Renin Profiling to Predict Response to Antihypertensive Therapy

To the Editor: The study by Dr Preston and colleagues¹ makes the point that age-race subgrouping is a more powerful predictor of response to therapy than renin profiling. However, their study is limited by a population of only men. We previously reported a study of 593 patients with mild hypertension, which evaluated their blood pressure response to both pharmacologic and nonpharmacologic therapy.² This study suggested that plasma renin index is a powerful predictor of response to both nonpharmacologic and pharmacologic treatment of hypertension even when controlling for age, race, and sex. A major difference between our study and that of Preston et al was that we used a plasma renin index that corrected the renin value for baseline urinary excretion of sodium rather than the classic renin profiling. The renin index method tended to normalize the data and allowed for a direct analysis of absolute renin value and blood pressure response. We found that patients with high renin index had a greater blood pressure response to both weight loss and a low-sodium, high-potassium diet than did those with low renin index and a greater blood pressure response to atenolol but not to chlorthalidone. For patients receiving a combined chlorthalidone and weight loss regimen, diastolic blood pressure showed a significant increase at 6 months per unit increase in plasma renin index.