Glossary

A

• Aerobic Performance: Activities involving endurance and cardiovascular exertion, like running and cycling. 

• Anaerobic Performance: Short, powerful bursts of all-out effort, such as sprinting or explosive movements. 

• Androgens: A group of hormones that includes testosterone. While typically having anti-inflammatory effects, in the context of PCOS, high levels of androgens can actually cause immune cells (macrophages) to promote inflammation.

• Anovulation: The failure of the ovaries to release an egg, which is a key feature of Polycystic Ovary Syndrome (PCOS).

• Anti-Müllerian Hormone (AMH): Produced by growing ovarian follicles, it is the most reliable blood marker used to estimate a woman's functional ovarian reserve.

• Arginine Vasopressin (AVP): A hypothalamic neuropeptide closely related to oxytocin that acts as a strong vasoconstrictor and increases fluid retention.

• Autoimmune Thyroid Disease (AITD): Conditions, such as Hashimoto's thyroiditis, where the immune system mistakenly attacks the thyroid gland. There is a significant association between AITD and PCOS.

• Assay: The specific laboratory method or technology (like an immunoassay or mass spectrometry) used to measure the concentration of a hormone or mineral in a sample.

B

• Beige Adipocytes (Beige Fat): Thermogenic cells that form within white adipose tissue. They arise from diverse progenitor populations, including smooth muscle-like and PDGFRα+ cells, and differ from brown adipose tissue in their origins, gene expression, and regulation.

• Beiging (or Browning): The process of forming beige fat or activating thermogenic responses, which can be triggered by cold exposure and is influenced by environmental and hormonal cues. Females typically exhibit a more robust browning response to cold exposure than males.

• Bisphenol A (BPA): A ubiquitous chemical found in plastic containers and canned goods that acts as an endocrine disruptor by mimicking hormones in the body.

• Blood-Brain Barrier (BBB): A  tightly locked layer of cells that defend your brain from harmful substances, germs and other things that could cause damage. 

• Brown Adipose Tissue (BAT): An active metabolic organ and thermogenic tissue. Females generally have higher BAT volume and more efficient thermogenic activity than males. BAT activity is associated with a lower risk of cardiovascular disease, type 2 diabetes, and inflammation.

C

• Calcitonin Gene-Related Peptide (CGRP): A sensory neuropeptide produced and stored in the neurons of the trigeminal ganglion. 

• Chronic Low-Grade Inflammation: A state where the body's immune and metabolic systems are constantly activated at a low level. PCOS is now fundamentally understood as a condition characterized by this type of body-wide inflammation.

D

• Dysbiosis: An imbalance of microbes within the body's ecosystems, such as in the gut or the vagina. Research indicates a clear link between dysbiosis and PCOS.

E

• Endocrine Disruptor: A chemical that interferes with the body's sensitive hormone signaling pathways.

• Epigenetic Modifications: Changes that alter how genes are expressed without changing the underlying DNA sequence. Harmful changes caused by fetal BPA exposure can potentially be passed to future generations through these modifications.

• Estradiol (E2): The primary estrogen produced by the ovaries, responsible for thickening the uterine lining and regulating the release of FSH and LH.

• Estrogen Receptor Alpha (ERα): A receptor through which estrogen primarily acts to increase UCP1 expression, promote mitochondrial biogenesis, and support the formation of beige fat within white adipose tissue.

F

• Follicular Phase: The first half of the menstrual cycle, starting on day one of a period and lasting until ovulation. It is characterized by rising estrogen levels and low progesterone.

• Follicle-Stimulating Hormone (FSH): A hormone produced by the pituitary gland that stimulates the ovaries to grow follicles and mature an egg for ovulation.

G

• Glucuronidation Pathway: A critical process the body uses to neutralize and excrete toxins. A weakness in this pathway can prevent the body from efficiently clearing out BPA and its own steroid hormones.

H

• Hyperandrogenism: Abnormally high levels of androgens (male hormones). It is a hallmark feature of PCOS that contributes to stubborn adult female acne and immune dysregulation.

