How Is Type 2 Diabetes Linked to Psoriatic Arthritis?

An abnormal response of the immune system causing inflammation is a key characteristic of psoriatic arthritis (PsA). The increased inflammation is noticeable in the joints as pain and swelling. In addition, researchers have shown that psoriatic disease causes inflammation throughout the body. This abnormal inflammation has several negative effects on the body, including insulin resistance and dysfunction in the lining of the blood vessels, which lead to atherosclerosis (the formation of abnormal fatty masses in the arteries) and ultimately to major cardiovascular events.¹

Obesity

Obesity is defined as having too much body fat. It is different than being overweight, which means weighing too much and can come from muscle, fat, bone and/or water in the body. Obesity occurs over time when more calories are consumed than used. Factors that influence weight include genetic makeup, overeating, eating high-fat foods, and lack of physical activity. Obesity increases the risk of diabetes, heart disease, stroke, some cancers, and PsA.^2,3

In addition to being a risk factor for PsA, obesity has demonstrated a negative effect on treatment in clinical trials, decreasing the effectiveness of TNF inhibitors. (TNF inhibitors are a biologic therapy that target tumor necrosis factor, a chemical that is active in the inflammatory response.)^1,2,4

Metabolic syndrome

Metabolic syndrome is a term for a group of conditions that increases risk of heart disease and diabetes. The conditions that make up metabolic syndrome are:

• Hypertension, or high blood pressure
• High blood glucose, or blood sugar levels
• High levels of triglycerides, a type of fat in the blood
• Low levels of HDL, the “good” cholesterol in the blood
• High levels of abdominal obesity, or too much fat around the waist ³

Metabolic syndrome is more prevalent in patients with PsA than the general public and confers a negative effect on treatment, decreasing the effectiveness of medications like TNF inhibitors.²

Diabetes

Diabetes is a disease in which the blood glucose (sugar) levels are too high. Glucose comes from food, and normally the hormone insulin helps the glucose into the cells of the body to provide energy. In type 1 diabetes, the body does not make insulin. In type 2 diabetes, which is more common, the body does not make or use insulin well, called insulin resistance. Over time, the high levels of glucose in the blood causes serious problems, damaging eyes, kidneys, and nerves, and increasing the risk of heart disease, stroke, and loss of limbs due to amputation.³

Patients with PsA are at a higher risk of developing type 2 diabetes, and diabetes has been observed in up to 18% of PsA patients.²

Ways to reduce risk

Weight loss not only decreases the risk of developing conditions like heart disease, stroke, and diabetes, it also works with PsA treatment to improve disease symptoms. Research has demonstrated that patients who lost weight while taking biologic medication that inhibits TNF-alpha had a greater improvement in symptoms than patients taking the medication alone. Researchers believe people with psoriatic disease who are also overweight may experience a double dose of inflammation. Other studies have noted that fat cells secrete many of the same cytokines (chemical messengers) involved in psoriatic disease, such as TNF-alpha.^5,6

Weight loss strategies include:

• Choosing low-fat, low-calorie foods
• Eating smaller portions
• Drinking water instead of sugary drinks
• Increasing physical activity³