Serum fatty-acid binding protein is associated with lung function in asthma

<bold>Background:</bold> Obesity is associated with asthma severity due to mechanical and metabolic features. The fatty acid-binding protein 4 (FABP4) contributes to metabolic dysfunction. It is unknown whether FABP4 plays a role in obesity-related asthma. <bold>Methods:</bold> FABP4 was measured in the serum of participants in the Severe Asthma Research Program using in-house ELISA. We compared mean FABP4 between sexes and by asthma severity. We used multivariable linear regression to assess the relationship between serum FABP4 and lung function, with adjustments for sex and body mass index (BMI). <bold>Results:</bold> FABP4 was measured in 102 individuals (60 [59%] severe, 26 [25%], 16 [16%] control) with a range 3.9 – 140.5, and with a median of 16.95 (IQR 10.58, 26.91) and was significantly greater in women (20.46, IQR 14.10, 31.68) compared to men (11.81, IQR 9.07, 20.79; p 0.0012) as well as in obese (25.11, IQR 15.15, 37.27) compared to non-obese (11.40, IQR 8.43, 19.55; p 0.0003). There was an increase in FABP4 from control (10.62, IQR 6.90, 16.03) to non-severe (13.34, IQR 9.73, 25.11) and to severe asthma (21.44, IQR 14.62, 36.61), which remained significant after multivariable adjustment (p 0.0068). After adjustments, there was an inverse relationship between serum FABP4 and FEV1 (r2 0.37; p 0.046; Figure 1) and FVC (r2 0.39; p 0.018). <bold>Conclusions:</bold> Elevated FABP4 is associated with worse lung function in adults with asthma, independent of sex and BMI. <fig><object-id>erj;64/suppl_68/PA3084/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>