Background To evaluate changes in pulse pressure (PP) and markers of cardiovascular autonomic neuropathy (CAN) according to duration of type 1 diabetes mellitus (T1DM).

OBJECTIVE -To evaluate pulse pressure changes according to duration of type 1 diabetes and to assess the influence of posture.RESEARCH DESIGN AND METHODS -We performed continuous measurement of blood pressure with a Finapres device during a 3 ϫ 1 min posture test (standing, squatting, standing) in 159 type 1 diabetic patients divided into four groups according to diabetes duration (Յ10, 11-20, 21-30, and Ͼ30 years, groups 1-4, respectively) and compared the results with those of age-matched nondiabetic subjects.RESULTS -Pulse pressure progressively increased according to type 1 diabetes duration (P Ͻ 0.0001), especially in women, but not in age-matched nondiabetic subjects (NS). Pulsepressure increase from group 1 to group 4 was amplified in the squatting position (from 50 Ϯ 17 to 69 Ϯ 14 mmHg) compared with standing (from 44 Ϯ 15 to 55 Ϯ 12 mmHg).CONCLUSIONS -Pulse pressure increases according to type 1 diabetes duration more in women than in men, and the squatting position sensitizes such pulse-pressure increase in both sexes.

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Aim. -Cardiovascular autonomic neuropathy (CAN) and pulsatile stress are considered to be independent cardiovascular risk factors. This study compared haemodynamic changes during an active orthostatic test in adult patients with type 1 diabetes (T1DM), using low versus high RR E/I ratios as a marker of CAN.Methods. -A total of 20 T1DM patients with low RR E/I ratios were compared with 20 T1DM patients with normal RR E/I ratios, matched for gender (1/1 ratio), age (mean: 46 years) and diabetes duration (22-26 years); 40 matched healthy subjects served as controls. All subjects were evaluated by continuous monitoring of arterial blood pressure (Finapres ® ) and heart rate using a standardized posture test (1-min standing, 1-min squatting, 1-min standing), thus allowing calculation of baroreflex gain.Results. -Compared with controls, T1DM patients showed lower RR E/I ratios, reduced baroreflex gains, higher pulsatile stress (pulse pressure × heart rate), greater squatting-induced pulse pressure rises, orthostatic hypotension and reduced reflex tachycardia. Compared with T1DM patients with preserved RR E/I ratios, T1DM patients with low RR E/I ratios showed reduced post-standing reflex tachycardia and baroreflex gain, and delayed blood pressure recovery, but no markers of increased pulsatile stress. Interestingly, decreased baroreflex gain was significantly associated with both pulsatile stress and microalbuminuria.Conclusion. -The use of RR E/I ratios to separate T1DM patients allows the detection of other CAN markers during an orthostatic posture test, but with no significant differences in pulsatile stress or microalbuminuria. In this context, squatting-derived baroreflex gain appears to be more informative. But. -La neuropathie autonome cardiaque (NAC) et le stress pulsatile sont considérés comme des facteurs de risque cardiovasculaire indépendants. Nous avons comparé les modifications hémodynamiques pendant un test actif d'orthostatisme chez des adultes diabétiques de type 1 (DT1) séparés selon la valeur de RR E/I ratio (basse versus élevée) comme marqueur de NAC. KeywordsMéthodes. -Vingt patients DT1 avec un ratio E/I abaissé ont été comparés à 20 patients DT1 avec un ratio E/I normal, appariés pour le sexe (1/1 ratio), l'âge (moyenne : 46 années) et la durée du diabète (22-26 années). Quarante sujets sains appariés ont servi de témoins. Tous les sujets ont été évalués par une mesure continue de pression artérielle (Finapres Résultats. -Comparés aux témoins, les patients DT1 ont un ratio E/I abaissé, un gain baroréflexe diminué, un stress pulsatile (pression puisée × fréquence cardiaque) accru, une augmentation plus marquée de pression puisée en position accroupie, une hypotension orthostatique et une tachycardie réflexe réduite. Comparés aux patients DT1 avec un ratio E/I préservé, les patients DT1 avec un ratio E/I abaissé ont une diminution de la tachycardie réflexe lors du redressement et une réduction du gain baroréflexe, un retard dans la correction de l'hypotension orthostatique, mais pas d'augm...