AB0306 OBESITY PHENOTYPES IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS

Abstract

Background:The so-called “obesity paradox” when cardiovascular risk is lower in overweight compared to lean patients accompanies some chronic conditions. A possible explanation for this phenomenon comes from variability of obesity phenotypes, i.e., “classical” obesity as exemplary perception of obesity is equal to increased body mass index (BMI) and metabolic disorders; but there are also “metabolically healthy” overweight individuals (increased BMI without metabolic disorders), and “latent” obesity phenomenon (when normal weight is associated with metabolic disorders, especially with insulin resistance (IR) and adipocytokines imbalance). Serum leptin concentrations increase has been established in obese, therefore, this adipocytokine synthesized in adipose tissue, can be used as a marker of body fat mass. Higher cardiovascular risks are known even in young patients with systemic lupus erythematosus (SLE), but obesity phenotypes have not been studied.Objectives:To find out the rate of various obesity phenotypes and to identify factors contributing to “latent” obesity in SLE pts without diabetes mellitus (DM) or hyperglycemia.Methods:A total of 49 SLE pts (46 women, 3 men, 40 [33;48] years old) without established DM or hyperglycemia were enrolled in the study. The median disease duration was 3,0[0,7;8,0] years, SLEDAI-2K was 5[2;8]. SLE pts were treated with glucocorticoids (GC) (84%) and hydroxychloroquine (78%), immunosuppressive drugs (20%) and biological agents (10%). Insulin levels were measured using electrochemiluminescence assay Elecsys (Roche Diagnostics), serum leptin concentrations were estimated using ELISA (DBS-Diagnostics Biochem Canada Inc.). IR was defined as Homeostasis Model Assessment of Insulin Resistance index (HOMA-IR) ≥2,77. Leptin levels were considered elevated at values ≥11,1 ng/ml for women, ≥5.6 ng/ml for men. The overweight / obesity status was determined by World Health Organization criteria in patients with body mass index (BMI) ≥25kg/m2.Results:Overweight / obesity were established in 45% of pts, normal BMI was in 55% of SLE pts. The combination of IR and high leptin levels was found in 32% of overweight / obese pts and 11% of pts with normal BMI (p=0,2), an isolated increased leptin levels - in 64% and 41%, respectively (p=0,1). Metabolic disturbances were absent in 4% of overweight pts and 48% of pts with a normal BMI (p=0,001). Thus, “classical” obesity was found in 43% of cases, “metabolically healthy” obesity - in 2%, and “latent” obesity - in 29% of SLE pts. Leptin levels correlated with BMI (r=0,5, p=0,02), waist circumference (r=0,5, p=0,02) in the overweight / obesity group, and with disease duration (r=0,5, p=0,02), SLEDAI-2K (r=-0,6, p=0,002), anti-dsDNA (r=-0,7, p<0,001), C3 complement (r=0,5, p=0,01), maximum (r=0,7, p<0,001) and current GCs doses (r=0,4, p=0,03) in patients with normal weight. There was a trend to association between leptin levels and duration of GCs therapy in SLE pts with normal BMI (r=0,4, p=0,06).Conclusion:Metabolic disorders - most often increased leptin levels - were diagnosed in the majority of overweight / obese patients, as well as in about 50% of SLE patients with normal weight. There were only isolated cases of “metabolically healthy” obesity in SLE patients. Metabolically obese normal weight (“latent” obesity) phenotype was strongly associated with GCs therapy and decreased disease activity.Disclosure of Interests:None declared