IGHE and gastroesophageal reflux disease: Lower plasma citric acid level was associated with new-onset prolonged cough and prolonged cough at follow-up among the 3375 subjects who had at least one of the 3 triggers without asthma, UACS, or GERD (Table S4a), even after adjustment with age, sex, body mass index, ex smoking, %FEV1, serum total IgE, blood eosinophil count, and blood collection time after meals (Table S4b).