Abstract
AIMS: The ankle-brachial index (ABI) can be a prognostic marker for chronic kidney disease (CKD) in Western populations. Since there is little relevant evidence for Asian populations, we investigated the relationship between ABI and the risk of incident CKD in a general Japanese population. METHODS: The cohort included 5,072 participants aged 30-79 without a history of renal disease or cerebro-cardiovascular disease. Incident CKD, defined as an estimated glomerular filtration rate ＜60 (mL/min/1.73 m(2)) and/or proteinuria (≥ 1＋ on urine dipstick), was compared among participants grouped according to baseline ABI: 0.90-0.99, 1.00-1.09, 1.10-1.19, 1.20-1.29, and 1.30-1.39. Hazard ratios for incident CKD were estimated using a Cox proportional hazards model, with the ABI 1.10-1.19 group serving as the reference. RESULTS: The CKD incidence rate (/100 person-years) was 1.80 during the mean follow-up period of 5.1 years. The CKD incidence rate was 3.04 in the ABI category 0.90-0.99, 1.58 in ABI 1.00-1.09, 1.72 in ABI 1.10-1.19, 2.01 in ABI 1.20-1.29, and 3.33 in ABI 1.30-1.39. The hazard ratios for developing CKD were 2.14 (95% confidence interval 1.16-3.92) in ABI 0.90-0.99, 1.08 (0.83-1.41) in ABI 1.00-1.09, 1.03 (0.83-1.29) in ABI 1.20-1.29, and 1.37 (0.77-2.47) in ABI 1.30-1.39, after adjusting for age, sex, systolic blood pressure, diabetes, and other confounding factors. CONCLUSIONS: In a general Japanese population, an ABI of 0.90-0.99 was associated with an increased risk of incident CKD, independent of traditional cardiovascular risk factors.