Age-specific impacts of body weight (BW) on PEF and FEF50 estimated for three different age groups of male and female participants.

(A): Partial regression coefficients of Ln(BW) for the reference means of Ln(PEF) in young-, middle-, and advanced-age groups of both genders. Partial regression coefficients of Ln(BW) for Ln(PEF) are defined as ΔLn(PEF)/ΔLn(BW). (B): Partial regression coefficients of Ln(BW) for Ln(FEF50) are defined as ΔLn(FEF50)/ΔLn(BW).