Urinary liver-type fatty acid-binding protein predicts progression to nephropathy in type 1 diabetic patients

Diabetes Care. 2010 Jun;33(6):1320-4. doi: 10.2337/dc09-2242. Epub 2010 Feb 25.

Abstract

Objective: Urinary liver-type fatty acid-binding protein (u-LFABP) is a marker of tubulointerstitial inflammation and has been shown to be increased in patients with type 1 diabetes and is further increased in patients who progress to micro- and macroalbuminuria. Our aim was to evaluate u-LFABP as a predictor of progression to micro- and macroalbuminuria in type 1 diabetes.

Research design and methods: From an inception cohort of 277 patients, u-LFABP, adjusted for urinary creatinine (enzyme-linked immunosorbent assay), was measured in 24-h urine samples from 165 normoalbuminuric patients 9.6 +/- 3.5 (mean +/-SD) years after onset of type 1 diabetes. The outcome measured was development of persistent micro- or macroalbuminuria or death.

Results: Patients were followed for a median of 18 (range 1-19) years; 39 progressed to microalbuminuria, 8 of those progressed further to macroalbuminuria, and 24 died. In a Cox regression model, baseline log u-LFABP levels predicted the development of microalbuminuria, adjusted for known risk factors (sex, age, A1C, systolic and diastolic blood pressure, albumin excretion rate, serum creatinine, and smoking) (hazard ratio [HR] 2.3 [95% CI 1.1-4.6]) and log u-LFABP predicted mortality (adjusted HR 3.0 [1.3-7.0]). u-LFABP (above versus below the median) predicted the development of macroalbuminuria (adjusted HR 2.6 [1.2-5.4]). As a continuous variable, u-LFABP tended to predict macroalbuminuria (HR 1.9, P = 0.2), but numbers were small.

Conclusions: High levels of the tubular inflammation marker u-LFABP predict the initiation and progression to diabetic nephropathy and all-cause mortality, independent of urinary albumin excretion rate and other established risk factors.

MeSH terms

  • Adult
  • Albuminuria / diagnosis
  • Albuminuria / etiology
  • Creatinine / urine
  • Diabetes Mellitus, Type 1 / complications
  • Diabetes Mellitus, Type 1 / urine*
  • Diabetic Nephropathies / etiology
  • Diabetic Nephropathies / urine*
  • Enzyme-Linked Immunosorbent Assay
  • Fatty Acid-Binding Proteins / urine*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Proportional Hazards Models
  • Risk Factors

Substances

  • Fatty Acid-Binding Proteins
  • Creatinine