What is the lipid profile

Kardiologie.org

Many patients find not being allowed to eat anything in the morning to be uncomfortable. According to an international consensus paper, “staying sober” is no longer necessary for routine lipid testing.

For a routine lipid determination, patients no longer have to appear sober in the practice - this view is now represented by international experts from the “European Atherosclerosis Society” (EAS) and the “European Federation of Clinical Chemistry and Laboratory Medicine” (EFLM) in a joint consensus paper. Only in special situations or in the case of conspicuously high plasma triglyceride concentrations of> 5 mmol / l may a fasting blood sample be necessary.

So far, it has been common practice in most countries to urge patients not to eat any more at least eight hours before the measurement; although in Denmark the routine lipid determination in the fasting state has not been recommended as a standard since 2009 and this is for the most part practiced so successfully.

More comfortable for the patient, doctor and laboratory staff

For patients, doctors and laboratory staff, lipid measurement in the non-fasting state is a great relief, which can ultimately also improve patient compliance, argue the authors of the consensus paper around Børge Nordestgaard from the University of Copenhagen. Because “staying sober” can be a burden, especially for children, diabetics and the elderly. In addition, the patients do not have to return to the practice for a separate appointment just to have their lipids measured soberly. The lipid determination does not necessarily have to be carried out in the morning, which relieves the laboratory staff. And, instant lipid measurement enables doctors to make faster decisions.

Concerns are unfounded

General concerns about lipid determination in the non-fasting state are a possible inadequate measurement accuracy and the lack of evaluated reference values. According to Nordestgaard and colleagues, however, there are now data from current cohort and registry studies that show that food intake only slightly influences the lipid profile and that the observed changes in lipid concentrations do not have a clinically significant effect. In addition, numerous studies show that lipid levels measured on an empty stomach reflect the cardiovascular risk similarly or even better.

Orient limit values ​​to current guidelines

According to the EAS / EFLM consensus paper, the respective limit values ​​should, if possible, be based on the target values ​​of current guidelines instead of traditional laboratory reference values. The following values ​​are considered abnormally high for lipid profiles not measured on an empty stomach:

  • Triglycerides: ≥2 mmol / l (175 mg / dl)
  • Total cholesterol: ≥5 mmol / L (190 mg / dL)
  • LDL cholesterol: ≥3 mmol / l (115 mg / dl)
  • HDL cholesterol: ≤1 mmol / l (40 mg / dl)
  • Lp (a): ≥50 mg / dl

The limit value for triglycerides is increased by 0.3 mmol / L compared to the fasting limit value, based on the mean deviation observed in studies that was observed with values ​​measured not on fasting.

Fasting lipid measurement makes sense in special situations

According to Nordestgaard and colleagues, however, the lipid measurement in the fasting state should not be completely written off. Both measurement methods should complement each other and not be mutually exclusive, they write. In general, when deciding whether to measure fasting or not fasting, one should consider the purpose of the lipid measurement - whether screening, risk assessment or diagnosis.

When it comes to diagnosing genetically caused dyslipidemia, for example, fasting blood tests have their justified role, say the experts, while it is less important in the case of the first stage of screening.
According to the consensus paper, a fasting blood test to determine lipids may be necessary in the following situations:

  • Triglyceride value> 5 mmol / L (440 mg / d) in the case of a non-fasting blood sample,
  • in the case of a planned start of therapy with drugs that could trigger severe hypertriglyceridemia such as steroids, estrogens or retinoic acid,
  • for the follow-up of hypertriglyceridemia-induced pancreatitis,
  • with known hypertriglyceridemia with subsequent referral to a lipid clinic and
  • if further blood tests are necessary, which must be done on an empty stomach, e.g. B. the determination of the fasting blood sugar.

Most patients do not need to be sober

For all other patients, a lipid measurement without a fasting blood sample is sufficient, including:

  • with children,
  • Diabetics (important because of the risk of hypoglycaemia),
  • older people,
  • CHD patients
  • Patients on stable medication,
  • for the initial lipid determination us
  • for cardiovascular risk assessment.

According to the consensus paper, however, it might make sense to urge patients not to eat fatty meals such as fast food on the day of the lipid determination and not to drink anything before the measurement, as drinking fluids can falsify the values.

It is also pointed out that patients should be referred to a lipid clinic or a specialist in the event of life-threatening readings (triglycerides> 10 mmol / l, LDL-C> 13 mmol / l, Lp (a)> 150 mg / dl) .