Impact of Abdominal Visceral Adiposity on Adult Asthma Symptoms

Background: Previous studies have shown the association of anthropometric measures with poor asthma symptoms, especially among women. However, the potential influence of visceral adiposity on asthma symptoms has not been investigated well. Objective: In this study, we have evaluated whether visceral adiposity is related to poor adult asthma symptoms independent of anthropometric measures and sex. If this relationship presented, we investigated whether it is explained by influence on pulmonary functions and/or obesity-related comorbidities. Methods: We analyzed data from 206 subjects with asthma from Japan. In addition to anthropometric measures (body mass index and waist circumference), abdominal visceral and subcutaneous fat were assessed by computed tomography scan. Quality of life was assessed using the Japanese version of the Asthma Quality of Life Questionnaire. Results: All obesity indices had inverse association with reduced asthma quality of life among females. However, only the visceral fat area showed a statistical inverse association with Asthma Quality of Life Questionnaire in males. Only abdominal visceral fat was associated with higher gastroesophageal reflux disease and depression scores. Although all obesity indices showed inverse association with functional residual capacity, only visceral fat area had a significant inverse association with FEV ₁ % predicted, independent of other obesity indices. Conclusions: Regardless of sex, abdominal visceral fat was associated with reduced asthma quality of life independent of other obesity indices, and this may be explained by the impact of abdominal visceral fat on reduced FEV ₁ % predicted and higher risk for gastroesophageal reflux disease and depression. Therefore, visceral adiposity may have more clinical influence than any other obesity indices on asthma symptoms.