Seems to early diabetic,comorbid conditions like HT,IHD,B.A, not known, and any other medication not mentioned. For early diabetic life style modification wit appropriate dose of metformin
is good,provided if your renal parameters are normal,but reduced dose of metformin is enough because of elderly, take it as 500mg bd, if cough
persist conult physician to find out the cause.
All the best