Captopril and kidney function in renovascular and essential hypertension

Area of Science:

• Nephrology
• Cardiology
• Pharmacology

Background:

• Severe hypertension presents diverse etiologies, including essential, renovascular, and unilateral small kidney.
• Captopril is a widely used angiotensin-converting enzyme (ACE) inhibitor for hypertension management.
• Long-term effects of captopril on renal function in different hypertensive subgroups require detailed investigation.

Purpose of the Study:

• To investigate the long-term effects of captopril on blood pressure and serum creatinine levels in patients with various forms of severe hypertension.
• To compare the impact of captopril on renal function across subgroups: essential hypertension, renovascular hypertension, and unilateral small kidney.
• To identify factors influencing changes in serum creatinine during captopril treatment.

Main Methods:

• A cohort of 25 patients with severe hypertension (essential, renovascular, unilateral small kidney) was treated with captopril.
• Mean blood pressure and serum creatinine levels were monitored over a mean control period of 34.9 months.
• Statistical analysis was performed to compare changes in serum creatinine across different patient subgroups and identify influencing factors.

Main Results:

• Captopril demonstrated comparable blood pressure reduction across all hypertensive subgroups.
• Patients with renovascular hypertension showed a significant increase in serum creatinine (117 to 162 mumol/l, p < 0.05).
• Essential hypertensives exhibited a slight decrease in serum creatinine (113 to 111 mumol/l), while those with unilateral small kidney maintained normal levels. Increased creatinine changes were associated with bilateral renal artery stenosis and high initial plasma renin activity.

Conclusions:

• Captopril is effective in reducing blood pressure in severe hypertension.
• Caution is advised when using captopril in patients with renovascular hypertension due to potential for significant renal function decline.
• Monitoring serum creatinine is crucial, especially in patients with renovascular hypertension, bilateral renal artery stenosis, or high plasma renin activity.