Blood pressure and vasoactive hormones with improved glycaemic control in patients with diabetes mellitus.

To assess the effects of improved glycaemic control on arterial pressure and plasma levels of vasoactive hormones, we studied 5 male insulin dependent (Type 1) diabetic patients before and one month after commencement of rigorous control of blood glucose levels. On each occasion, continuous ambulatory intra arterial pressure monitoring for a 10-hour period, together with hourly venous sampling for plasma glucose and vasoactive hormone determinations, was performed under standardised conditions of diet and posture. Mean (+/- SEM) plasma glucose before and after improved glycaemic control was 9.4 +/- 0.3 and 6.6 +/- 0.4 mmol/l respectively (P less than 0.001). There was a small but significant fall in arterial pressure in each patient as well as for the group overall (mean arterial pressure fall 4.8 +/- 1.2 mmHg, p less than 0.01) after improved glycaemic control. The fall in individual (10 hr mean) diastolic arterial pressure levels correlated with concomitant falls in plasma glucose levels (r = 0.92, p less than 0.05) but not with changes in any of the other variables measured.