At one time, people thought that psoriasis was just a skin disease. With the rapid development of medicine, the mystery of psoriasis has been peeled away layer by layer.
It is now clinically believed that psoriasis is a systemic and systematic disease caused by a combination of immune, genetic, environmental and other factors. Therefore, we should not only pay attention to the damage of psoriasis on the skin, but also pay attention to the risk of its “co-morbidity” and beware of the surprise attack of “companion diseases”.
One of the most common “companion diseases” of psoriasis is metabolic diseases and conditions, mainly type 2 diabetes, dyslipidemia, obesity, hypertension and other conditions.
1. Psoriasis and type 2 diabetes mellitus
(1) Mechanism of co-morbidity
The serum level of interleukin-17 is significantly elevated in patients with psoriasis, and interleukin-17, a cytokine, can interfere with insulin signaling through blood or paracrine action, thus affecting insulin sensitivity and leading to the development of type 2 diabetes.
Secondly, as leptin levels rise in type 2 diabetic patients, it can directly cause feedback downregulation of leptin receptor levels or make post-receptor signaling blocked, which eventually leads to leptin resistance. Leptin resistance is an independent risk factor for type 2 diabetes, which can further influence the course of psoriasis through the body’s immune and inflammatory response, leading to relapse or exacerbation of the disease.
(2) Combined treatment of the two
Clinically, the PPAR-γ ligand thiazolidinedione is mainly used as an insulin sensitizer for the treatment of type 2 diabetes, which may promote the differentiation of keratinocytes and inhibit their excessive proliferation.
Related studies also confirmed that the application of thiazolidinediones pioglitazone to patients with psoriasis could help 40% of patients to largely regress their skin lesions, and most patients had improved patchy damage, but the specific effects and roles need to be further explored.
2.Psoriasis and dyslipidemia
(1) Mechanism of co-morbidity
Dyslipidemia mainly includes low-density lipoprotein, very low-density lipoprotein, elevated serum triglycerides, and reduced high-density lipoprotein levels. Among them, HDL levels can inhibit certain cytokine-induced biological effects in vitro, and the reduction suggests possible anti-inflammatory activity in vivo.
And as psoriasis is an immune-related inflammatory disease, numerous inflammatory cytokines play an important role in the development of the disease, and the decrease in HDL level directly leads to the release of inflammatory cytokines, which contributes to the occurrence or exacerbation of psoriasis.
It is thus clear that there is a significant correlation between psoriasis and blood lipid levels, and effective control of blood lipid levels in patients with psoriasis may have positive implications for the improvement of psoriasis.
(2) Combined treatment of the two
If psoriasis is combined with dyslipidemia, the blood lipid level can be actively controlled while using topical drugs such as salicylic acid preparation, coal tar, or phototherapy to treat psoriasis, and those with reduced high-density lipoprotein level can apply relevant drugs under the guidance of doctors to increase plasma high-density lipoprotein level.
3.Psoriasis and obesity
(1) Mechanism of co-morbidity
It is found that, compared with non-obese normal people, the level of plasma Wnt5a (can promote the inflammatory response of vascular endothelial cells) of obese psoriasis patients is significantly higher, while the level of Sfrp5 (to a certain extent can inhibit the occurrence of inflammatory response) is significantly lower.
These two levels may be associated with the development of psoriasis and obesity. In addition, fatty liver, which is one of the important signs of obesity, also confirms the relationship between obesity and psoriasis in the side.
It was found that the incidence of non-alcoholic fatty liver in elderly psoriasis patients was 70% higher than that in non-psoriasis patients, and the incidence of fatty liver in arthritic psoriasis patients also showed a significant increase.
(2) Combined treatment of the two
For psoriasis combined with obesity, diet control and physical exercise can be used to improve the efficacy of the disease in the process of active treatment of psoriasis. For example, limit the intake of high-calorie and high-fat foods, such as fatty meat and barbecue, and increase the intake of high-quality protein such as milk and eggs and fresh fruits and vegetables rich in vitamin ingredients.
Under the premise that the condition allows, aerobic exercise is carried out about 3 times a week to improve the body’s calorie consumption, reduce fatty liver and control the development of weight.
4.Psoriasis and hypertension
Most patients with psoriasis will have changes in the renin-angiotensin-aldosterone system, and this process will induce the expression of the former pro-inflammatory factor bone bridge protein and anti-inflammatory cytokines to reduce the expression of lipocalin, thus making the body in an inflammatory state and increasing the probability of psoriasis onset and exacerbation of the disease.
Secondly, a cross-sectional medical study also found that the prevalence of hypertension in patients with psoriasis has increased, and the prevalence is closely related to the severity of psoriasis in particular, which means that the more severe the condition of psoriasis, the greater the probability of hypertension in combination with the patient.
Therefore, patients with psoriasis should also take strict measures to control blood pressure and continuously monitor changes in blood pressure while controlling the development of their own psoriasis. Later, they should follow medical advice to choose more matching and suitable antihypertensive drugs to improve the treatment effect of hypertension and psoriasis.
If psoriasis is still “single”, all we have to do is to prevent it from partnering up. If unfortunately it has already “partnered up”, we have to take care of it with both hands, not letting go of both the underlying disease and the concomitant disease! And we should promote the improvement of the underlying disease (psoriasis) to the greatest extent possible to avoid the formation of a vicious circle.
References
[1]Zhang Weishu,Sun Liyun. Exploration of the association between psoriasis and the pathogenesis of metabolic syndrome [J]. Chinese Journal of Integrative Dermatology and Venereology,2019,18(05):507-510.