Psoriasis is a chronic immune-mediated inflammatory skin disease characterized by uncontrolled proliferation of keratinocytes, release of proinflammatory cytokines, and recruitment of T cells to the skin that causes skin cells to multiply up to 10 times faster than normal which create red patches covered with white scales. these patches can grow anywhere, but mostly on the scalp, elbows, and knees.

Metabolic syndrome is a cluster of conditions that occur together, increasing the risk of heart diseases and type 2 diabetes mellitus characterized by abdominal obesity, insulin resistance, dyslipidemia, and elevated blood pressure.

Like in psoriasis, systemic inflammation also occurs in patients with metabolic syndrome, and levels of a number of inflammatory markers, such as Tumor Necrosis Factor, are elevated in both diseases. This made researchers question if there is a common etiology.

A cross-sectional, population-based twin study published by JAMA Dermatology, included 34 781 Danish twins, 20 to 71 years of age. Revealed a link between psoriasis and metabolic syndrome, in particular, obesity and type 2 diabetes mellitus, this connection is rather important as those two comorbidities can lead to increased mortality, especially due to cardiovascular diseases.

The study found that obesity is about twice as prevalent in patients with psoriasis compared with the general population. The same results have been obtained for type 2 diabetes mellitus.

Several factors might explain the association between psoriasis and the metabolic syndrome, notably genetics and environmental exposures (such as tobacco smoking, alcohol consumption…etc.). The twin design shows the relative contribution of genetic and environmental factors to a given disease which is necessary for this area of research.

The results support that Psoriasis, type 2 diabetes mellitus, and obesity are strongly associated with adults after taking key confounding factors (sex, age, and smoking …etc.) into account which indicates a common genetic etiology of psoriasis and obesity.

Conducting future studies on specific genes and epigenetic factors will unravel the direct correlation between those 3 disorders.