Prepare for whiplash. What I am about to share with you will confuse you and make your doctor quite anxious. But I feel obligated to share data that are contradictory. Pretending that there aren’t inconsistencies would not be honest. Here is the challenge we will be presenting. The American College of Cardiology (ACC) and the American Heart Association have created guidelines for blood pressure. The goal: get the numbers below 120/80. Anything over that is considered high blood pressure and dangerous. But a study published in JAMA Internal Medicine (Dec. 13, 2021) suggests that older people might live longer and have less dementia if their blood pressure is higher. You will be shocked to read how much higher.
A Historical Perspective on High Blood Pressure:
Please be patient. I will reveal the latest data on high blood pressure, dementia, age and mortality shortly. First, though, we need to review a little history. Until August 15, 2012, if you asked almost any American physician whether someone with a blood pressure reading of 145/95 should be treated with medication, the answer would have been a resounding yes!
Medical students and residents are taught that hypertension increases the risk of heart attacks, strokes and early death. Physicians have come to believe that aggressive treatment of patients with high blood pressure will lead to better outcomes.
The mantra “less is best” got a bit more confusing on August 15, 2012, when the Cochrane Collaboration published its analysis:
“Benefits of antihypertensive drugs for mild hypertension are unclear.”
The Cochrane Collaboration represents the highest level of scientific scrutiny of available studies. The experts who analyze the data are independent and objective and have come to be regarded as the ultimate authority on the medical interventions they evaluate. As far as we can tell, there is no better organization for assessing the pros and cons of pharmaceutical and alternative therapies than Cochrane.
There is no doubt that this review created extraordinary controversy and push-back from the medical community. A bedrock belief was being challenged. That’s because the Cochrane experts were suggesting that many Americans diagnosed with high blood pressure were probably being treated unnecessarily. The researchers reviewed data from nearly 9,000 patients enrolled in four randomized controlled trials. These were people who had been diagnosed with what is called stage 1 hypertension. That means their systolic blood pressure was between 140-159 and their diastolic blood pressure was between 90 and 99.
Here is what the Cochrane Collaboration found:
“Individuals with mildly elevated blood pressures, but no previous cardiovascular events, make up the majority of those considered for and receiving antihypertensive therapy. The decision to treat this population has important consequences for both the patients (e.g. adverse drug effects, lifetime of drug therapy, cost of treatment, etc.) and any third party payer (e.g. high cost of drugs, physician services, laboratory tests, etc.). In this review, existing evidence comparing the health outcomes between treated and untreated individuals are summarized. Available data from the limited number of available trials and participants showed no difference between treated and untreated individuals in heart attack, stroke, and death.”
The abstract concluded:
“Antihypertensive drugs used in the treatment of adults (primary prevention) with mild hypertension (systolic BP 140-159 mmHg and/or diastolic BP 90-99 mmHg) have not been shown to reduce mortality or morbidity in RCTs [randomized controlled trials]. Treatment caused 9% of patients to discontinue treatment due to adverse effects. More RCTs are needed in this prevalent population to know whether the benefits of treatment exceed the harms.”
Fast Forward to 2015:
In September of 2015 a study of blood pressure treatment was stopped abruptly. The SPRINT (Systolic Blood Pressure Intervention Trial) study was terminated early because the results were so good. Patients with hypertension who got their systolic BP below 120 were less likely to have heart attacks or other cardiovascular events (New England Journal of Medicine, Nov. 26, 2015). You can read more details of the SPRINT study at this link.
This clinical trial led many health professionals to rethink “normal” blood pressure. The label “hypertensive” used to be reserved for people with systolic blood pressure (the upper number) over 150 and diastolic blood pressure (the lower number) above 99. Nowadays, anyone with blood pressure readings greater than 120/80 is likely to be labeled hypertensive.
Most physicians feel it is their duty to treat high blood pressure aggressively to get the numbers below 120/80. That is what the guidelines require.
