Transgender PersonsNCT07148921
Perception of Pain During Gender Affirming Hormone Therapy
An observational study of Transgender Persons and Pain Threshold, run by Medical University of Vienna at 1 site in Austria.
Trial summary
It is known from the literature that women and men differ in their perception of pain. Why this is the case has not been conclusively clarified. Sex hormones could have a significant influence on this. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Transgender Persons, Pain Threshold, Perception of Pain
- What is being tested?
- Quantitative Sensory Testing, Patient Health Questionnaire 9 and Hormone concentrations
- How many people
- 40 participants
- Where
- 1 siteAustria
- Study dates
- 1 Dec 2024to Mar 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: The study population will consist of adult participants, who must meet all of the prespecified inclusion criteria to be eligible for inclusion in the study and must not meet any of the prespecified exclusion criteria.
Who may be able to join
- ≥ 18 years of age
- Assigned female at birth (AFAB)
- Diagnosed gender identity disorder/gender dysphoria and planned therapy with testosterone OR
- ≥ 18 years of age
- Assigned male at birth (AMAB)
- Diagnosed gender identity disorder/ gender dysphoria and planned therapy with estradiol
Who cannot join
- Any sex hormone intake during the last 6 months
- Acute or chronic pain
- Polyneuropathy
- Diagnosis of alcohol or drug addiction
- BMI under 18 or over 35
- Pregnancy
Show all 9Show fewer
- Breastfeeding
- Pharmacological analgesic therapy within the previous 7 days before each examination
- History of significant trauma or surgery to the hands with residual neurological deficit or pain.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Austria1 site, 1 recruiting
- Recruiting
Mecial University of Vienna
Vienna, State of Vienna, 1090
Monika Dille, MA, +43 (0)1 40400-41300, monika.dille@meduniwien.ac.at
About this study
Official title: Changes in Pain and Perception Thresholds Due to Gender Affirming Hormone Therapy: a Prospective Exploratory Cohort Study
It is known from the literature that women and men differ in their perception of pain. Why this is the case has not been conclusively clarified. Sex hormones could have a significant influence on this. The study team suspects that the classic hormone status of women is responsible for the lower pain threshold compared to men.
People undergoing gender affirming therapy receive biologically opposite-sex hormones in order to adapt their external appearance as well as their voice, emotional life etc. to the desired gender. The aim of this study is to longitudinally record whether the intake of opposite-sex sex hormones leads to a change in pain and perception thresholds in this patient collective. To this end, potential study participants will be informed about the study and asked whether they would like to participate before the start of hormone therapy during their first visit to the transgender outpatient clinic.
If consent is given, a questionnaire on mental health (PHQ 9), a blood sample to determine the hormone status and the first QST (quantitative sensory testing) measurement are then carried out. The second measurement with blood sampling takes place 3-4 weeks after the first measurement. The 3rd and 4th measurements with blood sampling are taken 3 and 6 months respectively after the first measurement. The PHQ 9 is measured again at the time of the last measurement. Study participation ends after a total of 6 months. The blood samples, the PHQ 9 and the QST measurements have no influence on the treatment of the study participants.
- Conditions
- Transgender Persons, Pain Threshold, Perception of Pain, Sex Hormones
- Being tested
- Quantitative Sensory Testing, Patient Health Questionnaire 9, Hormone concentrations
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Quantitative Sensory TestingDiagnostic test
Quantitative sensory testing (QST) is a psychophysical test procedure. With the help of calibrated stimuli and subjective sensory information, the functional state of the somatosensory system of a subject or patient is examined with regard to the expression of clinical signs.
