[24-hour arterial pressure study and diabetic neuropathy and angiopathy of the lower limbs]

To study the circadian variation of BP in diabetics with chronic late complications (autonomic neuropathy, peripheral neuropathy and macroangiopathy of the lower limbs).

We studied 35 NIDDM patients, 22 male and 13 female, with a mean age of 62.17 +/- 8.66 years, all with hypertension (HBP) or with BP levels close to normal, many of them under anti-hypertensive therapy (mean BP in clinical measurements: 164 +/- 23.16 mmHg systolic and 92.14 +/- 11.06 mmHg diastolic). Twenty-four suffer from autonomic neuropathy, 23 from peripheral neuropathy and 11 from macroangiopathy of the lower limbs. The control group is composed of 10 patients with essential HBP without other observable pathology, with a mean age of 68.5 +/- 3.63 years and BP in clinical measurements: systolic 192 +/- 15.49 mmHg and diastolic 88 +/- 4.21 mmHg (without any previous therapy). The record of the BP circadian profile was made, with the use of a Spacelab monitor, model 90207, 5 days after anti-hypertensive therapy was suspended.

The mean BPs in 24 hours were: control group-systolic BP 152.6 +/- 13 mmHg and diastolic 79.8 +/- 13 mmHg; diabetics-systolic BP 136.82 +/- 15 mmHg and diastolic 77.4 +/- 8 mmHg. The daily and nocturnal mean BPs were 158.5 +/- 8.5 and 146 +/- 8.4 mmHg (systolic) and 82.8 +/- 5.7 and 70.9 +/- 5.1 mmHg (diastolic) in the control group, while they were, in diabetics, 141.3 +/- 15.7 and 135.6 +/- 16.6 mmHg (systolic) and 79.6 +/- 7.1 and 72 +/- 8.2 mmHg (diastolic). In diabetic patients, considering the groups with and without autonomic neuropathy, the difference between daily and nocturnal mean BP was 1.6 vs 9.4 mmHg systolic and 4.9 vs 9.4 mmHg, diastolic.

In both groups, the mean BP levels in 24 hours were notoriously lower than those obtained from the clinical measurements: the differences were 40 mmHg (control group) and 27.2 mmHg (diabetics) for systolic BP and 8.2 mmHg (control group) and 14.7 mmHg (diabetics) for diastolic. The BP circadian profiles show a lower variability, with absence of the nocturnal reduction, specially evident in diabetic patients with autonomic neuropathy versus other groups.