The Role of Estrogen in Adipocyte Remodeling Following Surgical Menopause

The overarching aim of this study is to assess the downstream effects of abrupt estrogen deficiency in women undergoing elective bilateral oophorectomy by studying:

1. the rate of in vivo adipogenesis in the subcutaneous abdominal (scABD) and subcutaneous femoral (scFEM) adipose tissue depots following bilateral oophorectomy surgery using an innovative (and tested) 8-week incorporation of stable isotope (deuterium; 2H) administered in the form of heavy water (2H2O) to endogenously label adipose tissue DNA;
2. the changes in expression of subcutaneous adipose tissue genes and proteins specific to adipocyte expansion and function; extracellular matrix remodeling and fibrosis; and inflammation in the scABD and scFEM depots before and after elective bilateral oophorectomy.

This is a cross-sectional study that will enroll up to 10 women undergoing laparoscopic, elective bilateral oophorectomy at a local hospital in Baton Rouge, LA. Women will complete 7 study visits over 3 months; a single screening visit to assess eligibility, a pre-bilateral oophorectomy visit for imaging and adipose tissue biopsy collection, and 5 post-bilateral oophorectomy visits to "dose", maintain compliance and subject retention, and perform follow-up imaging and adipose tissue biopsy collection for outcome measures.

Eligibility Criteria:
Inclusion Criteria:

* Healthy females
* Ages 18-45 y
* BMI between 25 kg/m2 and 40 kg/m2 (±0.5 kg/m2 will be accepted)
* Are pre-menopausal (follicle-stimulating hormone, FSH\<40 mIU/mL)
* Asymptomatic for the following menopause-related symptoms: hot flashes, insomnia (trouble sleeping), or mood swings
* Planning to have a laparoscopically, elective bilateral oophorectomy
* No medical indication for increased cancer risk
* Are willing to drink heavy water (2H2O) over an 8-week period
* Medically cleared for participation in the study by OB/GYN and Medical Investigator
* Are willing to have blood and fat tissue stored for future use

Exclusion Criteria:

* Unstable weight in the last 3 months \[gain or loss \>7 lb (or 3.2 kg)\]
* Significant changes in diet or physical activity level within the past month
* Smoking or use of tobacco products within the last 3 months
* Amenorrhea (or absence of regular monthly cycles)
* History of clinically diagnosed diabetes or a fasting blood glucose \>126 mg/dL
* Average screening blood pressure \>140/90 mmHg
* Chronic use of systemic glucocorticoids, systemic adrenergic-stimulating agents, antipsychotic/antidepressant medications, thiazolidinediones, and other medications that cause clinically significant weight gain, weight loss or are known to make changes in fat cell number/size.
* Previous bariatric surgery (or other surgeries) for obesity or weight loss
* Use of over the counter or prescription weight loss products
* History of metabolic diseases (other than diabetes)
* History of neurological disease
* History of cardiovascular disease (or other chronic diseases)
* Unable or unwilling to have an MRI performed
* Pregnant, planning to become pregnant, or breastfeeding
* Use of hormone replacement therapy.
* Unwilling to discontinue any form or hormonal therapy (e.g., contraceptives including birth control pills, vaginal ring, injections, implant, or skin patch; hormonal supplements, etc.) upon enrollment (after the Screening Visit).