Association between high-normal ankle–brachial index and hypertension incidence: the Okinawa Peripheral Arterial Disease Study

No false elevation in ankle brachial index in patients with tibial plateau fractures and vascular risk factors

Objectives

The ankle brachial index (ABI) is a useful tool in detection of lower extremity vascular injury. However, diabetes mellitus (DM), chronic kidney disease (CKD), and peripheral vascular disease (PVD) may affect extremity perfusion leading to possible false elevation of the ABI value. If true in trauma patients, this can affect initial evaluation, diagnostics, and management. We therefore explored mean ABI values in tibial plateau fractures of patients with vascular risk factors to help determine whether there is a difference.

Design

This is a retrospective chart review of patients sustaining tibial plateau fractures with a specific ABI value recorded in the medical record. Patients were identified as either having vascular risk factors or not and data analysis performed to determine if their ABI differed and whether they were more likely to have a vascular injury.

Results

282 acute tibial plateau injuries with specific ABI values were identified, 46 of which carried the risk factors in question. The average risk factor group ABI was 0.95 ± 0.15 versus those without risk factors 1.0 ± 0.15 (p = 0.057). No patient with risk factors required a vascular intervention or four-compartment fasciotomy.

Conclusions

This study shows no statistical significance between the presenting ABI of patients with risk factors such as DM, CKD, or PVD and those without those risk factors who sustained acute tibial plateau fractures. Therefore, in general the ABI still holds as a useful screening tool for evaluation of vascular insult in the setting of acute lower extremity trauma.

The high normal ankle brachial index is associated with left ventricular hypertrophy in hypertension patients among the Han Chinese

Left ventricular hypertrophy (LVH) is the most common target organs damage in the hypertension patients. Abnormal low (≤0.9) or high (≥1.40) ankle brachial index (ABI) are associated with an increased risk of cardiovascular events. However, the relationships between a high ABI in the normal range (0.9–1.4) and LVH in Han Chinese hypertension are not entirely elucidated. This study included 3953 hypertension patients aged 40–75 years among Han Chinese. Hypertension was defined as systolic blood pressure≥140 mm Hg, diastolic blood pressure≥90 mm Hg, or history of antihypertensive drug use. Left ventricular mass (LVM) was measured by transthoracic echocardiography. LVH was diagnosed by using the criteria of LVM ≥49.2 g/m^2.7 for men and 46.7 g/m^2.7 for women. Our study suggested that the ABI was higher in patients with LVH than in those without (1.13±0.11, 1.11±0.11, p < 0.001). The prevalence of LVH in patients with the lowest (0.9 < ABI≤1.03), second (1.04≤ABI≤1.11), the third (1.12≤ABI≤1.20), and the highest quartile (1.21≤ABI < 1.40) of ABI was 37.2%, 38.2%, 45.5%, 45.7%, respectively. Logistic regression analysis suggested that the highest and third quartile of ABI were significantly associated with increased LVH risk (multivariate‐adjusted OR of highest group:1.83; third group:1.61). The association of ABI at second quartile with LVH was nonsignificant. Similar results were observed in less than 60 years and without coronary heart disease or diabetes group. Our observations in Chinese patients with hypertension indicated high ABI may be an important risk factor for LVH in hypertension patients among Han Chinese, even in the normal range.