Coexistence of hyper-uricaemia and low urinary uric acid excretion further increases risk of chronic kidney disease in type 2 diabetes

To investigate whether hyper-uricaemia and decreased urinary uric acid excretion (UUAE) are associated with increased risk of chronic kidney disease (CKD), and whether the coexistence of hyper-uricaemia and low UUAE further increases CKD risk in type 2 diabetes mellitus (T2DM). In this cross-sectional study based on serum uric acid (SUA) and UUAE levels, 2846 T2DM inpatients were divided into those with normal SUA and UUAE (group 1), normal SUA and low UUAE (group 2), hyper-uricaemia and normal UUAE (group 3), and hyper-uricaemia and low UUAE (group 4). Hyper-uricaemia was defined as SUA levels ≥ 420 μmol/L in men and ≥ 360 μmol/L in women. Low UUAE was defined as levels below the first UUAE quintiles (< 2161 μmol/24 h in men, 1977 μmol/24 h in women). There were trends for significantly increased prevalences of CKD (4.3%, 12.6%, 18.3%, 47.8%; P < 0.001), albuminuria (20.2%, 26.4%, 36.9%, 54.9%; P < 0.001) and macroalbuminuria (3.3%, 10.1%, 10.7%, 31.9%; P < 0.001) from groups 1 to 4, respectively. After controlling for multiple confounding factors, prevalences of CKD (P < 0.001) and urinary albumin levels (P = 0.013) showed significantly increasing trends, whereas eGFR levels were markedly decreased from groups 1 to 4 (P < 0.001). Hyper-uricaemia and low UUAE levels are closely associated with presence of CKD, and the concomitant presence of hyper-uricaemia and decreased UUAE levels further increased CKD risk in T2DM. Thus, the combined consideration of SUA and UUAE levels may help to identify those T2DM patients at higher CKD risk.