Figure 2 – Fitted values of FEV₁ by BMI and pancreatic status.

Predicted FEV1pp, based on adjusted linear model including the main effects of BMI and pancreatic status, as well as their interaction term, within each separate BMI category. FEV1 increases at relatively similar rates in PS across categories as BMI increases through the 85^th percentile, but then it decreases among overweight/obese PS subjects. In contrast, FEV1 increases at a markedly higher rate in PI subjects as BMI increases in the at-risk category (through the 25^th percentile), then keeps a steady rate as BMI increases through the 99^th percentile.