Background
This study was designed to investigate whether there was any difference in blood pressure (BP) readings between sitting and supine positions in diabetic and non-diabetic subjects.
Material and Method
BP in sitting and supine position was measured in 356 patients with type 2 diabetes (study group) and in 356 age- and sex-matched non-diabetic subjects (control group).
Results
The systolic and diastolic BP in the supine position was significantly higher than in the sitting position in both groups (P<0.001). The BP increment in the supine position was similar in the study and control groups (P>0.05). Multivariate logistic regression analysis of the study group showed that age was an independent predictor for the systolic pressure increment (P=0.001), whereas body mass index was an independent predictor for the increment in diastolic BP (P=0.04). The levels of sitting BP were inversely correlated with the pressure increments in the supine position in the diabetic patients (P<0.001).
Conclusions
In diabetic and non-diabetic subjects, BP in a supine position is higher than in the sitting position. In diabetic patients, age, body mass index and the levels of sitting BP seem to have significant impact on the pressure increment from a sitting to the supine position.

Keywords: Systole - physiology, Supine Position - physiology, Regression Analysis, Multivariate Analysis, Hypertension - physiopathology, Diastole - physiology, Diabetes Mellitus - physiopathology, Case-Control Studies, Blood Pressure - physiology, Aging, Age Distribution, Time Factors