I revisit a theoretical transmission mechanism from macro shocks to expected loss component of credit spreads in a calibrated DSGE model to demonstrate how aggregate shocks affect spreads. Technological and monetary policy shocks are found to be more important factors for spreads than fiscal policy shocks. I also extend the model to demonstrate that the effect of underlying macro disturbances on credit spreads is substantially amplified if the borrower faces a leverage constraint. Such a constraint also changes business cycle properties of credit-related quantities.