Increase in aperture value will enlarge the depth of field, producing wider focus, hence slower shutter speed required at the lowest ISO.
Decrease in aperture value will lessen the depth of field, producing narrower focus, hence faster shutter speed required at the lowest ISO.
Wider focus as in taking the bigger picture ie. landscape.
And narrower focus as in focusing a particular object and blurring the background ie. macro.
Did I got it wrong?