[Factors participating in the variability of glycosylated hemoglobin levels]. / Factores que participan en la variabilidad de los valores de hemoglobina glucosilada.

Glycated hemoglobin values are a good indicator of metabolic control of the diabetic patients; however the levels can be influenced by analytic, clinic and biological variability. In the first, it is important to know that the variation coefficient between-laboratory should be < 3-4%; the second, depends on the metabolic control of the patients, while the third is determined by internal and external factors. Family studies had shown that genetic factors are involved in the biological variability of glycated hemoglobin. In order to have a correct interpretation of the glycated hemoglobin levels, it is important to know the causes of variability.