Is Fasting Necessary for the Assessment of Clinical Biochemical Parameters

Introduction: Blood tests are usually requested for patients visiting polyclinics in the morning following fasting. However, as hospitals provide services for 24 hours, blood is collected from patients at every hour of the day, and fasting status cannot be completely ensured. Therefore, our study aimed to compare the fasting/non-fasting biochemical parameters of individuals. Materials and Methods: Our retrospective study examined 18 different most frequently requested blood tests of patients who visited certain polyclinics at our hospital only once as fasting and non-fasting values based on their hours of being requested. Results: In our study which analyzed a total of 70,352 individuals, statistically significant differences were observed in the fasting/non-fasting values. However, when the effect size values were measured for the tests, they were not clinically significant (0.006-0.104). Conclusion: There was no noticeable difference between the fasting and non-fasting parameters. It was concluded that, as long as there is no doubt on routine results, individuals could give blood samples throughout the day with or without fasting.