Are low erythropoietin and 1,25-dihydroxyvitamin D levels indicative of tubulo-interstitial dysfunction in diabetes without persistent microalbuminuria?

Diabetes Res Clin Pract. 2009 Sep;85(3):258-64. doi: 10.1016/j.diabres.2009.06.022. Epub 2009 Jul 19.

Abstract

Aims: To investigate the relationship between Erythropoietin (EPO) and 1,25-dihydroxyvitamin D levels, and tubular damage in patients with diabetes mellitus (DM) without persistent microalbuminuria.

Methods: We measured serum EPO and 1,25-dihydroxyvitamin D levels and tubular injury markers such as urinary N-acetyl-beta-d-glucosaminidase (NAG) and retinol binding protein (RBP) levels in 41 non-diabetic controls, 40 patients with Type 1 and 40 with Type 2 DM.

Results: Median serum EPO levels were lower in Type 1 (2.57 mIU/ml: p<0.001) and Type 2 DM (5.69 mIU/ml: p=0.044) than in controls (8.76 mIU/ml), though haemoglobin levels did not differ. Median 1,25-dihydroxyvitamin D levels were lower in Type 1 (41.0 pmol/l: p=0.001) and Type 2 DM (41.8 pmol/l: p=0.035) than in controls (56.1 pmol/l), though serum creatinine, calcium, phosphate and PTH levels did not differ. Median RBP excretion was higher in Type 2 DM (0.35 mg/l vs. 0.23 mg/l: p=0.013) than in controls. Median NAG excretion was higher in Type 1 DM (1,079 micromol/h vs.1,030 micromol/h: p=0.048) compared to controls.

Conclusions: Tubulo-interstitial damage with low levels of EPO and 1,25-dihydroxyvitamin D occurs early in Type 1 and Type 2 DM before persistent microalbuminuria.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Albuminuria / blood*
  • Blood Glucose / metabolism
  • Blood Pressure
  • Creatinine / blood
  • Diabetes Mellitus / blood*
  • Diabetes Mellitus, Type 1 / blood*
  • Diabetes Mellitus, Type 1 / physiopathology
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / physiopathology
  • Diabetic Nephropathies / blood*
  • Erythropoietin / blood*
  • Female
  • Glycated Hemoglobin A / metabolism
  • Humans
  • Kidney Tubules / pathology*
  • Male
  • Middle Aged
  • Reference Values
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Young Adult

Substances

  • Blood Glucose
  • Glycated Hemoglobin A
  • Erythropoietin
  • Vitamin D
  • 1,25-dihydroxyvitamin D
  • Creatinine