Several case-control studies have shown that patients with a higher body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared) have a higher risk of developing psoriasis than the general population.
Psoriasis is a common, noncontagious skin condition that causes rapid skin cell reproduction resulting in red, dry patches of thickened skin. The dry flakes and skin scales are thought to result from the rapid buildup of skin cells. Psoriasis commonly affects the skin of the elbows, knees, and scalp.
Psoriatic arthritis is a specific type of arthritis that develops in the joints and affects 6% to 42% of patients who have psoriasis. It can be very debilitating.
More recently it has become apparent that patients with psoriatic arthritis also show an increased frequency of cardiovascular diseases (ischaemic heart disease, atherosclerosis, peripheral vascular disease, congestive heart failure, and cerebrovascular disease) and that their traditional cardiovascular risk factors (type 2 diabetes, hyperlipidaemia, and hypertension) are also increased relative to controls.
A new study found that people who are obese by the age of 18 or earlier had an increased risk of developing psoriatic arthritis as compared to those with a normal weight.
Razieh Soltani-Arabshahi of the University of Utah School of Medicine and colleagues studied a volunteer sample of 943 patients with psoriasis, 50.2 percent were women and 26.5 percent in the cohort had psoriatic arthritis.
The researchers found that obesity at age 18 was predictive of psoriatic arthritis. Other predictors included younger age at psoriasis onset, being female and having larger body surface areas affected with psoriasis.
Additionally, the findings show the obese group having an earlier onset of psoriatic arthritis, followed by the overweight group and finally the normal BMI group. Skin symptoms appeared prior to arthritis in 78.9 percent of patients, while in 9.9 percent the joint manifestations were visible earlier.
Twenty percent of the overweight or obese group developed psoriatic arthritis by age 35 years while 20 percent of those individuals in the normal BMI group developed psoriatic arthritis by age 48.
The authors conclude that their findings, "support a growing concept that patients more prone to psoriatic arthritis might benefit from more frequent and meticulous screening measures for early detection and treatment of psoriatic arthritis, i.e., before the development of irreversible joint destruction."
Razieh Soltani-Arabshahi, Bob Wong, Bing-Jian Feng, David E. Goldgar, Kristina Callis Duffin, Gerald G. Krueger. Obesity in Early Adulthood as a Risk Factor for Psoriatic Arthritis. Archives of Dermatology. 2010;146(7):721-726.
The effect of weight loss alone on psoriasis has not yet been studied.
But why wait. Keeping your body weight at optimal BMI offers you a lot of advantages.
Obesity is often accompanied by excess fat storage in tissues other than adipose tissue, including liver and skeletal muscle, which may lead to local insulin resistance and may stimulate inflammation, as in steatohepatitis. In addition, obesity changes the morphology and composition of adipose tissue, leading to changes in protein production and secretion. Some of these secreted proteins, including several proinflammatory mediators, may be produced by macrophages resident in the adipose tissue. The changes in inflammatory status of adipose tissue and liver with obesity feed a growing recognition that obesity represents a state of chronic low-level inflammation.
During the last decade, it has become clear that inflammatory mechanisms are key players in pathological processes of several chronic diseases such as ischemic cardiovascular disease, colorectal cancer, stroke, type 2 diabetes, chronic obstructive pulmonary disease, and Alzheimer’s disease..
Bruunsgaard H. Physical activity and modulation of systemic low-level inflammation. Journal of Leukocyte Biology. 2005 Oct;78(4):819-35.Picture 1