The Impact of Severe Hypertriglyceridemia on Glycosylated Hemoglobin Test in Type 2 Diabetes Mellitus

Abstract

Background: although the glycosylated hemoglobin (HbA1c) test is a valid test for diabetes diagnosis and evaluation of glycemic control, many factors are known to affect the results of the HbA1c test and make it reflects a false image of the glycemic control. One of these factors is hypertriglyceridemia. Objectives: the study aims to assess the impact of severe hypertriglyceridemia (TG ≥ 1000 mg/dl) on HbA1c test results in type 2 diabetes mellitus. Method: a retrospective study on two groups of adult patients with type 2 DM; were implemented in Faiha Diabetes, Endocrine and Metabolism Centre (FDEMC) in Basrah–Iraq. A total of 267 patients with type 2 DM and severe hypertriglyceridemia and a total of 313 patients with type 2 DM and normal triglycerides levels were included. Then the mean HbA1c of the patients with severe hypertriglyceridemia was measured in each FBS range and compared to the mean HbA1c of the patients with normal triglycerides levels in the same FBS range to determine the impact of severe hypertriglyceridemia on the readings of HbA1c in the diabetic patients. Results: t he mean HbA1c in both groups was compared in each FBS range and revealed that despite of recording nearly the same mean FBS, HbA1c was higher in patients with severe hypertriglyceridemia by 1.33% in the FBS range 130-149 mg/dl with a statistically significant p-value = 0.003. While it was lower in the FBS range 200-229 mg/dl, 230-259 mg/dl, 260-299 mg/dl, 300-349 mg/dl and 350-399 mg/dl by 1.02%, 0.85%, 1.77%, 2.29% and 2.23%, respectively with a statistically significant p-value that equal to 0.005, 0.034, < 0.001, < 0.001 and 0.039, respectively. Conclusion: t his study reveal that severe hypertriglyceridemia has a significant impact on HbA1c test results. The HbA1c values in diabetic patients with severe hypertriglyceridemia are unpredictable.