The test includes:
- Cold detection threshold
- Warm detection threshold
- Paradoxical heat sensation
- Cold pain threshold
- Heat pain threshold
- Mechanical detection threshold
- Mechanical pain threshold
- Mechanical pain sensitivity
- Dynamic mechanical allodynia
- Wind-up phenomena
- Vibration threshold
- Pressure pain threshold
Patient Health Questionnaire 9Diagnostic test
The Patient Health Questionnaire 9 (PHQ-9), a validated and internationally used health questionnaire, will also be completed twice at the first study day before the sex hormone therapy is initiated and during the last study day in month 6. The questionnaire consists of 9 items on the topic of mental well-being.
Hormone concentrationsDiagnostic test
Blood concentrations of the following laboratory parameters will be determined:
- Follicle stimulating hormone (FSH)
- Luteotropic hormone (LH)
- Prolactin (PRL)
- Oestradiol (E2)
- Sex hormone-binding globulin (SHBG)
- Testosterone
| Study group | Role | What they receive |
|---|---|---|
| AFAB Group | Transgender men and transmasculine individuals Receives: Diagnostic Test: Quantitative Sensory Testing; Diagnostic Test: Patient Health Questionnaire 9; Diagnostic Test: Hormone concentrations | |
| AMAB Group | Transgender women and transfeminine individuals Receives: Diagnostic Test: Quantitative Sensory Testing; Diagnostic Test: Patient Health Questionnaire 9; Diagnostic Test: Hormone concentrations |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cold detection threshold
°C (Arithmetic mean after 3 measurement repetitions) With the Limits Method, the perception and pain thresholds are recorded as the first detected stimulus in the context of increasing stimulus intensities. This test will be performed with the Thermal Sensory Analyzer (TSA II, Medoc).
A thermode equipped with a Peletier element and a cooling water supply is placed on the skin. Then the following parameters are determined using the Limits method:
- Cold detection thresholds
- Heat detection thresholds
- Thermal difference thresholds for the detection of paradoxical heat sensations The contact area of the respective thermodes is 9.0 cm². By pressing a stop switch, which is connected to a computer unit, a threshold value determination can be made after a continuous ascending or descending temperature range with the thermode contact area, starting from a base temperature of 32°C. The temperature changes at a rate of 1°C/s.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Warm detection threshold
°C (Arithmetic mean after 3 measurement repetitions)
With the Limits Method, the perception and pain thresholds are recorded as the first detected stimulus in the context of increasing stimulus intensities. This test will be performed with the Thermal Sensory Analyzer (TSA II, Medoc).
A thermode equipped with a Peletier element and a cooling water supply is placed on the skin. Then the following parameters are determined using the Limits method:
- Cold detection thresholds
- Heat detection thresholds
- Thermal difference thresholds for the detection of paradoxical heat sensations The contact area of the respective thermodes is 9.0 cm². By pressing a stop switch, which is connected to a computer unit, a threshold value determination can be made after a continuous ascending or descending temperature range with the thermode contact area, starting from a base temperature of 32°C. The temperature changes at a rate of 1°C/s.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Thermal sensory limen
°C With the Limits Method, the perception and pain thresholds are recorded as the first detected stimulus in the context of increasing stimulus intensities. This test will be performed with the Thermal Sensory Analyzer (TSA II, Medoc).
A thermode equipped with a Peletier element and a cooling water supply is placed on the skin. Then the following parameters are determined using the Limits method:
- Cold detection thresholds
- Heat detection thresholds
- Thermal difference thresholds for the detection of paradoxical heat sensations The contact area of the respective thermodes is 9.0 cm². By pressing a stop switch, which is connected to a computer unit, a threshold value determination can be made after a continuous ascending or descending temperature range with the thermode contact area, starting from a base temperature of 32°C. The temperature changes at a rate of 1°C/s.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Paradoxical heat sensation
Number of Paradoxical heat sensation out of 3
The paradoxical heat sensations (PHS) can occur during the determination of the TSL (thermal sensory limen) by thrice alternating cold and warm stimuli. A paradoxical heat sensation occurs when the patient expresses heat perceptions during an actual cold stimulus, contrary to what is indicated by the software, or vice versa. In the aforementioned thermal threshold measurement, alternating high and low temperatures are set on the thermode. The study participant does not know the sequence and must recognize the respective tendency. Alternating the temperature changes is done without resetting the initial temperature. PHS has no unit, it is given as a number: PHS 0; 1; 2 or 3, depending on the number of false temperature perceptions.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Cold pain threshold
°C (Arithmetic mean after 3 measurement repetitions) With the Limits Method, the perception and pain thresholds are recorded as the first detected stimulus in the context of increasing stimulus intensities. This test will be performed with the Thermal Sensory Analyzer (TSA II, Medoc).
