Study of Postprandial Variation of Routine Haematological Parameters in Healthy Subjects

Routine hematological investigations are one of the most important parameters in reaching to the proper clinical diagnosis.Patient-related variables, such as physical exercise, stress and fasting status are important sources of variability in laboratory testing. However, no clear indications about fasting requirements exist for routine haematological tests.

We studied 40 healthy volunteers who consumed a light meal containing a standardized amount of carbohydrates, protein and lipids. Blood was taken for routine haematological tests pre prandially and 1, 2 and 4 hours postprandially.

After one hour and two hours of the meal, total leucocyte count and neutrophil count increased significantly, whereas lymphocyte counts, red blood cell count, haematocrit, and haemoglobin decreased significantly. A clinically significant variation was observed for all the above. Four hours after the meal, WBCs, neutrophils,lymphocytes, showed significant increase while RBCs, haemoglobin and haematocrit were significantly decreased.

The significant variation of several haematological parameters after a light meal demonstrates that the fasting time needs to be carefully considered in order to interpret the results of haematological tests correctly.