Many friends will find that their necks and armpits are always black, and they can't be washed clean, like this:
Image source: Zhan Kuhailuo
This pigmentation is very uneven, with a fluffy feel to the touch, and sometimes accompanied by skin tags (raised warts):
Image Credits: Ref. 1 (right), Ref. 5 (left)
It often appears in areas that are prone to friction or in skin folds, such as the neck, armpits, groin, etc.
Such a look is really troubling. Many people may use rough bath cloths, bath brushes to rub vigorously, and buy various ointments, whitening essences, and so on online.
However, it is likely that the improvement will not be significant, but will be exacerbated by overstimulation, and even if there is some improvement in the short term, it will rebound quickly.
In fact, this is not an ordinary melanin precipitation, but a "disease state" -
Acanthosis nigricans
Acanthosis nigricans itself is benign and has no other harm than aesthetic effects, but it is a very important "disease signal", which often means that the body's endocrine and metabolic abnormalities have occurred.
Don't ignore the distress signals your body gives you! 🆘
The neck and armpits are black
It is likely to be insulin resistance
That's right, it is the "insulin resistance" antibody that has attracted more and more attention from all walks of life and is considered by many cutting-edge scholars to be the root of all evils of various diseases.
Acanthosis nigricans is a clear sign of "insulin resistance" and is more common in all age groups, with younger people being more prominent. (But not all patients with insulin resistance develop acanthosis nigricans.)
What is insulin resistance?
Insulin is secreted by the pancreas, and its main function is to "deliver" glucose to various organs and tissues throughout the body to supply energy for metabolism.
Image source: Adapted from online images
Insulin resistance is the inability of various organs and tissues to receive glucose delivered by insulin.
Image source: Adapted from online images
This is not a joke, firstly, the organs and muscles lose the sugar supply and cannot metabolize normally, and secondly, the glucose that cannot be sent out is accumulated in the blood vessels, and the body cannot stand the high blood sugar.
So what to do?
The logic of the body is rough and simple, and it must be a dereliction of duty on the pancreas if the sugar is not delivered well, so the pressure is put on the pancreas.
The pancreas can only produce more insulin and let them "collectively pressurize" the cells to shoehorn sugar into it to maintain blood sugar and metabolism homeostasis.
Image source: Adapted from online images
This approach did work, and even stabilized the situation for quite some time, but it came at a cost.
Insulin resistance inevitably leads to a high concentration of insulin in the blood, which is known as "hyperinsulinemia".
The blood, which carries high concentrations of insulin, is transported indiscriminately to all tissues throughout the body, and this is a problem: it doesn't respond where it should respond, and it overresponds where it shouldn't.
For example, in acanthosis nigricans, studies have found that high levels of insulin can stimulate skin keratinocytes, dermal fibroblast proliferation [1], and affect tyrosinase activity [2], resulting in darkened, thickened skin appearance and skin tag formation.
However, acanthosis nigricans is only the tip of the iceberg of the most harmless, physical effects of insulin resistance.
Image source: Zhan Kuhailuo
For insulin resistance, the sooner the intervention is better
The function of insulin is crucial, and the scope of influence involves every cell in the body, and once it goes wrong, many organs and tissues will be affected.
It not only affects blood sugar, but also blood pressure and blood lipids, so metabolic syndrome is also known as "insulin resistance syndrome".
In addition to endocrine diseases, cardiovascular, neurological, reproductive, musculoskeletal and even certain cancers are all closely related to insulin resistance.
For example, polycystic ovary syndrome, which is becoming more common in women, is related to insulin resistance, and common manifestations include excessive body hair, abnormal menstruation, acne and hair loss.
Image source: Zhan Kuhailuo
Insulin resistance is also often associated with obesity, especially abdominal obesity. It affects the metabolism of fat, promotes the growth of fat cells, and prevents its breakdown [3].
This is also why, we often see acanthosis nigra appearing in obese people, not because they don't like to be clean, but because they have metabolic problems.
Obesity and insulin resistance are actually a chicken-and-egg or egg-and-egg problem. Obesity does cause and worsen insulin resistance, but it can also be that insulin resistance precedes and causes obesity.
So, how exactly does insulin resistance come about?
It is related to genetics, and it is inseparable from modern lifestyle.
Insulin resistance in modern people has become very common, and a study showed that the standardized prevalence of insulin resistance in adults aged 25 years and above in China is 29.22%[4], that is, one in every 3~4 people.
Moreover, most people are not visibly manifested. Although Acanthosis nigricans usually means insulin resistance, insulin resistance does not necessarily present with Acanthosis nigricans.
There are few superficial signals of disease, and Acanthosis nigricans is one, which can be said to be a blessing in misfortune.
Our body is very tolerant, and we like to carry any problems by ourselves without telling you, and maintain our operation through various compensatory means until we can't bear it. Many chronic diseases have been carried by the body for 10 to decades before the definite symptoms appear.
