Background and aim Adolescents with type 1 diabetes (T1DM) and obesity present higher cardiovascular risk and ambulatory blood pressure measurements (ABPM) can identify the non-dipper status, often the first sign of hypertension. The aim of our observational cross-sectional case-control study conducted in T1DM, overweight and healthy adolescents was to assess blood pressure (BP) parameters to identify subclinical cardiovascular risk.

Methods We performed ABPM for 24 h in 39 adolescents (26 male and 13 female) with T1DM followed in our Paediatric Department between January 2011 and December 2012. We compared the data of patients with those of overweight subjects and healthy controls.

Results ABPM revealed no significant difference between T1DM patients and overweight subjects except for night-time diastolic BP values (p = 0.000). Instead we found significant difference between type 1 diabetic patients and healthy controls in all 24 h Systolic (p = 0.000), 24 h Diastolic (p = 0.002), Day-time Systolic (p = 0.005), Night-time Systolic (p = 0.000), Day-time diastolic (p = 0.038) and Night-time Diastolic (0.000) BP values. We detected hypertension in 10/39 (25.6%) T1DM patients and in 8/39 (20.5%) overweight subjects (p = 0.591), whereas no-one of healthy controls presented hypertension (p = 0.001). We observed non-dipper pattern in 32/39 (82%) T1DM patients, in 26/39 (66.6%) overweight subjects (p = 0.120), and in 13/39 (33.3%) of healthy controls (p = 0.000).

Conclusions ABPM studies allows to identify patients at risk for the development of hypertension, who might benefit from the early introduction of anti-hypertensive therapies. In evaluating BP in T1DM and overweight subjects, ABPM should be used since a reduced dipping can indicate incipient hypertension.