The endocrine system is not only glands internal secretion, but also individual cells that synthesize hormones and hormone-like substances. These cells (we talked about them earlier) are called APUD and are scattered throughout the body - they are also in the skin. So the skin is not only a target for the effects of hormones, but also an independent endocrine organ. We understand what hormonal processes occur in the skin and how hormones affect its condition.
Text: Evdokia Tsvetkova, endocrinologist, leading
telegram channel "Endonovsti", Daria Kibalina, dermatologist
The fact that the endocrine system can affect the condition of the skin is no surprise. The skin is sensitive to hormones of the adrenal glands, pituitary gland, thyroid gland, gonads - they regulate melanin synthesis, hair growth, sebum secretion, cell division and collagen synthesis. But the skin itself is an organ that is actively involved in endocrine regulation. Therefore, what happens to her (for example, an illness or a burn) can affect hormone levels. The skin produces hormones that regulate the work of other glands, including the adrenal glands, control the production of skin pigment, and have analgesic and anti-stress effects. In addition, important transformations of some substances into others take place in the skin - for example, testosterone is converted into dehydrotestosterone, androgens - into estrogens, thyroxine - into triiodothyronine.
Androgens and acne
The skin contains enzymes that are involved in the metabolism of sex hormones. This means that even if their amount in the blood is normal, the level of hormones in the skin may deviate from the desired level due to a lack of such enzymes. This quickly affects her condition - which is why she changes so much during periods of hormonal changes such as puberty or menopause, with endocrine diseases or after surgical removal of the genital glands.
Androgens, traditionally referred to as male sex hormones, contribute to the development of alopecia, seborrhea and acne. This happens because because of them, the hair follicles on the head die off and the production of sebum increases. The sebaceous glands are very sensitive to androgens - they are activated if testosterone becomes in excess. So the sebum becomes larger, it mixes with the keratinized skin scales and clogs the pores - as a result, blackheads and comedones are formed. At the same time, favorable conditions may appear for the growth of bacteria that cause acne - Propionibacterium acnes.
This can happen not only in adolescents, but also in adults, for example, in the second phase of the menstrual cycle. Before menstruation, the level of steroid hormones - the precursors of testosterone - rises in the body, and they start the processes that lead to a rash on the face. So although a dermatologist is often consulted with complaints of acne, in some cases it is an endocrinologist who can help.
Androgens also affect the hair follicles. Cheeks and temples, the area above the upper lip and chin, chest, lower abdomen, inner thighs, back and lower legs are areas where hair growth depends on the level of androgens. If they are in excess, the typical woman may develop hirsutism, when facial and body hair grows in a typical male pattern, or androgenetic alopecia, when hair falls out on the scalp. In men, such alopecia is considered a physiological condition, in women it is a sign of endocrine disorders. Symptoms of hyperandrogenism (acne, seborrhea, hirsutism) are observed in 10-30% of women.
How skin changes during the menstrual cycle
The skin can be affected by a violation of the production of estrogens, usually called female sex hormones: when they are deficient, aging processes are accelerated, hair begins to grow more actively in hormone-dependent zones, and with an excess, pigmentation can increase. But the fluctuations in hormone levels associated with the menstrual cycle also affect the condition of the skin.
The menstrual cycle is divided into two phases: follicular and luteal. In the first, follicular, phase, the follicle containing the egg gradually matures and begins to prepare for ovulation. During this phase, estrogen levels are still low, while androgens, on the contrary, are at their peak. The skin becomes oily under the influence of the latter, acne may worsen. But the ovarian follicles continue to grow and begin to produce estrogens - at this moment, the synthesis of hyaluronic acid increases in the skin, which makes it moisturized and elastic. Finally, in the middle of the menstrual cycle, the pituitary gland begins to produce luteinizing hormone - the hormone of ovulation. The follicle first rounds up as much as possible, and then bursts, and the egg comes out of it. At this time, the skin of the face looks the most radiant.
