Chronic urticaria and the metabolic syndrome: a cross-sectional community-based study of 11 261 patients.

BACKGROUND: Emerging evidence suggests that chronic urticaria (CU) is associated with chronic, low-grade, inflammatory process.

OBJECTIVE: To evaluate the association between CU and metabolic syndrome and its components in a large community-based medical database.

METHODS: A cross-sectional study of CU patients and matched controls was performed. CU was defined as eight urticaria diagnoses (with each two diagnoses registered within a period of 6 weeks) from 2002 to 2012. Data regarding the prevalence of metabolic syndrome, its components and possible complications were collected.

RESULTS: The study included 11 261 patients with CU and 67 216 controls. In a univariate analysis, CU was significantly associated with higher body mass index (BMI) and a higher prevalence of obesity, diabetes, hyperlipidaemia, hypertension, metabolic syndrome, chronic renal failure and gout. Multivariate analysis demonstrated a significant association between CU and metabolic syndrome (OR = 1.12, 95% CI 1.1-1.2, P < 0.001) and its components - obesity (OR = 1.2, 95% CI 1.1-1.3, P < 0.001), diabetes (OR = 1.08, 95% CI 1.01-1.15, P = 0.001), hyperlipidaemia (OR = 1.2, 95% CI 1.1-1.2, P < 0.001) and hypertension (OR = 1.1, 95% CI 1.1-1.2, P < 0.001).

CONCLUSIONS: CU patients may have one or more undiagnosed components of metabolic syndrome despite their young age. Thus, appropriate targeted screening is advised.