[Epidemiological study on the relationship between the siesta and blood pressure].

OBJECTIVE: Use epidemiological approaches to investigate the correlation between the siesta and blood pressure.

METHOD: From March 1(st,) 2011 to June 30(th) 2013, a total of 950 people were collected from East Jiaozhou Qingdao region using variable sampling methods including stratified method, the entire group method, random and proportional methods. Medical professionals conducted a person-to-person survey, collecting the data and inputting it into computers, after which a database was established using STATA 12.0. We analyzed the correlation between the siesta time and blood pressure/hypertension by using rank correlation method (Spearman). Logistic regression method was used to analyze the relationship between high blood pressure and different time and habit of the siesta after adjusting age, sex and BMI.

RESULTS: There was a negative correlation between the time of siesta and the systolic pressure with r=-0.18, P<0.001; there was no relationship between the time of siesta and the diastolic pressure with r=-0.07, P=0.02; also, there is a negative correlation between the time of siesta and the hypertension morbidity, with r=-0.22, P<0.001. In the Logistic regression analysis about the period of time to take a nap and the risk of hypertension, it was found that the relative risk factors for hypertension were more than 60-year-old, BMI >25 kg/m(2) and no siesta habits.

CONCLUSIONS: The time of siesta is negatively correlated to the systolic pressure, rather than the diastolic pressure, and it can generally reduce the incidence of hypertension. The relative risk factors of hypertension are more than 60-year-old, BMI >25 kg/m(2) and no siesta habits in all four seasons. We recommend that take a nap a day, or it might be even better for systolic blood pressure to take longer siesta.