Comparison of fasting and postprandial levels of commonly used biochemical and hematological parameters

Aim: Physicians and patients may have varying preferences for optimal blood analysis time. We aimed to determine the tendency for the optimal blood analysis time of the physicians and patients and also to determine the difference in some commonly used biochemical and hematological parameters, between fasting and food intake. Methods: Questionnaire and cross-sectional designs were used. The doctors and patients were conducted to a survey about the appropriate time for blood tests before the study. 112 patients were included in study. Blood samples were collected after 8-10 hours of fasting and 2 hours after 600-700 calories lunch. Blood creatinine, alanine aminotransferase, sodium, glucose, calcium, albumin, total cholesterol, triglyceride, HDL, LDL, alkaline phosphatase, total bilirubin, lactate dehydrogenase, complete blood count, erythrocyte sedimentation rate, prothrombin time and TSH were studied and the values were compared. Results: In our survey, 75% of patients (54 patients in the outpatient clinic and 98 patients in the blood collection unit, a total of 152) and 77% of doctors were thinking that fasting was the appropriate time for blood tests. There were significant increase in glucose (p<0.01), triglyceride (p<0.01) and platelets (p=0.035) and significant decrease in sodium (p=0.01) after the food intake. There was no statistically significant difference in the other parameters. Conclusion: The majority of physicians and patients had the opinion that blood tests should be given in fasting. Although there were significant differences in glucose, triglyceride, thrombocyte and sodium levels in our study, thrombocyte and sodium differences may not exhibit any clinical importance. Notwithstanding, high postprandial levels of glucose and triglyceride are valuable indicators for cardiovascular disease and diabetes risk