An interventional study of Breast stimulation in Prolactin and Breast Stimulation, sponsored by University Hospital Tuebingen. Recruiting at 1 site in Germany. Open to female participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-05-14.
Sponsored by University Hospital Tuebingen · Not applicable, Interventional, and Other
Prolactin is a multifunctional hormone which acts in different cell types rather than just modulating reproduction and lactation. One additional point is its action on glucose metabolism which is described especially in rodents. Prolactin affects proliferation, survival and insulin production of pancreatic beta cells in animal models. But also in human studies prolactin is linked to insulin action. Low systemic levels of prolactin are associated with increased prevalence of diabetes and while higher levels are associated with higher insulin sensitivity.
Acute metabolic effects of prolactin in young, healthy and non-lactating women should be accessed. Therefore, the induction of a transient increase of circulating prolactin levels is necessary to study the acute effects of this hormone on metabolic processes. This can most likely be achieved in non-pregnant and non-lactating women without pharmacological intervention.
As the main stimulus of prolactin release from the pituitary gland is the mechanical stimulation of the breast / nipple, like a suckling baby, stimulation by a breast pump might trigger prolactin release.
Due to other studies in this field, only a minority of women respond to breast stimulation with an increase in prolactin levels. Therefore, this pilot study will assess if an electric milk pump can stimulate prolactin release in non-lactating women. The second aim of the study is to identify factors which determine response and non-response to breast stimulation.
Prolactin will be measured in blood serum. The primary objective of this study is to identify women in whom a 30-minute breast stimulation causes a marked prolactin release. Response is defined as an increase at least twice the baseline value.
Second outcomes are the quantification and duration of prolactin increase as well as to detect differences in responders and non-responders. Therefore, demographic data as well as anthropometric data will also be assessed. A 10-minute electrocardiography and non-invasive measurement of resting energy expenditure by indirect calorimetry will also be performed. History of menstrual cycle, intake of contraceptive, parity and lactation experience will be recorded. Physical activity level and feeling of hunger will be assessed by questionnaires.
Feeling of hunger, resting energy expenditure, blood pressure, heart rate and body temperature will be assessed repeatedly to register differences before and after stimulation. Blood and urine samples will be assessed for safety.
University Hospital Tuebingen is the lead sponsor of 476 studies on the registry; 104 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
A 30-minute stimulation with moderate intensity by an electric milk pump (Elvie Pump) will be performed.
Other: Breast stimulation
Breast stimulation by the Elvie Pump to trigger prolactin release.
Prolactin release - yes/no
The primary objective of this study is to identify women in whom breast stimulation causes a marked prolactin release. Response is defined as an increase at least twice the baseline blood value.
Time frame: Sample collection will be from 0 to 90 minutes
Prolactin levels
Quantification, duration and trajectory of prolactin increase will be assessed by measuring prolactin levels in blood
Time frame: Sample collection will be from 0 to 90 minutes
Differences in subjects age
Differences between responders and non-responders will be assessed: differences in age by recording birth date
Time frame: 1 minute
Differences in subjects BMI
Differences between responders and non-responders will be assessed: differences in Body Mass Index by measuring height and weight of subjects and calculate the BMI
Time frame: 4 minutes
Differences in subjects body fat content
Differences between responders and non-responders will be assessed: differences in body fat content by bioelectrical impedance analysis
Time frame: 3 minutes
Differences in subjects menstrual cycle phase
Differences between responders and non-responders will be assessed: differences in phase of menstrual cycle by recording the menstrual history
Time frame: 2 minutes
Differences in subjects intake of hormonal contraception
Differences between responders and non-responders will be assessed: differences in intake of hormonal contraception recording intake of medication
Time frame: 2 minutes
Differences in subjects parity
Differences between responders and non-responders will be assessed: differences in parity by recording family history
Time frame: 2 minutes
Differences in subjects history of lactation
Differences between responders and non-responders will be assessed: differences in history of lactation experience by recording history of lactation
Time frame: 2 minutes
Differences in subjects heart rate variability parameters: time domain (beats per minute)
Differences between responders and non-responders and within subjects will be assessed: differences in the time domain by two 10-minute 3 lead ECG measurements before and after stimulation
Time frame: 10 minutes
Differences in subjects heart rate variability parameters: Root Mean Square of successive RR interval differences (RMSSD)
Differences between responders and non-responders and within subjects will be assessed: differences in RMSSD by two 10-minute 3 lead ECG measurements before and after stimulation
Time frame: 10 minutes
Differences in subjects heart rate variability parameters: Standard deviation of RR-intervals (SDNN)
Differences between responders and non-responders and within subjects will be assessed: differences SDNN by two 10-minute 3 lead ECG measurements before and after stimulation
Time frame: 10 minutes
Differences in subjects heart rate variability parameters: frequency domain parameters
Differences between responders and non-responders and within subjects will be assessed: differences in low (LF) and high (HF) frequency power by two 10-minute 3 lead ECG measurements before and after stimulation
Time frame: 10 minutes
Differences in subjects heart rate variability parameters: Low to high frequency power ratio
Differences between responders and non-responders and within subjects will be assessed: differences in LF/HF - Ratio by two 10-minute 3 lead ECG measurements before and after stimulation
Time frame: 20 minutes
Differences in subjects physical activity level
Differences between responders and non-responders will be assessed: differences physical activity level by questionnaire including the baecke index
Time frame: 10 minutes
Differences in subjects stress reaction
Differences between responders and non-responders will be assessed: differences in stress, measured by cortisol levels in blood
Time frame: Sample collection will be from 0 to 90 minutes
Changes in feelings of hunger through stimulation
Register change of feeling of hunger before and after stimulation by 15 questions on a five-point Likert scale survey about food cravings (FCQ-S)
Time frame: 10 minutes
Changes in resting energy expenditure through stimulation
Register change of resting energy expenditure before and after stimulation by indirect calorimetry
Time frame: 30 minutes (each 15 minutes)
Changes in blood pressure through stimulation
Register changes in blood pressure before and after stimulation using an automatic instrument with a digital readout
Time frame: 4 minutes
Changes in heart rate through stimulation
Register changes in heart rate before and after stimulation using an automatic instrument with a digital readout
Time frame: 4 minutes
Changes in body temperature through stimulation
Register changes of body temperature before and after stimulation by an ear thermometer
Time frame: 1 minute
Changes of Hypothalamic-Pituitary-Adrenal axis activity
Changes in Corticotropin levels are assessed by measurement in blood
Time frame: 90 minutes
Changes of Hypothalamic-Pituitary-Somatotropic axis activity
Changes in Somatotropin and insulin-like growth factor 1 levels are assessed by measurement in blood
Time frame: 90 minutes
Changes of Hypothalamic-Pituitary-Prolactin axis activity
Changes in Prolactin levels are assessed by measurement in blood
Time frame: 90 minutes
Changes of Hypothalamic-Pituitary-Thyroid axis activity
Changes in levels of Thyroid-stimulating hormone, Triiodthyronine and Thyroxine are assessed by measurement in blood
Time frame: 90 minutes
Changes of Hypothalamic-Pituitary-Gonadal axis activity
Changes in levels of Follicle stimulating hormone, Luteinizing hormone, estradiol and progesterone are assessed by measurement in blood
Time frame: 90 minutes
Plan to share: No — There is no plan to make individual participant data available to other researchers.
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University Hospital Tuebingen