A thermode equipped with a Peletier element and a cooling water supply is placed on the skin. Then the following parameters are determined using the Limits method:
- Cold detection thresholds
- Heat detection thresholds
- Thermal difference thresholds for the detection of paradoxical heat sensations The contact area of the respective thermodes is 9.0 cm². By pressing a stop switch, which is connected to a computer unit, a threshold value determination can be made after a continuous ascending or descending temperature range with the thermode contact area, starting from a base temperature of 32°C. The temperature changes at a rate of 1°C/s.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Heat pain threshold
°C (Arithmetic mean after 3 measurement repetitions) With the Limits Method, the perception and pain thresholds are recorded as the first detected stimulus in the context of increasing stimulus intensities. This test will be performed with the Thermal Sensory Analyzer (TSA II, Medoc).
A thermode equipped with a Peletier element and a cooling water supply is placed on the skin. Then the following parameters are determined using the Limits method:
- Cold detection thresholds
- Heat detection thresholds
- Thermal difference thresholds for the detection of paradoxical heat sensations The contact area of the respective thermodes is 9.0 cm². By pressing a stop switch, which is connected to a computer unit, a threshold value determination can be made after a continuous ascending or descending temperature range with the thermode contact area, starting from a base temperature of 32°C. The temperature changes at a rate of 1°C/s.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Mechanical detection threshold
mN (geometric mean of 5 even suprathreshold and 5 even subthreshold stimulus strengths)
The mechanical detection threshold is measured with a set of standardized von Frey filaments. The von Frey filaments used in this test are glass fiber filaments with different diameters and varying lengths and with a spherical contact surface of approximately 0.5 mm diameter. The set used for the test consists of filaments with the strengths 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64, 128, 256 and 512 mN. The contact time on the skin surface should be about 2 s during testing. To determine the tactile detection threshold, the geometric mean of 5 straight suprathreshold and subthreshold stimulus strengths is determined using a modified Levels method.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Mechanical pain threshold
mN (geometric mean of 5 even suprathreshold and 5 even subthreshold stimulus strengths) Needle stimulators (Pinprick) are used to determine the mechanical pain threshold. The models used consist of blunt needles with a fixed stimulation intensity of 8, 16, 32, 64, 128, 256 and 512 mN and a blunt circular skin contact surface with a diameter of 0.25 mm. The individual needle stimulators (pinpricks) are applied in 5 series of ascending and descending stimulus intensity with a skin contact time of about 1-2 s at a perpendicular angle to the skin. Likewise in this test, the actual mechanical pain threshold is calculated according to the Levels method as the geometric mean of 5 just above-threshold and 5 just below-threshold stimulus intensities.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Mechanical pain sensitivity
Geometric mean of all numeric values (scale 1-100) Needle stimulators (Pinprick) are used to determine the mechanical pain threshold. The models used consist of blunt needles with a fixed stimulation intensity of 8, 16, 32, 64, 128, 256 and 512 mN and a blunt circular skin contact surface with a diameter of 0.25 mm. The individual needle stimulators (pinpricks) are applied in 5 series of ascending and descending stimulus intensity with a skin contact time of about 1-2 s at a perpendicular angle to the skin. Likewise in this test, the actual mechanical pain threshold is calculated according to the Levels method as the geometric mean of 5 just above-threshold and 5 just below-threshold stimulus intensities.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Dynamic mechanical allodynia
