Toe brachial index in middle aged patients with diabetes mellitus type 2: not just a peripheral issue

To explore risk factors for peripheral arterial disease (PAD) as well as the association between toe blood pressure and subclinical and clinical central vascular disease in patients with type 2 diabetes.

Toe brachial index (TBI) was cross-sectionally analyzed in 742 middle-aged (54-66 years) patients with type 2 diabetes as well as non-diabetic controls and related to other vascular measures (e.g. carotid intima media thickness (IMT), presence of carotid plaque, central arterial stiffness and left ventricular mass index) and previous cardiovascular events.

A TBI ≤ 0.7 was seen in 22% of the patients but only one patient had severe TBI reduction (TBI ≤ 0.3). The corresponding figures in the controls were 13% and 0%, respectively. Mean TBI was significantly lower in patients with type 2 diabetes than in controls (0.81 ± 0.14 vs. 0.87 ± 0.15, p<0.001). In patients with diabetes, a lower TBI was associated with increased central arterial stiffness (p<0.001), IMT (p<0.001) and carotid plaque (p<0.001) as well as with decreasing glomerular filtration rate (p<0.001). Lower TBI was found in patients with previous macrovascular ischemic events. Furthermore, TBI was negatively correlated with age (p<0.001), diabetes duration (p<0.001) and HbA1c (p=0.01).

PAD, assessed with TBI, is common in a Swedish middle-aged diabetes type 2 cohort, affecting about one-fifth. As ankle pressure may be confounded by falsely high values in patients with diabetes due to media calcification we conclude that information about TBI may improve the risk evaluation regarding arteriosclerotic disease in both small and large vessels in type 2 diabetes.