Urinary albumin excretion within the normal range predicts the development of diabetes in Korean men

Urine albumin creatinine ratio (UACR) is a reliable index of urinary albumin excretion. Elevated UACR is known to be associated with increased risk for diabetes complications. However there is only limited information about the predictability of UACR within normal range for diabetes. Therefore, this study was designed to investigate the association between UACR within the normal range and the development of diabetes.

The 1410 non-diabetic Korean men with UACR within the normal range were identified in 2005 and followed-up until 2010. All subjects were classified into four categories according to their baseline level of UACR, from the lowest to the highest quartile. Cox proportional hazards analysis was used to evaluate the independent hazard ratios (HRs) for diabetes according to the UACR levels of their quartile group.

During follow-up, diabetes developed in 114 out of 1410 subjects (8.1%), and incidence of diabetes increased in proportion to the level of UACR (quartile 1; 4.5%, quartile 2; 7.9%, quartile 3: 8.8%, quartile 4: 11.1%, p = 0.002). The subjects with incident diabetes had a higher UACR than those without incident diabetes (6.6 ± 5.5 μg/mg v 5.3 ± 4.2 μg/mg, p=0.013). When quartile 1 was considered as the reference, HRs (95% confidential interval) for diabetes was higher in quartile 2 (1.04; 0.45-2.38), quartile 3 (1.09; 0.47-2.52) and quartile 4 (2.16; 1.02-4.57), even after adjusting for other potential confounders.

Elevated UACR, even within the normal range, could predict the future development of diabetes.