Early Changes in 24-Hour Ambulatory Blood Pressure are Associated with High Normal Albumin Excretion Rate in Children with Type 1 Diabetes Mellitus

Abstract

The relationship between urinary albumin excretion rate (AER) and elevated blood pressure (BP) is unclear as a cause-effect phenomenon in the development of diabetic nephropathy. The aim of this study was to examine the association between AER, HbA1c and BP in children with normoalbuminuria. 24-hour ambulatory BP assessment was performed in 78 children with type 1 diabetes mellitus (DM1), age mean +/- SD 13.4 +/- 2.7 yr, range 7.3-18.3 yr, DM1 duration mean +/- SD 6.6 +/- 2.9 yr, range 2.1-11.9 yr. Using generalised linear mixed models with systolic (SBP) and diastolic (DBP) blood pressure as dependent variables, the effects of AER and HbA1c were examined, adjusting for age, gender, DM1 duration and insulin dose. Patients with high normal AER (7-20 microg/min) had higher SBP during daytime and night-time compared to the low normal AER (< or = 7 microg/min) (mean +/- SD 118.20 +/- 7.98 and 110.33 +/- 7.08 mm Hg, p = 0.02; mean +/- SD 108.76 +/- 9.21 and 100.20 +/- 7.75 mm Hg, p = 0.03, respectively). DBP was also higher both during day- and night-time when compared to the < or = 7 microg/min group (mean +/- SD 73.40 +/- 6.50 and 64.86 +/- 5.67 mm Hg, p = 0.002; mean +/- SD 62.50 +/- 6.75 and 56.30 +/- 5.56 mm Hg, p = 0.03 day- and night-time, respectively). A rise in SBP and DBP is associated with increased levels of AER even within the normal range.