Hypertension progress in DM

A 52-year-old woman with type 2 diabetes mellitus, hyperlipidemia, and hypertension is evaluated during a routine office visit. She has a 30-pack-year smoking history. Her mother had diabetes and required hemodialysis. Medications are insulin, metoprolol, fosinopril, hydrochlorothiazide, atorvastatin, and low-dose aspirin.

On physical examination, blood pressure is 165/95 mm Hg. Retinal microaneurysms are noted on funduscopic examination. There is no jugular venous distention. The lungs are clear. Cardiac examination reveals a regular rhythm with an S4. There is bilateral pedal edema. The distal pulses are absent in both feet.

Laboratory Studies
Hemoglobin A1c 7.2%
Glucose 180 mg/dL
Creatinine 1.2 mg/dL
24-Hour urine protein excretion 1.8 g/24 h

Which of the following factors is most likely to cause this patient's chronic kidney disease to rapidly progress to end-stage renal disease?
A Cigarette smoking
B Poorly controlled diabetes mellitus
C Poorly controlled hypertension
D Proteinuria

Answer and Critique (Correct Answer = C)

Key Point
Reduction in blood pressure slows the progression of renal disease and the development of cardiovascular disease in patients with diabetes mellitus.

Poorly controlled diabetes mellitus or hypertension, proteinuria, and cigarette smoking are all risk factors for chronic kidney disease progression. However, treatment of hypertension is the cornerstone in preserving renal function in patients with diabetic nephropathy. Reduction in blood pressure has been shown to influence progression of renal disease and the development of cardiovascular disease in patients with diabetes. The goal of treatment of blood pressure in patients with both type 1 and type 2 diabetes mellitus is to maintain a blood pressure ≤130/80 mm Hg in the absence of significant proteinuria and ≤125/75 mm Hg if accompanied by a urine protein concentration >1 g/24 h. Angiotensin-converting enzyme inhibitors or angiotensin receptor blockers constitute first-line treatment of hypertension, even in patients with advanced diabetic nephropathy.

The beneficial effect of strict metabolic control of diabetes on the progression of advanced renal disease is less established than is strict control of blood pressure. Nevertheless, metabolic control should be improved in this setting in order to minimize the risk for metabolic, microvascular, and macrovascular complications of diabetes. Proteinuria is a well-recognized risk factor for the progression of renal disease, including diabetic nephropathy. Cigarette smoking has been shown to have significant detrimental effects on the kidney and may cause increased proteinuria and an accelerated decline in renal function. Nevertheless, uncontrolled hypertension is the major factor contributing to progressive renal failure.
Bibliography

1. Barnett A. Prevention of loss of renal function over time in patients with diabetic nephropathy. Am J Med. 2006;119:S40-7. [PMID: 16563947] [PubMed]