Relationship between Blood Pressure and Indices Describing Forearm Blood Flow

Abstract

Background The aim of the study was to assess relationship between blood pressure derived from 24-hour blood pressure profile and conventional technique and indices describing forearm blood flow.
Methods The study group included 24 healthy volunteers (F : M = 6 : 18) aged 49 ± 9 years, with body mass index (BMI) 27.7 ± 4.0 kg/m2. The forearm strain-gauge plethysmography was performed in the sitting position on dominant arm. The manual conventional graphic technique was used to calculate the parameters of the blood flow as follows: arterial inflow (AI), venous capacitance (VC), venous outflow es- timated between 0.5 and 2.0 s (V0,5-2,0). The blood flow profile was studied using Spacelabs 90207 devices. The average systolic, diastolic blood pressure were calculated for 24-h period as well as for awake (SBPa, DBPa) and sleep time period. Results The V0,5-2.0 correlates significantly with 24-h, daytime as well as night-time systolic and diastolic blood pressure. The VC index correlated significantly with night-time systolic and diastolic pressure. VC correlated significantly also with 24-h diastolic pressure. The highest correlation coefficients were estimated when the relationship of blood flow indices (V0,5-2,0, VC) with diastolic blood pressure was studied. Significant correlation between arterial inflow (AI) and 24h mean arterial pressure was found in subjects characterised by AI > 5 cc/100cc/min.
Conclusions Our results showed that ambulatory - but not conventional - blood pressure correlates with the indices of venous outflow and arterial inflow in forearm assessed by means of strain-gauge plethysmography. The method used has limited value to differentiate arterial inflow below 5 cc/100ce/min.