J Clin Hypertens (Greenwich). 2012;14:686–693. ©2012 Wiley Periodicals, Inc.

The aim of the current study was to compare ambulatory blood pressure (ABP) with office blood pressure (OBP) in diagnosing hypertension (HTN) in type 1 diabetes. The cross-sectional study included 569 type 1 diabetes patients, with a mean±standard deviation (SD) age of 55±13 years and diabetes duration of 33±16 years, and 315 (55%) men. Blood pressure ≥130/80 mm Hg defined HTN. ABP was measured by tonometry and OBP by sphygmomanometry. Elevated ABP with normal OBP defined masked uncontrolled HTN, and normal ABP with elevated OBP defined isolated uncontrolled clinic HTN. Mean±SD 24-hour ABP, daytime ABP, and OBP was 128±16/75±10 mm Hg, 133±16/77±11 mm Hg, and 136±14/76±8 mm Hg, respectively (P<.001). With 24-hour and daytime ABP, HTN was present in 256 (45%) and 304 (53%) patients; normal BP in 102 (18%) and 88 (15%) patients; isolated uncontrolled clinic HTN in 154 (27%) and 104 (%) patients; and masked uncontrolled HTN in 57 (10%) and 73 (13%) patients. Twenty-four–hour ABP and OBP showed disagreement in diagnosing HTN in 211 (37%) patients. Daytime ABP and OBP disagreed in 177 (31%) patients. HTN by 24-hour and daytime ABP was present in 313 (55%) and 377 (66%) patients. ABP measurements were well-tolerated and successful in 98%. A total of 92% would volunteer for repeat measurements and 83% preferred the tonometry to conventional cuff-based devices. In patients with type 1 diabetes, tonometric ABP measurements are feasible. ABP and OBP disagree in diagnosing HTN in 31% to 37% of patients. Furthermore, 55% to 66% of patients do not reach target BP of <130/80 mm Hg despite regular follow-up.