Diastolic Blood Pressure Abnormalities and Their Relationship with Glycemic Control in Pediatric Type 1 Diabetes

Background/Objectives: Type 1 diabetes (T1D) in children is associated with increased cardiovascular risk, partly due to coexisting blood pressure (BP) disturbances. Ambulatory blood pressure monitoring (ABPM) is recommended for detecting subtle BP abnormalities, yet the relationship between glycemic control, T1D duration, and specific BP disturbances remains unclear. This study evaluated associations between HbA1c levels, T1D duration, and ABPM-derived BP parameters in a pediatric population with T1D. Methods: We included 357 children and adolescents (aged 7-18.8 years) with T1D treated at a tertiary center. All participants underwent 24 h ABPM. Glycemic control was assessed using HbA1c; values > 6.5% were considered suboptimal. We analyzed associations between HbA1c, T1D duration, and various BP parameters, including daytime and nighttime systolic and diastolic BP, nocturnal dipping, and hypertension defined by ABPM criteria. Logistic regression analyses were performed to identify independent predictors of elevated HbA1c. Results: Arterial hypertension was confirmed in 10% of patients, and 41% showed a non-dipping BP profile. There were no significant differences in HbA1c or T1D duration between dippers and non-dippers. However, patients with HbA1c > 6.5% had significantly higher 24 h diastolic BP and were more likely to meet hypertension criteria (p = 0.009). In univariate regression, both longer T1D duration (OR = 1.086; p = 0.033) and higher 24 h diastolic BP (OR = 1.065; p = 0.0068) were associated with elevated HbA1c. Both remained significant in multivariate analysis. Conclusions: Impaired glycemic control in children and adolescents with T1D was independently associated with higher 24 h diastolic BP and longer diabetes duration.