How Fat Affects Lupus

By Linda Rath

Systemic lupus erythematosus (lupus) is a chronic inflammatory disease that mainly affects women, especially women of color. In addition to lupus symptoms, many also struggle with their weight. Obesity is more common in people with lupus than the general population. Being overweight but having a body mass index below 30 can still cause serious problems for people with lupus.

Excess weight affects both physical and mental functioning in lupus patients, according to Patricia Katz, PhD, a professor at the University of California, San Francisco (UCSF), and noted lupus researcher. In one of her studies, lupus patients who were obese had limitations in employment, basic physical functions such as climbing stairs, and daily activities including self-care. 
 
“Not only do obese women do worse at first, but they also had a greater decline in functioning [over time],” Dr. Katz says. In another study, Katz and her colleagues found that women who were obese, inactive or both had higher levels of cognitive impairment, meaning they had trouble with things like memory, focus and planning. Katz says the inflammatory cytokines that fat releases create inflammation in different parts of the body, including the brain. 

A 2018 study by Dr. Katz’s group found that obese women with lupus reported more severe symptoms, depression, pain and fatigue than women who weren’t as heavy. Many of the women were economically and educationally disadvantaged. But even when those factors were considered, their depression, pain and fatigue were greater. Dr. Katz says it’s possible that because the women didn’t feel well, they didn’t exercise and therefore gained weight. But given that obesity makes symptoms worse in other rheumatic diseases, it’s more likely that obesity came first. 
 
Sarah Patterson, MD, a research fellow at UCSF and the study’s lead researcher, says, “Pain and fatigue are known to have profound effects on quality of life and remain a major area of unmet need for people with lupus. The relationship we observed between excess fat and worse outcomes underscores the need for lifestyle interventions targeting lupus patients who are overweight.”

The same inflammatory cytokines that cause lupus symptoms increase your risk of other health problems, especially heart disease.  Traditional heart risk factors, including high blood pressure, smoking, lack of exercise and treatment with corticosteroids, don’t fully explain why women who have lupus may be five to eight times more likely to have a heart attack than other women. One explanation is that low-grade inflammation causes plaque to build up inside blood vessels much earlier than normal. The plaque narrows arteries, raising blood pressure and reducing the flow of blood to your heart and other organs. Some plaques are unstable and can rupture, triggering a blood clot that can lead to heart attack or stroke.