Author + information
- Rehan Malik,
- Zubair Shah,
- James Vacek,
- Deepak Parashara,
- Buddhadeb Dawn,
- Kamal Gupta and
- Salman Waheed
Background: Both ankle brachial index (ABI) and hemoglobin A1c (A1c) are independently associated with mortality. The combination of ABI and A1c with all-cause and cardiovascular (CV) mortality has not been examined.
Methods: We followed 1,813 participants from NHANES for 11.5 years (median). We divided the sample into categories by ABI and A1c as: reference (ABI 0.9-1.3, A1c<6.5), abnormal ABI (ABI<0.9, A1c<6.5), abnormal A1c (A1c>6.5, ABI 0.9-1.3) and abnormal both (ABI<0.9, A1c>6.5). Cox proportional hazards models were used with adjustment for CV risk factors. Harrell C-statistic was used to test improvement in risk prediction.
Results: Mean age was 60 years with 54% females. 5% had abnormal ABI while 9% had abnormal A1c. Those with A1c>6.5 were more likely to have abnormal ABI than A1c<6.5 (9% vs. 4%, p=0.02). Compared to the reference, adjusted hazard ratios (95% CI) for all cause mortality were 1.5 (1.1-2.1), 1.5 (0.7-3.2) and 3.3 (1.5-7.4) and CV mortality were 1.9 (0.9-4.3), 1.1(0.4-3.3) and 8.1(2.3-28.5) for abnormal ABI, abnormal A1c and abnormal both groups, respectively. There was an improvement of risk prediction for mortality when A1c was added to the adjusted model with ABI (c-statistic 0.79 to 0.80, p=0.02).
Conclusions: A1c can be used to stratify individuals with abnormal ABI into low risk category when A1c is normal. Further studies are needed to examine if diabetic individuals with peripheral artery disease can benefit from this risk stratification strategy when A1c is at target.
Poster Hall, Hall C
Sunday, March 19, 2017, 9:45 a.m.-10:30 a.m.
Session Title: Diabetes and Other Issues in Cardiovascular Prevention
Abstract Category: 32. Prevention: Clinical
Presentation Number: 1277-046
- 2017 American College of Cardiology Foundation