Nighttime blood pressure readings: Why it’s more important than daytime BP; tips to keep hypertension at bay  |  Photo Credit: iStock Images
- People who experience high blood pressure at night are at increased risk for cardiovascular events
- The problem is, a person can have high blood pressure for years without any symptoms
- Researchers expalin why spikes in blood pressure while you sleep can have potentially deadly consequences
New Delhi: High blood pressure, or hypertension, is a common condition that develops over many years, affecting nearly everyone eventually. It increases a person’s risk of serious health issues such as heart attacks and strokes. However, many people may not be aware of the fact that they can experience spikes in blood pressure while sleeping, a condition called nocturnal hypertension, that can have potentially deadly effects.
According to a new study, individuals who have high blood pressure at night have a higher risk of developing heart failure and other forms of cardiovascular disease. The study published in the journal Circulation indicates that nocturnal hypertension is dangerous and difficult to catch as routine BP checks are usually done during daytime hours. Even people whose daytime blood pressure is normal can experience nocturnal hypertension.
Nighttime systolic blood pressure – an independent risk factor for cardiovascular events
Studies have shown that blood pressure at night is an important predictor of heart disease and stroke. The current study showed that a nighttime systolic blood pressure – the ‘top’ number – that is 20 millimeters of mercury or mm Hg (the unit of measure for blood pressure) above daytime readings increases your risk for heart disease by 18 per cent.
“Results indicate that nighttime systolic blood pressure was a significant, independent risk factor for cardiovascular events,” said Dr Kazuomi Kario, the lead author of the study and a professor of cardiovascular medicine at Jichi Medical University in Tochigi, Japan.
“The study highlights the importance of including nighttime blood pressure monitoring in patient-management strategies and will hopefully encourage physicians to ensure that antihypertensive therapy is effectively lowering blood pressure throughout the 24-hour dosing period,” Dr Kario added.
A total of 6,359 people were analysed by Japanese researchers, using wearable monitors to measure both daytime and nighttime blood pressure. All participants had at least one cardiovascular risk factor, mostly high blood pressure and free of symptomatic cardiovascular disease at baseline. Most study participants were taking medication to control their blood pressure.
During 2-year to 7-year follow-ups of the participants, researchers found that there were 306 cardiovascular events. They observed that those who had nighttime systolic blood pressure – 20 millimeters of mercury (mm Hg) above their daytime systolic reading – were significantly more likely to have atherosclerotic cardiovascular disease and heart failure. The researchers also found that disrupted circadian BP rhythm (riser pattern, nighttime BP higher than daytime BP) was linked with higher overall cardiovascular disease risk, especially heart failure compared with normal circadian rhythm.
The researchers also observed that individuals whose blood pressure was controlled with medication had an increased risk of stroke if their BP dipped too low at night.
Nighttime blood pressure readings more important
Researchers said nighttime blood pressure readings are a more accurate measurement of an individual’s circulatory health, and that these findings suggest the importance of antihypertensive strategies targeting nighttime systolic BP.
The researchers also urge medical professionals to have people’s blood pressure monitored while sleeping, considering that nighttime BP levels and an elevated pattern were associated with total cardiovascular event rate, in particular heart failure.
Dr Raymond Townsend, a medical expert with the American Heart Association and director of the Hypertension Program at University of Pennsylvania, told Healthline that ideally all blood pressure measurements would be taken at night, not during the day.
“When you’re asleep at night, it’s the purest time for blood pressure,” he said. “It’s a window into how that person’s system is working,” Dr Raymond Townsend, a medical expert with the American Heart Association and director of the Hypertension Program at the University of Pennsylvania, told Healthline, adding that ideally all blood pressure measurements would be taken at night, not during the day.
How to control high blood pressure
According to experts, having regular sleeping patterns, taking blood pressure medication in the evening as well as limiting salt intake can help lower improve hypertension throughout the day and night, while reducing mortality overall.
And here are a few tips to lower your blood pressure naturally:
- Exercise regularly and increase your activity level, focusing on the ones that raise your heart and breathing rates.
- Lose weight if you’re overweight — losing even 5-10 pounds can lower your risk of high blood pressure.
- Restrict the intake of sugar and refined carbohydrates, which can help you lose weight and lower your blood pressure.
- Eat a diet rich in fresh fruits, vegetables, whole grains and low-fat dairy products. Avoid or reduce saturated fat and cholesterol to lower your blood pressure. Cut back on salt and increase the intake of potassium-rich foods like bananas that can lower blood pressure.
- Stop smoking and manage stress, which is important for your blood pressure and overall health. Also, limit alcohol intake, if you drink, as drinking too much can increase blood pressure.
Making simple lifestyle changes can significantly reduce your numbers and lower your risk of complications, perhaps, without requiring medications.
Disclaimer: Tips and suggestions mentioned in the article are for general information purpose only and should not be construed as professional medical advice. Always consult your doctor or a dietician before starting any fitness programme or making any changes to your diet.