Immediately after ovulation, the second phase begins - luteal, which continues until the next menstruation begins. During this phase, in the ovary, at the site of the bursting follicle, a corpus luteum is formed, which produces progesterone. This hormone promotes fluid retention - so that by the start of your period your weight may increase and your face may look puffy. At the same time, the epidermis becomes looser, the skin, in order to protect itself, produces an increased amount of sebum, and acne may appear again. If fertilization does not occur, then the corpus luteum is depleted and dies, the level of progesterone decreases with it, and the cycle begins again.
According to Inna Tsvetkova, a dermatologist and cosmetologist at the ROSH clinic, when planning procedures, you can take into account the phase of the cycle - for example, pain sensitivity is often increased in the luteal phase (5-7 days before the onset of menstruation) and during menstruation. During this period, the fragility of blood vessels and bleeding increase, the risk of bruising is higher. In the evening, the pain threshold and the skin's ability to recover are somewhat reduced. Of course, the pain sensation depends on the general condition, the level of stress and fatigue. There are no uniform rules for everyone, but it is better to carry out interventions against the background of general well-being, and ideally also in the follicular phase of the cycle and during the daytime.
True, these rules do not apply if the patient uses hormonal contraceptives - in this case, the menstrual cycle is absent and the hormone levels do not fluctuate, which means that there will be no dependence of pain sensitivity on the phase of the cycle. By themselves, contraceptive drugs often balance the condition of the skin, eliminate the manifestations of acne and hirsutism. But they should be prescribed by a gynecologist-endocrinologist, who will take into account all aspects.
What Happens After Menopause
Skin aging processes are associated, in particular, with exposure to ultraviolet radiation and gravity, but during menopause an important additional factor appears - a decrease in estrogen levels. At the same time, the risks of cardiovascular diseases or bone fractures increase - against their background, skin aging is often not taken seriously, especially since it seems natural. But it is important to understand that the processes in the skin reflect what happens in other hormone-dependent tissues - that is, the skin can serve as an indicator of overall health.
In women, in the skin, especially the face, legs and genitals, there are a lot of estrogen receptors - and due to the lack of the latter, the so-called menopausal, or hormonal, aging occurs. It is expressed in the thinning of the skin, the breakdown of collagen and elastin fibers, the processes of keratinization and exfoliation of the epidermis are disrupted.The synthesis of collagen and hydrophilic glycosaminoglycans is suppressed - substances that give the skin smoothness and elasticity and help it maintain the face contour. If there is less estrogen and androgens are still active, then the skin becomes oily, acne or facial hair may appear.
Estrogens partially regulate the growth of capillaries in the skin - when they are deficient, blood flow decreases, and less oxygen and nutrients enter the skin. It becomes thinner, and due to increased moisture loss - and drier; wrinkles appear, pigmentation changes, lipid synthesis is disrupted. To exclude the effects of photoaging, a histological analysis of abdominal skin samples was carried out (it is less likely to be under the sun). It turned out that the content of type I collagen in the skin decreases from the age of forty, but especially sharply - after the onset of menopause: by 30% in the first five years, and then by 2.1% per year. With age, the arrangement of collagen fibers becomes less and less ordered - and this leads to the appearance of first superficial and then deep wrinkles.
For skin changes associated with menopause, hormone replacement therapy, that is, estrogen preparations, is very effective. They reduce the oiliness of the skin, reduce the appearance of acne, inhibit the growth of facial hair, give the skin elasticity, slow down the aging process, and eliminate dryness. But these drugs are not prescribed solely because of dissatisfaction with the appearance of the skin - the indications for them are somewhat more serious. Such therapy should be prescribed if a woman is concerned about hot flashes, sweating with mood changes and sleep disturbances. Other indications are frequent cystitis, urinary retention disorders, dryness and itching in the vulva and impairment of sex life, osteoporosis or a high risk of developing it, premature, early or surgical (removal of the ovaries) menopause.
