Impact of Bariatric Surgery on Female Sexual Function and Sex Hormones

BACKGROUND:

Obesity is associated with significant physiological and psychological morbidity. While the metabolic effects of bariatric surgery are well-documented, its impact on female sexual health remains understudied, particularly in Middle Eastern populations. Sexual function is regulated by complex interactions between sex hormones (estrogen, testosterone, SHBG), psychological status (depression, anxiety), and body image. Obesity disrupts the hypothalamic-pituitary-gonadal axis through increased aromatase activity in adipose tissue, leading to hormonal imbalances. Weight loss following bariatric surgery may restore hormonal homeostasis and improve psychological well-being, potentially enhancing sexual function. However, the mediating pathways linking these changes have not been systematically examined.

OBJECTIVES:

Primary: To assess changes in female sexual function (FSFI scores) and sex hormone levels (total testosterone, free testosterone, estradiol E2, SHBG, and calculated Free Androgen Index) from baseline to 6 months after bariatric surgery.

Secondary: (1) To assess changes in depressive symptoms (Beck Depression Inventory-II) and anxiety symptoms (Beck Anxiety Inventory); (2) To assess changes in quality of life (Bariatric Quality of Life Index); (3) To assess body image satisfaction at 6 months; (4) To assess changes in partner sexual function (International Index of Erectile Function); (5) To explore mediating pathways linking weight loss, hormonal changes, mood improvement, and sexual function improvement;

METHODS:

Design: Prospective single-center observational cohort study. Setting: Department of General Surgery (Bariatric Surgery Unit), Kasr Al-Ainy Faculty of Medicine, Cairo University, Egypt.

Population: 40 morbidly obese female patients aged 18-45 years with stable, sexually active partner relationships, scheduled for primary bariatric surgery (sleeve gastrectomy or gastric bypass).

Procedures:

Eligible participants provide informed consent at baseline. Assessments occur at two time points: pre-operatively (within 2 weeks before surgery) and 6 months post-operatively.

At each assessment, participants undergo:

1. Clinical evaluation: height, weight, BMI, smoking history, marital status, menstrual history (cycle regularity, last menstrual period), medication review
2. Psychometric assessments:

* Arabic Female Sexual Function Index (ArFSFI) - 19 items, 6 domains
* Beck Depression Inventory-II (BDI-II) - 21 items
* Beck Anxiety Inventory (BAI) - 21 items
* Bariatric Quality of Life Index (BQL) - 30 items
* Post-bariatric body image satisfaction questionnaire (6 months only)
3. Hormonal assessment: Fasting morning blood sample (8:00-11:00 AM) during luteal phase for measurement of total testosterone, free testosterone, estradiol E2, and SHBG using electrochemiluminescence immunoassay. Free Androgen Index (FAI) is calculated as (total testosterone \[nmol/L\] × 100)/SHBG \[nmol/L\].
4. Partner assessment: International Index of Erectile Function (IIEF) completed by partner

Significance:

This study will provide comprehensive, mechanistic insights into the multi-dimensional improvements in female sexual health following bariatric surgery. By including hormonal, psychological, and partner assessments, it addresses critical gaps in the literature and provides culturally-relevant data for Middle Eastern populations. Findings may inform pre-operative counseling and post-operative care for women undergoing bariatric surgery.

• Sleeve Gastrectomy (Procedure): Laparoscopic sleeve gastrectomy involves resection of approximately 80% of the stomach, creating a tubular gastric pouch. This restrictive procedure reduces gastric capacity and alters gut hormones.
• Gastric Bypass (Procedure): Laparoscopic gastric bypass creates a small gastric pouch (15-30 mL) that is anastomosed to the jejunum, bypassing the remainder of the stomach and proximal small intestine. This combined restrictive and malabsorptive procedure produces significant weight loss and metabolic improvements.

Primary outcomes

• Change in Female Sexual Function [Baseline and 6 months post-operative]: Change in total score and domain scores of the Arabic Female Sexual Function Index (ArFSFI) from baseline to 6 months after bariatric surgery. The FSFI is a 19-item self-report questionnaire assessing sexual function over the past 4 weeks across six domains: desire (score range 1.2-6.0), arousal (0-6.0), lubrication (0-6.0), orgasm (0-6.0), satisfaction (0.8-6.0), and pain (0-6.0). Total score ranges from 2.0 to 36.0, with higher scores indicating better function. The Arabic version is validated in Egyptian populations. The cutoff for sexual dysfunction is ≤26.55.
• Change in Sex Hormone Levels [Baseline and 6 months post-operative]: Change in serum levels of reproductive hormones from baseline to 6 months after bariatric surgery. Measured parameters: (1) Total Testosterone (ng/dL), (2) Free Testosterone (pg/mL), (3) Estradiol E2 (pg/mL), (4) Sex Hormone Binding Globulin (SHBG) (nmol/L), and (5) calculated Free Androgen Index (FAI). FAI = (Total Testosterone \[nmol/L\] × 100) / SHBG \[nmol/L\]. Samples collected fasting between 8:00-11:00 AM during luteal phase. Measured by electrochemiluminescence immunoassay.

