Why do you need to fast when measuring blood lipids?

In our daily lives, we are required to fast for many tests, especially for blood lipid tests. Doctors will emphasize this in particular. This is because the test found that the test results after eating will deviate from the actual results, which will affect the doctor's judgment and is not conducive to personal health. Therefore, people must pay attention to fasting before measuring blood lipids.

1. Blood lipid test requires fasting

Whether fasting is necessary before blood lipid testing has been a hot topic in recent years. Currently, the testing standards of many countries stipulate that fasting for 8 to 16 hours is required before blood lipid testing, but a major consensus published in the European Heart Journal in 2016 broke this common sense. The consensus was released by the European Atherosclerosis Society and the European Federation of Clinical Chemistry and Laboratory Medicine, and listed several major studies in recent years on the impact of fasting time on blood lipids. It was found that eating will have a certain impact on both children and adult men and women.

Except for some impact on triglycerides, fasting time does not significantly affect other blood lipid levels. Before the consensus was released, Denmark had already begun to routinely use non-fasting blood lipids as a monitoring method. When the patient's non-fasting triglycerides were >4.0 mmol/L, fasting triglycerides could be rechecked.

Therefore, in order to increase patients' compliance with lipid monitoring, the consensus is that non-fasting lipids can be routinely monitored.

2. Why do you need to be on an empty stomach when having blood drawn?

Fasting generally means not eating for 8-14 hours before the examination. If you have a physical examination at 8 am, it is best not to eat after 10 pm the night before. No matter how late, it should not be later than midnight.

During a blood test, blood sugar, blood lipids, liver function and other items are often checked. Drawing blood while fasting can prevent food components from interfering with test results and more truly reflect the body's biochemical changes.

If you eat before having your blood drawn, some indicators will fluctuate. For example, blood sugar and blood lipids will inevitably increase. The test results cannot be compared with the reference values ​​measured on a fasting basis, so accurate clinical judgments cannot be made.