If we detect this state early, correct it early, and not let the body help itself, we can greatly delay the onset of chronic diseases.
Let's do it!
If you suspect skin manifestations of acanthosis nigricans, here are some suggestions:
The first step is to go to the hospital for a diagnosis.
Go to the dermatology department or endocrinology department of a regular hospital to register to see if there are any abnormal states of blood sugar, blood lipids, and blood pressure, and girls should judge whether there are polycystic ovaries.
Rarely, acanthosis nigricans is a manifestation of an internal malignancy or is associated with certain drugs and needs to be diagnosed and ruled out by a doctor.
If you have reached the state of illness, you must treat it according to the doctor's instructions.
If you have severe insulin resistance, or if you have problems such as obesity or difficulty losing weight, your doctor may also prescribe medications to help improve your insulin sensitivity.
However, it should be reminded that when it comes to insulin resistance, the current medical treatment has limited effect, and lifestyle modification is more important.
The second step, most basic and important, is to change your lifestyle.
Insulin resistance alone can be largely reversed by lifestyle modifications.
🥗 Eat
1. Eat less refined sugars, high GI foods, ultra-processed foods, and more whole grains and fresh vegetables. The structure of an anti-inflammatory diet can also be helpful:
2. Try to limit your eating time to 8~10 hours, try to eat during the day, and keep your mouth shut at night.
3. Don't go on a long-term diet, the loss of muscle and bones will aggravate the state of insulin resistance, making it easy to rebound from weight loss.
🏃 ♀️ Moving
1. Reduce sedentary time and stand up for a minute or two every half hour.
Muscles are very susceptible to insulin resistance, so don't let your muscles sit idle all the time, move them from time to time and let them take in some sugar.
2. Make it a habit to exercise, as long as you move, it will be useful.
If you don't exercise much, you can start with a simple one, increase your cadence when walking, or go to the gym to climb on the treadmill for 10~15 minutes a day.
3. Increasing resistance training and building muscles can improve insulin sensitivity more efficiently.
You don't have to go to the gym to lift weights as soon as you come up, do some simple bodyweight exercises, such as push-ups and squats, or you can buy a pair of dumbbells with the right weight and follow the videos on the Internet.
😴 Sleep
1. Sleep enough for 7~8 hours a day to ensure sleep quality;
2. Don't turn on the lights while sleeping, even the light from a night light can worsen insulin resistance.
🚭 Rings
Quitting smoking, whether it's smoke in one hand or second-hand smoke, can worsen insulin resistance.
As long as you stick with it, acanthosis nigricans will get better as your insulin resistance slowly improves.
However, this is a long-term process that requires patience, and some friends may want to improve their appearance quickly, so they can try topical skin treatments.
The third step is local improvement.
Topical use of tretinoin cream, adapalene, vitamin D analogues (calcipotriene cream), urea cream, may improve acanthosis nigricans. [1]
However, some ointments are more irritating to the skin, so it is highly recommended to use them under the guidance of a doctor. How to match several ointments, how often to use them, and how to use them will vary from person to person.
Also, be sure not to rub the affected skin too much and try to exfoliate violently, as this can cause lichenification and worsen skin pigmentation. [1]
Insulin resistance is a common test for modern people, and with or without acanthosis nigricans, the life advice in this article is universal.
Remember to forward it to family and friends and we will work together! 💪
This article is reviewed by experts
Planning and production
策划:Deanna | 监制:Feidi
Illustration: See annotation | Cover image source: Zhan Ku Hailuo
bibliography
[1] Up To Date 临床顾问：黑棘皮病.
[2] Torley D, Bellus GA, Munro CS. Genes, growth factors and acanthosis nigricans. Br J Dermatol. 2002 Dec; 147(6):1096-101. doi: 10.1046/j.1365-2133.2002.05150.x. PMID: 12452857.
[3] Chakrabarti P, Kim JY, Singh M, Shin YK, Kim J, Kumbrink J, Wu Y, Lee MJ, Kirsch KH, Fried SK, Kandror KV. Insulin inhibits lipolysis in adipocytes via the evolutionarily conserved mTORC1-Egr1-ATGL-mediated pathway. Mol Cell Biol. 2013 Sep; 33(18):3659-66. doi: 10.1128/MCB.01584-12. Epub 2013 Jul 15. PMID: 23858058; PMCID: PMC3753874.
[4] Chinese Society of Diabetes. Expert consensus on clinical issues related to insulin resistance (2022 edition) [J] . Chinese Journal of Diabetes Mellitus, 2022, 14(12) : 1368-1379. DOI: 10.3760/cma.j.cn115791-20220905-00446.
[5] Edwards L, Lynch PJ (2010). Genital Dermatology Atlas. Lippincott Williams & Wilkins. p. 209. ISBN 9781608310791./utd