Favorable effects of insulin sensitizers pertinent to peripheral arterial disease in type 2 diabetes: results from the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial.

OBJECTIVE: The aim of this manuscript was to report the risk of incident peripheral arterial disease (PAD) in a large randomized clinical trial that enrolled participants with stable coronary artery disease and type 2 diabetes and compare the risk between assigned treatment arms. RESEARCH DESIGN AND METHODS: The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial randomly assigned participants to insulin sensitization (IS) therapy versus insulin-providing (IP) therapy for glycemic control. Results showed similar 5-year mortality in the two glycemic treatment arms. In secondary analyses reported here, we examine the effects of treatment assignment on the incidence of PAD. A total of 1,479 BARI 2D participants with normal ankle-brachial index (ABI) (0.91-1.30) were eligible for analysis. The following PAD-related outcomes are evaluated in this article: new low ABI≤0.9, a lower-extremity revascularization, lower-extremity amputation, and a composite of the three outcomes. RESULTS: During an average 4.6 years of follow-up, 303 participants experienced one or more of the outcomes listed above. Incidence of the composite outcome was significantly lower among participants assigned to IS therapy than those assigned to IP therapy (16.9 vs. 24.1%; P<0.001). The difference was significant in time-to-event analysis (hazard ratio 0.66 [95% CI 0.51-0.83], P<0.001) and remained significant after adjustment for in-trial HbA1c (0.76 [0.59-0.96], P=0.02). CONCLUSIONS: In participants with type 2 diabetes who are free from PAD, a glycemic control strategy of insulin sensitization may be the preferred therapeutic strategy to reduce the incidence of PAD and subsequent outcomes.

Ankle-brachial index and cardiovascular outcomes in the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial.

BACKGROUND: Peripheral arterial disease increases cardiovascular risk in many patient populations. The risks associated with an abnormal ankle-brachial index (ABI) in patients with type 2 diabetes and stable coronary artery disease have not been well described with respect to thresholds and types of cardiovascular events. METHODS: We examined 2,368 patients in the BARI 2D trial who underwent ABI assessment at baseline. Death and major cardiovascular events (death, myocardial infarction and stroke) during follow-up (average 4.3 years) were assessed across the ABI spectrum and by categorized ABI: low (≤0.90), normal (0.91-1.3), high (>1.3), or noncompressible. RESULTS: A total of 12,568 person-years were available for mortality analysis. During follow-up, 316 patients died, and 549 had major cardiovascular events. After adjustment for potential confounders, with normal ABI as the referent group, a low ABI conferred an increased risk of death (relative risk [RR] 1.6, CI 1.2-2.2, P = .0005) and major cardiovascular events (RR 1.4, CI 1.1-1.7, P = .004). Patients with a high ABI had similar outcomes as patients with a normal ABI, but risk again increased in patients with a noncompressible ABI with a risk of death (RR 1.9, CI 1.3-2.8, P = .001) and major cardiovascular event (RR 1.5, CI 1.1-2.1, P = .01). CONCLUSIONS: In patients with coronary artery disease and type 2 diabetes, ABI screening and identification of ABI abnormalities including a low ABI (<1.0) or noncompressible artery provide incremental prognostic information.