title: Serum ionized magnesium levels in type 2 diabetic patients with microalbuminuria or clinical proteinuria.
abstract: OBJECTIVE
  The association between microalbuminuria and magnesium depletion is a controversial issue, and serum ionized magnesium levels have not been previously studied in patients with different grades of diabetic nephropathy. Therefore, the aim of this study was to evaluate circulating ionized magnesium concentrations in patients with non-insulin-dependent diabetes mellitus (NIDDM) and incipient or overt diabetic nephropathy.
  
  
  METHODS
  We measured fasting plasma glucose, creatinine, creatinine clearance estimate, total cholesterol and triglycerides, and serum ionized magnesium (ion-selective electrodes, ISE) in 30 NIDDM patients with urinary albumin excretion rate (UAER) <20 microg/min (normoalbuminuria), 30 NIDDM patients with microalbuminuria (20 < UAER < 200 microg/min), 30 NIDDM patients with clinical proteinuria (UAER >200 microg/min), and 20 healthy subjects.
  
  
  RESULTS
  Serum ionized magnesium levels were significantly reduced in diabetic patients when compared to control subjects (0.39 +/- 0.06 vs. 0.58 +/- 0.05 mmol/l, p < 0.001). Moreover, diabetic patients with microalbuminuria or clinical proteinuria showed a significant decrease in serum ionized magnesium with respect to normoalbuminuria group (normoalbuminuria: 0.45 +/- 0. 02 mmol/l; microalbuminuria: 0.36 +/- 0.05 mmol/l, p < 0.001; clinical proteinuria: 0.35 +/- 0.04 mmol/l, p < 0.001). Serum ionized magnesium showed a significant negative correlation with plasma HbA1c and triglycerides in both microalbuminuria and clinical proteinuria groups. Multiple linear regression analysis showed that circulating ionized magnesium levels decrease together with the increase of plasma HbA1c and triglycerides in NIDDM patients with incipient or overt nephropathy, also after adjusting for age, sex, BMI, diabetes duration, systolic and diastolic blood pressure, hypoglycemic therapy, plasma creatinine, creatinine clearance, plasma cholesterol and fasting glucose.
  
  
  CONCLUSIONS
  Microalbuminuria and clinical proteinuria, as well as poor glycometabolic control and hypertriglyceridemia, are associated to relevant alterations in magnesium metabolism, and the measurement of serum ionized magnesium seems to represent a useful biochemical tool for the study of magnesium disturbances in patients with different grades of diabetic nephropathy.
authors.affiliation: Department of Internal Medicine, University of Messina, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Corsonello
authors.forename: R
authors.initials: R
authors.lastname: Ientile
authors.forename: M
authors.initials: M
authors.lastname: Buemi
authors.forename: D
authors.initials: D
authors.lastname: Cucinotta
authors.forename: V N
authors.initials: VN
authors.lastname: Mauro
authors.forename: S
authors.initials: S
authors.lastname: Macaione
authors.forename: F
authors.initials: F
authors.lastname: Corica
mesh_terms: D000419:Albuminuria / Q000097:blood*; D000704:Analysis of Variance; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005260:Female; D006801:Humans; D016014:Linear Models; D008274:Magnesium / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011507:Proteinuria / Q000097:blood*; D014280:Triglycerides / Q000097:blood
chemical_list: D014280:Triglycerides; D008274:Magnesium