1. Incidence of Abnormal Ankle-Brachial Index in Diabetic Patients Asymptomatic of Arteriosclerotic Vascular disease
Brintha Vasagar, MD, MPH, Katee Castleman, MD, Jonathan Eichorn, DO, Adam Rajoulh, MD, and Jeffery Swartz, MD

2. Introduction
Diabetes affects 9.3% of the American population had diabetes in 2012: 29.1 million people
73,000 non-traumatic lower-limb amputations in diabetics in 2010: 60% of the non-traumatic lower-limb amputations
Risk factors include smoking, hypertension, hypercholesterolemia, type 2 diabetes
Seen in 75% of PAD
96% of men with PAD have at least one of these
No specific screening recommendation for these risk factors
USPSTF Recommendations: Insufficient evidence in asymptomatic patients

3. Ankle-Brachial Index (ABI)
Recognized as an important indicator of peripheral artery disease (PAD), a common manifestation of atherosclerosis and crucial risk factor for coronary artery and cerebrovascular disease

4. Aims
To determine the incidence of abnormal ABI in adult diabetics asymptomatic of arteriosclerotic vascular disease

5. Study Population

6. Study Population Inclusion criteria: Exclusion criteria: Diabetes
Age 20 to 80 years
Exclusion criteria:
Documented history of cerebrovascular disease
Coronary artery disease
Intermittent claudication
Subjective history of chest pain
Systolic blood pressure >160 mm Hg
Diastolic blood pressure >100 mm Hg

7. Materials & Methods ABIs were calculated using Stanford 25 Protocol
Brachial, dorsalis pedis, and posterior tibialis blood pressures were measured bilaterally
Appropriately sized manual blood pressure cuff
Doppler ultrasound
ABI Calculation:
Patients were notified of their results within two weeks of study completion
Appropriate follow-up designated by primary care provider
Highest pressure in right foot
Right ABI =
Highest pressure of both arms

8. Demographics 46 participants, mean age 57 years (Median 56.5 years)
20 men (43%), 26 women (57%)
12 smokers (26%), 34 non-smokers (74%)

9. Results Normal ABIs (ABI 0.9 -1.3): 63%
Abnormal ABIs showing elevated values (ABI >1.3): 28%
Abnormal ABIs showing mild disease (ABI ): 9%
33% of smokers had abnormal ABIs, while 38% of non-smokers had abnormal ABIs
75% of men had abnormal ABIs, while 8% of women had abnormal ABIs

11. DISCUSSION 63% with Normal ABIs
Is MAC obscuring PAD?
28% of abnormal ABIs were elevated, only 9% with abnormal ABIs showing mild disease
Supports assertion of MAC in diabetic population limiting utility of ABIs
Female gender correlated with more abnormal ABIs
Not supported by large scale studies
May be due to small sample size
No correlation with smoking status
Opposed by large scale studies
Does not account for participants who might have smoked for many years previously
Age correlation
No clear correlation, despite several large studies showing increased risk of PAD with age

12. Alternative Methods of Diagnosing PAD
In screening diabetic patients for PAD, other studies show higher sensitivity with CWD (72.2%) and TBI (63.6%) compared to ABI (45.2%)

13. Conclusions
37% of diabetics screened had abnormal ABIs, suggesting screening may be beneficial even in asymptomatic patients
MAC may elevate ABIs into the normal range despite PAD - large number of false negatives
TBI and CWD may be considered as alternatives to ABI screening in the diabetic population asymptomatic for PAD