Genetic Polymorphism of the Androgen Receptor-Gene and Sexual Function in Middle Aged Women (CAG-Libido)

This study is currently recruiting participants. (see Contacts and Locations)
Verified May 2014 by University Hospital Inselspital, Berne
Sponsor:
Collaborators:
University Hospital Muenster
University of Zurich
Information provided by (Responsible Party):
University Hospital Inselspital, Berne
ClinicalTrials.gov Identifier:
NCT01977313
First received: October 30, 2013
Last updated: May 19, 2014
Last verified: May 2014
  Purpose

It is known that with increasing age sexual desire is declining in women. Decreasing levels of androgens are believed to have an influence, but cannot explain the loss of libido completely. A possible explanation might be that the effect of the androgen is depending on the functionality of the androgen receptor. It is known that this functionality is genetically determined by the polymorphism of the androgen receptor gene. In the gene there is a varying number of CAG-repeats: the longer the CAG-Repeat, the lower the functionality of the androgen receptor, the lower the effect of the androgens. In this pilot study, the investigators would like to invite 45 healthy heterosexual middle-aged women to the University Hospital of Bern, where they answer questionnaires about their sexual function and where they give a blood sample to assess the testosterone serum levels and the genetically determined androgen receptor subtype.

The investigators believe that lower androgen levels and/or longer CAG-repeats in the androgen receptor gene are related to lower libido scores in healthy middle-aged women.


Condition
Libido
Receptors, Androgen
Polymorphism, Genetic
Androgen Effect

Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Cross-Sectional
Official Title: Genetic Polymorphism of the Androgen Receptor-Gene and Sexual Function in Middle Aged Women

Resource links provided by NLM:


Further study details as provided by University Hospital Inselspital, Berne:

Primary Outcome Measures:
  • 2 Subscores of the Female Sexual Function Index (FSFI): Satisfaction and Desire [ Time Frame: 1 Day of visit ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Other 4 Subscores of the FSFI: Arousal, Lubrication, Orgasm and Pain [ Time Frame: 1 Day of visit ] [ Designated as safety issue: No ]
  • CAG-repeats of the androgen receptor gene [ Time Frame: 1 Day of visit ] [ Designated as safety issue: No ]
  • Testosterone serum levels [ Time Frame: 1 Day of visit ] [ Designated as safety issue: No ]
  • Androgenity score [ Time Frame: 1 Day of visit ] [ Designated as safety issue: No ]
    Calculated from Gender-specific Index of Testosterone serum levels, CAG repeats and libido scores

  • Other influences on libido in middle aged women [ Time Frame: 1 Day of visit ] [ Designated as safety issue: No ]

Biospecimen Retention:   Samples With DNA

Whole blood, serum


Estimated Enrollment: 45
Study Start Date: September 2013
Estimated Study Completion Date: May 2015
Estimated Primary Completion Date: May 2015 (Final data collection date for primary outcome measure)
Groups/Cohorts
All study participants
All study participants

Detailed Description:

Background

It is known that with increasing age sexual desire is declining in women. Multiple factors are being discussed to have an influence on this topic, such as cultural, individual and biological factors. Decreasing levels of sexual hormones and specifically androgens are believed to have an influence, hence a lot of women benefit from a testosterone replacement therapy. Yet the sole decline of androgen levels with inclining age cannot explain the loss of libido completely.

A possible further factor might be the androgen receptor: It is known that the effect of the androgen in its target cells is depending on the functionality of the androgen receptor. This functionality is genetically determined by the polymorphism of the androgen receptor gene: In the gene there is a sequence with a varying number of CAG-repeats. This CAG-repeat is coding for a polyglutamine stretch in the androgen receptor which is responsible for the binding of co-activator proteins. The better these co-activator proteins are bound to the androgen receptor, the better the transcriptional activity of the latter. Previous studies have shown that the longer the CAG-Repeat, the weaker the binding of co-activator proteins, the lower the functionality of the receptor and therefore the lower the effects of the androgen on the target cell. Given this circumstances the same level of androgen can have different effects in two individuals.

