loss contributes to weight loss; in addition, improvements in β cell function have been seen. Because the SGLT2 inhibitors have a distinct mechanism of action that is independent of insulin secretion, the efficacy of this class of drugs is not anticipated to decline in the presence of severe insulin resistance. The weight loss seen with SGLT2 inhibitors is similar to that seen with glucagon-like peptide 1 agonists, and may be more acceptable because they are oral agents. The resulting weight loss will further assist in decreasing insulin resistance, leading to increased glucose disposal thus contributing to an increased insulin secretion-insulin sensitivity (ISSI) index, the primary outcomes measure. The non-diabetic female with PCOS offers a unique model to study the relationship between insulin resistance and adiposity. Women with PCOS demonstrate abnormal body composition characterized by a greater percent body fat, body fat mass, and increased ratio of fat to lean mass (F/L ratio). Studies using dual-energy X-ray absorptiometry (DEXA) methodology report a higher degree of metabolic dysfunction in patients with PCOS which appears be directly associated with their higher F/L ratio. Given that monotherapy and combined therapy with exenatide once weekly (EQW),and dapagliflozin (DAPA) along with DAPA/ metformin XR therapy are associated with weight loss introduces a confounder to the current study since it prevents distinguishing direct effects of the compounds on β-cell function vs. effects due to reduced adiposity. To control for loss of body mass and provide appropriate intervention in the remaining study arm we propose the use of a comparator weight loss drug alone, combination phentermine (PHEN)/topiramate (TPM) extended release (ER). To avoid the confounding relationship of body fat and insulin resistance, we will enroll only obese non-diabetic women with PCOS. All patients will receive diet and lifestyle counselling, including advice on exercise, according to usual clinical routine commencing during the lead-in period and continuing throughout the study We propose a randomized, single-blind, parallel 5 treatment group 24-week trial designed to directly compare the therapeutic effects of exenatide once weekly (EQW), dapagliflozin (DAPA), EQW plus DAPA, combined DAPA/metformin ER and the weight loss medication, phentermine/topiramate extended release (PHEN/TPM ER) on metabolic and endocrinological parameters in obese non-diabetic women with PCOS.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
119
2 mg SC injection every 7 days
One pill (10 mg) by mouth daily (QD) in am
2 mg SC injection every 7 days One pill (10 mg) by mouth QD in am
DAPA/MET ER-5 mg /1000 mg - 1 pill by mouth in am with food for 4 weeks DAPA/MET ER-10 mg /2000 mg - 2 pills in am by mouth with food -final dose
PHEN 3.75/TPM ER 23mg - 1 pill by mouth once daily in am for 2 weeks. After 2 weeks, PHEN 7.5mg/TPM ER 46mg- 1 pill by mouth once daily in am
Woman's Hospital
Baton Rouge, Louisiana, United States
Oral Disposition (Insulin Sensitivity-insulin Secretion) Index
An estimation of β-cell compensatory function, the insulin secretion-sensitivity index (IS-SI) will be derived by applying the concept of the oral disposition index to measurements obtained during the 2-h OGTT and calculated as the index of insulin secretion factored by insulin sensitivity (ΔINS/ΔPG 30 x Matsuda SIOGTT) from the OGTT. A higher score shows improved pancreatic insulin responsiveness relative to resistance.
Time frame: 24 weeks of treatment
Absolute Body Weight
Treatment effect on body weight at 24 weeks of treatment
Time frame: 24 weeks of treatment
Body Mass Index (BMI)
Treatment efficacy in reducing body mass at 24 weeks of treatment
Time frame: 24 weeks of treatment
Change in Percent Body Weight
Treatment effect on change in percent body weight from baseline
Time frame: Change from baseline (time 0) to study end (24 weeks)
Central Adiposity (Waist Circumference)
Treatment effect on loss of central adiposity after 24 weeks
Time frame: 24 weeks of treatment
Waist-to-Hip Ratio (WHR)
Treatment impact on central adiposity after 24 weeks
Time frame: 24 weeks of treatment
Waist-to-Height Ratio (WHtR)
Treatment impact on WHtR which is a measure of central adiposity
Time frame: 24 weeks of treatment
Total Fat Mass (kg) Evaluated by DEXA
Treatment impact on total fat mass by DEXA
Time frame: 24 weeks of treatment
Total Body Fat (%) by DEXA
Treatment impact on percent total body fat by DEXA
Time frame: 24 weeks of treatment
Android-Gynoid Ratio (AGR) as Determined by DEXA
treatment impact on measure of central adiposity as determined by android/gynoid ratio
Time frame: 24 weeks of treatment
Trunk/Leg Fat Ratio by DEXA
Treatment impact on trunk/limb ratio (measure of central adiposity) by DEXA
Time frame: 24 weeks of treatment
Fasting Blood Glucose
Treatment impact on fasting concentration of glucose in the blood
Time frame: 24 weeks of treatment
OGTT Mean Blood Glucose (MBG)
Treatment effect on MBG measured during the oral glucose tolerance test
Time frame: 24 weeks of treatment
Fasting Insulin Sensitivity (HOMA-IR)
Treatment effect on the ratio HOMA-IR which is insulin resistance measure derived from fasting blood glucose and insulin and is calculated by insulin (mU/ml)\*glucose (mmol/L)/22,5. The higher thenumber the more insulin resistant.
Time frame: 24 weeks of treatment
Matsuda Sensitivity Index Derived From the OGTT(SI OGTT)
The SI IOGTT is a measure of peripheral insulin sensitivity derived from the values of Insulin (microunits per milliliter) and Glucose (milligrams per deciliter) obtained from the OGTT and the corresponding fasting values. SI (OGTT) = 10,000/ \[(G fasting x I fasting) x (G OGTTmean x I OGTTmean)\], where fasting glucose and insulin data are taken from time 0 of the OGTT and mean data represent the average glucose and insulin values obtained during the entire OGTT. The square root is used to correct for nonlinear distribution of insulin, and 10,000 is a scaling factor in the equation. The higher value, the more sensitive to insulin.
Time frame: 24 weeks of treatment
Corrected First Phase Insulin Secretion (IGI/HOMA-IR)
Treatment effect on insulin secretion from 0 to 30 minutes after glucose load corrected for by fasting insulin sensitivity. A higher score shows improved first phase insulin secretion in response to glucose
Time frame: 24 weeks of treatment
Total Cholesterol Levels
Treatment effect on blood concentrations of total cholesterol
Time frame: 24 weeks of treatment
Triglyceride (TRG) Levels
Treatment effect on blood concentrations of triglycerides
Time frame: 24 weeks of treatment
Total Testosterone Concentrations
Treatment effect on blood concentrations of total testosterone
Time frame: 24 weeks of treatment
Dehydroepiandrosterone Sulfate (DHEA-S) Levels
Treatment effect on blood concentrations of DHEA-S
Time frame: 24 weeks of treatment
Free Androgen Index (FAI)
Treatment effect on FAI calculated from total testosterone divided by sex hormone binding globulin (SHBG) levels. A higher score indicates a worse outcome.
Time frame: 24 weeks of treatment
Systolic Blood Pressure (SBP)
Treatment effect on SBP after 24 weeks of treatment
Time frame: 24 weeks treatment
Diastolic Blood Pressure (DBP)
Treatment effect on DBP after 24 weeks
Time frame: 24 weeks of treatment
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