Geometric mean of all numeric values (scale 1-100) A set consisting of the previously described needle stimulators, a cotton swab, a soft brush and a cotton ball will be used to determine the mechanical pain sensitivity of the skin and to detect the presence of any dynamic mechanical allodynia to light touch stimuli. Stimulus-response behaviours to needle stimuli and primarily non-painful, light touch stimuli are sequenced and evaluated. Subjects are asked to rate the perception of the stimulus on a numerical rating scale from 0 to 100 (0= no pain; 100= most pain imaginable). In the same test procedure, the extent of any dynamic mechanical allodynia is also determined, using the cotton ball (3 mN), cotton swab (100 mN) and standardised brush (Somedic, Sweden; 200-400 mN). These 3 tactile stimuli are stroked over the subject's skin by the examiner for about 2 s for at least 2 cm. Again, the subjects rate the stimulus on a numerical scale from 0 to 100.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Wind-up ratio
Wind-up quotient (Sensation intensity of the stimulus series 1Hz/single stimulus) Needle stimulators with an intensity of 256 mN are used to determine the wind-up phenomenon. To determine wind-up, the sensitivity of the skin to a single stimulus is compared with that to a series of stimuli (10 needle stimuli) in the test area. The subject rates on a numerical pain scale the applied stimuli, i.e., the single stimulus and the entire stimulus series. The application of the single stimulus followed by the stimulus series is repeated 5 times. The wind-up quotient is calculated from the ratio of the perceived pain intensity over the stimulus series divided by the pain intensity after the single stimuli.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Vibration detection threshold
Arithmetic mean after 3 measurement repetitions on a 8/8 scale Rydel-Seiffer tuning fork A Rydel-Seiffer tuning fork with a vibration frequency of 64 Hz and an 8/8 scale is used to determine the vibration threshold. To check the threshold values the struck and vibrating tuning fork is placed on the test area, preferably over a bony contact point such as the ankle. The test person indicates when he or she no longer feels the vibrations of the tuning fork. For this point in time, the stimulus intensity is recorded on the scale of the tuning fork. After determining the vibration threshold 3 times, the arithmetic mean of the threshold values can be calculated.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Pressure pain threshold
kPa (Arithmetic mean after 3 measurement repetitions) The measurement of the pressure pain threshold is carried out with the aid of a pressure algometer, on a blunt rubberized contact surface of about 1 cm², with which pressure of 0 to 2000 kPa can be applied. The pressure is gradually increased at a rate of 0.5 kg/cm²-s. The pressure pain threshold is documented as the value in Kpa at which the perception of pressure quality first changes to a painful sensory impression. The pressure pain threshold is calculated as an arithmetic mean after 3 repeated measurements.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Temperature of the skin
°C
The temperature of the skin will be measured with a temperature probe.
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Secondary outcomes (7)
Patient Health Questionnaire 9
Consists of 9 items concerning patient mental well-being. The EQ-5D-5L, a validated and internationally used health questionnaire, will also be completed twice at the first study day before the sex hormone therapy is initiated and during the last study day in month 6. It consists of a page with questions on mobility, self-care, usual activities, pain/discomfort and anxiety/depression as well as an assessment of one's own state of health on a scale of 1-100 (100 = best health you can imagine).
Measured: At the time of enrollment and on the last study day after 6 months.
Hormone concentrations (follicle stimulating hormone)
Laboratory measurement of follicle stimulating hormone (FSH) in mIU/mL
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Hormone concentrations (luteotropic hormone)
Laboratory measurement of luteotropic hormone (LH) in mIU/mL
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Hormone concentrations (prolactin)
Laboratory measurement of prolactin (PRL) in ng/mL
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Hormone concentrations (oestradiol)
Laboratory measurement of oestradiol (E2) in pg/mL
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Hormone concentrations (sex hormone-binding globulin)
Laboratory measurement of sex hormone-binding globulin (SHBG) in nmol/L
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Hormone concentrations (testosterone)
Laboratory measurement of testosterone in ng/mL
Measured: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Aug 2025
- Study start1 Dec 2024
- Primary completionDec 2025 (estimated)
- Study completionMar 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Transgender PersonsStudies of the same condition, open and under way.
