Associations Between Pulmonary Function And Body Composition Parameters In Healthy, Non-smoking Adults

Spirometry is often used to assess lung function and the severity of lung disease. Relationships have been identified between pulmonary function and body composition in diseased populations (e.g., COPD, asthma). However, less is known about this relationship in metabolically healthy individuals. PURPOSE: To examine the relationship between body composition and pulmonary function in metabolically healthy, non-smoking adults. METHODS: 109 adults (M: 51 and F: 58; Age = 42.3 ± 11.4 yrs, Body Fat% = 24.8 ± 8.4%) consented to participate and met the inclusion criteria for the study. Participant ages ranged from 25 to 65 and had not been diagnosed with a chronic disease. All participants completed a standardized blood draw following an overnight fast to assess their metabolic and lipid profiles. Participants also completed a body composition analysis using dual-exergy x-ray absorptiometry (DEXA). Finally, participants completed a pulmonary function assessment measuring forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), slow vital capacity (SVC), and maximal voluntary ventilation (MVV) using BreezeSuite. RESULTS: Higher BF% was negatively correlated with FVC, MVV, and FEV1 (p < 0.01). A corresponding linear regressions found that a one-point increase in BF%, resulted in a FVC decrease of 49.1% (95%CI = -.084, -.041; p < .001), a FEV1 decrease of 45.5% (95%CI = -.068, -.030; p < .001), and a MVV decrease of 51.6% (95%CI = -3.626, -1.708; p < .001). Additionally, a one-point increase in body mass index (BMI) and lumbar spine (L-Spine) bone mineral content (BMC,) resulted in FVC increases of 20.5% (95%CI = .010, .094; p < .001) and 29% (95%CI = .009, .032; p < .001) respectively. While one-point increases in FEV1 resulted in increases of 13.5% (95%CI = -.008, .065; p < .001) and 32% (95%CI = .009, .029; p < .001) respectively. Results indicated that increases in BMI and L-Spine BMC were not significantly related to MVV. CONCLUSION: Those with leaner mass, higher BMC, and lower total BF% show enhanced lung function. As total BF% increases, their pulmonary function displays a steady decline. In conclusion, in order to preserve pulmonary function in healthy obese and overweight populations, individuals should aim to reduce BF% and increase overall lean mass.