Effects of menopause and hormone replacement therapy on glucose metabolism and weight regulation
Research by Monash University.
The menopausal transition is associated with increased susceptibility to weight gain and the development of type 2 diabetes. Within the body there are different types of fat tissue, including white and brown fat. White fat stores energy and expands when people gain weight. Brown fat; however, uses energy by producing heat. Brown fat is also involved in the metabolism of glucose and therefore provides a link between weight gain and the development of type 2 diabetes. We predict that a change in brown fat activity may underpin the increase in weight gain that occurs at menopause.
This study aims to determine measure brown fat activity in individuals with ovaries across different stages of reproductive life. The study will determine whether a decline in brown fat activity occurs at menopause and whether menopausal hormone therapy (MHT; previously known as hormone replacement therapy (HRT)) can reverse this. Thermogenesis or heat production in brown fat can be assessed by measuring skin temperature. This project will use thermal imaging to measure skin temperature of the neck and collarbone region, which is the primary site of brown fat tissue in adults. This study will determine whether changes in ovarian steroids, either across the menstrual cycle, at menopause or with MHT, impact on brown fat activity in response to two physiological stimuli – cold exposure and glucose consumption. It will provide further understanding as to why individuals become more susceptible to weight gain at menopause.
Who can participate in the study?
Peri-menopausal participants (40-50 y/o). Peri-menopause is the stage of natural transition towards menopause where ovarian hormones begin to decline. It is often noted due to the irregular nature of menstrual cycle. Participants in the peri-menopausal group will be non-MHT users.
Post-menopausal participants (50-60 y/o). Post-menopause is classified as the absence of menstruation for 1 year. We will recruit post-menopausal individuals that are both users and non-users of MHT. Further details on who can participate can be found in the attached plain language statement.
What does participation involve?
You will be required to have 2 visits, (possibly 3) to the Department of Physiology at Monash University (26 Innovation Walk, Clayton VIC 3168). Full details on these visits can be found in the attached plain language statement.
How much time is required?
The first visit will take 1 hour of your time. Visits 2 and/ or 3 will take approximately 3-3.5 hours each. Participation in this study will therefore take up to 4 hours if the participant opts to attend two laboratory visits. All three laboratory visits will required 8 hours.
Possible benefits and risks to participants
Thermal imaging cameras operate via the detection of infrared electromagnetic radiation and are considered completely safe. The use of cold (15°C) water to induce heat production within the body can be a source of discomfort; however, the duration of this state will be transient and is only done to achieve an appropriate change in brown fat heat production.
A 15mL blood sample will be collected on Visit 2 and/ or Visit 3. This is less than the amount that is required in blood donations (which is greater than 400ml). The blood will be acquired through the antecubital vein (inner elbow). After which, a cotton bud will be applied with pressure to limit bleeding. This is a regular medical practice with few risks, although the main risk is that if inadequate pressure is applied following needle removal from the vein, some internal bleeding may occur which can lead to bruising and discomfort. The small tear imposed on the vein by the needle can also, on rare occasions, cause a small blood clot to form; however, this normally dissolves quickly. Infection occurrence at the site of venepuncture is very rare.
Payment
A gift card to the value of $150.00 will be provided after visits 1 and 2 or visits 1 and 3 as a reimbursement for the participant's given time. Additional $100 (total $250) will be provided if the participant chooses to complete all three laboratory visits.
Confidentiality
Participants will be identified by a code ensuring the anonymity of the data collected. The infrared images will be taken at a distance of 1 meter in which only the upper chest and neck will be visible, with all effort taken to exclude the face from the image and ensure that individuals cannot be identified from the pictures. If published, only summary statistics will be made known, and some select images will be presented.
Project ID: 32642