In a cohort of middle-aged patients with well-controlled hypertension, those who took a long midday nap appeared to have better blood-pressure control that their peers, in a new study.
Asked about the seemingly indulgent amount of midday sleep, Kallistratos admitted to heartwire from Medscape that "people who don't work have the luxury to sleep for about 60 minutes." Sixty minutes also corresponded to a drop in blood pressure that is associated with "a meaningful decrease in risk of cardiovascular events," whereas a shorter nap may not have shown this effect.Midday sleep was associated with a 6-mm-Hg lower average systolic blood pressure, he noted in a press conference today. "Six mm Hg is a small amount, but we have to keep in mind that reductions of 2 mm Hg may decrease the risk of cardiovascular events by up to 10%," he said.
To heartwire , session comoderator Dr JR Gonzalez Juanatey (Hospital Clínico Universitario de Santiago, Santiago de Compostela, A Coruña, Spain) agreed with this potential mechanism. "The message for hypertensive, high-risk patients is that a short nap after lunch could exert a positive cardiovascular effect," he said."The benefit seems to continue after the midday nap, because we observed a change in blood pressure at night and a change in dipping status," he emphasized. "My feeling is this is due to the decrease in sympathetic 'overdriving,' " he said
A Midday Snooze
Is a midday nap just a habit, or is it beneficial for patients with hypertension? This is the question Kallistratos and colleagues aimed to answer.
They performed a prospective study that enrolled 200 men and 186 women with a mean age of 61 years and a mean blood pressure of 129/76 mm Hg. "Their blood pressure was well controlled " Kallistratos noted. The patients had other cardiovascular risk factors: they were generally overweight (mean body-mass index [BMI] 28.8), and 57% had dyslipidemia, 27% had diabetes, and 31% smoked.
Patients were classified as midday "nappers" or "nonnappers," based on their replies to questions asking if and when they napped.
After adjusting for age, gender, BMI, smoking status, salt, alcohol intake, exercise, and coffee consumption, the researchers found that the patients who took a midday nap had a 5% lower average 24-hour ambulatory systolic blood pressure than patients who did not sleep at all at midday.
Compared with patients who did not take midday naps, those who did had lower average daytime systolic BP when they were awake (126 mm Hg vs 131 mm Hg) and average nighttime systolic blood-pressure readings that were 7 mm Hg (6%) lower (115 mm Hg vs 122 mm Hg).
Kallistratos acknowledged that this was an observational study; "however, it would be difficult to randomize patients to sleep or not sleep at midday, he said.
It is possible that the findings would be different in patients with uncontrolled hypertension. "We will continue the study including patients with untreated, uncontrolled hypertension and healthy subjects" to see if the blood-pressure decrease is the same, he said.