A Spanish study has found that taking medications for high blood pressure before going to bed at night may control blood pressure more effectively. Taking these pills before bed may also significantly lower the risk for diabetes.
Researchers at the University of Vigo in Spain enrolled 2,012 men and women with high blood pressure (hypertension) in a randomized prospective study. Their average age was 53, and none had been diagnosed with diabetes when the study started. Half the participants were then randomly assigned to take all their hypertension medicines at night and half were assigned to take them all in the morning.
The participants took part in the study for an average of almost 6 years. During that time, 171 developed diabetes. The researchers who assessed whether they developed diabetes did not know which group the patients were in.
After adjusting for fasting glucose, waist circumference, mean sleeping blood pressure, chronic kidney disease, and other factors, the participants who took their medicine before going to sleep had a 57% lower risk for diabetes. Taking medications at night also resulted in a greater relative decline in blood pressure while asleep.
Those who took their medication before bed also got a greater benefit from three classes of blood pressure drugs: angiotensin receptor blockers, ACE inhibitors, and beta-blockers.
Blood pressure normally dips a bit during sleep. But a nighttime dip in systolic pressure (the first of the two blood pressure numbers) of less than 10% is known to be associated with a higher risk of death.
The authors of the study noted that switching the time of day when blood pressure medications are taken does not cost anything. They recommend that patients with hypertension speak with their physicians about when to take their medications each day.
The study was published in the journal Diabetologia.