- More trials run by Medical University of ViennaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Medical University of Vienna
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Oliver Kimberger, Medical University of Vienna
- Investigators
- Oliver Kimberger, Prof., Principal investigator, Medical University of Vienna, Dept. of Anaesthesiology, Critical Care and Pain Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07148921
- Sponsor's protocol ID
- 1103/2024
- Status last verified
- Aug 2025
- First submitted
- 24 Apr 2025
- Last updated
- 29 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Changes in Pain and Perception Thresholds Due to Gender Affirming Hormone Therapy: a Prospective Exploratory Cohort Study
- ClinicalTrials.gov ID
- NCT07148921
- Acronym / sponsor ID
- 1103/2024
- Conditions
- Transgender Persons, Pain Threshold, Perception of Pain, Sex Hormones
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Medical University of ViennaUniversity, hospital or other
- Study start
- 1 Dec 2024 (actual)
- Primary completion
- Dec 2025 (estimated)
- Study completion
- Mar 2026 (estimated)
- First posted
- 29 Aug 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
It is known from the literature that women and men differ in their perception of pain. Why this is the case has not been conclusively clarified. Sex hormones could have a significant influence on this. The study team suspects that the classic hormone status of women is responsible for the lower pain threshold compared to men.
People undergoing gender affirming therapy receive biologically opposite-sex hormones in order to adapt their external appearance as well as their voice, emotional life etc. to the desired gender. The aim of this study is to longitudinally record whether the intake of opposite-sex sex hormones leads to a change in pain and perception thresholds in this patient collective. To this end, potential study participants will be informed about the study and asked whether they would like to participate before the start of hormone therapy during their first visit to the transgender outpatient clinic.
If consent is given, a questionnaire on mental health (PHQ 9), a blood sample to determine the hormone status and the first QST (quantitative sensory testing) measurement are then carried out. The second measurement with blood sampling takes place 3-4 weeks after the first measurement. The 3rd and 4th measurements with blood sampling are taken 3 and 6 months respectively after the first measurement. The PHQ 9 is measured again at the time of the last measurement. Study participation ends after a total of 6 months. The blood samples, the PHQ 9 and the QST measurements have no influence on the treatment of the study participants.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| AFAB Group | – | Diagnostic Test: Quantitative Sensory Testing, Diagnostic Test: Patient Health Questionnaire 9, Diagnostic Test: Hormone concentrationsTransgender men and transmasculine individuals |
| AMAB Group | – | Diagnostic Test: Quantitative Sensory Testing, Diagnostic Test: Patient Health Questionnaire 9, Diagnostic Test: Hormone concentrationsTransgender women and transfeminine individuals |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The study population will consist of adult participants, who must meet all of the prespecified inclusion criteria to be eligible for inclusion in the study and must not meet any of the prespecified exclusion criteria.
