Objectives: Mortality rates at 10 years are higher in diabetic patients with chronic lower extremity peripheral arterial disease than in non-diabetic peripheral arterial disease patients. We tested the hypothesis that the predictors of mortality differ between diabetic and non-diabetic peripheral arterial disease patients.
Methods: We studied 331 consecutive patients who were <75 years of age, symptomatic for peripheral arterial disease, and admitted to a tertiary care hospital. Our cohort included 216 patients without diabetes mellitus and 115 with diabetes mellitus. The outcome measure was all-cause mortality at 10 years post-admission.
Results: Mortality rates at 10 years were 29% among non-diabetic peripheral arterial disease patients and 58% among diabetic peripheral arterial disease patients. We identified the following independent predictors of death in the 216 peripheral arterial disease patients without diabetes: age ≥65 years (risk ratio: 2.15; 95% confidence interval: 1.28-3.59), ankle brachial index <0.60 mmHg/mmHg (risk ratio: 1.88; 95% confidence interval: 1.14-3.08), history of peripheral arterial disease-specific intervention (risk ratio: 1.81; 95% confidence interval: 1.10-2.97), and high-sensitivity C-reactive protein ≥5.0 mg/L (risk ratio: 2.11; 95% confidence interval: 1.28-3.47). For the 115 peripheral arterial disease patients with diabetes, independent predictors of mortality were as follows: age ≥65 years (risk ratio: 1.72; 95% confidence interval: 1.05-2.83) and amino-terminal pro-B-type natriuretic peptide ≥125 ng/L (risk ratio: 2.10; 95% confidence interval: 1.22-3.60).
Conclusion: In this study, the predictors of death at 10 years differed between peripheral arterial disease patients with and without diabetes. Among the biomarkers tested, high-sensitivity C-reactive protein was independently associated with outcomes in non-diabetic patients, whereas amino-terminal pro-B-type natriuretic peptide was an independent predictor of death in patients with diabetes. Our findings suggest that in future studies, risk assessment and treatment strategies should be differentially applied to the two peripheral arterial disease subgroups.
Keywords: Atherosclerosis; biomarkers; diabetes mellitus; mortality; peripheral artery disease.