“The time of day when you take your blood pressure-lowering medication counts,” said lead author Ramon Hermida, a professor and director of the bioengineering and chronobiology labs at the University of Vigo in Spain.
With earlier research showing mixed results, Hermida’s team designed a large randomized study that could provide conclusive evidence on whether it made a difference when blood pressure medications were taken. They recruited 19,084 hypertensive patients — 10,614 men and 8,470 women — who were randomly assigned to take their blood pressure-lowering medications first thing in the morning or at bedtime.
The volunteers all wore ambulatory blood pressure-measuring devices, which kept track of blood pressure 24 hours a day.
The researchers found, after accounting for such factors as age, gender, Type 2 diabetes, chronic kidney disease, smoking, cholesterol levels and previous cardiovascular events, that timing of medications made a difference.
At their final evaluation, patients who took their medications at night had significantly lower LDL cholesterol, higher HDL cholesterol and lower sleeping blood pressure.
During follow-up, 3,246 volunteers experienced a cardiovascular event: 274 had heart attacks, 302 had procedures to open clogged arteries, 521 were diagnosed with heart failure, 345 had a stroke and 310 died of a cardiovascular cause.
Risk of these events, and of dying from them, was significantly lower in the bedtime group. Those who took their medications at bedtime were 45 percent less likely to die of cardiovascular causes overall, 56 percent less likely to die of cardiovascular disease, 61 percent less likely to die of hemorrhagic stroke and 46 percent less likely to die of ischemic stroke — the more common kind.
Those taking medications at bedtime were also 34 percent less likely to have a heart attack and 49 percent less likely to have a stroke.