Visceral adiposity and respiratory outcomes in children and adults: a systematic review

Background This review aimed to examine the associations of visceral adipose tissue (VAT) with pulmonary function and asthma in children and adults, and chronic obstructive pulmonary disease (COPD) in adults. Methods Five databases were searched up to February 12, 2021, to identify articles that described associations of VAT with pulmonary function, asthma, and COPD. Information on participant characteristics, study design and assessment, and key findings were retrieved. Results A total of 43 studies were considered eligible, of which most studies were cross-sectional and in adults. The quality of included studies was generally moderate. In adults, strong evidence was found that a higher abdominal VAT was associated with asthma, and a higher intrathoracic VAT was associated with lower forced expiratory volume in the first second and forced vital capacity. Inconclusive results were found although a substantial number of studies suggested inverse association of abdominal VAT with pulmonary function. There is a limited number of studies addressing the relationship between VAT and COPD. Conclusion The literature to date provides strong evidence in adults for the associations of higher abdominal VAT with asthma, and higher intrathoracic VAT with lower lung function parameters. Future high-quality studies are warranted that adjust sufficiently for key confounding factors such as fat distribution.