Diabetic kidney disease (DKD) is one of the microvascular complications of DM with the highest mortality rate of diabetes, with a progressive increase of albuminuria and a progressive decrease of glomerular filtration rate as the main clinical features(1). In China, DKD occurs in about 20%∼40% of patients with diabetes, which is the leading cause of end-stage renal disease(2). The appearance of microalbuminuria is the early manifestation of DKD and the persistent microalbuminuria has also been shown to be associated with the risk of coronary heart disease and death(3). Early DKD can be treated with drugs such as angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs), Sodium-glucose co-transporter 2 inhibitor (SGLT2i), glucagon like peptide-1 receptor antagonist (GLP1-RA) and finerenone, which have been shown to reduce the risk or delay the progression of diabetic nephropathy(3). Hence, early detection of albuminuria and taking intervention measures accordingly are necessary to delay the development of DKD and other adverse health outcomes in clinical practice. It is recommended that albuminuria, that is usually tested by urine creatinine/albumin ratio (UACR), should be assessed annually for all persons with type 2 diabetes mellitus (T2D), starting at diagnosis of diabetes(3). However, screening for albuminuria is underutilized, particularly at diagnosis of diabetes. In the USA, albuminuria is assessed in less than half of patients with T2D in a given year(4). Data from UKPDS that mainly enrolled white Caucasian with newly diagnosed T2D in 1977 showed that 7.3% of patients had microalbuminuria at diagnosis of diabetes and progressed to macroalbuminuria at a rate of 2.8% per year(5). It is estimated that 60.5% of T2D patients developed albuminuria and the prevalence of microalbuminuria in Asians with T2D is significantly higher than in Caucasians(2, 6, 7). However, there is limited information on the prevalence of albuminuria among patients with newly diagnosed T2D in Asia and its impact on the progression of renal function.

Due to the slow rate for renal function decline, most studies on risk factors of progression of renal function have been carried out in participants with advanced chronic kidney disease. It is challenging to assess progression of renal function in patients in the early stage of diabetes with baseline eGFR 90 mL/min/1.73 m2 or more. In recent years, a surrogate marker for worsening of renal function, eGFR slope, can reliably predict an intervention’s effect on the progression of CKD at an earlier stage(8, 9, 10). Therefore, it is possible to study the risk factors of renal function progression in patients with newly diagnosed type 2 diabetes.

The objectives of this study were to determine: 1) the incidence of albuminuria among patients with newly diagnosed type 2 DM in the primary care setting in China; and 2) the impact of incidence of albuminuria on progression of DKD estimated by eGFR slope.