Background
The prognostic utility of ankle brachial index (ABI) may be hampered in persons with diabetes due to peripheral arterial stiffening in the ankles. Stiffening of toe arteries occurs infrequently in diabetes.
Objectives
We aim to determine the nature of the relationship of the toe brachial index (TBI) and ABI with cardiovascular (CVD) mortality, and to determine whether the associations are modified in individuals with diabetes.
Methods
Individuals with clinically suspected atherosclerotic PAD who underwent ABI and TBI measurements in a vascular laboratory were followed longitudinally for CVD mortality.
Results
Among 469 (89% men) participants, the mean age was 68 ± 9 years and 36% had diabetes. The mean ABI was 0.83 ± 0.28 and the mean TBI was 0.60 ± 0.24. During 7.0 years (median) follow-up, there were 158 CVD deaths. Association of the ABI categories with CVD events differed in diabetic vs. non-diabetic participants (P-interaction = .002). In contrast, association of the TBI categories with CVD events were similar irrespective of diabetes status (P-interaction = .17). Among diabetic patients, a U-shaped relationship was observed between ABI categories and CVD death; both those with low (< 0.90) and high (> 1.30) ABI were at higher risk than those with normal (0.90–1.30) ABI. In non-diabetic patients, association of ABI categories with CVD death was linear, such that those with ABI > 1.30 were at the lowest risk, whereas those with ABI < 0.90 were at higher risk. In contrast, the association of TBI categories with CVD death was linear irrespective of diabetes status. High TBI categories consistently predicted low risk, whereas risk was higher with progressively lower TBI categories.
Conclusions
Among diabetic individuals with clinically suspected PAD, both those with low and high ABI are at higher risk of CVD death. In contrast, a linear relationship was observed between TBI categories and CVD death irrespective of diabetes status. These findings suggest that stiffened ankle arteries may limit the predictive value of the ABI in individuals with diabetes; a limitation that may be overcome by measurement of the TBI.
Purpose
To examine the intra-examination repeatability of proton density fat fraction (PDFF) and T1 and T2 of liver water and fat as estimated by a novel multi-repetition time (TR)-echo time (TE) 1H MRS stimulated echo acquisition mode (STEAM) sequence that acquires 32 spectra for a range of TRs and TEs in single breath-hold.
Materials and Methods
Sixty-seven subjects undergoing liver MRI examinations at 3T had three multi-TR-TE sequences acquired consecutively in a single session. This sequence was designed to allow accurate estimation of T1 and T2 of both water and fat, as well as PDFF, in a single breath-hold. A standard long-TR, multi-TE sequence was also acquired to allow comparison of estimated PDFF. Regression and interclass correlation (ICC) analyses were performed.
Results
There was strong agreement between PDFF estimated by the multi-TR-TE and long-TR, multi-TE sequences (slope 0.997; intercept -0.03; R = 0.997). The multi-TR-TE sequence had high repeatability for estimating PDFF (ICC = 0.999), water T2 (ICC = 0.920), water T1 (ICC = 0.845) and fat T2 (ICC = 0.760), and moderate repeatability for estimating fat T1 (ICC = 0.556).
Conclusion
A novel multi-TR-TE sequence can estimate PDFF and water and fat T1 and T2 in a single breath-hold. Refinement may be needed to improve repeatability for fat T1 estimation.
The inverse association between CAC density and incident CHD and CVD events is robust across strata of other CVD risk factors. Added to the ASCVD risk score, CAC volume and density provided the strongest prediction for CHD and CVD events, and the highest correct reclassification.
We observed a significant and independent association between elevated Lp(a) and PAD only among HA women and men, despite higher serum Lp(a) levels among AAs. Future studies are needed to determine the role that lowering of Lp(a) may have on the burden of PAD in HAs.
Background and aims
This study investigated the associations of non-alcoholic fatty liver disease (NAFLD) and abdominal aortic calcification (AAC) volume and density, and whether these relationships vary by race/ethnicity and/or sex, information that are limited in current literature.
Methods
We studied 1,004 adults from the Multi-Ethnic Study of Atherosclerosis to assess the relationship between NAFLD (liver-to-spleen ratio <1) and the following measures of AAC: presence (volume score >0, using Poisson regression); change in volume score (increasing vs. no change, using Poisson regression); and morphology (volume and density score, where volume score >0, using linear regression); and interaction by race/ethnicity and sex.
Results
Among Blacks, those with NAFLD had greater prevalence for AAC compared to Whites regardless of sex (Prevalence Ratio [PR]=1.41, CI=1.15–1.74, p-interaction=0.02). Concurrent interaction by race/ethnicity and sex was found comparing Chinese and Blacks to Whites (p-interaction=0.017 and 0.042, respectively) in the association between NAFLD and the prevalence of increasing AAC. Among women, this relationship was inverse among Chinese (PR=0.59, CI=0.28–1.27), and positive among Whites (PR=1.34, CI=1.02–1.76). This finding was reversed evaluating the men counterpart. Black men also had a positive association (PR=1.86, CI=1.29–2.70), which differed from the inverse relationship among White men, and was greater compared to Black women (PR=1.45, CI=1.09–1.94). NAFLD was unrelated to AAC morphology.
Conclusions
NAFLD was related to the presence of AAC, however, limited to Blacks. Significant concurrent interaction by race/ethnicity (Chinese and Blacks vs. Whites) and sex was found in the relationship between NAFLD and increasing AAC. These findings suggest disparities in the pathophysiologic pathways in which atherosclerosis develops.
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