A 50 year old male with type 2 diabetes mellitus is found to have 24-hr urinary albumin of 250 mg. Which of thefollowing drugs may be used to retard progression of renal disease –
**Core Concept**
The question is testing the concept of renoprotective therapy in diabetic nephropathy. Diabetic nephropathy is a common complication of type 2 diabetes mellitus, characterized by albuminuria (excretion of albumin in the urine) and progressive renal fibrosis. The goal of renoprotective therapy is to slow the progression of renal disease and prevent the need for renal replacement therapy.
**Why the Correct Answer is Right**
Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are the preferred renoprotective agents in diabetic nephropathy. They work by blocking the renin-angiotensin-aldosterone system (RAAS), which is activated in diabetic nephropathy. By inhibiting the conversion of angiotensin I to angiotensin II, ACEIs reduce the levels of aldosterone, which in turn decreases sodium reabsorption and reduces intraglomerular pressure. This leads to a reduction in proteinuria and slows the progression of renal disease.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because beta-blockers are not a primary treatment for diabetic nephropathy. While they may have some renoprotective effects, they are not as effective as ACEIs or ARBs in reducing proteinuria and slowing renal disease progression.
**Option B:** This option is incorrect because diuretics are not a primary treatment for diabetic nephropathy. They may be used to manage hypertension, but they do not have a direct renoprotective effect.
**Option C:** This option is incorrect because calcium channel blockers (CCBs) may actually worsen proteinuria and renal disease progression in diabetic nephropathy. They can increase intraglomerular pressure and worsen renal function.
**Clinical Pearl / High-Yield Fact**
The RENAAL study demonstrated that the ARB losartan significantly reduced the risk of end-stage renal disease (ESRD) and death in patients with diabetic nephropathy. This study highlights the importance of early initiation of renoprotective therapy in patients with diabetic nephropathy.
**Correct Answer: C. Calcium channel blockers are generally not recommended as first-line therapy for diabetic nephropathy.**