Endocrine Abstracts

JOINT3549

Introduction: Among the diagnostic criteria for Diabetes Mellitus (DM) is the determination of glycated hemoglobin levels. In addition, it plays a crucial role in the long-term monitoring of diabetic patients, as it has been identified as a significant predictor of chronic complications of the disease. Hemoglobin is a hemoprotein found in red blood cells. Several pathologies can affect this protein, including hemolytic anemias (which may be intrinsic, such as hemoglobinopathies, enzyme defects, membrane disorders, or extrinsic, such as immune/non-immune causes). Thus, the glycated hemoglobin values used for DM monitoring may be altered in the presence of any of these hematological diseases.

Clinical Case: A 46-year-old male was referred from the Primary Care consultation after being diagnosed with type 2 DM. The diagnosis was made incidentally due to elevated fasting blood glucose levels during pre-anesthetic laboratory studies. The reason for referral was the presence of abnormally low glycated hemoglobin levels in relation to the blood glucose levels usually presented by the patient. The patient’s personal medical history includes grade 2 obesity, cholelithiasis, hepatic steatosis, and monoclonal gammopathy of uncertain significance. Upon the first evaluation, it was found that the patient’s son is being studied for chronic hemolytic anemia and type 1 DM. Given the characteristics of the patient and his offspring, it was decided to rule out any erythrocyte abnormalities in both individuals and to conduct a genetic panel study.

Results: The following analytical results were obtained during the next evaluation: • Fasting blood glucose of 140 mg/dL, glycated hemoglobin of 4.20%.• Hemoglobinopathies and enzyme defects were ruled out. A heterozygous mutation in the PIEZO1 gene, c.7367G > A (p. Arg245His), was detected in both the father and the son. This mutation is responsible for the membrane disorder known as hereditary dehydrated stomatocytosis or hereditary xerocytosis. Hereditary xerocytosis arises due to alterations in erythrocyte permeability. It is characterized by chronic hemolytic anemia, primarily due to a slight increase in erythrocyte potassium permeability, leading to dehydration, rigidity, and hemolysis of red blood cells.

Conclusion: In some cases, such as hereditary xerocytosis and other hemolytic anemias, glycated hemoglobin is not useful for routine chronic monitoring of diabetic patients, as its values may be altered. In these cases, as demonstrated in this patient, glucose monitoring systems play a crucial role and serve as an excellent tool for improving the control of diabetic patients.