Common sense may not be all that common, and what is worse, it might even be WRONG!
So let us apply common sense to the treatment of blood pressure.
High blood pressure kills. When it does not kill, it causes serious illnesses.
So common sense would dictate that lowering your blood pressure would help you avoid all those problems, right?
Not so fast.
What does high BP do?
It creates havoc!
Close to a billion people in the world have high blood pressure (BP), also called hypertension. Four out of ten adults over 25 have this disease, which causes heart attacks, strokes, kidney failure, blindness, and poor circulation in the legs.
In 2010, high BP was the leading cause worldwide for years of life lost as a result of death or disability.
Risk begins where?
Normal blood pressure is now defined as less than 120/80 millimeters of mercury (mm Hg). The “top number” is the systolic BP, occurring when the heart muscle contracts to pump blood out to the rest of the body. The diastolic BP (bottom number) occurs when the heart muscle relaxes, and the heart fills up with blood returning to it from the rest of the body.
Interestingly, according to a study published in the prestigious journal Lancet in 2002, the risk of heart disease and vascular disease increases progressively as the BP goes above 115 mm Hg systolic. This is, of course, well within the so-called normal range.
So should we lower the systolic BP to 115 mm Hg?
There is no good evidence for any benefit from that, except in the recently-stopped SPRINT trial, which we shall discuss in detail later.
Does lowering BP help?
It certainly does.
Treating hypertension can reduce the risk of having a stroke by 35–40%.
It also drops your risk of having a heart attack, but by a more modest 15–25%.
The risk of developing heart failure can go down by up to 64% by treating high BP appropriately.
There is also a strong link between high BP and kidney failure. Uncontrolled hypertension is the second most common cause of end-stage kidney disease in the US, and it also leads to a more rapid worsening of chronic kidney disease.
So how low to go?
The common recommendation currently is to lower the systolic BP below 140 mm Hg.
By and large, randomized, controlled trials of patients with high BP document the benefits of lowering systolic BP to below 150 mm Hg. Data for lowering the BP below that level are more limited.
A study published in the New England Journal of Medicine in 2010 showed that in patients with type 2 diabetes mellitus, whether you reduced the systolic BP to below 140 or below 120 mm Hg, the rate of occurrence of major cardiac events (such as heart attack or death from cardiovascular causes) did not change significantly. However, the rate of stroke was lower in those people whose systolic BP target was below 120 mm Hg. http://www.nejm.org/doi/full/10.1056/NEJMoa1001286.
How about a stroke?
Does a lower BP goal help prevent further strokes?
A study published in the Lancet in 2013 addressed this issue. http://www.ncbi.nlm.nih.gov/pubmed/23726159?dopt=Abstract.
The researchers took a group of patients with a previous stroke, and tried to lower their systolic BP to below 130 mm Hg. They also took another group of similar patients, but this time the target was below 150 mm Hg.
What were the results? There was no significant difference between the two groups in the overall risk of having another stroke. However, the risk of having a bleed in the brain was lower in the lower BP target group.
What are the guidelines?
Well, you can take your pick.
There is the JNC 8, or the Eighth Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. But you also have the ASH/ISH (American Society of Hypertension/International Society of Hypertension). Not to forget the ESH (European Society of Hypertension). All of them have set out guidelines recently. All are different.
Not to be outdone, the ACC/AHA (American College of Cardiology and American Heart Association) have issued a “scientific advisory” on treating hypertension.
Of course, the newest kid on the block is the SPRINT study, which was stopped early in August 2015.
Which one to choose?
We will address all of the guidelines mentioned above in our next article in this series.
So stay tuned.
What should you do in the meantime?
Conclusions
- Check your BP regularly, and in the manner outlined previously in http://goo.gl/pSIJSz.
- Recognize the problems which high BP can create.
- Remember that controlling your BP WILL lead to significant benefits.
- Discuss with your personal physician what your BP target should be. He or she knows your health conditions and is best placed to give appropriate and personalized advice.
Want to read more?
These issues, and others, are discussed in greater detail in my eBook “High Blood Pressure: 10 Reasons Your Blood Pressure Is NOT Under Control,” available at: