title: Clinical significance of nonalbuminuric renal impairment in type 2 diabetes.
abstract: OBJECTIVE
  In type 2 diabetes, prevalence of nonalbuminuric renal impairment is increasing worldwide, though its clinical significance remains unclear. This large-cohort study aimed at evaluating the association of this phenotype with cardiovascular risk factors and other complications.
  
  
  METHODS
  Type 2 diabetic patients from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicenter Study (n = 15,773), visiting consecutively 19 hospital-based Diabetes Clinics in years 2007-2008, were examined. Serum creatinine was assessed by the Jaffe method; albuminuria was measured by immunonephelometry or immunoturbidimetry.
  
  
  RESULTS
  Of patients with renal impairment, as identified by an estimated glomerular filtration rate (eGFR) less than 60 ml/min per 1.73 m², 56.6% were normoalbuminuric, 30.8% were microalbuminuric, and 12.6% were macroalbuminuric. Percentages were similar when GFR was estimated using the more accurate Chronic Kidney Disease Epidemiology Collaboration equation instead of the simplified Modification of Diet in Renal Disease formula, and were independent of age, thus indicating that the increasing prevalence of this phenotype does not reflects misclassification of elderly patients. Nonalbuminuric renal impairment was not associated with HbA(1c) and correlated less strongly with retinopathy and hypertension than albuminuria, either alone or associated with reduced eGFR. It was associated with a higher prevalence of cardiovascular disease (CVD) than albuminuria alone, but lower than albuminuric renal impairment. Female sex correlated with nonalbuminuric renal impairment and male sex with the albuminuric forms.
  
  
  CONCLUSIONS
  These data show that type 2 diabetic patients with nonalbuminuric renal impairment exhibit distinct clinical features, suggesting predominance of macroangiopathy as underlying renal pathology, and that this phenotype is associated with significant CVD burden.
authors: Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy.
authors: Giuseppe
authors: G
authors: Penno
authors: Anna
authors: A
authors: Solini
authors: Enzo
authors: E
authors: Bonora
authors: Cecilia
authors: C
authors: Fondelli
authors: Emanuela
authors: E
authors: Orsi
authors: Gianpaolo
authors: G
authors: Zerbini
authors: Roberto
authors: R
authors: Trevisan
authors: Monica
authors: M
authors: Vedovato
authors: Gabriella
authors: G
authors: Gruden
authors: Franco
authors: F
authors: Cavalot
authors: Mauro
authors: M
authors: Cignarelli
authors: Luigi
authors: L
authors: Laviola
authors: Susanna
authors: S
authors: Morano
authors: Antonio
authors: A
authors: Nicolucci
authors: Giuseppe
authors: G
authors: Pugliese
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007674:Kidney Diseases / Q000503:physiopathology*; D008297:Male