P1288FACTORS ASSOCIATED WITH THE ANKLE BRACHIAL INDEX TRAJECTORY OVER TIME AMONG PATIENTS RECEIVING HAEMODIALYSIS
Authors: Harada Manae , Suzuki Yuta , Watanabe Takaaki , Yamamoto Shohei , Isobe Yusuke , Imamura Keigo , Ito Haruka , Yamabe Sachi , Yoshikoshi Shun , Takeuchi Yasuo , Horiguchi Yoriko , Aoyama Naoyoshi , Matsunaga Atsuhiko , Yoshida Atsushi 
Published: June 2020

Abstract

Background and Aims
Measurement of the ankle brachial index (ABI) is a simple, noninvasive means of diagnosing peripheral arterial disease. Additionally, a lower ABI has also been shown to be associated with a higher mortality rate. A high prevalence of a low ABI has been reported in patients with chronic renal failure, especially among patients receiving haemodialysis. Therefore, identifying factors that predict a decline in the ABI is important for developing treatment strategies. However, little is known about the factors associated with a decline in the ABI over time in patients receiving haemodialysis. Furthermore, most patients receiving haemodialysis have low levels of daily physical activity and are thus prone to arteriosclerosis. Here, we examined the factors including the level of physical activity associated with the ABI trajectory over time among patients receiving haemodialysis.

Method
The subjects were 236 outpatients (mean age of 64.2±12.0 years, 148 men, mean body mass index of 22.0±4.1 kg/m2) receiving maintenance haemodialysis thrice a week at a haemodialysis centre. The exclusion criteria for the study were as follows: major amputation of a lower extremity at baseline and lower-extremity peripheral revascularization and amputation of a lower extremity during follow-up. The ABI was determined using a blood pressure pulse-wave inspection apparatus (Form3; Omron Colin, Tokyo, Japan). The lowest values of ankle pressure were used for the calculations. As background factors for the patients, we investigated age, sex, body mass index, haemodialysis vintage, comorbidities (diabetes, cerebrovascular disease, and cardiovascular disease), serum chemistry (haemoglobin and albumin), and level of physical activity. The patients were classified with a low level of physical activity if they used a wheelchair at home or in the hospital or required walking assistance. The ABI and background factors were investigated at baseline and 1, 2, and 3 years. To determine factors associated with the ABI trajectory over time, we conducted multivariate generalised estimating equations analysis.

Results
The mean ABI at baseline was 1.12 (median = 1.16; 25th–75th percentile = 1.07–1.21). Age (-0.02 per year; 95% confidence interval, -0.003 to -0.001), cardiovascular disease (-0.06 per year; 95% confidence interval, -0.115 to -0.023), and level of physical activity (-0.09 per year; 95% confidence interval, -0.135 to -0.041) were associated with the ABI trajectory over time.

Conclusion
Increased ageing, the incidence of cardiovascular disease, and a decreased level of physical activity are independently associated with a decline in the ABI over time. Clinical attention should be paid to low physical activity levels among patients receiving haemodialysis. Studies should examine whether interventions for low physical activity levels can improve the trajectory of the ABI in patients receiving haemodialysis.