Final answer:
Diabetic nephropathy is the type of kidney condition most likely responsible in a diabetic patient with moderate proteinuria and progressive renal insufficiency. It is a progressive kidney disease caused by damage to the capillaries in the glomeruli of the kidneys due to long-standing diabetes mellitus.
Step-by-step explanation:
The type of kidney condition most likely responsible in a diabetic patient with moderate proteinuria and progressive renal insufficiency is diabetic nephropathy. Diabetic nephropathy is a progressive kidney disease caused by damage to the capillaries in the glomeruli of the kidneys due to long-standing diabetes mellitus. It is not fully understood how diabetes leads to the damage of glomerular capillaries, but it is thought that high levels of glucose in the blood are involved.