Secondary outcomes

• Change in Depressive Symptoms [Baseline and 6 months post-operative]: Change in Beck Depression Inventory-II (BDI-II) scores from baseline to 6 months after bariatric surgery. The BDI-II is a 21-item self-report inventory measuring depression severity over the past two weeks. Each item scored 0-3, total scores 0-63. Higher scores indicate more severe depression. Cutoffs: 0-13 minimal, 14-19 mild, 20-28 moderate, 29-63 severe. Arabic validated version used.
• Change in Anxiety Symptoms [Baseline and 6 months post-operative]: Change in Beck Anxiety Inventory (BAI) scores from baseline to 6 months after bariatric surgery. The BAI is a 21-item self-report questionnaire measuring anxiety severity with focus on somatic symptoms. Each item scored 0-3, total scores 0-63. Higher scores indicate more severe anxiety. Cutoffs: 0-7 minimal, 8-15 mild, 16-25 moderate, 26-63 severe. Arabic validated version used.
• Change in Quality of Life [Baseline and 6 months post-operative]: Change in Bariatric Quality of Life (BQL) Index scores from baseline to 6 months after bariatric surgery. The BQL Index is a 30-item validated instrument with two sections: Section 1 (16 items) assesses non-QoL factors (comorbidities, symptoms, medications); Section 2 (14 items) assesses QoL factors on 5-point Likert scale. Total scores range 14-78, with higher scores indicating better quality of life.
• Body Image Satisfaction [Baseline and 6 months post-operative]: Assessment of body image satisfaction at 6 months after bariatric surgery using the Post-bariatric Body Image Satisfaction Questionnaire. This instrument measures satisfaction with appearance after weight loss on a 5-point Likert scale from "strongly satisfied" to "strongly dissatisfied."
• Change in Partner Sexual Function [Baseline and 6 months post-operative]: Change in International Index of Erectile Function (IIEF) scores from baseline to 6 months after the participant's bariatric surgery. The IIEF is a 15-item questionnaire assessing male sexual function across five domains: erectile function (score 1-30), orgasmic function (0-10), sexual desire (2-10), intercourse satisfaction (0-15), and overall satisfaction (2-10). Total scores range 5-75, higher scores indicate better function. Completed by participant's stable partner. Arabic validated version used.
• Correlation Between Mood Improvement and Sexual Function Improvement [Baseline to 6 months post-operative]: Pearson or Spearman correlation coefficients examining the relationship between change in Beck Depression Inventory-II score (ΔBDI-II), Beck Anxiety Inventory (BAI) and change in Female Sexual Function Index total score (ΔFSFI) from baseline to 6 months post-operative. This analysis tests whether psychological improvement mediates improvements in sexual function.
• Correlation Between Hormonal Changes and Sexual Function Improvement [Baseline to 6 months post-operative]: Pearson or Spearman correlation coefficients examining the relationship between change in Free Androgen Index (ΔFAI) and change in Female Sexual Function Index total score (ΔFSFI) from baseline to 6 months post-operative. This analysis tests whether hormonal normalization mediates improvements in sexual function.

Sex: Female, ages: 18 Years to 45 Years

Inclusion Criteria:

* Female gender
* Age 18-45 years (childbearing period)
* Body Mass Index (BMI) ≥40 kg/m² or ≥35 kg/m² with obesity-related comorbidities, meeting international criteria for bariatric surgery
* Scheduled for primary bariatric surgery (sleeve gastrectomy or Roux-en-Y gastric bypass)
* Presence of a stable, sexually active intimate partner relationship
* Sexually active
* Willingness to participate and provide informed consent
* Ability to complete Arabic-language questionnaires

Exclusion Criteria:

* Women who are not sexually active
* Post-menopausal women (amenorrhea ≥12 months without other cause)
* Current pregnancy or lactation
* History of medication use that can interfere with sexual function, including:
* Antidepressants
* Antipsychotics/psychotropic drugs
* Beta-blockers
* Spironolactone
* Hormonal contraceptives (unless stable for ≥3 months and continued throughout study)
* Hormone replacement therapy
* Major uncontrolled medical conditions:
* Chronic heavy smoker (smoking index ≥400 pack-years)
* History of pelvic floor surgery or gynecological malignancy
* Partner with known erectile dysfunction or use of erectile dysfunction medications
* Previous bariatric surgery (revisional procedures)
* Inability or unwillingness to provide informed consent