Digital photoplethysmography is a portable, operator-independent, reproducible and simple method of measuring arterial stiffness. Ranges of normality of arterial stiffness will depend on the individual's age, race, lipid levels, HR and blood pressure.

Isoflavone supplementation from red clover may favourably influence blood pressure and endothelial function in postmenopausal type 2 diabetic women.

INSR (insulin-resistance syndrome) affects 25% of the Australian population and is associated with increased cardiovascular risk. In the present study, we postulated that early cardiovascular changes in these individuals may be associated with an activated RAS (renin-angiotensin system). We studied 26 subjects: 13 with INSR [waist circumference, 99+/-6 cm; HOMA (homoeostasis model assessment) score, 2.5+/-0.3] and 13 NCs (normals controls; waist circumference, 77+/-2 cm; HOMA score, 1.4+/-0.2). All received intravenous GTN (glyceryl trinitrate; 10, 20 and 40 microg/min), L-NMMA (N(G)-monomethyl-L-arginine; 3 mg/kg of body weight), AngII (angiotensin II; 8 and 16 ng/min), the selective AT(2)R (AngII type 2 receptor) inhibitor PD123319 (10 and 20 microg/min) and AngII (16 ng/min)+PD123319 (20 microg/min). At the end of each infusion, arterial stiffness indices [SI (stiffness index) and RI (reflection index)] and haemodynamic parameters were measured. There was a significantly higher RI response to AngII (P=0.0004 for both 8 and 16 ng/min doses) and to PD123319 (P=0.004 and P=0.03 for 10 and 20 microg/min doses respectively) in subjects with INSR compared with NCs. Co-infusion of AngII and PD123319 did not lead to additive changes in RI. RI responses to L-NMMA and GTN were not significantly different in both groups. No significant differences in SI and haemodynamic responses were detected. In conclusion, AT(1)R (AngII type 1 receptor) and AT(2)R activity produce arterial stiffness changes in subjects with INSR. Evidence of increased AT(1)R- and AT(2)R-mediated responses in small-to-medium-sized arteries in INSR was found, and may play an early role in the pathogenesis of vascular changes in INSR before haemodynamic changes become apparent.

The results suggest the functional expression of AT2 receptors in small vessels that determine the inflection of the digital volume pulse wave in patients with INSR, possibly as an indicator of early vascular damage.