Model 7600

Urinary albumin concentrations were measured using an ELISA Kit (Nanjing Jiancheng Bioengineering Institute, Nanjing, China) according to the manufacturer's instructions. Blood urea nitrogen (BUN), serum creatinine (Scr) and urea creatinine were measured using an automatic biochemistry analyzer (Hitachi Model 7600, Hitachi High-Technologies, Tokyo, Japan). Creatinine clearance (Ccr) was computed using the following formula: creatinine clearance [Ccr] (ml min⁻¹) = [urea creatinine/serum creatinine] × urine volume (ml).

The whole blood was collected from the abdominal aorta and centrifuged at 1,000 g for 10 min at 4°C. Total cholesterol (TC) and triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) in the serum were measured using an automatic analyzer (Hitachi model 7600 Hitachi High-Technologies Corporation, Ibaraki, Japan).

Experienced physicians were trained to collect clinical data from all patients. These data included demographic data (such as age, sex and blood pressure), medical history (such as diabetes duration, history of hypertension and smoking), prescription information (such as glucose-lowering therapies and statins treatments), and biochemical measurements. Glucose-lowering therapies were acquired by searching the electronic medical record system and then were categorized into subclasses, which included insulin injections, sulfonylureas (SUs), metformin, thiazolidinediones (TZDs), α-glucosidase inhibitors (AGIs), dipeptidyl peptidase-4 inhibitors (DPP-4Is), SGLT-2Is and glucagon-like peptide-1 receptor agonists (GLP-1RAs).
Fasting venous blood samples were taken to detect biochemical indices, such as serum CysC levels, hepatic function index, creatinine, uric acid (UA), lipid profiles, whole blood glycosylated hemoglobin A1c (HbA1c), etc. The serum CysC was measured by latex-enhanced immunoturbidimetry in an automated biochemical analyzer (Model 7600, Hitachi). The renal function index, eGFR, was assessed by the equation from the Modification of Diet in Renal Disease study (25 (link)), that is eGFR_M.

Samples of milk replacers and starter were analyzed for dry matter (DM), total CP, ash, total P, total Ca (AOAC, 1980 ), and total ether extract (EE) by supercritical fluid extraction (TFE 2000 Leco Fat Extractor, St. Joseph, MI), and gross energy (GE) by bomb calorimeter (Parr 6300 Automatic Bomb Calorimeter, Parr Instrument Company, Moline, IL). The content of total protein (TP), albumin, globulin, blood urea nitrogen (BUN), β-hydroxybutyric acid (β-HB) in blood sera was determined using the standard kit (Biosino bio-technology and science incorporation) by biochemical analyzer (Model 7600; Hitachi, Tokyo, Japan). The contents of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) in blood sera were determined according to the radioimmunoassay kit.