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

OBJECTIVES: To 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. METHOD: A 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. RESULTS: The 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. CONCLUSION: A 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.