New High Blood Pressure Guidelines

Blood pressure 4The guidelines for treating high blood pressure (hypertension) were recently revised. In brief, the authors raised the acceptable limit for systolic blood pressure for individuals 60 years and older. Additionally, they questioned the previous recommendation of aiming for lower blood pressures for patients with diabetes and kidney disease. As was the case with cholesterol, the conclusions were challenged by many experts, particularly challenging the choice of studies that produced the conclusions.

The previous blood pressure treatment goal of less than 140/90 mm Hg for individuals 60 years or older has been raised by the new guidelines to 150/90 mm Hg. The former goal was based on studies showing an increased cardiovascular risk in individuals with blood pressure over 140/90 mm Hg and risk improvement when the blood pressure was lowered. For instance, lowering blood pressure by 10 mm Hg in patients with hypertension reduces the risk of cardiovascular and stroke death by 25% to 40%.

However, the studies documenting results such as the above often had a goal of less than 160 mmHg and often did not examine the subset of patients 60 years and older. Two recent relatively short-duration studies comparing a goal of less than 140 mm Hg with less than 150 mm Hg in patients over 65 years showed no outcome difference. Using a review of many studies, the guideline authors did not find sufficient evidence that the more aggressive treatment goal of 140/90 mm Hg vs. 150/90 mm Hg benefits older adults.

The obvious question is: What is the harm of a more aggressive goal since so many studies, however imperfect, document improvement with lower blood pressure? Medication side effects are the worry. Too many times physicians become cemented on a number and push medications to the point where an individual experiences dizziness (the most common antihypertensive medication side effect.) The risk from falls can exceed the more remote risk from hypertension. Therefore, on balance the guideline authors suggest flexibility when treating patients 60 years and older.

That said, if an older hypertensive individual tolerates a goal of 140/90 without side effects there is no reason to decrease or stop medication allowing an increase in blood pressure to 150/90. Furthermore, many think that there is reason to believe that the lower goal, absent the concern of medication side effects, probably is more beneficial.


Are Extra Vitamins a Good Idea?


The standard authorities state that for most healthy adults consuming a well-balanced diet, multivitamins (which usually contain 50%-150% of the recommended adult daily requirement of the standard vitamins) are not needed. However, some evidence suggests that taking a daily multivitamin causes a small decrease in cancer risk.

All authorities agree that there are important areas where extra vitamins are needed:

It is very important for women who might become pregnant to take a supplemental dose of 400 mcg of folic acid daily. The extra folic acid insures against inadequate reserves and prevents neural tube defects in the newborn such as spinal bifida.

A multivitamin is important for individuals with malabsorption (such as celiac disease, gluten-sensitivity), a vegan diet, alcoholism and certain other chronic conditions.

For other adults folic acid supplementation is unnecessary and perhaps unwise. An increased level of folic acid can mask vitamin B12 deficiency, a very serious deficiency problem, and may stimulate the growth of some cancers.

In order to prevent osteoporosis and decrease the risk of falls (a curious, but substantiated association) adults need a minimum of 800 units of vitamin D daily, taken either through dietary sources or as a supplement. Unlike all other vitamins, vitamin D can be produced by humans internally. In this case sunlight is needed, and exposure is often insufficient.

Dietary sources of vitamin D include milk, yogurt and soy milk—all of which are usually fortified with vitamin D. Salmon, sardines, tuna and cheese are other good sources of vitamin D.

Since vitamin D levels are often low in adults and since vitamin D deficiency causes bone problems and has been possibly linked to other diseases, taking 600-800 units daily, particularly in older adults, seems prudent.

Vitamin A levels are usually normal in the industrialized world and supplementation is not needed and, indeed, may be harmful. Excessive doses in pregnant women can cause abnormalities in the newborn. Additionally, in all adults excessive doses can cause osteoporosis as well as possibly increasing the risk of cancer and cardiovascular disease.

Likewise, vitamin E levels are usually adequate and high dose vitamin E (more than 400 units daily) supplementation is unwarranted since excessive vitamin E levels are associated with increased all-cause mortality.

Vitamin C supplementation is safe, but has no proven benefit.

Older persons should consider taking a B12 supplement since levels of this very important vitamin can drop with age. Liver, fish, beef, cheese and eggs are dietary sources of vitamin B12. A vegan diet eliminates many dietary sources, making supplementation necessary.

Aspirin and Disease Prevention

AspirinRecently the New York Times ran an op-ed entitled “The 2,000-Year-Old Wonder Drug” extolling the benefits of aspirin for a number of illnesses including cardiovascular disease and cancer. Although quite enthused about aspirin as a disease preventive, the author does advise medical consultation about the risks versus the benefits.

Is aspirin usually a good idea for middle-aged American? For those with known cardiovascular disease it usually is. However, one year ago a large study in the Archives of Internal Medicine did not show a reduction in cardiovascular or cancer deaths in patients without prior cardiovascular disease taking low-dose aspirin. A reduction in non-fatal heart attacks was noted. This benefit, however, was associated with a 30% increased risk of significant bleeding. The authors conclude against the routine use of aspirin for patients at low risk for cardiovascular disease.

More concerning, than the well-known risk of bleeding from the stomach or intestines, is the possibility of bleeding in the brain. Although the absolute risk of intracranial vessel bleeding is small (two hemorrhagic strokes per 10,000 patients taking aspirin) the consequences can be devastating.

Also, does aspirin prevent cancer? The evidence suggests that it is effective in preventing colon cancer and might be effective in preventing other cancers, although the evidence for the latter is less clear. The dose necessary to produce a statistically significant reduction in colon cancer is not certain, but some suggest that a full aspirin (325 mg) rather than low-dose aspirin (81 mg) might be needed.

The increased risk of bleeding associated with any dose of aspirin, and the possibility of greater risk with a higher dose, along with the very useful colon cancer prevention strategy of colonoscopy now in place caused the American Cancer Society not to recommend the routine use of daily aspirin to prevent colon cancer.

Patients at low risk for cardiovascular disease should consult their doctor before committing to a lifetime of daily low-dose aspirin. Low risk is defined as a patient whose 10-year absolute risk of a first coronary disease event is less than 10%. The doctor can calculate the risk by using a formula derived from the Framingham study of cardiovascular disease.

Aspirin is the wonder drug touted in the New York Times but, as usual in medical matters, every situation is different.

Zithromax and Sudden Death

A recent study in the New England Journal of Medicine described an increased risk of death from cardiovascular causes in patients taking azithromycin. Azithromycin (Z-pack, Zithromax) is a very commonly used antibiotic and this warning merits concern.

The increased risk of cardiac death relates to the tendency of azithromycin to increase the risk of an irregular heartbeat. In this study a similar risk of increased cardiac death was noted in patients who took levofloxacin but not in patients who took amoxicillin.

The increased risk was small (47 additional deaths per 1,000,000 courses of treatment) and largely limited to patients with very significant heart problems. This increased risk is probably significantly less than that which had been noted with erythromycin in the past.

Since vulnerability is limited mostly to patients with significant heart problems (the top 10% severity of heart disease in this study) and, presumably, patients taking a number of cardiac medications some caution is needed when prescribing to these patients. Since the blood concentration of azithromycin causes the problem, particular caution is needed in patients with very severe heart disease who are also taking cardiac medications that will raise the blood concentration of azithromycin such as diltiazem and verapamil.