Cachexia in Systemic Lupus Erythematosus: Risk Factors and Relation to Disease Activity and Damage

Objective: Cachexia is a disorder characterized by involuntary weight loss in addition to loss of homeostatic control of both energy and protein balance. Despite an abundance of data from other inflammatory diseases, cachexia in systemic lupus erythematosus (SLE) remains a largely undescribed syndrome. The present study was undertaken to define the prevalence of cachexia in SLE and to identify the main factors that place patients at risk of developing cachexia.

Methods: A total of 2,452 patients in a prospective SLE cohort had their weight assessed at each visit. Patients were categorized into 5 predetermined groups based on weight. Cachexia was defined based on modified Fearon criteria (5% stable weight loss in 6 months without starvation relative to the average weight in all prior visits and/or a weight loss of >2% without starvation relative to the average weight in all prior cohort visits and a body mass index [BMI] of <20 kg/m² ). Risk of cachexia within 5 years of cohort entry was based on Kaplan-Meier estimates. The association of prior disease manifestations with risk of cachexia adjusted by current steroid use was determined using Cox regression. An analysis of variance test was used to determine whether Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) scores varied based on cachexia status.

Results: Within 5 years of cohort entry, 56% of patients developed cachexia, 18% of which never recovered their weight during follow-up. The risk factors for cachexia development were a BMI of <20 kg/m² , current steroid use, vasculitis, lupus nephritis, serositis, hematologic lupus manifestations, positive anti-double-stranded DNA, anti-Sm, and anti-RNP. Patients with intermittent cachexia had significantly higher SDI scores compared to those with continuous cachexia or without cachexia.

Conclusion: Cachexia is an underrecognized syndrome in patients with SLE. SLE patients with intermittent cachexia have the highest risk of future organ damage.