The relationship between red blood cell distribution width and blood pressure in patients with type 2 diabetes mellitus in Lagos, Nigeria

Background: High red blood cell distribution width (RDW) is related to impairment of erythropoiesis, reflecting chronic inflammation and increased levels of oxidative stress, both of which are telltale signs of type 2 diabetics. The aim of this study was to evaluate the relationship between the RDW and fasting blood sugar/blood pressure, and compare the results from diabetics with nondiabetic controls. Methods: This was an unmatched case-control study involving 200 participants consisting of 100 diabetics and 100 nondiabetic controls. Blood (4.5 mL) was collected from all of the diabetics and nondiabetic controls, and placed into EDTA anticoagulant tubes. A full blood count was performed using the Sysmex KX-21N, a three-part auto analyzer able to run 19 parameters per sample, including RDW. Blood pressure was measured during sample collection and in a sitting position. Results: The mean fasting blood sugar level was 95.20 +/- 30.10 mg/dL in the controls, and 147.85 +/- 72.54 mg/dL in the diabetics. The mean blood pressures for diabetics was 138/90 mmHg and for non-diabetics 120/80 mmHg. The mean RDW-SD (RDW standard deviation) was 46.44 +/- 4.64 fl in the controls, and 46.84 +/- 3.18 in the diabetics. The mean RDW-CV (RDW coefficient of variation) was 14.74%+/- 1.94% in controls, and 14.80 +/- 0.71 for diabetics. No statistically significant correlation was found between the RDW-SD and fasting blood sugar/blood pressure in the diabetics. A statistically significant positive correlation was found between the RDW-CV and blood pressure in the diabetics. Conclusion: A positive correlation between the RDW-CV and blood pressure was established in the diabetics in this study.