The impact of blood pressure measurement methods on the assessment of differences in blood pressure levels between patients with normoalbuminuric type 1 diabetes and healthy controls

The aim of the study was to investigate the impact of various blood pressur e (BP) measurement methods on the assessment of differences in BP levels be tween patients with normoalbuminuric type 1 diabetes and healthy controls. We measured intra-arterial BP (i.a.), sphygmomanometric BP (sphygmo), 24-h ambulatory blood pressure (ABPM, auscultatory, Profilomat(R)) and oscillome tric BP (Dinamap(R)) in 51 patients with normoalbuminuric type 1 diabetes ( DP) with a mean diabetes duration of 8.4 years and 42 healthy controls (C). Results are expressed as mean rt SE. There was no significant difference i n i.a. BP between DP and C (systolic/diastolic BP and mean arterial pressur e (MAP) 116.2 +/- 1.2/61.7 +/- 0.8 (82.8 +/- 0.9) mm Hg in DP vs 115.6 +/- 1.2/63.2 +/- 0.9 (83.4 +/- 1.1) in C). Sphygmo BP was 117.7 +/- 1.3/69.8 +/ - 1.0 mm Hg in DP vs 116.5 +/- 1.5/67.8 +/- 1.3 in C (NS). Also, ABPM was n ot significantly different between both groups. Daytime BP between 10.00-23 .00 h was 120.9 +/- 1.2/84.4 +/- 0.9 mm Hg in DP vs 120.4 +/- 1.5/83.7 +/- 1.0 in C (NS). Night-time BP between 01.00-07.00 h was 102.4 +/- 1.2/69.3 /- 0.9 mm Hg in DP vs 103.4 +/- 1.5/69.1 +/- 1.3 in C (NS). In contrast, sy stolic Dinamap(R) BP was higher in DP (118.6 +/- 1.3 in DP vs 113.4 +/- 1.4 mm Hg in C, P = 0.01) as was MAP (85.6 +/- 0.7 in DP vs 83.3 +/- 1.0 mm Hg in C, P = 0.05). Diastolic Dinamap(R) BP was not significantly different ( 66.6 +/- 0.7 in DP vs 65.0 +/- 1.0 mm Hg in C). We conclude that intra-arte rial BP was similar in patients with normoalbuminuric type 1 diabetes and h ealthy controls. Also, when using auscultatory BP devices there were no app arent differences in blood pressure. In contrast, using the oscillometric m ethod (Dinamap(R)), BP especially systolic, was higher in diabetic patients . Measurements with an oscillometric device (Dinamap(R)) might therefore ov erestimate BP in patients with normoalbuminuric type 1 diabetes, thus confu sing conclusions on the relationship between development of hypertension an d microalbuminuria in the early phase of diabetes.