Change of urinary type IV collagen excretion rate in patients with diabetic nephropathy and its implication

【Objective】To explore the change of urinary type IV collagen excretion rate in patients with diabeticnephropathy and its implication.【Methods】This study included 25 healthy subjects (control group) and 90 patientswith type 2 diabetes mellitus, diabetic patients were divided into three groups according to their urinary albumin ex-cretion rate (UAER): 30 patients with normal UAER (SDM group), 30 patients with microalbuminuria (EDN group)and 30 patients with clinical proteinuria (CDN group). Urinary type IV collagen excretion rate, UAER, fasting andpostprandial 2 h plasma glucose, HbA1c, urinar!y 1 - microglobulin excretion rate, urinary β2- microglobulin excre-tion rate, blood creatinine were measured.【Results】Urinary type IV collagen excretion rate was increase by degreesin the control group subjects, in the SDM group patients, in the EDN group patients, in the CDN group patients. Uri-nary type IV collagen excretion rate was positively correlated with UAER, HbA1c, urinar!y 1 - microglobulin excretionrate, urinary β2- microglobulin excretion rate, duration of diseases and diastolic blood pressure. In a general multi-variate regression, UAER, duration of diseases and diastolic blood pressure were significantly independent determi-nants for urinary type IV collagen excretion rate. Urinary type IV collagen excretion rate of 10 patients (33.3%) inthe SDM group were significantly increased.【Conclusion】Urinary type IV collagen excretion rate may as a specificindicator of early diabetic nephropathy, it may has premonitory implication in diabetic patients with normal UAER.