Another option to help improve skin condition when there is no indication for menopausal hormone therapy is topical dehydroepiandrosterone (DHEA) medications. This substance is a precursor of sex steroid hormones, which is converted into androgens and estrogens by enzymes. The skin contains these enzymes, so DHEA becomes a local source of estrogen. DHEA preparations at a concentration of 0.3% are applied to the skin and increase collagen production, reduce the activity of enzymes that destroy proteins, slightly increase sebum production - as a result, the dermal layer becomes denser, and the epidermis becomes more hydrated.
Often they talk about phytoestrogens - substances of plant origin, somewhat similar in structure to estrogens. They are found in red clover, soybeans, alfalfa, flax, licorice, red grapes, and hops. True, at present there is no evidence of their hormone-like action. Studies were conducted either in animals or in extremely small groups of people and were short-lived. But no side effects have been identified, so these substances will not cause harm.
Inna Tsvetkova notes that many cosmetic procedures (for example, peels and resurfacing) are based on dosed damage to the skin and its subsequent healing. If the healing processes are disrupted due to estrogen deficiency in postmenopausal women, it is important to think about whether it is advisable to carry out the procedure at all; it may be necessary to correct the estrogen deficiency first with hormonal therapy or topical DHEA.
Melatonin and circadian rhythms
Diurnal, or circadian, rhythms are present in all living organisms - they help to adapt physiology and behavior to day and night. In a person, during a day, not only a change from sleep to wakefulness occurs - eating behavior, hormone secretion, blood pressure, and body temperature change. Leather is no exception. Skin parameters such as temperature, barrier properties, microcirculation, pain sensitivity, itching, sebum production, pH change with time.Thus, in typical women, cutaneous microcirculation reaches its peak at night. Sebum production is at its maximum at noon, skin pH decreases at night (becomes more acidic) and rises during the day. The temperature of the skin changes during the day, while on the face it reaches its maximum in the early morning. Recovery of skin damage slows down from 20:00 to 23:00, and by three in the morning, on the contrary, reaches a peak.
All types of skin cells have a similar clockwork, but the most pronounced one is in the cells of hair follicles, in the so-called secondary growth zone. These are the cells that are activated first before the hair shaft begins to form; the activity of the circadian cells of the hair follicles quite accurately repeats the periods of wakefulness and sleep of a particular person.
It is known that wild mammals have a seasonality of hair growth - it depends on the activation of genes that regulate circadian rhythms. Certain changes in hair (gray hair and shedding) are common symptoms of aging in mammals. Having linked all these data, scientists suspected that circadian genes may be involved not only in the regulation of circadian rhythms. They are involved in processes such as DNA repair or regulation of the accumulation of reactive oxygen species in cells, which means they are likely participants in the aging process.
With sleep disturbances or working at night, the activation of circadian genes is lost, and this affects health: body weight and waist circumference increase, cell tolerance to glucose and insulin sensitivity decrease. The same shift occurs in the skin and hair, but has not yet been studied in detail. When sufficient data is available, it can be used to improve the condition of the skin and hair, or, for example, indirectly diagnose metabolic disorders.
The main hormone in circadian rhythms is melatonin. It is produced in the pineal gland, cells of the retina, brain, intestines, thymus, in the placenta and, of course, in the skin. It is already known that melatonin is an antioxidant, photoprotector and circadian synchronizer; it helps to overcome the effects of circadian rhythm disturbances associated with lack of sleep, shift work or flights. Perhaps in the future it will be able to be used for cosmetic purposes as well.
Does the skin shine
from the "hormone of happiness"
Endorphins are hormones that, during stress or arousal, bind to opioid receptors, dulling pain or euphoria. They are produced in the adrenal glands and central nervous system - and also in the skin. There are receptors for endorphins on the surface of various skin cells - keratinocytes, melanocytes and fibroblasts. Activation of these receptors affects cell movement, accelerates wound healing and increases collagen synthesis; endorphins in the skin can dull the sensitivity of nerve fibers, increasing the pain threshold. One of the ways to stimulate the production of endorphins is massage; however, synthesis in this case occurs in the central nervous system, but stimulates its signals coming from the skin.
