Risk factors related to low ankle-brachial index measured by traditional and modified definition in hypertensive elderly patients

The intrinsic prognostic value of the ankle-brachial index is independent from its mode of calculation

The object of this study was to compare the prognostic value of different methods of ankle-brachial index (ABI) calculation. From April 1998 to September 2008, we calculated the ABI in 1223 patients before coronary artery bypass grafting. The ABI was calculated according to five different calculation modes of the numerator. The patients were classified into three groups: clinical peripheral artery disease (PAD), subclinical PAD if no clinical history but abnormal ABI (< 0.90 or > 1.40), and no PAD. The primary outcome was total mortality. During a follow-up of 7.6 years (0.1-15.9), 406 patients (33%) died. The prevalence of the subclinical PAD varied from 22% to 29% according to the different modes of ABI calculation. Areas under the ROC curve to predict mortality according to different calculation modes varied from 0.608 ± 0.020 to 0.625 ± 0.020 without significant differences. The optimal ABI threshold to predict mortality varied for every method, ranging from 0.87 to 0.95. In multivariate models, ABI was significantly and independently associated with total mortality (hazard ratio (HR) = 1.46, 95% CI: 1.15-1.85, p = 0.002); however, this association was not significantly different between the various methods (HRs varying from 1.46 to 1.67). The use of the optimal ABI threshold for each calculation mode (rather than standard 0.90) allowed a slight improvement of the model. In conclusion, the ABI prognostic value to predict mortality is independent from its method of calculation. The use of different optimal thresholds for each method enables a comparable prognosis value.

Cyclophilin A is associated with peripheral artery disease and chronic kidney disease in geriatrics: The Tianliao Old People (TOP) study

Cyclophilin A (CyPA), secreted by vascular smooth muscle cells in response to oxidative stress, is important in the pathogenesis of progressive peripheral arterial occlusion disease (PAOD), which is common among chronic kidney disease. We explored the prevalence of PAOD in Taiwan’s elderly (≥ 65 years old) population and its association with CyPA and renal function. Residents of Tianliao District, a rural community in southern Taiwan, were surveyed. An ankle-brachial index (ABI) < 0.91 was defined as PAOD. Chronic kidney disease (CKD) was defined based on eGFR levels < 60 mL/min/1.73 m². Serum CyPA was measured. Of the 473 participants, 68 (14.4%) had PAOD. Multiple logistic regression analysis showed PAOD was significantly associated with lower eGFR, lower BMI, higher glycated hemoglobin and higher pulse pressure. Serum CyPA levels in participants with PAOD were significantly higher than those with normal ABI values (47.3 ± 0.4 vs. 25.5 ± 0.2 ng/mL, p < 0.001). Moreover, eGFR inversely correlated with serum CyPA level (p < 0.05) in participants with CKD, but not in participants with normal renal function. In conclusion, with a prevalence of PAOD as high as 14.4% in an elderly community, CyPA might be the link between PAOD and advanced impaired renal function.

Cardiovascular Risk Factors and Distributions of the Ankle-Brachial Index among Type 2 Diabetes Mellitus Patients

Background. The aim of present study is to observe the association between the levels of ankle-brachial index (ABI) and cardiovascular risk factors among people with type 2 diabetes mellitus in north India. A cross-sectional study was carried out at a centre for heart and diabetic clinic in the state of Punjab on 1121 subjects (671 males and 450 females) with type 2 diabetes mellitus. History of symptoms related to cardiovascular diseases was noted, and blood pressure and anthropometric measurements were recorded. Ankle-brachial index (ABI) was measured using ultrasonic Doppler flow detector. Subjects with ABI ≤0.9 and ≥1.30 were classified as having low and high ABI, respectively. Females had a higher BMI and brachial-ankle pulse wave velocity (P < 0.001). Whereas, males had higher diastolic blood pressure and duration of type 2 diabetes mellitus. The differences of systolic blood pressure and ankle-brachial index were not found significant between the sexes. The prevalence of low ABI (<0.9) was 4.47% in men and 4.67% in women and high ABI (≥1.30) was prevalent in 14% of men and 10.45% of women. Age, BMI, baPWV, and blood pressures were significantly associated with ABI value in both sexes. The results suggested that the ABI might be used as a strong indicator for cardiovascular risk factors in type 2 diabetic subjects.