Key inclusion criteria (6 listed)
- ≥ 18 years of age
- Assigned female at birth (AFAB)
- Diagnosed gender identity disorder/gender dysphoria and planned therapy with testosterone OR
- ≥ 18 years of age
- Assigned male at birth (AMAB)
Key exclusion criteria (9 listed)
- Any sex hormone intake during the last 6 months
- Acute or chronic pain
- Polyneuropathy
- Diagnosis of alcohol or drug addiction
- BMI under 18 or over 35
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Quantitative Sensory TestingQuantitative sensory testing (QST) is a psychophysical test procedure. With the help of calibrated stimuli and subjective sensory information, the functional state of the somatosensory system of a subject or patient is examined with regard to the expression of clinical signs. The test includes: * Cold detection threshold * Warm detection threshold * Paradoxical heat sensation * Cold pain threshold * Heat pain threshold * Mechanical detection threshold * Mechanical pain threshold * Mechanical pain sensitivity * Dynamic mechanical allodynia * Wind-up phenomena * Vibration threshold * Pressure pain threshold | Diagnostic test | AFAB Group, AMAB Group |
| Patient Health Questionnaire 9The Patient Health Questionnaire 9 (PHQ-9), a validated and internationally used health questionnaire, will also be completed twice at the first study day before the sex hormone therapy is initiated and during the last study day in month 6. The questionnaire consists of 9 items on the topic of mental well-being. | Diagnostic test | AFAB Group, AMAB Group |
| Hormone concentrationsBlood concentrations of the following laboratory parameters will be determined: * Follicle stimulating hormone (FSH) * Luteotropic hormone (LH) * Prolactin (PRL) * Oestradiol (E2) * Sex hormone-binding globulin (SHBG) * Testosterone | Diagnostic test | AFAB Group, AMAB Group |
Primary outcome
Cold detection threshold
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
°C (Arithmetic mean after 3 measurement repetitions) With the Limits Method, the perception and pain thresholds are recorded as the first detected stimulus in the context of increasing stimulus intensities. This test will be performed with the Thermal Sensory Analyzer (TSA II, Medoc). A thermode equipped with a Peletier element and a cooling water supply is placed on the skin. Then the following parameters are determined using the Limits method: * Cold detection thresholds * Heat detection thresholds * Thermal difference thresholds for the detection of paradoxical heat sensations The contact area of the respective thermodes is 9.0 cm². By pressing a stop switch, which is connected to a computer unit, a threshold value determination can be made after a continuous ascending or descending temperature range with the thermode contact area, starting from a base temperature of 32°C. The temperature changes at a rate of 1°C/s.
Warm detection threshold
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
°C (Arithmetic mean after 3 measurement repetitions) With the Limits Method, the perception and pain thresholds are recorded as the first detected stimulus in the context of increasing stimulus intensities. This test will be performed with the Thermal Sensory Analyzer (TSA II, Medoc). A thermode equipped with a Peletier element and a cooling water supply is placed on the skin. Then the following parameters are determined using the Limits method: * Cold detection thresholds * Heat detection thresholds * Thermal difference thresholds for the detection of paradoxical heat sensations The contact area of the respective thermodes is 9.0 cm². By pressing a stop switch, which is connected to a computer unit, a threshold value determination can be made after a continuous ascending or descending temperature range with the thermode contact area, starting from a base temperature of 32°C. The temperature changes at a rate of 1°C/s.
Thermal sensory limen
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
°C With the Limits Method, the perception and pain thresholds are recorded as the first detected stimulus in the context of increasing stimulus intensities. This test will be performed with the Thermal Sensory Analyzer (TSA II, Medoc). A thermode equipped with a Peletier element and a cooling water supply is placed on the skin. Then the following parameters are determined using the Limits method: * Cold detection thresholds * Heat detection thresholds * Thermal difference thresholds for the detection of paradoxical heat sensations The contact area of the respective thermodes is 9.0 cm². By pressing a stop switch, which is connected to a computer unit, a threshold value determination can be made after a continuous ascending or descending temperature range with the thermode contact area, starting from a base temperature of 32°C. The temperature changes at a rate of 1°C/s.
Paradoxical heat sensation
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Number of Paradoxical heat sensation out of 3 The paradoxical heat sensations (PHS) can occur during the determination of the TSL (thermal sensory limen) by thrice alternating cold and warm stimuli. A paradoxical heat sensation occurs when the patient expresses heat perceptions during an actual cold stimulus, contrary to what is indicated by the software, or vice versa. In the aforementioned thermal threshold measurement, alternating high and low temperatures are set on the thermode. The study participant does not know the sequence and must recognize the respective tendency. Alternating the temperature changes is done without resetting the initial temperature. PHS has no unit, it is given as a number: PHS 0; 1; 2 or 3, depending on the number of false temperature perceptions.
