text_1: Drug may delay high blood pressure in some
text_2: This article discusses a recent New England Journal of Medicine article on a randomized, controlled, double-blinded trial of candesartan, an Angiotensin II Receptor Blocker (ARB), to prevent hypertension in prehypertensive patients. Candesartan works by blocking the action of a substance in the body that causes blood vessels to tighten. As a result, candesartan relaxes blood vessels and this lowers blood pressure. There is evidence of disease mongering in this story: The classification of “prehypertension” (systolic 130-139 mm Hg and 85-89 mm Hg diastolic) is still debatable by some medical experts, and whether prehypertension alone is a strong predictor of future heart disease is also debatable. Blood pressure increases as a natural part of aging, so whether prehypertension or mild hypertension should be viewed as a condition or disease and treated with costly medication needs further study. Hypertension is only one of several risk factors that contributes to heart disease. A prehypertensive or mildly hypertensive person with low risk factors and a healthy lifestyle may not benefit from drug treatment as much as someone with greater risk of heart disease and an unhealthy behaviors, such as a poor diet, lack of exercise and smoking. The story does mention lifestyle modifications, such as diet and exercise, as a “cornerstone of controlling blood pressure,” however, comparison is only anecdotal and there is no mention of studies examining the effect of lifestyle modification on prehypertension or hypertension. The story mentions limiting salt and water as part of lifestyle modification. A reduced sodium diet may help control hypertension, but reducing water will not help most people decrease blood pressure. There is not much quantitative information on the risk reduction from taking an ARB to prevent hypertension. There was some modest protective benefit in the treatment group at 4 years (absolute reduction 9.8%), though the story says those who took the drug for 2 years and then a placebo for an additional 2 years “matched the placebo group”. There is no discussion of the side effects of this anti-hypertensive drug, nor is there discussion of long-term safety of taking this medication for many years as a means of prevention. The most common side effects of ARBs are cough, elevated potassium levels, low blood pressure, dizziness, headache, drowsiness, diarrhea, abnormal taste sensation (metallic or salty taste), and rash. In this study, gastrointestinal problems, dizziness and headaches were more common in the treatment group, though in most cases, the difference was small. This class of drugs are typically more expensive than other anti-hypertensive medications, but there is no mention of the cost of taking this medication daily for prevention of hypertension. Also, there is no comparison of ARB treatment with less costly anti-hypertensive medications such a diuretics, or a cost comparison with lifestyle modification. Lastly, the story appropriately notes that the makers of the candesartan sponsored and help design the study. What is not mentioned is that the lead author also serves as a consultant to the drug company and has other grant support from AstraZeneca, the makers of the drug.