Fasting Isn't Required Before Lipid Levels Are Measured

Summary and Comment |
May 5, 2016

Fasting Isn't Required Before Lipid Levels Are Measured

  1. Thomas L. Schwenk, MD

Predictive value for adverse cardiovascular events is as good, and sometimes better, for nonfasting levels.

  1. Thomas L. Schwenk, MD

In this evidence-based clinical review, the author identified three meta-analyses and five clinical practice guidelines that addressed whether fasting was required to measure lipid levels accurately and whether prediction of incident cardiovascular disease (CVD) events differed between fasting and nonfasting lipid levels.

The reviewer came to the following conclusions:

  • Nonfasting testing results in clinically insignificant changes compared with fasting results in total, high-density, and low-density lipoprotein cholesterol levels and in only modest changes in triglyceride levels.

  • Nonfasting and fasting lipid levels are at least equally predictive for adverse CVD events; nonfasting levels sometimes were more strongly predictive, presumably because nonfasting is the predominant metabolic condition for most people.

  • Clinical practice guidelines have shifted during the past 5 years to endorse nonfasting testing in most routine circumstances.

  • The recent European Atherosclerosis Society/European Federation for Laboratory Medicine guidelines recommend that, when triglyceride levels are >400 mg/dL with nonfasting testing, ordering a fasting test is appropriate (Eur Heart J 2016 Apr 26; [e-pub]).

  • No studies directly compared the cost or convenience of nonfasting versus fasting testing, but a Danish study (where nonfasting testing has been the standard since 2009) showed that only 10% of patients who underwent nonfasting testing required repeat fasting testing.

Comment

Nearly all clinicians have had the common experience of requiring patients to return for fasting lipid tests that frequently result in extra expense and inconvenience for patients and breakdowns in care for patients who do not return. The author believes that nonfasting lipid–level assessment should become routine clinical practice. Having already practiced this way for many years, I agree.

Editor Disclosures at Time of Publication

  • Disclosures for Thomas L. Schwenk, MD at time of publication Editorial boards UpToDate

Citation(s):

Reader Comments (12)

Evan Dyce, RN BSN Nurse/NP/PA, Family Medicine/General Practice

There are useful reference levels available in the clinical guideline produced by:

Nordestgaard, B. G., Langsted, A., Mora, S., Kolovou, G., Baum, H., Bruckert, E.,…Langlois, M. (2016). Fasting is not routinely required for determination of a lipid profile: clinical and laboratory implications including flagging at desirable concentration cut-points—a joint consensus statement from the European Atherosclerosis Society and European Federation of Clinical Chemistry and Laboratory Medicine. European Heart Journal 62(7), 930-946. doi: 10.1373/clinchem.2016.258897

DINAKER MANJUNATH Physician, Internal Medicine, GYD CLINICS

Finally the obsession to get Fasting only lipids for all patients will hopefully be put to rest.

Ritupam Das Other, Other

Good news

MBBS, FCPS Cradiology Other, Cardiology, Tabba Heart Institiute, karachi Pakistan

As a cardiologist, I need to start the statins asap in my patients. Fasting is an issue in many patients especially in diabetics and acutely ill ones. I hope this gets to the guidelines too.

SURESH AMIN Pathology, Vadodra India

I hold this view for last 10 years.This is vindication of my stand. While practising laboratory medicine my lab adopted a policy – fasting is not necessary for lipid measurement. However patients were told that they may be required to come again, if their random triglyceride was higher than 400 mg/DL. They they have come with 14 hrs fast and previous day abstinence of alcohol. There will be no additional charge for this repeat. In one year this resulted only 2 repeats.

STEVEN HUFF Physician, Family Medicine/General Practice

I would restate the question of Dr. Argiriou: What reference levels should be used for nonfasting lipid assessment? What reference levels were used in the cited studies?

Joseph M Indovina Other Healthcare Professional, Other

As a Clinical Chemist with 35+ years of Clinical Laboratory experience I urge caution with non fasting lipid test interpretation. Clearly physician clinical judgement, patient history, and a careful physical examination plays an important role in determining patient CVD risk. Please note however that physicians need to keep in mind that the majority of lipid investigations used to help evaluate CVD risk involve fasting patients. As an example, the US National Cholesterol Education program recommends:
" A fasting lipoprotein profile including major blood
lipid fractions, i.e., total cholesterol, LDL cholesterol,
HDL cholesterol, and triglyceride, should be obtained
at least once every 5 years in adults age 20 and over A fasting lipoprotein profile including major blood
lipid fractions, i.e., total cholesterol, LDL cholesterol,
HDL cholesterol, and triglyceride, should be obtained
at least once every 5 years in adults age 20 and over"

Further:
" If
the testing opportunity is nonfasting, only the values for
total cholesterol and HDL will be usable. In otherwise
low-risk persons (0–1 risk factor), further testing is not
required if the HDL-cholesterol level is ≥40 mg/dL and
total cholesterol is <200 mg/dL. However, for persons
with multiple (2+) risk factors, lipoprotein measurement
is recommended as a guide to clinical management."

Osman Espinoza Physician, Internal Medicine, Office

This is awesome news. I have also felt that fasting Lipids is cumbersome for patient and, sometimes costly. I like that this article gives a somewhat clear clinical guideline making triglyceride over 400 the threshold to order a fasting lipid profile.

Argirios Argiriou, MD Physician, Family Medicine/General Practice, Private Surgery, Kavala, Greece.

Which reference values should we use when it comes to nonfasting cholesterol levels?

JAYANTA BHATTACHARYA Physician, Family Medicine/General Practice, Home

On what rationale previous guide line of fasting before testing was accepted and on what exact rationale it is now discarded? Patient convenience and cost reduction must not that strong to override biochemical reasonings.

Lawrence Green MD Physician, Neurology, Crozer Chester Medical Center

This is especially valuable information for Type ! diabetics for whom fasting may be risky with overnight hypoglycemia

Dr Cynthia Bush MD Physician, Internal Medicine, Gainesville, Florida

Thank goodness, we're finally coming around to this conclusion!
My own anecdotal experience has demonstrated this.

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