Waist circumference better than BMI for predicting prolonged chronic spontaneous urticaria

Rather than body mass index (BMI), waist circumference (WC) seems to be a better predictor of prolonged chronic spontaneous urticaria (CSU), a new study has found.

A total of 52,667 CSU patients (mean age, 54.5 years; 54.4 percent women) participated in the study, and close to half (42.18 percent; n=22,215) had had CSU for >3 years. Those with high WC (44.59 percent) and BMI (43.43 percent) also tended to have had longer disease durations (p<0.05 for both). Smoking, alcohol use, exercise, and household income all did not seem related to CSU duration.

Multivariable Cox proportional hazards models found that a high WC was a significant risk factor for longer CSU. For instance, men with WC between 90–95 cm, along with women with WC between 85–90 cm were 5-percent more likely to have had a longer disease (hazard ratio [HR], 1.056, 95 percent confidence interval [CI], 1.006–1.109).

Men with WC 95–100 cm and women with WC 90–95 cm likewise saw a significantly greater likelihood of longer disease (HR, 1.082, 95 percent CI, 1.016–1.152). No such effect was found for the topmost category, which comprised men with WC ≥100 cm and women with WC ≥95 cm.

On the other hand, none of the BMI categories could significantly predict the occurrence of CSU >3 years.

All models used the second category (BMI: 18.5–23 kg/m²; WC: 85–85 cm in men, 75–80 cm in women) as a reference and were adjusted for age, sex, and comorbidities, such as hyperlipidaemia, hypertension, and diabetes mellitus.