What is hypertension in diabetes? Ambulatory blood pressure in 137 normotensive and normoalbuminuric Type 1 diabetic patients

Aims To establish reference data for ambulatory blood pressure (AMBP) in no rmotensive, normoalbuminuric Type 1 diabetic patients and characterize the relation to clinic blood pressure (BP). To evaluate the statement of the th ird working party of the British Hypertension Society (BHS) that a target c linic BP in diabetes < 140/80 corresponds to a target day-time AMBP < 130/7 5 mmHg. Patients and methods AMBP were performed in 172 normoalbuminuric, adult Typ e 1 diabetic patients, who had never received anti-hypertensive drugs. Clin ic BP was determined as the mean of at least three auscultatory (Hawskley r andom zero manometer) and as the mean of at least three oscillometric (Spac elabs) BP values obtained just prior to ambulatory monitoring. Five patient s with more than three missing hours/24 h were excluded. Results For 30 patients auscultatory clinic BP exceeded 140 mmHg systolic a nd/or 90 mmHg diastolic. For the remaining 137 normotensive patients day-ti me AMBP was 125.7/77.2 mmHg and oscillometric clinic BP was 125.3/76.5 mmHg (mean difference 0.3/0.7 mmHg; 95% confidence interval (CI) -0.9 to 1.5/-0 .3 to 1.7 mmHg, P = 0.6/P = 0.2). Sixty-five percent of the patients had a diastolic day-time AMBP > 75 mmHg. Conclusions Clinic BP and day-time AMBP measured by the same method were in distinguishable. The target for day-time diastolic AMBP (< 75 mmHg) propose d by the BHS is too low and is based on the misconception that in normotens ive subjects day-time AMBP is lower than clinic BP. If the BHS guidelines a re strictly adhered to, the consequence may be overtreatment in patients wi th normoalbuminuria and no end organ damage.