Author + information
- Salman Waheeda,b,
- Zubair Shaha,b,
- James Vaceka,b,
- Deepak Parasharaa,b,
- Buddhadeb Dawna,b and
- Kamal Guptaa,b
Background: Both ankle brachial index (ABI) and body mass index (BMI) are independently associated with mortality. The prevalence of low, normal and high ABI and the association of ABI with all-cause and cardiovascular mortality according to BMI have not been examined.
Methods: We followed 2,263 subjects from NHANES 1999-2000 for a median of 10.5 years. We divided the weighted sample into categories by ABI as ABI>1.3 (high), ABI 0.9-1.3 (normal) and ABI<0.9 (low), and BMI as BMI<30 (non-obese) and BMI>30 (obese). Logistic regression was used with adjustment for demographic characteristics, cardiovascular risk factors and brachial and ankle BP cuff sizes to examine the prevalence of low, normal and high ABI for each BMI category. Cox proportional hazards models were used with adjustment for demographic characteristics and cardiovascular risk factors to examine the association of ABI with all-cause and cardiovascular mortality stratified by BMI.
Results: Mean age was 56 years with 52% female. 31% were obese. Overall, 82%, 13% and 5% had normal, high and low ABI, respectively. Prevalence of low ABI was 3.2% in obese and 5.5% in non-obese subjects. In our adjusted model, obese subjects were less likely to have low ABI (odds ratio: 0.43, p=0.004) than non-obese. Prevalence of ABI>1.3 was similar between the two BMI categories (odds ratio: 1.09, p=0.6). Compared to normal ABI, the adjusted hazard ratio (95% CI) for all-cause and cardiovascular mortality for those with low ABI were 1.7 (1.0-2.8) and 2.5 (1.1-5.5) for the non-obese and 1.4 (0.4-4.6) and 0.9 (0.4-2.4) for obese subjects, respectively.
Conclusions: Prevalence of low ABI is lower in obese compared to non-obese. While ABI<0.9 remains significantly associated with all-cause and cardiovascular mortality among non-obese, there is no significant association of low ABI with either all-cause or cardiovascular mortality among obese. These findings need further research as they question the reliability of using ABI as a marker of peripheral arterial disease (PAD) or marker of risk in obese individuals. Further studies are needed to examine the performance of ABI compared to other imaging studies for PAD in order to validate ABI as a marker of PAD in obese.
Poster Hall, Hall C
Saturday, March 18, 2017, 9:45 a.m.-10:30 a.m.
Session Title: Updates on Risk Factors for Cardiovascular Disease
Abstract Category: 32. Prevention: Clinical
Presentation Number: 1187-061
- 2017 American College of Cardiology Foundation