Predictors of decrease in ankle-brachial index among patients with diabetes mellitus

Screening for peripheral arterial disease, a complication among patients with diabetes, is performed by periodic assessment of ankle-brachial index. We aimed to study the degree of ankle-brachial index change over time and factors associated with significant change.

We assessed difference between two ankle-brachial index measurements over time in a consecutive series of 82 patients with Type 2 diabetes. All patients had ankle-brachial index > 0.9 but ≤ 1.3 for the first measurement, and significant ankle-brachial index decrease was defined as a decrease of > 0.1 in the follow-up measurement compared with the baseline.

The mean follow-up duration was 27.6 (median 30.0) months. Significant ankle-brachial index decrease was seen in 20.7% of patients, including 5% with follow-up ankle-brachial index of ≤ 0.9, consistent with the diagnosis of peripheral arterial disease. After adjusting for age and gender, higher baseline HbA(1c) and serum creatinine levels, increase in follow-up serum LDL cholesterol levels compared with baseline and history of retinopathy were predictors of significant ankle-brachial index decrease.

Our study suggests that, within two years, one in five patients with diabetes and a normal ankle-brachial index may have significant progression of peripheral arterial disease. Annual ankle-brachial index assessment and better control of hyperlipidaemia may thus be required for at-risk patients with poor glycaemic control, renal impairment and retinopathy.