Our blood pressure normally rises and falls throughout the day. It is at its highest in the morning and can vary from one arm to the other. The systolic reading (the first of two numbers, assessed when the heart is pumping) can rise by as much as 30 mmHg if you are sitting and waiting for the reading to be taken. This is usually taken into account when the pressure reading is taken in a hospital or doctor’s surgery, as people usually feel anxious when having their blood pressure checked.
If you are concerned that you may be placed on medication from false readings, it is possible to monitor your own blood pressure by checking it throughout the day at home. There are many devices available, such as the fully automatic digital monitors that measure your blood pressure at the upper arm rather than the wrist or finger.
High blood pressure is a symptom of modern lifestyle. As well as everyday stress, our constant need to be always on the go and consuming processed foods, it is not helped by a sedentary lifestyle.
Increasing your consumption of fresh vegetables and fruit, avoiding processed food and pre-prepared meals and starting an exercise regime to suit you can have more beneficial effects than medication, depending on your circumstances.
The confusing issue with blood pressure is where do you set the bar for what is safe and what is dangerous. The problem is similar to the levels set for high and low cholesterol. They keep changing. Up to last December, a dangerously high blood pressure (BP) reading was 140/90 mmHg (the first figure being the systolic pressure, when the heart contracts to pump blood, and the second being the diastolic reading, when the heart is at rest, measured in millimetres of mercury).
This level was redefined as 150/90 mmHg last January in the US for everyone aged 60 or over, the group taking the majority of anti-hypertensive agents such as ACE inhibitors (JAMA, 2013).
Even so, the Eighth Joint National Committee (JNC8) said American doctors should be recommending a healthy diet, weight control and exercise before prescribing any medication. The committee states that there is only moderate evidence to suggest that medication helps reduce hypertension.
Conversely, in the UK, a high BP reading is still set at 140/90 mmHg, although it too may follow America’s more relaxed definition soon. What this actually means in real terms is that fewer people will be taking beta blockers.
This may be as a result of researchers estimating that around 800,000 people across Europe have died over the past few years from stroke and hypotension (dangerously low blood pressure) after taking these drugs. However, within hours of this research being posted on the website of an academic journal, they were removed.
Just to clarify the history of what has constituted high blood pressure through the ages, medicine has continually changed its mind over the numbers. It appears that the cut-off definition of high and low blood pressure shifts every decade.
It is possible to monitor your own blood pressure by checking it throughout the day at home
• In the 1960s – adding 100 to a person’s age was considered the acceptable upper systolic limit.
• In the 1980s – high blood pressure was defined as >160/100 mmHg for all age groups.
• In the 1990s – the trigger point for medication was lowered to >140/90 mmHg.
• In 2014 – the hypertension level was redefined as >150/90 in the US.
Less than 50 years ago, doctors used a simple rule of thumb to determine whether the patients’ health was at risk. As blood pressure tends to rise with age, the old measure was to add 100 to the patient’s age, so an accepted upper systolic limit for a 60-year-old would have been 160.
Subsequently, this was considered too arbitrary and dangerous (although there was very little evidence to suggest more people were dying then, as a result of hypertension), so a more definitive reading of 160/100 mmHg was set for all age groups.
Eventually, this too was considered too cavalier and the current danger level of 140/90 was agreed upon in 1997. That is until the JNC8’s declaration last December.
The JNC8 is made up of 17 of America’s leading cardiologists and experts on hypertension. They assess the best practice guidelines by analysing the results of ‘gold standard’ studies. The panel was at pains to clarify that it had not redefined high blood pressure, although that is clearly what they did.
The panel states that a more reasonable reading for someone aged 60 and over should be 150/90. However, the previous threshold remains the best for anyone aged 30 or younger, or with diabetes or chronic kidney disease.
Ultimately, the panel confirmed that anti-hypertensive drugs have only moderate levels of success and are perhaps best as a short-term remedy if you are not diabetic or have kidney disease. It reiterated the need for a healthy diet, regular moderate exercise and a controlled lifestyle.
kathryn@maltanet.net