This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Which of the following is the most impoant factor in determining the development of diabetic nephropathy? 
Select and explain. 
A. Duration of the disease, B. Hypeension, C. Pre-existing renal disease, D. Control with treatment
A: Duration of the disease
Answer: A: Duration of the disease 
Explanation: Most impoant risk factor for development of diabetic nephropathy is the duration of diabetes. 30% of patients with type 1 diabetes develop microalbuminuria after 20 years of onset of diabetes. 5 -25% of patients develop clinically significant renal failure at the time of diagnosis and 30% develop ESRD at 20years duration.