Cold pain threshold
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
°C (Arithmetic mean after 3 measurement repetitions) With the Limits Method, the perception and pain thresholds are recorded as the first detected stimulus in the context of increasing stimulus intensities. This test will be performed with the Thermal Sensory Analyzer (TSA II, Medoc). A thermode equipped with a Peletier element and a cooling water supply is placed on the skin. Then the following parameters are determined using the Limits method: * Cold detection thresholds * Heat detection thresholds * Thermal difference thresholds for the detection of paradoxical heat sensations The contact area of the respective thermodes is 9.0 cm². By pressing a stop switch, which is connected to a computer unit, a threshold value determination can be made after a continuous ascending or descending temperature range with the thermode contact area, starting from a base temperature of 32°C. The temperature changes at a rate of 1°C/s.
Heat pain threshold
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
°C (Arithmetic mean after 3 measurement repetitions) With the Limits Method, the perception and pain thresholds are recorded as the first detected stimulus in the context of increasing stimulus intensities. This test will be performed with the Thermal Sensory Analyzer (TSA II, Medoc). A thermode equipped with a Peletier element and a cooling water supply is placed on the skin. Then the following parameters are determined using the Limits method: * Cold detection thresholds * Heat detection thresholds * Thermal difference thresholds for the detection of paradoxical heat sensations The contact area of the respective thermodes is 9.0 cm². By pressing a stop switch, which is connected to a computer unit, a threshold value determination can be made after a continuous ascending or descending temperature range with the thermode contact area, starting from a base temperature of 32°C. The temperature changes at a rate of 1°C/s.
Mechanical detection threshold
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
mN (geometric mean of 5 even suprathreshold and 5 even subthreshold stimulus strengths) The mechanical detection threshold is measured with a set of standardized von Frey filaments. The von Frey filaments used in this test are glass fiber filaments with different diameters and varying lengths and with a spherical contact surface of approximately 0.5 mm diameter. The set used for the test consists of filaments with the strengths 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64, 128, 256 and 512 mN. The contact time on the skin surface should be about 2 s during testing. To determine the tactile detection threshold, the geometric mean of 5 straight suprathreshold and subthreshold stimulus strengths is determined using a modified Levels method.
Mechanical pain threshold
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
mN (geometric mean of 5 even suprathreshold and 5 even subthreshold stimulus strengths) Needle stimulators (Pinprick) are used to determine the mechanical pain threshold. The models used consist of blunt needles with a fixed stimulation intensity of 8, 16, 32, 64, 128, 256 and 512 mN and a blunt circular skin contact surface with a diameter of 0.25 mm. The individual needle stimulators (pinpricks) are applied in 5 series of ascending and descending stimulus intensity with a skin contact time of about 1-2 s at a perpendicular angle to the skin. Likewise in this test, the actual mechanical pain threshold is calculated according to the Levels method as the geometric mean of 5 just above-threshold and 5 just below-threshold stimulus intensities.
Mechanical pain sensitivity
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Geometric mean of all numeric values (scale 1-100) Needle stimulators (Pinprick) are used to determine the mechanical pain threshold. The models used consist of blunt needles with a fixed stimulation intensity of 8, 16, 32, 64, 128, 256 and 512 mN and a blunt circular skin contact surface with a diameter of 0.25 mm. The individual needle stimulators (pinpricks) are applied in 5 series of ascending and descending stimulus intensity with a skin contact time of about 1-2 s at a perpendicular angle to the skin. Likewise in this test, the actual mechanical pain threshold is calculated according to the Levels method as the geometric mean of 5 just above-threshold and 5 just below-threshold stimulus intensities.
