Study: Fasting before blood tests may not be necessary for most analyses - Sarmad

A recent study has shown that fasting before blood tests may not be necessary for many routine analyses, as the duration of fasting was associated with limited changes in the results of most tests included in the study.

The science website ScienceAlert reported that researchers from Asan Medical Center at the University of Ulsan in Seoul analyzed more than 9.7 million blood test results conducted on approximately 101,000 adult patients between 2021 and 2023. They compared the results according to fasting duration, which ranged from less than eight hours, to eight to 12 hours, and more than 12 hours.

The researchers found a clear association between fasting duration and the results of only 10 out of the 121 tests included in the study. The most notable were glucose, triglycerides, gamma-glutamyl transferase (GGT), and lipase enzymes, as their values were higher among individuals who fasted for less than eight hours.

Conversely, the results of most other tests were not significantly affected by fasting duration. Furthermore, fasting for more than 12 hours did not lead to any additional clinically significant differences in the results of any of the tests included in the study.

The study’s findings were published in JAMA Internal Medicine. The researchers noted that their results could support adopting fasting requirements that vary depending on the type of test, rather than applying a uniform rule to all blood tests.

They clarified that these findings do not mean that fasting instructions issued by physicians or laboratories should be discarded, nor do they prove that fasting is unnecessary in all cases. However, they provide data that could contribute to reevaluating fasting requirements, particularly since this practice was historically linked to glucose and lipid tests and later expanded to include broader panels of blood tests.

Fasting before certain blood tests is a common practice aimed at minimizing the impact of food and drink intake on specific results. However, the need for fasting varies depending on the type of test and its medical purpose.