A new twin study has revealed the potential of a common genetic cause between psoriasis, type 2 diabetes and obesity.
Psoriasis is a chronic, inflammatory skin disease that the Centers for Disease Control and Prevention (CDC) describes as an autoimmune disease that involves the rapid growth of skin cells. It affects two to three percent of white people around the world and has been linked to obesity and diabetes.
Symptoms of psoriasis include patches of thick, red skin that possess silvery scales that cause pain or itching.
Using data from 33,588 Danish twins aged 20 to 71 years old, Ann Lønnberg of the University of Copenhagen in Denmark and her team examined the link between psoriasis and type 2 diabetes and obesity. Of the group, 4.2 percent of participants were affected by psoriasis - 630 men and 771 women - and 1.4 percent had diabetes - 235 women and 224 men.
Each participant completed a questionnaire about psoriasis that was then compared to type 2 diabetes diagnosis and body mass index (BMI). The results revealed that psoriasis was present in approximately 7.6 percent of participants with diabetes, but only in 4.1 percent of participants without diabetes. Furthermore, those with psoriasis had an average BMI of 25, which was higher on average than those without (24.4).
In a study of 720 sets of twins with type 2 diabetes, only one twin of the pairs had psoriasis, and this twin, on average, had a higher BMI and was more likely to be obese that the twin without psoriasis.
The authors believe that psoriasis and obesity could stem from the same genetic cause, although they note that one condition does not necessary cause the other. Further research needs to be conducted to better understand this possible connection.
"Psoriasis, type 2 diabetes mellitus and obesity are strongly associated in adults after taking key confounding factors such as sex, age and smoking into account," the authors conclude. "Results indicate a common genetic etiology of psoriasis and obesity. Conducting future studies on specific genes and epigenetic factors that cause this association is relevant."
The findings were published in the April 27 issue of the journal JAMA Dermatology.
