Cholestrol and BP. Situation?

Problem: My father has hypertention and Cholestrol problem. What's done/Current situation ? He has done 24 hr holter test which came normal, ECG which reads bradycardia. Doctor then prescribed statin medication, and bp medicine. Again During recheckup TMT was done, where doctor found some problem so he prescribed Kimet xl 25. It been 3 months he is having Kimet in addition to his bp and Cholestrol medicine. I sometimes check his bp which reads diastolic pressure Near 60 or sometimes Low or sometimes it's 70 and systolic between 130-110. Im also taking care of his diet like using canola oil, fatless chicken breast, etc. Query: So is there anything i have to be careful specifically because i sometimes find his bp diastolic readings Low.