Prevalence and risk factors of allergic rhinitis and asthma in the southern edge of the plateau grassland region of northern China: A cross-sectional study

BACKGROUND: The prevalence rates of allergic rhinitis (AR) and asthma in the border region of China may be different from those in the central region of plateau grasslands. A survey was performed to investigate the prevalence and risk factors for AR, asthma, and AR combined with asthma among adults (age ≥ 20 years) residing in the southern border of plateau grasslands in northern China. METHODS: From May to August 2018, a cross-sectional survey was completed by subjects that were selected using a cluster random sampling method. The subjects completed a questionnaire and were administered skin prick tests (SPTs). Risk factors for AR, asthma, and AR combined with asthma were examined by multivariate logistic regression analyses. RESULTS: A total of 1815 adult subjects in the selected region completed study. The prevalence rates of physician-diagnosed AR, asthma, and AR combined with asthma were 13.9% (253), 9.8% (177), and 2.9% (52), respectively. Among the patients with AR, 20.6% were found to have concurrent asthma; among the patients with asthma, 29.4% were found to have concurrent AR. Artemisia and Humulus pollen were the most common sensitizing pollen types. Approximately 70% of subjects with AR and <30% of asthma patients were sensitized to Artemisia and Humulus pollen. Symptoms of AR and asthma mainly appeared during August. A multivariable logistic regression analysis identified sensitization pollen as an independent risk factor for both AR and AR combined with asthma (AR: OR = 16.23, 95% CI: 10.15–25.96; AR combined with asthma: OR = 6.16, 95% CI: 1.28–29.66). An age >40 years old, family history of asthma, moderate-to-severe AR, adverse food reactions, and mold allergies were independent risk factors for AR combined with asthma. CONCLUSIONS: This study identified the prevalence rates of AR and asthma in the southern borders of the plateau grassland in northern China (>1500 m above sea level). Sensitization pollen is an independent risk factor for AR and AR combined with asthma.