Vascular Compliance Is Reduced in the Early Stages of Type 1 Diabetes

Introduction:  A reduction in vascular compliance is associated with hypertension, hypercholesterolemia, and diabetes.  It may predispose patients to cardiovascular disease.  Therefore, researchers wanted to examine if vascular compliance is reduced in type 1 diabetic patients before they develop clinically apparent diabetes-related cardiovascular complications.

Methods:  This study was done using pulse-wave analysis, comparing vascular compliance between patients with type 1 diabetes (59 patients; age range 17-61 years) and nondiabetic controls (57 controls; age range 23-79 years).  To determine the differences between the groups, researchers used analysis of covariance; adjustment for age was done if needed.

Results:  In the type 1 diabetic group, 32 of the 59 patients had no evidence of diabetes complications; 27 had microvascular complications.

The control group had large artery compliance (C1) and small artery compliance (c2) that were inversely proportional to their age (C1: r = -0.55; C2: r = -0.50; p < 0.01 for both).

Control subjects were compared to type 1 diabetes patients without microvascular complications.  In this comparison (adjusted for age), C1 in the control group was 1.51 ± 0.04 (SEM) mL/mmHg; in the diabetic group, it was 1.33 ± 0.06 (SE) mL/mmHg.

Also when adjusted for age, C2 in the control group was 0.080 ± 0.005 (SE) mL/mmHg, and C2 was 0.065 ± 0.005 (SE) mL/mmHg in the diabetic group (p = 0.03 for both C1 and C2).

Conclusions:  Before any diabetes complications are clinically apparent, vascular compliance in both large and small arteries is reduced in patients with type 1 diabetes.  The results of this study emphasize that vascular changes begin early and may contribute to the increased risk of cardiovascular events in diabetic patients; larger prospective studies are needed for confirmation of this study’s results, as well as to determine medical intervention efficacy.

Commentary by Colleen Flynn MD

A decrease in vascular compliance occurs with aging, and it indicates stiffer vessels, leading to higher pulse pressures, and more difficult-to-control blood pressure. Patients with diabetes develop decreased vascular compliance at younger ages, making it even more important to treat hypertension early and appropriately in this population.