I have the exact same thing. I have an appointment with the doctor next friday, I will let you know what they say. Have you found out anything since you posted?
There is no specific diagnosis to account for shortness of breath limited to bending over, unless your fiancé has experienced rapid weight gain, with the gain of fat mostly around the abdomen and flanks, 2) is pregnant or, 3) if he/she has developed a large quantity of fluid within the abdomen. If that is not the case, then your fiancé should have an examination of the abdomen, lungs and heart.
Good luck.