| Abstract: | Dynamic artery blood pressure (Finapres) response to active standing up, normally consisting of initial rise, fall and recovery above the baseline (overshoot), was compared with the early steady-state artery blood pressure level to measure sympathetic vasomotor function in healthy subjects (n=23, age 35±9 years; mean±SD) and in type I diabetic patients without autonomic neuropathy (AN) (group 1: n=18, 38±13 years), with AN but no cardiovascular drugs (group 2a: n=7, 44±11 years) and with both AN and cardiovascular drugs (group 2b: n=10, 47±7 years). Systolic and diastolic overshoot were similar in the control (15±13/15±11 mmHg) and group 1 subjects. Systolic overshoot disappeared in 57% of patients in group 2a (?1±9 mmHg; P<0·03), whereas artery blood pressure still overshot in diastole (8±7 mmHg; NS). Systolic overshoot disappeared in all patients in group 2b (?22±22 mmHg; P<0·0006) and diastolic overshoot disappeared in 60% of these patients (?6±16 mmHg; P=0·0006). Systolic early steady-state level was not lower in group 2a than in group 1 (NS), but it was impaired in group 2b (P<0·006), in which six diabetic patients had a pathological response beyond the age-related reference values. There was a strong association between the overshoot and steady-state levels (P for χ2<0·001, n=58). Overshoot of the control subjects and patients in group 2b correlated to their respective steady-state blood pressure levels (r≥0·76; P≤0·001). In conclusion, baroreceptor reflex-dependent over-shoot of the artery blood pressure after active standing up diminishes with the development of AN and it is associated with the early steady-state level of the artery blood pressure. |
