Psoriasis, Obesity, and Heart Disease
What Is Psoriasis?
Psoriasis is a chronic inflammatory disease of the skin. In this disorder, the immune system mistakenly speeds up the life cycle of skin cells. This causes dead cells to collect on the surface of the skin. The immune system also triggers inflammation, which makes the skin turn red.
There are five types of psoriasis. The most common - which is present in approximately eighty percent of cases - is plaque psoriasis. In this form, thick, scaly patches develop on the skin. The scales are dead skin cells and are white or silver in color. They lie on top of red areas of skin that are inflamed and often itchy.
Psoriasis is known to be linked to both obesity and heart disease. Many scientific investigations have supported the following ideas.
- If a person is obese, the likelihood of their having psoriasis is increased.
- If a person has psoriasis, the likelihood of their having heart disease is increased, whether or not they are obese.
- Obesity increases the chance of heart disease.
- Inflammation is involved in psoriasis, obesity and heart disease.
Determining the actual relationship between psoriasis and other health problems is a complex task. It's sometimes hard to distingush between cause and effect. Nevertheless, the evidence indicates that psoriasis is connected to obesity and cardiovascular disease in some way.
Obese people are more likely to have psoriasis. Does this mean that obesity can cause psoriasis, or is obesity a possible consequence of psoriasis? In addition, psoriasis is associated with an increased risk of heart disease. Does psoriasis cause heart disease, or are the psoriasis and heart disease both the result of another problem in the body? Researchers want to solve these puzzles.
Experiencing the Disease
What Happens in Psoriasis?
Skin cells are produced in the deep layer of our skin. They slowly migrate upwards, maturing as they travel and dying when they reach the surface of the skin. The migration normally takes about a month. The dead cells are eventually shed from the surface of the body.
In somebody with psoriasis, new skin cells are made too rapidly and they migrate too quickly. The cells reach the surface of the skin in as little as a few days. The dead cells pile up, producing scaly areas. This process is accompanied by inflammation, a process in which surface blood vessels expand and cause redness. The inflammation stimulates nerves and causes itching or pain.
A Model Shows Her Skin Condition While Wearing a Swimsuit
In an autoimmune disease, a person's immune system attacks his or her own cells. Psoriasis is sometimes classified as an autoimmune disease, since cells in the immune system called T cells alter the action of skin cells.
Cause of the Disease
Researchers know that the immune system is behaving abnormally in someone suffering from psoriasis. Our immune system's usual job is to attack and destroy dangerous bacteria or viruses inside the body. A type of white blood cell called a T cell is activated by the presence of the invaders and causes a chain of events that destroy them. In someone with psoriasis, for some reason activated T cells are present in the skin. They stimulate the rapid production and maturation of skin cells as well as the release of inflammatory chemicals. The chemicals cause inflammation in the skin and sometimes in the joints as well.
The symptoms of psoriasis may be worse at some times and much better at others, but the problem is generally lifelong and recurring. Triggers that may cause a flare-up or make psoriasis worse include stress, some infections, cold and dry weather, certain medications, injury to the skin, smoking and excessive alcohol intake.
Psoriasis has a genetic component and is sometimes inherited. Researchers say that a trigger is needed to stimulate the first appearance of psoriasis in a person without the disorder, even in genetically susceptible people. Some of the factors that cause psoriasis to recur - such as certain infections and medications - may also act as the initial trigger.
Types of Psoriasis
There are five types of psoriasis.
- Plaque: the most common type of psoriasis. White, scaly patches and red, inflamed areas appear on the skin. The patches of abnormal tissue are known as lesions. They may appear anywhere on the body but are most common on the elbows, knees, legs, the lower back and the scalp. The fingernails may also change their appearance and become thickened, ridged or pitted.
- Guttate: small red spots appear on the skin
- Pustular: the skin develops white blisters surrounded by red skin
- Erythrodermic: very large and very red areas appear on the skin. Most of the body has a fiery appearance. The skin scales are thin, unlike the thick scales in plaque psoriasis. The skin may be painful as well as extremely itchy.
- Inverse: red skin appears in the folds and hidden areas of the body, such as under the arms, in the groin and under skin folds of overweight people.
Psoriasis is not an infection and isn't contagious. We can't "catch" psoriasis by touching someone's lesions or rash. About two percent of people around the world suffer from the disorder. Ten to thirty percent of people with psoriasis also develop a type of arthritis known as psoriatic arthritis.
