Diabetes mellitus is a common disease and has been increasing in recent years. However, many people do not feel any symptoms of discomfort at the beginning of the diagnosis of the disease through physical examination, so the disease is delayed and treatment is delayed.
The main manifestations of diabetes mellitus are not only elevated blood sugar and increased food intake and urine output, but the onset of this disease is a chronic process, and many complications and even life-threatening can occur as the disease progresses.
Diabetic patients need to pay special attention to the fact that, in addition to the typical symptoms, there are some manifestations that suggest the onset and progression of the disease.
1. Why does high blood sugar manifest itself in the feet?
This condition is medically known as diabetic arterial vascular disease of the lower extremities. The pathogenesis of the disease is complex.
With the progress of research, scientists have found that the hyperglycemic state of the body can cause vascular endothelial damage through various alteration mechanisms such as increased oxidative stress level, blocked pentose phosphate pathway, polyol pathway, and activated protein kinase C pathway, which ultimately causes the occurrence of diseases.
In recent years, many studies have found that metabolites can also affect the occurrence and development of diseases, such as retinol-binding protein 4, homocysteine, and changes in insulin receptor substrate-1, which can induce insulin resistance and lead to the occurrence of diseases.
Retinol-binding protein 4 induces disease mainly through, and vitamin D use has also been found to have a role in the prognosis of this disease.
Elevated homocysteine not only increases the risk of stroke, but also promotes insulin resistance by inducing endoplasmic reticulum stress in adipocytes. In addition, in the process of oxidation of this metabolite, a large number of substances that damage the vascular endothelium can be generated, which can aggravate the vascular inflammatory response.
The expression of endothelial nitric oxide synthase can be down-regulated through abnormal expression of insulin receptor substrate-1, which can regulate vascular endothelial cells in the normal phase and reduce the risk of disease occurrence and development.
2. These five conditions indicate that blood sugar is elevated, so you must seek medical attention as soon as possible!
The first: itching.
The incidence of this condition increases in diabetic patients, and even 27.5% of patients experience generalized itching, which may be related to the increase in blood sugar after meals. When this indicator is elevated, it tends to irritate nerve endings, which leads to itching.
At present, it is believed that pruritus caused by diabetes mellitus is mainly caused by triggering primary neuropathologies in the peripheral or central nervous system, and Sun S et al. found that trp channels play a key role in the transduction of this pruritus signal.
There are seven related protein families in the trp channel, among which TRPV1, 2, 4, TRPM2, 3, 8, and TRPA1 channels are expressed in sensory neurons1. TRPV3 and TRPV4 are expressed in cutaneous keratinocytes. These expression channels guarantee the transduction of pruritus.
The second: numbness.
This symptom is essentially a human peripheral neuropathy that occurs due to an increase in blood sugar. In the high-sugar environment of the human body, the main nutrients such as glucose and protein will undergo irreversible non-enzymatic reactions to produce advanced glycation end products.
This substance can trigger the activation of tyrosine protein kinase and other pathways, leading to the occurrence of inflammatory response and oxidative stress response in the body, and can also increase the expression of apoptosis signals represented by cysteine protease, so that nerve cells can be damaged.
Moreover, methylglyoxal produced in the glycolytic pathway can induce lesions by activating transient receptor potential cation channels. The polyol pathway can reduce the nerve growth factors and trophic factors secreted by Schwann cells, and break the normal conduction exchange between the cells and axons, resulting in nerve fiber damage.
The third type: brown spots appear.
At present, the mainstream belief that the lesion is due to pigmentation caused by local microcirculation disorders, but as research progresses, many different insights have emerged.
It has been suggested that inflammatory factors can also contribute to the disease. When biological and physical stimuli occur, the secretion of inflammatory factors such as granulocyte-macrophage colony-stimulating factor increases, which promotes the transport of black to the skin.
Immune factors are also associated with the development of the disease.
The team of Professor Qiu Mingcai of Tianjin Medical University found that a large number of immune complex deposits were found in local biopsy of skin lesions and renal pathological examination of patients with this disease, but the specific mechanism needs to be further studied. meantime
Fourth: dry, chapped skin.
This symptom is also known as peripheral neuropathy. Neurogenesis can cause sweat glands to malfunction and reduce perspiration of the skin, leading to dryness. In addition, the lesion is also prone to involve blood vessels, resulting in thickening of the intima, poor elasticity, and poor blood flow, resulting in dry skin on the feet.
At the same time, when blood sugar rises, the cells on the surface of the human skin are hypertonic, and the excess water will diffuse to the tissue fluid and plasma, resulting in a lack of water on the skin surface. Long-term dryness of the skin will make it easy to crack.
Fifth: the wound is not easy to heal.
Excess sugar and protein in the blood are reacted with non-enzymatic glycosylation, and the advanced glycation end products produced not only predispose to vascular lesions of the disease, but also promote wound healing disorders.
This substance can significantly inhibit the proliferation of endothelial cells, change the structure of collagen and elastin in the blood vessel wall, reduce its elasticity, damage the microvasculature, affect the blood circulation at the wound, and lead to the occurrence of diseases.
Moreover, the substance can delay wound healing by inhibiting fibroblast collagen synthesis.
These anomalies are not trivial. If blood sugar levels are not controlled in time, the condition of the foot will deteriorate, and the wound will never heal, from a small wound to a wound that will never heal. The skin barrier is an effective way to protect the body from infection, and if the wound does not heal, the probability of wound infection increases, and it may even evolve into critical illness and sepsis.
But don't think of these manifestations as a minor problem, the disease has a high clinical disability rate. Timely detection of foot abnormalities and active cooperation with medical staff to control blood sugar levels can effectively prevent the occurrence of the disease!
Bibliography:
［1］Sun, S. and X. Dong, Trp channels and itch. Semin Immunopathol, 2016. 38(3):р. 293-307.
［2］NARUSE K. Schwann cells as crucial players in diabetic neuropathy[J]. Adv Exp Med Biol, 2019, 1190: 345-356.DOI: 10. 1007/978-981-32-9636-7_22.
[3] Qiu Mingcai, Lin Shan, Gao Zhihong, et al. Skin biopsy and kidney biopsy of patients with type 2 diabetes mellitus with anterior tibial dark spots[.Tianjin Medicine,2004,32(5):257-259.
[4] Zhou Wan, Zhang Lijun. Correlation between the expression of retinol-binding protein 4 and nuclear factor xB and atherosclerosis in diabetic rats. Chinese Journal of Diabetes Mellitus,2011,19:620-623.]
［5］PERRONE A, GIOVINO A, BENNY J, et al. Advanced glycation end products (AGEs): biochemistry, signaling, analytical methods, and epigenetic effects JJ. Oxid Med Cell Longev, 2020,2020:3818196.