ACE/ARB therapy for patients with diabetes to prohibit diabetic nephropathy

• Elderly man with chronic diabetes found to have signs of CKD (elevated BUN and creatinine) and albuminuria who could have benefitted from an ACE inhibitor or ARB
• Key idea: Two most common causes of CKD include hypertension and diabetes, with diabetes leading to nephropathy because it leads to preferential arteriosclerosis of the efferent arteriole > afferent arteriole, thus leading to high pressure in glomerulus, resulting elevated GFR and damage to glomerulus over time (ACE inhibitor or ARB can reduce this damage by dilating the afferent arteriole, leading to a decreased GFR)
• Key idea: ACE inhibitors or ARBs should be initiated at onset of microalbuminuria in all diabetic patients

This is one of those questions where the last sentence really, really matters. Also the fact that there were two BPH drugs means it's probably worth scouring the question for clarification, if you were thinking about this question from a chief complaint perspective (like I was).