Autokit micro albumin

Plasma BNP levels were measured by radioimmunoassay (Shionoria BNP kit, Shionogi, Osaka, Japan) and CRP levels were determined by latex-enhanced immunonephelometric assay on a BN II analyzer (Dade Behring, Marburg, Germany). The detection limit of the CRP assay was 0.03 mg/dl and CRP values < 0.03 mg/dl were recorded as 0.015 mg/dl. A single-void morning urine sample was collected and urinary albumin was measured by a turbidimetric immunoassay (Autokit Micro Albumin, Wako, Osaka, Japan). The sensitivity limit for albumin was 5 mg/l. The urinary concentration of albumin was taken as 2.5 mg/l in patients with urinary albumin below the sensitivity limit. Urinary excretion of albumin was expressed as the ratio of urinary albumin to urinary creatinine (UACR). Abnormal albuminuria was defined as UACR ≥ 30 mg/g Cr. eGFR was calculated according to the Modification of Diet in Renal Disease equation37 (link) with coefficients modified for Japanese patients38 (link).

Blood samples were drawn in the morning. Spot urine samples were collected in the morning and urinary albumin excretion (UAE) was measured using an immunoturbidimetric assay (Autokit Micro Albumin, Wako, Osaka, Japan). The average value for UAE was determined from triplicate urine collections. The characteristics of each patient were obtained from the initial interview and routine physical examination conducted at entry. Nephropathy was classified into three levels according to the level of UAE: normoalbuminuria (<30 mg/g Cr), microalbuminuria (30–300 mg/g Cr), and macroalbuminuria (>300 mg/g Cr). Neuropathy was diagnosed on the basis of the diagnostic criteria for diabetic neuropathy proposed by the Diagnostic Neuropathy Study Group.¹¹ Retinopathy was classified into three levels: “no diabetic retinopathy,” “simple diabetic retinopathy,” and “proliferative diabetic retinopathy.”¹² Macrovascular complications were defined as the presence of a history of cerebrovascular disease, cardiovascular disease, or atherosclerosis obliterans, based on the patient's medical history.