Study of Correlation of Mean Red Cell Volume and Red Cell Distribution Width with HbA1c and its Association with Microvascular Complications in Patients with Type 2 Diabetes Mellitus

Dr. Jaydip Chabhadiya, Dr. Sundeep T Malhan, Dr. Hema Bojani

Abstract: Background: Type 2 diabetes mellitus (T2DM) is a growing public health issue, with an estimated 537 million (10.5%) adults affected globally. In India, approximately 89.8 million adults (10.5% of the population) have diabetes. Chronic hyperglycemia in diabetes leads to microvascular complications (retinopathy, nephropathy, neuropathy), which are major causes of morbidity. Hematologic indices such as red blood cell distribution width (RDW) and mean corpuscular volume (MCV) have emerged as potential inflammatory markers and may reflect glycemic control. Objective: To evaluate the relationships of RDW and MCV with long-term glycemic control (HbA1c) and their associations with diabetic microvascular complications. Methods: In this cross-sectional study, 125 adults with established T2DM (on treatment) were enrolled (April 2023-June 2024). Exclusion criteria included type 1 diabetes, anemia (Hb<12 g/dL in women, <13 g/dL in men), renal failure, malignancy, pregnancy, and use of antiplatelets/anticoagulants. All subjects underwent clinical examination, fundus evaluation for retinopathy, monofilament testing for peripheral neuropathy, and urine albumin-creatinine ratio for nephropathy. Laboratory tests included HbA1c and complete blood count (for RDW and MCV). Correlations between RDW/MCV and HbA1c were assessed using Pearson correlation, and associations with complications were analyzed using chi-square tests and odds ratios. Results: The mean age of participants was X years (range Y-Z), with a male: female ratio of A: B.68% had poor glycemic control (HbA1c ≥7%). RDW and MCV showed moderate positive correlations with HbA1c (r=0.45 and r=0.35 respectively; p<0.001 for both), indicating that higher RDW and higher MCV were associated with worse glycemic control. Higher HbA1c itself correlated moderately with the presence of neuropathy (r≈0.40), retinopathy (r≈0.36), and nephropathy (r≈0.38; all p<0.001). Lower MCV was significantly associated with lower prevalence of retinopathy (X²=4.38, p=0.036) and nephropathy (X²=3.96, p=0.047); e. g. patients with low MCV had only about half the odds of retinopathy compared to normal/high MCV (OR≈0.54). Normal-range RDW was significantly linked to a reduced likelihood of retinopathy (X²=7.12, p=0.008), although RDW was not significantly associated with neuropathy or nephropathy in this cohort. In multivariable analysis, poor glycemic control (HbA1c≥7%) markedly increased the odds of neuropathy (OR≈4.8, p<0.001) and retinopathy (OR≈3.5, p≈0.01). Conclusions: In our T2DM cohort, higher RDW and MCV were associated with higher HbA1c, and both indices showed significant associations with key microvascular complications. Notably, elevated RDW and MCV predicted diabetic retinopathy, while low MCV predicted lower risk of retinopathy and nephropathy. These findings suggest that routine CBC parameters (RDW and MCV) may serve as inexpensive markers of glycemic control and risk stratification for microvascular complications in diabetes. Further prospective studies are warranted.

Keywords: type 2 diabetes mellitus, red blood cell indices, glycemic control markers, diabetic microvascular complications, routine blood parameters

How to Cite?: Dr. Jaydip Chabhadiya, Dr. Sundeep T Malhan, Dr. Hema Bojani, "Study of Correlation of Mean Red Cell Volume and Red Cell Distribution Width with HbA1c and its Association with Microvascular Complications in Patients with Type 2 Diabetes Mellitus", Volume 15 Issue 1, January 2026, International Journal of Science and Research (IJSR), Pages: 124-127, https://www.ijsr.net/getabstract.php?paperid=MR26101190211, DOI: https://dx.doi.org/10.21275/MR26101190211