Frequency of Polymorphisms in SLC47A1 (rs2252281 and rs2289669) and SLC47A2 (rs34834489 and rs12943590) and the Influence of SLC22A1 (rs72552763 and rs622342) on HbA1c Levels in Mexican-Mestizo Patients with DMT2 Treated with Metformin Monotherapy

Diabetes type 2 (DT2) entails significant health, economic, and productivity repercussions around the world. Poor glycaemic control, defined as an HbA1c >7.0%, has been associated with a number of complications. In spite of the large share of healthcare resources allocated to DT2 treatment, the proportion of controlled Mexican patients is among the lowest in the world (34.4%). Certain protein-encoding genetic polymorphisms involved in metformin transport may affect glycaemic control. We focused on determining the frequency of rs2289669, rs2252281, rs12943590, and rs34834489 polymorphisms in Mexican-Mestizo patients from the Tertiary Care Regional Hospital of Ixtapaluca, State of Mexico, Mexico, as well as assessing their possible association with therapeutic efficacy, as estimated through glycated haemoglobin. The individual polymorphism analysis did not reveal an association with glycaemic control; however, when combined with rs72552763 and rs622342, we found a significant positive correlation between HbA1c levels and metformin dose, which prevailed among patients carrying allelic variants of rs2289669 or rs12943590 who were also simultaneously carrying allelic variants of rs72552763 or rs622342. Patients carrying the reference allele of rs34834489 reported a significant positive correlation between HbA1c levels and metformin dose as well, regardless of their rs72552763 or rs622342 genotype. Thus, we identified alleles and allelic combinations of <i>SLC47A1</i>, <i>SLC47A2</i>, and <i>SLC22A1</i> polymorphisms posing a potential glycaemic control risk in Mexican-Mestizo patients.