Diagnosis in prediabetes

Abstract

During type 2 prediabetes (PDT2), in addition to increasing the risk of progression to type 2 diabetes mellitus (T2DM), both microvascular and macrovascular complications can develop¹. According to the American Diabetes Association (ADA), this condition is diagnosed by an impaired fasting glucose (IFG) of 100 to 125 mg/dL, an impaired glucose tolerance (IGT) of 140 to 199 mg/dL at 120 minutes after the oral glucose tolerance test (OGTT), or a glycated hemoglobin A1c (HbA1c) of 5.7% to 6.4%².

The Argentine Diabetes Society (SAD) has recently adopted the ADA criteria for IFG and HbA1c^3,4 while the classic criteria for IGT have not changed to date⁵.

Other organizations do not agree with the cutoff point that defines the lower limit of IFG; For both the International Diabetes Federation (IDF) and the World Health Organization (WHO), this value is 110 mg/dL^6,7. Another discrepancy between societies is the lower cutoff for HbA1c, given that the International Expert Committee (IEC) defines it at 6%⁸.

Recently, the IDF has formalized the criterion for TGA at 60 minutes after the OGTT with values ​​of ≥155 and <209 mg/dL. There is evidence regarding the correlation of this parameter with both progression to T2DM and macro- and microvascular complications⁹.

The lack of concordance between these diagnostic determinations is well known; a patient may have T2DM due to one criterion or the other, due to two, or due to all three simultaneously^10,11. PDT2 grading by GAA, HbA1c, and TGA has a low to medium correlation and poor concordance in the studied populations, so it would be advisable to perform all accepted determinations, interpreting the results in conjunction with the genotype and phenotype of the particular patient.