Chronic spontaneous urticaria and metabolic syndrome: a relationship conundrum

Chronic spontaneous urticaria (CSU) and metabolic syndrome (MetS) are associated with low-grade inflammation. Despite intensive research and various hypothesis, there is lack of specific pathomechanisms of urticaria. Previous studies have suggested low-grade inflammation in obesity which may be linked to urticaria. However, there is limited literature on association of MetS and CSU. So, this study was conducted to evaluate the association of MetS and its components in patients with CSU. This was a hospital-based and cross-sectional cohort study in which 481 patients of CSU and 240 age- and gender-matched controls were recruited. MetS was defined using the revised National Cholesterol Education Program Adult Treatment Panel III. BMI, waist circumference, blood pressure, fasting blood sugar, plasma insulin, and lipid profile were measured after overnight fasting. Pearson's Chi-squared test was used to calculate significance. Logistic regression analysis was done to assess MetS as a predictor of CSU. All patients were started on antihistamines according to the severity of the disease. CSU patients comprised 220 men (45.7%) and 261 women (54.3%) with 97 patients (20.12%) qualifying criteria for metabolic syndrome compared with 73 (30.42%) controls without any significant difference (p = 0.177). CSU was significantly associated with a higher prevalence of central obesity (p = 0.003) but CSU patients with central obesity did not have a higher urticaria activity score (p = 0.727) or serum IgE levels (p = 0.359). In conclusion, our study found an increased association of central obesity with CSU that was not related to the severity of urticaria. This is of significance as obesity is the most prevalent and first component of MetS to be developed. There was no increase in the overall prevalence of MetS in patients with CSU. The increased association of obesity and urticaria in our study can be partially explained by the role of antihistamines in modulation of metabolic pathway and appetite. Future research into the same can give better insights and thus can aid in better management options in CSU patients.