Women's Health - Sex hormones Flashcards
What is the role of the hypothalamic-pituitary-ovarian (HPO) axis in the female reproductive system?
A: The HPO axis maintains hormonal balance by stimulating the production of LH and FSH, supporting follicle development, ovulation, corpus luteum maintenance, and the production of progesterone, oestrogen, and inhibin.
Q: What does raised oestrogen and testosterone do in the HPO axis?
A: They exert negative feedback over FSH and LH secretion.
Q: What is pregnenolone and where is it synthesised?
A: Pregnenolone is a hormone synthesised from cholesterol in steroidogenic tissues such as the adrenal gland, gonads, and brain by the mitochondrial enzyme CYP11A1.
Q: What are the primary functions of progesterone?
A: Maintains the endometrium for implantation, increases cervical mucus, supports bone health, and aids mammary development.
Q: What can low progesterone lead to, and what are its symptoms?
A: Low progesterone leads to oestrogen dominance. Symptoms include irritability, mood swings, insomnia, and an increased risk of breast cancer.
Q: Name three types of oestrogens and their primary sites of production.
A: Oestrone (E1), oestradiol (E2), and oestriol (E3), produced via aromatase conversion in the ovaries, bone, breast, and adipose tissue.
Q: What is oestrogen dominance and its associated conditions?
A: A state of excess oestrogenic activity. Associated with fibroids, endometriosis, PMS, infertility, breast/ovarian cancers, thyroid dysfunction, and anxiety.
Q: What are the main pathways of phase 1 oestrogen biotransformation?
A: Conversion to 2-OH-E (protective), 4-OH-E (pro-carcinogenic), and 16α-OH-E (highly proliferative).
Q: What enzymes are involved in phase 2 oestrogen metabolism?
A: Sulphation, methylation, or glucuronidation enzymes, including COMT, which deactivate reactive oestrogen metabolites.
Q: What is the oestrobolome, and why is it important?
A: A collection of gut microbes that metabolise oestrogens, maintaining oestrogen homeostasis and reducing oestrogen load.
Q: How can beta-glucuronidase activity be balanced in the microbiome?
A: Increase dietary fibre, calcium D-glucarate, probiotics, and prebiotics; focus on a healthy gut microbiome.
Q: Where is testosterone produced, and what are its primary functions in women?
A: Produced in the ovaries and adrenal cortex. Functions include supporting ovarian density, libido, bone strength, mood, and cognition.
Q: What enzyme converts testosterone to DHT, and how is this pathway regulated?
A: 5α-reductase converts testosterone to DHT. It is upregulated by insulin, inflammation, and obesity, and downregulated by nettle root, saw palmetto, lycopene, turmeric, and zinc.
Q: What is the role of sex hormone-binding globulin (SHBG)?
A: SHBG transports oestradiol, testosterone, and DHT in the blood, ensuring only unbound hormones are biologically active.
Q: What factors can lower SHBG levels?
A: Hyperinsulinemia, obesity, metabolic syndrome, T2DM, hypothyroidism, and PCOS.
Q: What is prolactin, and what are its functions?
A: Prolactin is a hormone that regulates lactation, breast maturation, and menstrual inhibition.
Q: What can cause hyperprolactinaemia in non-pregnant women?
A: High cortisol (stress), pituitary tumours, vitamin D deficiency, circadian disruption, and dopamine antagonist drugs like domperidone.
Q: What stimulates the anterior pituitary to produce and release LH and FSH?
A: GnRH (gonadotropin-releasing hormone).
Q: What hormones are produced by the corpus luteum, and what is its primary function?
A: Progesterone, oestrogen, and inhibin. The corpus luteum supports the endometrium for implantation and early pregnancy.
Q: What is the “pregnenolone steal theory”?
A: It states that high stress increases pregnenolone use for cortisol production, reducing availability for sex hormone production.
Q: What dietary sources support healthy pregnenolone levels?
A: Avocado, flax and chia seeds, olive oil, walnuts, B vitamins, vitamin K, and vitamin D3.
Q: What are some natural ways to balance progesterone levels?
A: Support oestrogen detoxification, increase fibre intake, eat three balanced meals per day, avoid alcohol, and consider magnesium, vitamin C, B6, zinc, and Vitex Agnus castus.
Q: What role does aromatase play in oestrogen production?
A: Aromatase converts androgens into oestrogens in tissues like the ovaries, bone, breast, and adipose tissue.
Q: What receptor types do oestrogens bind to?
A: ERα, ERβ, and GPER (G-protein coupled estrogen receptor).
Q: What are the primary functions of oestrogen?
A: Reproductive tract development, menstrual cycle regulation, cell proliferation, glucose homeostasis, immune robustness, and bone and cardiovascular health.
Q: What are some causes of oestrogen dominance?
A: Synthetic HRT, oral contraceptives, xenoestrogens, heavy metals, obesity, poor liver detoxification, genetic mutations, intestinal dysbiosis, and chronic stress.
Q: How does chronic stress affect the HPO axis?
A: Chronic stress downregulates LH and FSH, leading to decreased ovulation and hormonal imbalances.
Q: What is the difference between 2-OH-E, 4-OH-E, and 16α-OH-E in oestrogen metabolism?
A:
2-OH-E: Weakest and protective form.
4-OH-E: Pro-carcinogenic metabolite.
16α-OH-E: High binding affinity with proliferative effects.
Q: What foods support phase I oestrogen metabolism?
A: Cruciferous vegetables, I3C, turmeric, resveratrol, berries, rooibos tea, and celery.
Q: Which nutrients support methylation in phase II oestrogen metabolism?
A: Folate, vitamins B2, B6, B12, SAMe, and choline.
Q: What are the effects of high beta-glucuronidase activity in the microbiome?
A: Reactivation of oestrogens, leading to increased enterohepatic circulation and oestrogen dominance.
Q: What conditions are associated with high beta-glucuronidase activity?
A: Endometriosis and oestrogen dominance.
Q: How can testosterone levels impact women with PCOS?
A: High testosterone can lead to androgen dominance, causing symptoms like anovulation, hirsutism, and acne.
Q: What factors upregulate and downregulate the conversion of testosterone to DHT?
Upregulate: Insulin, inflammation, and obesity.
Downregulate: Nettle root, saw palmetto, lycopene, turmeric, and green tea.
Q: What conditions are associated with low SHBG levels?
A: Hyperinsulinemia, obesity, metabolic syndrome, T2DM, hypothyroidism, and PCOS.
Q: What role does prolactin play in reproductive health?
A: Prolactin regulates lactation, breast maturation, and menstrual inhibition.
Q: How can stress and high cortisol levels increase prolactin?
A: High cortisol affects dopamine regulation, which can lead to increased prolactin secretion.