Objective

In this pilot study, the investigators would like to correlate the testosterone serum levels, the functionality of the androgen receptor and the libido in 45 healthy, heterosexual middle-aged women.

Methods

45 healthy middle-aged women are being recruited and are being invited to come to the University Hospital in Berne. Here they will answer standardised questionnaires about their sexual function and libido and will give a blood sample to measure all the relevant parameters (fasting, premenopausal women: 1.-5. day of cycle): Total Testosterone, SHBG, Estrogen, DHEAS, FSH, LH, CAG repeats of the androgen receptor gene, TSH, fT3, fT4, Prolactin, Ferritin, CRP, Hemoglobin.

A statistician will then assess the collected data. No interventions are planned.

The following collaborators are providing support for this study: Dr. rer. nat. Ulrich Stefenelli, Würzburg, Germany, and Dr. med. Stefan Schmid, Rheinfelden, Switzerland.

  Eligibility

Ages Eligible for Study:   45 Years to 65 Years
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

A community sample of 45 healthy heterosexual women, aged 45-65.

Criteria

Inclusion Criteria:

  • Female
  • Healthy
  • Heterosexual
  • Aged 45-65
  • Written Informed Consent
  • Living since at least 1 year in a relationship
  • Ready to answer questionnaires about their sexual function
  • Ready to give a blood sample
  • German speaking

Exclusion Criteria

  • Serious diseases such as Cancer, Parkinsons Disease, Multiple Sclerosis, Diabetes mellitus
  • Sexual Abuse in personal history
  • Thyroid dysfunction
  • Substance abuse (>1pack/cigarettes per day, alcohol, drugs)
  • Psychiatric diseases in personal history
  • Acute stressful life event
  • Libido affecting diseases such as dyspareunia, vaginism, orgasm disorders, urine incontinence
  • Medication with the following substances in the past 8 weeks before day of visit:
  • Systemic corticoids
  • Blood pressure medication with beta-blockers, spironolactone, thiazide diuretics
  • Psychotropic medication such as antidepressants, benzodiazepins, antiepileptics, antipsychotics (1st generation)
  • Opioid analgetics
  • Hormonal contraceptives
  • Libido stimulating medication such as androgens (Testosterone, Dehydroepiandrostendionsulfate, Dihydrotestosterone and PDE5-Inhibitants
  • Antiandrogens
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01977313

Contacts
Contact: Petra Stute, PD Dr. med. 0041 31 632 13 03 petra.stute@insel.ch
Contact: Juliette Wanner, Study Coordinator 0041 31 632 13 70 juliette.wanner@insel.ch

Locations
Switzerland
Dep. of gynaecological Endocrinology and reproduction medicine, Clinic for Gynaecology and Obstetrics, Bern University Hospital Recruiting
Bern, Switzerland, 3010 Bern
Principal Investigator: Petra Stute, PD Dr. med.         
Sponsors and Collaborators
University Hospital Inselspital, Berne
University Hospital Muenster
University of Zurich
Investigators
Principal Investigator: Petra Stute, PD Dr. med. Clinic for Gynaecology and Obstetrics, Insel University Hospital Bern, Switzerland
  More Information

No publications provided

Responsible Party: University Hospital Inselspital, Berne
ClinicalTrials.gov Identifier: NCT01977313     History of Changes
Other Study ID Numbers: 087/13
Study First Received: October 30, 2013
Last Updated: May 19, 2014
Health Authority: Switzerland: Ethikkommission

Additional relevant MeSH terms:
Androgens
Hormones
Hormones, Hormone Substitutes, and Hormone Antagonists
Pharmacologic Actions
Physiological Effects of Drugs

ClinicalTrials.gov processed this record on October 23, 2014