Dynamic mechanical allodynia
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Geometric mean of all numeric values (scale 1-100) A set consisting of the previously described needle stimulators, a cotton swab, a soft brush and a cotton ball will be used to determine the mechanical pain sensitivity of the skin and to detect the presence of any dynamic mechanical allodynia to light touch stimuli. Stimulus-response behaviours to needle stimuli and primarily non-painful, light touch stimuli are sequenced and evaluated. Subjects are asked to rate the perception of the stimulus on a numerical rating scale from 0 to 100 (0= no pain; 100= most pain imaginable). In the same test procedure, the extent of any dynamic mechanical allodynia is also determined, using the cotton ball (3 mN), cotton swab (100 mN) and standardised brush (Somedic, Sweden; 200-400 mN). These 3 tactile stimuli are stroked over the subject's skin by the examiner for about 2 s for at least 2 cm. Again, the subjects rate the stimulus on a numerical scale from 0 to 100.
Wind-up ratio
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Wind-up quotient (Sensation intensity of the stimulus series 1Hz/single stimulus) Needle stimulators with an intensity of 256 mN are used to determine the wind-up phenomenon. To determine wind-up, the sensitivity of the skin to a single stimulus is compared with that to a series of stimuli (10 needle stimuli) in the test area. The subject rates on a numerical pain scale the applied stimuli, i.e., the single stimulus and the entire stimulus series. The application of the single stimulus followed by the stimulus series is repeated 5 times. The wind-up quotient is calculated from the ratio of the perceived pain intensity over the stimulus series divided by the pain intensity after the single stimuli.
Vibration detection threshold
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Arithmetic mean after 3 measurement repetitions on a 8/8 scale Rydel-Seiffer tuning fork A Rydel-Seiffer tuning fork with a vibration frequency of 64 Hz and an 8/8 scale is used to determine the vibration threshold. To check the threshold values the struck and vibrating tuning fork is placed on the test area, preferably over a bony contact point such as the ankle. The test person indicates when he or she no longer feels the vibrations of the tuning fork. For this point in time, the stimulus intensity is recorded on the scale of the tuning fork. After determining the vibration threshold 3 times, the arithmetic mean of the threshold values can be calculated.
Pressure pain threshold
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
kPa (Arithmetic mean after 3 measurement repetitions) The measurement of the pressure pain threshold is carried out with the aid of a pressure algometer, on a blunt rubberized contact surface of about 1 cm², with which pressure of 0 to 2000 kPa can be applied. The pressure is gradually increased at a rate of 0.5 kg/cm²-s. The pressure pain threshold is documented as the value in Kpa at which the perception of pressure quality first changes to a painful sensory impression. The pressure pain threshold is calculated as an arithmetic mean after 3 repeated measurements.
Temperature of the skin
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
°C The temperature of the skin will be measured with a temperature probe.
7 secondary outcomes
Patient Health Questionnaire 9
Time frame: At the time of enrollment and on the last study day after 6 months.
Hormone concentrations (follicle stimulating hormone)
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Hormone concentrations (luteotropic hormone)
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Hormone concentrations (prolactin)
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Hormone concentrations (oestradiol)
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Hormone concentrations (sex hormone-binding globulin)
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Hormone concentrations (testosterone)
Time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Aug 2025.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Oliver Kimberger, Prof. principal investigator
Medical University of Vienna, Dept. of Anaesthesiology, Critical Care and Pain Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Transgender Persons and Pain Threshold, run by Medical University of Vienna at 1 site in Austria.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 29 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Austria. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Aylin Bilir, Dr. med. univ. (+43 (0)1 40400-41020, aylin.bilir@meduniwien.ac.at), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Cold detection threshold (time frame: At the time of enrollment and after 3-4 weeks, 3 months and 6 months.). The study lists 14 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Aug 2025.