Elderly patients with diabetes are at increased risk of
frailty and disability in
activities of daily living (
ADL). Recent evidence has shown that oxidative stress is associated with these conditions. In this cross-sectional study, we aimed to assess whether serum level of
bilirubin, a strong
endogenous antioxidant, can predict
ADL disability in elderly patients with diabetes. Forty elderly patients aged 70 years and older with diabetes and
ADL disability and 158 elderly patients with diabetes and without
ADL disability were continuously recruited. Multivariate logistic regression models showed that serum
bilirubin level was a significant predictor for
ADL disability. Receiver operating characteristic analysis showed that the area under the curve (AUC) of serum
bilirubin level alone for
ADL disability was 0.887 (95% CI 0.837-0.936, P < 0.001) and the cut-off value was 0.4 mg/dL (sensitivity = 88.0% and specificity = 65.0%). The predictive ability was further increased by the addition of age (AUC = 0.921) or addition of age, body mass index, red blood cell count,
cerebrovascular disease and
chronic renal failure (AUC = 0.953). In conclusion, low serum
bilirubin level is a strong predictive
biomarker for
ADL disability in elderly patients with diabetes, and its clinical utility is suggested.