The SPRINT-MIND Trial:
There was a follow up to the SPRINT trial.
The SPRINT-MIND study asked:
“Does intensive blood pressure control reduce the occurrence of dementia?”
It was published in JAMA (Feb. 12, 2019).
“Among ambulatory adults with hypertension, treating to a systolic blood pressure goal of less than 120 mm Hg compared with a goal of less than 140 mm Hg did not result in a significant reduction in the risk of probable dementia. Because of early study termination and fewer than expected cases of dementia, the study may have been underpowered for this end point.”
High Blood Pressure and Dementia:
There is evidence that hypertension in middle age is associated with a greater risk of dementia. How much greater? 60% greater! That was conclusion of a review published in The Lancet (Aug. 8, 2020).
But the authors of a new analysis published in JAMA Internal Medicine (Dec. 13, 2021) point out that in late life:
“…this association disappears, with few studies finding associations with increased risk and most studies reporting neutral or even decreased risks associated with hypertension.”
The researchers analyzed seven cohort studies involving 17,286 participants. Their findings will challenge conventional wisdom that less is best. They found that elderly people may actually do better when their systolic blood pressure is higher than the guidelines usually recommend. That’s because the lowest risk point for dementia and mortality combined was 163 mm of mercury for systolic pressure. That is substantially higher than most doctors like to see.
People between 60 and 70 years of age had the lowest risk when their systolic blood pressure was around 135. After age 70, however, the optimal range was 160 to 165. Most cardiologists would cringe at such data.
The Controversy Continues:
What are we to make of this controversial association? The authors acknowledge that a randomized controlled trial found lower mortality and dementia risk among certain people whose systolic blood pressure was reduced below 120. How do we reconcile this contradiction?
To do this, the authors say, we need future studies to:
“…test BP management that is tailored to one’s age, life expectancy, and health context.”
In the meantime, people with hypertension should absolutely consult their health care providers to determine the most appropriate treatment approach to control high blood pressure.
Not the First Rodeo:
This is not the first time data have challenged the 120/80 goal for everyone, regardless of age. In 2017 we posed a question in this article:
Will Low Blood Pressure Increase the Danger of Dementia in Older People?
Is lower blood pressure always better? Many people think that 120/80 is ideal but older people may be at risk for dementia if diastolic BP goes too low.
We cited an Italian study published in JAMA Internal Medicine, April, 2015.
The authors concluded:
“Low daytime SBP [systolic blood pressure] was independently associated with a greater progression of cognitive decline in older patients with dementia and MCI [mild cognitive impairment] among those treated with AHDs [antihypertensive drugs]. Excessive SBP lowering may be harmful for older patients with cognitive impairment. Ambulatory blood pressure monitoring can be useful to help avoid high blood pressure overtreatment in this population.”
You can read about the 90+ Study at this link. It too is a man bites dog story.
If you want to learn more about the Cochrane Collaboration conclusions, we encourage you to read the reports by Jeanne Lenzer in the BMJ and Slate. She did a good job reviewing the findings and making them understandable.
If you would like to learn more about ways to control high blood pressure with nondrug approaches, we suggest you check out our Guide to Blood Pressure Treatment.
A Word of Caution:
No one should EVER stop taking a medication without consulting their physician. Those with definite hypertension must be treated aggressively with medication. Hypertension does cause heart attacks, strokes and kidney damage and leads to premature death.
We do encourage those with mild hypertension to make sure their physicians read the review in the BMJ and then take time to review the Cochrane Collaboration report. We also think health professionals should read the latest research in JAMA Internal Medicine titled:
We hope there will be more serious consideration of nondrug approaches such as losing weight, deep breathing, exercising and learning how to relax and shed some of the stress that can contribute to higher blood pressure readings. Health coaches can assist in this process. So can family and friends. Older people with high blood pressure require careful oversight by well-informed health care providers.