Effects of circadian blood pressure patterns on development of microvascular complications in pediatric patients with type 1 diabetes mellitus

PURPOSE: The effects of circadian blood pressure (BP) alterations on the development and progression of microvascular complications in type 1 diabetes mellitus (T1DM) patients are unknown. We evaluated the effects of circadian BP alterations with development of microvascular complications during follow-up with patients with childhood-onset T1DM. METHODS: We investigated the medical records of 81 pediatric patients with T1DM who underwent 24-hour ambulatory BP monitoring (ABPM) between January 2009 and February 2010. RESULTS: Mean age at diagnosis and ABPM evaluation was 8.0±3.9 and 15.6±2.4 years, respectively. Hypertension (daytime, nighttime, and 24-hour mean hypertension) data were available in 42 patients. During the 8 years of follow-up after ABPM, microvascular complications occurred in 8 patients (diabetic retinopathy [DR] alone in 5, microalbuminuria alone in 2, and both in 1), of whom 7 had nondipper BP. Nighttime diastolic BP, nighttime mean arterial pressure, and glycated hemoglobin A (HbA1c) level were higher in patients with DR than in those without DR (P<0.05 for all). Daytime or nighttime BP and presence of dipper BP were not related to microvascular complications, but diabetic microvascular complications were more likely to occur in patients with an older age at diagnosis and higher HbA1c level. The proportion of patients with DR was higher in those with nondipper hypertension (83.3%) compared with dipper and nondipper normotension (0% and 16.7%, respectively; P=0.021). CONCLUSIONS: As a predictor of microvascular complications, nondipper hypertension was not significant. Glycemic control rather than nondipper hypertension is the predominant factor determining DR in T1DM patients.