Association between an elevated inter-arm systolic blood pressure difference, the ankle–brachial index, and mortality in patients with diabetes mellitus

Abstract

ObjectivesTo estimate the prevalence of an inter-arm blood pressure difference greater than 10mmHg in patients with type 2 diabetes, and the association of this measurement with the presence of a low ankle–brachial index and mortality at 5-year follow-up. MethodA validated blood pressure measurement protocol was used. The blood pressure was calculated for each arm to obtain mean systolic differences. Peripheral arterial disease was confirmed by an ankle–arm index less than 0.9. The medical history of the patient was reviewed in the computerized clinical notes after 5 years of follow-up. ResultsThe study included 139 patients with a mean age of 70.1 years (49% male), and a mean duration of diabetes mellitus of 10.8 years. A total of 50 (36%) patients had an inter-arm systolic blood pressure difference greater than 10mmHg. Patients with an inter-arm systolic blood pressure greater than 10mmHg had lower ankle–arm index (0.91±0.30 vs. 1.04±0.28, P=0.005), and higher mortality rates from all causes (48.0% vs. 28.9%; hazard ratio 1.64; 95% confidence interval: 1.06–2.53; P=0.03), compared with those with lower inter-arm systolic blood pressure difference. ConclusionA high proportion of patients with type 2 diabetes have an elevated systolic blood pressure difference between arms. A significant relationship was found between elevated inter-arm systolic blood pressure difference, lower ankle–brachial index and greater all-cause mortality.