Is the new Mayo Clinic Quadratic equation useful for the estimation of glomerular filtration rate in type 2 diabetic patients?

Abstract

OBJECTIVE:

To test the Mayo Clinic Quadratic (MCQ) equation against isotopic glomerular filtration rate, compared with the Modification of Diet in Renal Disease (MDRD) and the Cockcroft-Gault formulas, in type 2 diabetes.

RESEARCH DESIGN AND METHODS:

Based on values obtained with iothalamate, 118 type 2 diabetic patients were divided into three groups according to renal function: hyperfiltration (26), normal function (56), or chronic kidney disease (CKD) stages 3-4 (36). ANOVA, the Bland-Altman procedure, and Lins coefficient (Rc) were performed to study accuracy.

RESULTS:

In the hyperfiltration and normal function groups, all prediction equations significantly underestimated the value obtained with isotopic glomerular filtration rate (P < 0.05). In the CKD group, all equations also presented significant differences with the isotopic method. However, MDRD had a bias of -5.3 (Rc 0.452), Cockcroft-Gault formula -0.2 (Rc 0.471), and the MCQ -4.5 (Rc 0.526).

CONCLUSIONS:

The MCQ and prediction equations proved inaccurate (excessive underestimation) in type 2 diabetic patients with hyperfiltration or normal renal function. With regard to CKD, the results obtained provided no evidence of superiority of the MCQ over the MDRD or the Cockcroft-Gault formula.

• Authors: Néstor Fontseré, Jordi Bonal, Isabel Salinas, Manel Ramírez de Arellano, Jose Rios, Ferran Torres, Anna Sanmartí, Ramón Romero
• Journal: Diabetes care (Diabetes Care) Vol. 31 Issue 12 Pg. 2265-7 (Dec 2008) ISSN: 1935-5548 [Electronic] United States
• PMID: 18835955 (Publication Type: Journal Article)

Chemical References

• Contrast Media
• Iothalamic Acid

Topics

• Aged
• Analysis of Variance
• Contrast Media
• Diabetes Mellitus, Type 2 (physiopathology)
• Female
• Glomerular Filtration Rate
• Humans
• Iothalamic Acid
• Male
• Middle Aged
• Reproducibility of Results