[Factors associated with low ankle-brachial index in patients with type 2 diabetes and prediabetes]

To elucidate factors associated with an established marker of occlusive atherosclerosis of lower extremities - low ankle-brachial index (ABI) - in patients with diabetes mellitus or prediabetes.

We examined 182 patients with diabetes (n=158), impaired glucose tolerance (n=17), or impaired fasting glucose (n=7). We analyzed history, demographic parameters, anthropometric data (body mass index [BMI], waist circumference), levels of plasma high and low density lipoprotein cholesterol, triglycerides, degree of glycemic control, and presence of signs of atherosclerosis of other localizations.

ABI was < or = 0.9 in 47/182 patients (23.6%). Patients with ABI < or = 0.9 were older, more often had history of smoking (p<0.001). They also had higher leukocyte count (p=0.002). Body mass index was elevated in most patients, however it was lower in those with decreased ABI (29.8+/-4.4 and 32.1+/-5.2 in patients with ABI < or = 0.9 and >0.9, respectively, p=0.006). Factors independently related to ABI < or = 0.9 were age (OR 1.12; 95%CI 1.05-1.19; p=<0,001), history of smoking (OR 7.06, 95%CI 2.23-22.3, p=0.001), leukocyte count (OR 1.36; 95% CI 1.05-1.75, p=0.019), and BMI (OR 0.856, 95%CI 0.768-0.995). Leukocyte count above 7.6 x 10(3)/mm(3) compared with that < or = 7.6 x 10(3)/mm(3) was associated with more than 3 fold increase of OR (3.38, 95%CI 1.49-7.48, p=0.003). BMI <30.8 conferred almost similar increase of risk to have ABI < or = 0.9 (OR 2.9, 95%CI 1.28-6.73, p=0.011). None of biochemical parameters including characteristics of control of glycemia was related to the presence of low ABI.

In this group of mostly overweight patients with type 2 diabetes and prediabetes besides such classical factors as age and smoking white blood cells count but not lipids were associated with low ABI. Observed association of low ABI with smaller BMI within overall increased range is in line with some recent clinical reports but requires confirmation in specially designed studies.