While there is no convincing data on the action of cosmetics with an endorphin-like effect - but they are being studied. For example, a peptide called calmosensin has been developed, which is even called the "feel good peptide." Clinical studies have shown that when it is applied to the skin, the sensitivity to irritating factors: temperature, mechanical, chemical, is dulled. Therefore, it can be used in cosmetics for dry or sensitive skin, skin with impaired barrier properties, as well as in after-sun products. Extracts of some plants also have endorphin-like activity - for example, the components of the sacred vitex plant are able not only to bind to opioid receptors, but also to stimulate the production of endorphins in the skin.
How the skin changes
with endocrine diseases
One of the most important hormones is somatotropin (growth hormone), which is responsible for the lengthening of bones in children and adolescents, that is, the growth of the body in length.A protein is synthesized in the skin and liver that helps realize these effects - it is called insulin-like growth factor-1 (IGF-1). In addition to bone growth, these substances have other important functions. They play an important role in the processes of skin repair, increase the resistance of cells and slow down their natural death. IGF-1 is involved in the regulation of fat synthesis and stimulates the development of skin cells - fibroblasts. With age, IGF-1 levels decrease - and this contributes to skin aging as its thickness decreases and the production of protective lipids decreases. IGF-1 also helps estrogen to exert its effects in the skin.
Excess and deficiency of growth hormone are the result of problems with the pituitary gland. In addition to the obvious consequences in the form of excess growth or, conversely, lagging behind, these disorders are reflected in the condition of the skin. With an excess of growth hormone, it becomes thick, loose, with deep grooves, especially pronounced on the forehead, the pads of the fingers and toes thicken, and the nails become brittle. Growth hormone deficiency is characterized by pale, thin, dry skin with reduced sebum production. Perhaps the appearance of fine wrinkles and loss of pubic and axillary hair - in this case, treatment with growth hormone makes the skin denser and thicker.
The thyroid gland synthesizes two hormones - thyroxine (T4) and triiodothyronine (T3), the molecules of which differ from each other by one iodine atom. Thyroxine is an inactive substance, and it is converted into triiodothyronine directly in the cells where it acts. In the skin, these are fibroblasts. True, there are receptors for these hormones in different skin cells and hair follicles. For example, increased stimulation of such receptors in the cells of the sebaceous glands is associated with increased skin oiliness and the development of acne, and decreased stimulation with dry skin. Changes in the skin can occur not only when the synthesis of hormones by the thyroid gland is disrupted, but also when the number of receptors for them changes in the skin itself.
Diseases of the thyroid gland affect the skin: for example, with hypothyroidism (lack of thyroid hormones), the skin can become dry, flaky, itchy. Other characteristic symptoms are brittle nails, brittle hair, loss of the outer third of the eyebrows. With hyperthyroidism, the skin can be hot and moist, very sensitive to touch, there are foci of hyperpigmentation, the hair becomes thinner, the nails become soft, shiny, and their growth is accelerated. The hydration of the epidermis is also affected by thyroid-stimulating hormone - the pituitary hormone that controls the work of the thyroid gland; however, the mechanism of this influence is not yet clear.
Adrenal cortex hormones affect the skin condition very strongly; in particular, their excess, hypercortisolism, leads to pathological thinning of the skin, easy bruising, hirsutism and acne. Multiple purple or pink striae (stretch marks) appear on the skin of the abdomen, fatty tissue is redistributed on the face and neck, the face becomes round, spider veins appear on the skin. With adrenal insufficiency, hyperpigmentation of the skin and mucous membranes is possible - first of all, it is noticeable above the joints, for example, on the elbows and on the bends of the fingers. Pigmented streaks may appear on the nails. However, remember: a doctor should make a diagnosis based on a whole set of data, and not on isolated symptoms - so you should not panic over the fragility of nails alone.
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