An Unknown Peak in Hemoglobin Chromatogram associated with Diabetic Markers and Oxygen Saturation in COVID-19 Patients

Coronavirus disease-19 (COVID-19) is associated with glycemic control, oxygen requirements and mortality among patients. Considering the vital role of hemoglobin in oxygen transport, this study focused on the effect of COVID-19 and diabetes on hemoglobin chromatogram patterns, especially in the context of inflammatory markers (IL6, hs-CRP, LDH and ferritin) and oxygen saturation. The study group (n= 242) was divided into four subgroups: COVID-19 patients (n=120; diabetics and non-diabetics) and non-COVID-19 controls (n=122; diabetics and non-diabetics). Hb chromatograms were obtained and analyzed using ion-exchange high-pressure liquid chromatography. All routine hematological and inflammatory markers were estimated in the samples drawn at admission. The total monocyte count and inflammatory marker levels were highest among diabetic patients in the COVID subgroup (p<0.0001). An unknown peak (retention time 0.33-0.36) was observed in the hemoglobin chromatogram of patients with diabetes (both COVID-19 and non-COVID-19 subgroups). These patients with novel peaks presented significantly lower SpO2 levels at admission than those without diabetes but without this peak (p=0.07) and those without diabetes and peak (p=0.001) among the COVID-19 patients. The COVID-19 patients with this peak showed significantly poor glycemic control [HbA1c, fasting blood sugar and insulin sensitivity (QUICKI) (p<0.05)]. The area under the unknown peak (UNA) showed a positive linear correlation with HbA1b (r=0.801; p<0.0001), HbA1c (r=0.65, p>0.0001) and FBS (r=0.56, p>0.0001). This study reveals that COVID-19 patients with unknown peaks in the Hb chromatogram had higher inflammation, poor glycemic control and a significant need for oxygen.