• Hypothalamus: The area of the brain that controls body temperature, hunger, and thirst.

I

• Insulin Resistance: A metabolic condition where the body's cells do not respond effectively to insulin, frequently linked to PCOS and low SHBG levels.

• Iron (Ferritin): Critical for oxygen transport to reproductive organs and hormone synthesis, with ferritin serving as the primary measure of the body's stored iron.

L

• Luteal Phase: The second half of the menstrual cycle, beginning after ovulation and lasting until the next period. This phase is defined by high levels of progesterone and a second, lower peak of estrogen.

• Luteinizing Hormone (LH): A pituitary hormone that triggers ovulation and stimulates the ovaries to produce steroid hormones.

M

• Magnesium: A mineral acting as a cofactor for hundreds of enzymes, regulating insulin sensitivity, estrogen metabolism, and smooth muscle relaxation in the uterus.

O

• Obesogen: An endocrine-disrupting chemical that can predispose the body to store fat and promote obesity by interfering with metabolic programming. 

• Oestrogen (Estrogen): Any of a group of steroid hormones that regulate sexual development and function, including maintenance of the menstrual or estrus cycle, in women

• Ovarian Reserve: The remaining quantity and quality of a woman's resting follicles (egg supply), which naturally declines with age.

• Oxytocin: A hormone released by the pituitary gland that causes increased contraction of the uterus during labor and stimulates the ejection of milk into the ducts of the breasts.

P

• Progesterone: A hormone secreted after ovulation that prepares and stabilizes the uterine lining so an embryo can successfully implant.

• Prolactin: A hormone responsible for milk production; excess levels can inhibit ovulation signals, causing irregular or absent periods.

• PCOS (Polycystic Ovary Syndrome): A common endocrine and metabolic disorder characterized by irregular ovulation, excess androgens, and specific ultrasound findings of the ovaries.

R

• Receptor Activity-Modifying Protein 1 (RAMP1): An essential protein component of the CGRP receptor. Its gene expression fluctuates depending on the female reproductive cycle and is directly regulated by oestrogen, acting as a crucial molecular link connecting hormonal changes to migraine susceptibility.

S

• Selenium: An antioxidant crucial for converting thyroid hormones into their active form and protecting ovarian follicles from oxidative damage.

• Sex Hormone-Binding Globulin (SHBG): A liver-produced protein that binds to sex hormones (like testosterone), controlling how much active, "free" hormone circulates in your bloodstream.

T

• Testosterone (Total and Free): For women, an androgen produced by the ovaries and adrenal glands that acts as a precursor to estradiol and influences follicle maturation and libido.

• Thermogenesis: The process of heat generation by brown and beige fat. 

• Thyroid Hormones (TSH, Free T4): Hormones that regulate the body's metabolism; their dysfunction is a common cause of ovulatory and menstrual disturbances.

• Trigeminal Ganglion (TG): A cluster of nerve cell bodies within the trigeminovascular system that contains pain-signaling neurons responsible for producing CGRP. It is densely populated with receptors for oestrogen, progesterone, oxytocin, and vasopressin.

• Trigeminal Nucleus Caudalis (TNC): A brainstem structure that serves as the central hub for receiving peripheral sensory and pain input from the head and face.

• Trigeminovascular System (TGVS): A sensory neural network that connects peripheral cranial structures to the central nervous system. This system lacks blood-brain barrier protection, making it directly accessible to circulating hormones. 

V

• Ventromedial Prefrontal Cortex (vmPFC): The brain's emotional regulation hub. Under the influence of estradiol, this area of the brain strengthens its activity in response to safe (neutral) cues.

• Vitamin D (25-OH D): A pro-hormone essential for insulin regulation, egg quality, and maintaining a healthy endometrial lining.

Z

• Zinc: A mineral essential for follicle-stimulating hormone (FSH) synthesis, egg maturation, and protecting embryos from oxidative stress.