The obesity paradox in primary Sjögren's disease: immunometabolic associations of chemerin, platelet count, and statin use.

INTRODUCTION

Sjögren's disease is characterized by autoimmune destruction of exocrine glands. Obesity generally worsens the course of many diseases; however, earlier observations in our cohort suggested a paradoxically lower disease activity (ESSDAI) in overweight/obese patients. This cross-sectional study aimed to investigate potential mechanisms underlying these findings.

METHODS

Chemerin and oxidized low-density lipoprotein (oxLDL) levels were measured in a subset of regularly followed patients (n=75). Patients were stratified by body mass index (BMI): BMI <25 kg/m² ("non-obese", n=27) and BMI ≥25 kg/m² ("overweight/obese", n=48). Demographic, laboratory, and immunological parameters, disease activity (ESSDAI), extraglandular manifestations, and treatments were compared using biostatistical analyses.

RESULTS

Chemerin and oxLDL levels did not differ significantly between groups. ESSDAI was significantly lower in overweight/obese patients (5.04 vs. 2.76; p=0.04), while complement c3 levels were higher (1.20 vs. 1.46 g/L; p<0.001). Across all patients, chemerin positively correlated with BMI, age at diagnosis, c3, c4, CRP, platelet count, and leukocyte count. Hemoglobin and hematocrit were higher in overweight/obese patients, whereas neutrophil ratio was lower and lymphocyte ratio slightly higher. Statin therapy was also more frequent in the overweight/obese group (p=0.04). In this group, BMI and platelet count independently predicted chemerin levels, while platelet count predicted chemerin in normal-weight patients.

CONCLUSION

Despite its positive correlation with BMI, chemerin levels were not significantly higher in overweight/obese patients, suggesting relatively lower levels. This may partly explain their more favorable immunological profile. Increased statin use may also contribute through anti-inflammatory effects.