Arterial blood pressure changes in children and adolescents with insulin-dependent diabetes mellitus.

Diabetic nephropathy may develop in childhood and is often related to hypertension. The 24-hour ambulatory blood pressures were measured in 63 children with insulin-dependent diabetes mellitus and were compared with those of 54 healthy siblings. The patients were without clinical complications. The 24-hour recording of their blood pressures revealed higher 24-hour systolic blood pressure (SBP) (115.8 +/- 8.2), 24-hour diastolic blood pressure (DBP) (67.5 +/- 4.6), 24-hour mean arterial pressure (MAP) (81.8 +/- 5.2) compared with control subjects: 24-hour SBP (112.7 +/- 6.7), 24-hour DBP (64.7 +/- 4.1), 24-hour MAP (78.9 +/- 4.5) (p = 0.03, p = 0.001, p = 0.002, respectively). Of the daytime blood pressures, SBP, DBP, MAP were also higher (117.7 +/- 8.7, 69.7 +/- 5.2, 83.8 +/- 5.8) compared with those of siblings (114.9 +/- 6.9, 67.3 +/- 4.3, 81.1 +/- 4.9) (p = 0.05, p = 0.009, p = 0.008, respectively). Of the nighttime blood pressures, SBP, DBP, MAP were higher in patients (108.7 +/- 8.9, 59.5 +/- 6.9, 74.6 +/- 6.9) compared with control subjects (104.8 +/- 7.0, 55.1 +/- 5.0, 70.5 +/- 5.1) (p = 0.01, p = 0.0002, p = 0.0006, respectively). Furthermore, the blood pressure burden was evaluated. Blood pressure burden was defined as the percentage of the increased blood pressure readings greater than the 95th percentile divided by the total number of recorded blood pressures during a corresponding period. Patients had a 43% higher 24-hour SBP burden (19.6 +/- 16.5) and a 50% higher 24-hour DBP burden (12.3 +/- 9.6) in relation to that of control subjects (13.7 +/- 12.8, 8.3 +/- 12.3) (p = 0.03, p = 0.009, respectively). The SBP burden (17.9 +/- 14.6) and DBP burden (11.5 +/- 9.2) of the day was approximately 50% higher in the patients in the relation to control subjects (11.9 +/- 11.1, 7.8 +/- 6.7) (p = 0.01, p = 0.01, respectively). Therefore it seems that hemodynamic changes may appear early in children with diabetes.

Myocardial trophic effects of blood pressure in children with insulin-dependent diabetes mellitus.

To evaluate the effect of blood pressure (BP) on the left ventricular mass index (LVMI), 66 children with IDDM 13 +/- 3 years of age were studied and compared with 58 healthy age-matched siblings. The 24 h BP recordings disclosed that children with diabetes had higher DBP (68 vs. 65 mm Hg, P = 0.002), especially at night (60 vs. 55 mm Hg, P = 0.00007), with a minimisation of the normal nocturnal hypotension (-9.9 vs. -12.4 mm Hg, P = 0.04). Their LVMI was higher (79 vs. 71 g/m2, P = 0.02); it was independent of BP values and variability (P = NS), but it was positively correlated with heart rate (r = -0.46, P = 0.0005). In the control group, LVMI was significantly correlated with the mean SBP (r = 0.46, P = 0.0005); with its variability (r = 0.32, P = 0.02) and, to a lower extent, with heart rate (r = -0.29, P = 0.03). It is concluded that in children with diabetes mellitus the participation of BP in myocardial hypertrophy is not so obvious, although the BP load is increased. The increase of the LVMI occurs early in life and before the onset of hypertension.