Obesity, Disease Activity Paradox Found in Systemic Lupus Erythematosus

SAN DIEGO — Findings from a study presented here at the 2017 ACR/ARHP Annual Meeting showed an inverse correlation between body mass index (BMI) and disease activity in systemic lupus erythematosus (SLE) after adjusting for use of prednisone.

“This is the first evidence to our knowledge of an obesity paradox in systemic lupus,” the researchers wrote.

To study how BMI changes would affect disease activity, researchers examined 2406 patients in a prospective SLE cohort, assessing their weight at each visit. Patients were categorized into 5 groups according to weight: low (BMI <20 kg/m²), normal weight (reference; BMI 20-24.9 kg/m²), overweight (BMI 25-29.9 kg/m²), obese (BMI 30-34.9 kg/m²), and severely obese (BMI >35 kg/m²).

To calculate adjusted mean of SLE Disease Activity Index (SLEDAI) over time, only patients who attended the clinic at 3-month intervals for a minimum of 3 visits were included. This led to a total of 1896 patients being included in the analysis: 1763 (93%) women, 53% Caucasians, 39% African Americans. The researchers performed within-person analyses to assess whether disease activity level changed if a participant’s BMI changed.

The researchers found that the adjusted mean of SLEDAI over time was not different between the different BMI groups.

Although they hypothesized that BMI at the beginning of the study would be predictive of future disease activity, and that changes in BMI would be associated with disease activity, they actually found that SLEDAI significantly decreased by 0.03 with a 1-unit increase in BMI. The mean centered BMI (individual average BMI) and mean centered SLEDAI (individual average SLEDAI) were similarly associated.

“Body weight at cohort entry was not predictive of future disease activity. There was an inverse correlation between changes in body mass index and disease activity even after adjusting for prednisone use,” the researchers concluded.

Disclosures: G. Stojan, None; W. Fu, None; M. Petri, Anthera Inc, GlaxoSmithKline, EMD Serono, Eli Lilly and Company, Bristol Meyer Squibb, Amgen, United Rheumatology, Global Academy, Exagen.