Association between hematological parameters, serum retinol, and glycemic indices in diabetes mellitus: a preliminary case-control study

Background: The global prevalence of type 2 diabetes mellitus (T2DM) is on the rise. Hyperglycemia, free radical damage, and inflammation are commonly implicated as the etiopathological factors of diabetes mellitus. This preliminary study aims to investigate the association of the disease with serum retinol and hematological parameters and compare these parameters with non-diabetic controls. Methods: The biophysical profiles of 85 subjects with diabetes and the same number of healthy controls were recorded using standard techniques. Biochemical and hematological investigations were carried out. The data are expressed as median with interquartile range (IQR) values. Mann–Whitney U-test was conducted to assess the difference between the two groups. Results: There were a significant increase in median values of glycated hemoglobin (HbA1c), fasting blood glucose (FPG), and white blood cells (WBC) and a significant decrease in median values of monocytes in subjects with T2DM as compared to controls. There was a significant negative correlation between eosinophils and FPG in subjects with T2DM. In healthy controls, there was a significant positive correlation between serum retinol, certain hematological parameters, and HbA1c; and there was a significant negative correlation between WBC and FPG. The T2DM group had a significant negative correlation between eosinophil count and FBG. Conclusion: Our study shows that serum retinol levels are not reflective of oxidative stress, but a routine WBC and differential count can shed light on the chronic inflammatory status. These results help with the formulation of targeted treatment to delay progression of the disease and prevent its complications. Relevance for Patients: Vitamin A plays a pivotal role safeguarding the immunity and eye health for diabetic patients, but serum retinol estimation is not reflective of inflammatory or glycemic control status in diabetic patients. They would benefit from a hematocrit test.