The results of laboratory investigations (blood and urine) performed on the day that patients underwent body composition monitoring were collected from their electronic medical records. The hemoglobin (Hb) concentration in whole blood samples was determined using an ADVIA 2120i hematology system (Siemens Healthcare Diagnostics, Erlangen, Germany). The levels of total cholesterol, total protein, serum albumin, uric acid, blood urea nitrogen, sCr, sodium, potassium, calcium, phosphorus, and total CO2 in the serum samples were measured on a Cobas 8000 c702 Chemistry Analyzer (Roche Diagnostics, Rotkreuz, Switzerland). The urine protein to Cr ratio was calculated using random urine samples. Cystatin C was measured using an automated AU-5800 analyzer (Beckman Coulter, Brea, CA, USA). The estimated GFR (eGFR) was calculated using the CKD-Epidemiology Collaboration (CKD-EPI) formula [26 (link)].
Diabetes was defined as a fasting blood glucose level of ≥126 mg/dL, glycated Hb of ≥6.5%, or the use of an antidiabetic agent. Hypertension was defined as a systolic or diastolic blood pressure of ≥140 mmHg or ≥90 mmHg, respectively, or the use of antihypertensive agents. Body mass index (BMI, kg/m2) was calculated using the weight and height at the time of body composition measurement and was classified into five groups based on the criteria for the Asian population.