September 17, 2015 general

You have likely heard about SPRINT (Systolic Blood Pressure Intervention Trial ), a new blood pressure study sponsored by the National Institutes of Health. Researchers studied what happened to the health of persons over age 50 when their blood pressure was managed at a much lower level (systolic at 120 mm Hg) than previously thought acceptable for that age range (140 mm Hg). The study was stopped early because preliminary data showed the lower target produced a roughly 33% drop in rates of cardiovascular disease and 25% fewer deaths. That sure sounds good at first, but this news may create what legislators often refer to as “unintended consequences”. That is because of what lawmakers also say about legislation—”the devil is in the detail”. Drug companies must be over the moon knowing that most likely anyone over age 50 will rush to the doctor and ask for a prescription for a blood pressure medication. However, doctors have not seen the actual data and many are concerned because don’t know the following facts:

• Was the effect just as positive for subjects at the far end of the age range? Frequent radio guest John Young, MD said something like this on his free weekly conference call, “As we age, arteries become less flexible and it takes more pressure to get blood to the brain. If I try to get blood pressure down to 120 in my patients older than 70, they drop over and many will die.” This reminds me of a recent task force report that showed the cardio-protective benefits of low dose aspirin outweigh the risk of hemorrhage but only in persons in a specific age range (women 55-79 and men 45-79). For others the benefit did not justify the risk.
• More than a dozen medications were included in the SPRINT study and the average was 2 medications per person to reach the 120 goal. Did some drugs or combinations work better and more safely than others?
• The study also looked at kidney and brain function but those results have not yet been analyzed. What if lowering blood pressure in the elderly increased dementia?
• What other factors were correlated with the results? For example, I don’t see that smokers were excluded. Did race matter? The study covered the whole US and Puerto Rico. Were the results less impressive in areas with more sun or more minerals in the soil?

Another study showed that a component of egg whites (a peptide) acts in a similar manner and about as effectively as a prescription medication for high blood pressure. Previous studies hinted at the same effect. No, these small studies don’t constitute proof, but on the other hand, unless you are allergic to eggs, the risk from eating them is pretty small.

The SPRINT study is a good example of why it is probably prudent to not jump right on the news of any single study, especially one that isn’t totally fleshed out. Check with your doctor. He or she can give you personalized advice tempered by past experience with other patients at your age and in your general health status.

That reminds me. Last week I talked about research showing that vitamin C mimicked some effects of exercise. That was just one study representing a small part of the puzzle, so I hope tht no one got the idea I was saying to stop exercising.