Relationship of Body Compartments and Lung Function in Adults and Elderly.

<bold>Background:</bold> Recent studies have shown associations of body compartments (BC) and lung function (LF) but population-based studies investigating the impact of these associations in adults and elderly are scarce. Hence, we aimed to investigate the impact of BC on LF in a broad aged general population. <bold>Methods:</bold> This analysis included 10,622 adults (18%, ≥65 years) from the Austrian LEAD general population cohort. Dual-energy X-ray absorptiometry scans were used to quantify body compartments (appendicular lean mass index (ALMI), visceral adipose tissue mass (VAT), fat mass index, fat-free mass index). LF parameters FEV1, FVC, TLC, FRC, and RV were assessed using spirometry and body plethysmography. Controlling for demographics, socioeconomic status, smoking habits, and nutrition, the associations between BC and LF were evaluated using multiple linear regression models. R² values were adjusted for observations and predictors. <bold>Results:</bold> R² for FEV1, FVC and TLC multiple linear regression models were ≥0.5 and ≤0.4 for RV and FRC for adults and elderly. FMI was a significant predictor with negative associations for all LF parameters for adults and elderly. Additionally, ALMI was significant, with positive associations, in FEV1, FVC and TLC for adults and elderly. VAT and FFMI showed associations with FEV1, FVC and FRC only in younger adults, not in elderly. <bold>Conclusion:</bold> FMI and ALMI are significantly contributing to LF in the general adult population with additional contributions of VAT and FFMI in adults <65 years.