March 2003

• Vitamin E supplements
• News on blood pressure drugs

Vitamin E supplements

If you’ve been taking vitamin E supplements, you’re not alone. The positive results of early studies on the antioxidant led many to take it in hopes of preventing or slowing everything from respiratory infections to macular degeneration. But what proves hopeful in early, preliminary studies doesn’t always pan out in larger research settings, and vitamin E is a case in point.

Age- Related Macular Degeneration

Age- Related Macular Degeneration (AMD) is the breakdown of cells of the macula, the small part of the eye that allows us to see things sharply and in color. Little is known about what causes AMD, which is the leading source of vision loss in people older than 55.

Early observational studies showed vitamin E might help prevent macular degeneration. To test this theory, researchers recruited close to 1,200 participants between the ages of 55 and 80 to receive either a daily vitamin E supplement or a placebo for four years. Participants underwent annual eye exams to detect signs of development or progression of AMD and changes in visual function.

The results of this study showed the incidence of AMD was similar among participants in the two groups. In the vitamin E group 8.6% developed AMD, whereas 8.1% in the placebo group did. Though this study clearly indicates that vitamin E does not help prevent or slow the progression of AMD, the study period was short, so it doesn’t prove that vitamin E doesn’t help in the long run.

(British Journal of Medicine, July 6, 2002)

Respiratory Infections

Early studies showed that vitamins and minerals, particularly vitamin E, may boost immune response in healthy elderly people. With this in mind, Dutch researchers set out to investigate whether either of the supplements lessens the rate and severity of respiratory infections in the elderly.

The researchers enlisted 652 participants over the age of 60 and broke them randomly into four groups. Each day, they either took a multivitamin with minerals and a placebo, a vitamin E pill and a placebo, both a multivitamin with minerals and vitamin E pill, or two placebos. After fifteen months of follow-up, the researchers found that the rate of respiratory infections did not differ among the groups. However, those who took vitamin E supplements actually had respiratory infections that were more severe — they were longer, caused more symptoms, and restricted more of the sufferer’s activities.

(Journal of the American Medical Association, August 14, 2002)

February 2003 Update

News on blood pressure drugs

Behind the scenes at your doctor’s office debate continues about which drug should be the first line of treatment for high blood pressure. Diuretics (also known as water pills) have been around for decades, but the makers of newer, more specialized — and more costly — drugs have been wooing physicians and their patients. The question isn’t whether these drugs work effectively to lower blood pressure; they do. But evidence indicating which is best at reducing heart disease and other cardiovascular events has been missing — until now.

The ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) study was designed to compare a diuretic to three other commonly prescribed classes of antihypertensive drugs — calcium channel blockers (CCBs), alpha-adrenergic blockers, and angiotensin-converting enzyme (ACE) inhibitors. The study involved 42,000 patients over the age of 55 with hypertension and one other risk factor for heart disease, such as previous heart attack or stroke. Each of the patients was randomly assigned to receive one of the study drugs for four to eight years. Researchers monitored the patients’ blood pressures and recorded evidence of heart disease and cardiovascular events.

Part of the study was halted early when evidence showed patients taking the alpha-adrenergic blocker had higher rates of cardiovascular disease and heart failure than patients taking the diuretic.

The primary results of the comparison of the ACE inhibitor lisinopril and the CCB amlodipine to the diuretic chlorthalidone were striking. The occurrence of death from heart disease was the same across each of the groups, and the rate of nonfatal heart attack was also similar. However, a slightly higher percentage of patients taking the diuretic chlorthalidone achieved better blood pressure control. Chlorthalidone was also better at preventing heart failure than amlodipine, the CCB. Patients taking the ACE inhibitor lisinopril had a higher risk of stroke, angina, and heart failure. In particular, black participants who took lisinopril had a 40% higher risk of stroke than black participants who took the diuretic.

The findings of the ALLHAT study indicate that when it comes to drugs for high blood pressure, newer and more costly does not mean better. In fact, diuretics should be the first line of treatment for many people with high blood pressure. Not only are they better at controlling high blood pressure while preventing major cardiovascular events, diuretics also cost less than the other drugs. A one-year supply of Chlorthalidone costs about $96, while the CCB amlodipine would set you back $480. Lisinopril costs $384 a year for the brand name drug (either Zestril or Prinovil), and $240 for the generic.

What should you do with these study results? If you’re just starting drug treatment for high blood pressure, you might want to try a diuretic first. If you, like most people, need a combination of drugs to keep your blood pressure in check, one should probably be a diuretic. If you’re already taking a different kind of medicine and it is working well for you, there’s no need to switch. However, if you want to cut down your drug bills, you might want to talk to your doctor about a diuretic.

(Journal of the American Medical Association, December 18, 2002)

February 2003 Updat