Psoriasis and Psoriatic Arthritis
Psoriasis and Obesity
Scientists at the Kaiser Permanente Southern California Department of Research and Evaluation studied the health records of 710,949 children. The researchers found that:
- Obese children were almost forty times more likely to have psoriasis than children of normal weight
- Very obese children were almost eighty times more likely to have psoriasis than children of normal weight
- In children with psoriasis, severe or widespread psoriasis was four times more likely to be present in obese children than in children of normal weight
Chemicals that are associated with chronic inflammation have been found in the bloodstream of obese people. It's been proposed that these chemicals can either cause psoriasis or make it worse. It's known that weight loss can improve psoriasis.
On the other hand, some scientists think that obesity is a consequence of psoriasis instead of a cause. Depression and embarrassment leading to a decreased desire to exercise and poor food choices could all result in weight gain in people with psoriasis, especially when the psoriasis is severe. In addition, some researchers have suggested that psoriasis may cause metabolic dysfunction that leads to weight gain. Psoriasis is associated with an increased incidence of type 2 diabetes, even in patients of normal weight.
Cardiovascular Problems That May Be Linked to the Disease
Coronary heart disease, or CHD, is a condition in which the arteries that supply oxygen and nutrients to the heart muscle are narrowed due to the buildup of a hard, fatty material in the arteries. This material is called plaque and is made of fat, cholesterol, calcium and other substances. Narrowing or hardening of the arteries is known as atherosclerosis.
Cerebrovascular disease is a problem that develops due to changes in the blood vessels in the brain. One type of cerebrovascular disease is a stroke, which involves an interruption in the blood flow to the brain.
Peripheral artery disease is a condition in which the arteries in the arms or legs are narrowed and blood flow is reduced.
Anyone who suspects that they have psoriasis or who has an unexplained skin problem should visit a doctor for a diagnosis. The doctor should also be consulted about treatments for the problem.
Psoriasis, Heart Disease and Cardiovascular Problems
Many studies have suggested that there is a link between psoriasis and heart disease, a heart attack or a stroke. It's thought that in these cases not only the skin is inflamed but also structures inside the body, such as the heart and the arteries. Part of the increased risk may be due to the fact that some people with psoriasis are obese, but scientists say that even in lean people psoriasis is linked to an increased chance of cardiovascular problems. Here are some results of research studies.
- Scientists in Denmark found that people under fifty with psoriasis had a greatly increased risk of stroke and irregular heart rhythms, especially if they had severe psoriasis. The increased risk was much less in people over fifty.
- Researchers at the University of Miami in Florida found that psoriasis patients who swallowed certain anti-inflammatory medications to help their disorder were less likely to have a heart attack than people who only placed an ointment on their skin. This is further evidence suggesting that in at least some people with psoriasis the inflammation is not limited to their skin. The most effective medications were the ones known as Tumor Necrosis Factor (TNF) inhibitors, but other medications helped as well.
- Scientists at the University of Pennsylvania surveyed a large number of people and concluded that a sixty year old person with severe psoriasis has a thirty six percent higher chance of having a heart attack than a person of the same age without psoriasis.
- In 2009, other researchers concluded from their survey that people with psoriasis were almost twice as likely to suffer from coronary heart disease, cerebrovascular disease or peripheral artery disease as people without psoriasis.
More About Treatments
A Psoriasis Poll
Do you have psoriasis?
It's important for psoriasis patients to maintain a healthy weight. Whatever the true relationship between obesity and psoriasis, obesity may make psoriasis worse. Obesity also increases the risk of other serious health problems, including heart attacks and type 2 diabetes.
Preventing Possible Complications of the Disease
Someone with psoriasis should discuss treatment options with their doctor in detail. The doctor and patient need to decide whether an ointment (a "topical medication" that is applied to the skin), light treatment (phototherapy) or a medicine that is swallowed or injected (a "systemic medication" that travels through the body) is the best idea for the patient's situation and medical background. The advantages and disadvantages of each form of treatment need to be carefully considered. Sometimes a combination of treatments works best.
People with psoriasis need to persevere while trying different treatments. There isn't a cure for psoriasis, but there are many good treatment options that can be very helpful in clearing lesions. A treatment that works in one person may not work in another person, however. Someone may be lucky and find an effective treatment for their case of psoriasis very quickly, but the search may also take some time. If you have psoriasis and know that certain triggers stimulate a flare-up, it's important to investigate ways to avoid these triggers in addition to using medications that your doctor recommends.
References and Further Information
- An exploration of the link between psoriasis, obesity, and heart disease from the National Psoriasis Foundation
- An exploration of the link between obesity and psoriasis in children in the Children's Health Study
- Psoriasis and Increased Risk of Diabetes information from the University of Pennsylvania
- Psoriasis and Stroke facts from the BBC
- Psoriasis Treatments and Reduced Heart Attack Risk from Reuters
© 2012 Linda Crampton