A study of 59,124 patients in 223 medical care centers had one group of patients check their blood pressures several times throughout the day and night, while the other group had blood pressure checked in their doctors’ offices only. After 10 years, 12.1 percent of patients died, including 4.0 percent from heart disease (Lancet, June 17, 2023;401(10393):P2041-2050). The study found that having patients check their blood pressure several times during the day and night, and following those results, was six times more effective in predicting death overall and death from heart attacks than just taking patients’ blood pressure in the doctor’s office.

• This study agrees with many previous studies that found that blood pressure tends to rise at night (JAMA, 2019; 322: 409-420). People who have high blood pressure only at night are still at significantly increased risk for death from heart attacks or death from any cause.

• Earlier studies have found that nighttime high blood pressure is a better predictor for heart attacks and premature death than daytime blood pressure (Circulation, 2020;142:1810-1820; Hypertension, 2005; 45: 240-245).

• Many people have normal blood pressure during the day and high blood pressure just at night. Sustained day-and-night high blood pressure is a stronger predictor of heart attacks than having high blood pressure only at night.

• People who had only “white coat syndrome” (high blood pressure only in the doctor’s office) were not at increased risk for premature death.

• High systolic blood pressure is a far better predictor of premature death than having just high diastolic blood pressure (Hypertension, 2008; 51: 55-61)

If You Find It Difficult to Control Your Blood Pressure
Doctors followed more than 19,000 high-blood-pressure patients for six years and found that taking blood pressure medications at night reduced risk of heart-related death and disease by nearly half (Cardiovasc J Afr, Nov-Dec 2019;30(6);368-372, PMC8802365). Compared with those who took their pills in the morning, those who took their pills at night had a more than 40 percent lower risk for heart attacks, heart failure, stroke or having surgery to open blocked heart arteries. Their risk for dying from heart diseases was reduced by 66 percent. If the results of this study can be confirmed with other studies, all patients will be given new guidance on when to take their medications. Blood pressure usually rises in the evening and drops by 10-20 percent when you lie down in bed, but some people can suffer an increase in blood pressure during sleep.

My Recommendations
Half of all adult North Americans have high blood pressure, and only 40 percent of those taking medications have their hypertension well-controlled (Int J Cardiol Hypertens, July 31, 2020;6:100044). Ideal blood pressure would be below 120/80, but it can often take three or more medications to reach that ideal level. Taking multiple drugs increases risk for side effects such as fainting or low blood pressure. If you are having difficulty controlling your high blood pressure, ask your doctor if it would be alright to try taking your blood pressure medications at night.