Break the fast? Update on patient preparation for cholesterol testing.

OBJECTIVE: To provide an update on the clinical usefulness of nonfasting versus fasting lipid testing to improve patient compliance, patient safety, and clinical assessment in cholesterol testing. QUALITY OF EVIDENCE: Recommendations are identified as supported by good, fair, and poor (conflicting or insufficient) evidence, according to the classifications adopted by the Canadian Task Force on Preventive Health Care. MAIN MESSAGE: Screening for dyslipidemia as a risk factor for coronary artery disease and management of lipid-lowering medications are key parts of primary care. Recent evidence has questioned the fasting requirement for lipid testing. In population-based studies, total cholesterol, high-density lipoprotein cholesterol, and non-low-density lipoprotein cholesterol all varied by an average of 2% with fasting status. For routine screening, nonfasting cholesterol measurement is now a reasonable alternative to a fasting cholesterol measurement. For patients with diabetes, the fasting requirement might be an important safety issue because of problems with hypoglycemia. For the monitoring of triglyceride and low-density lipoprotein cholesterol levels in patients taking lipid-lowering medications, fasting becomes more important.
CONCLUSION: Fasting for routine lipid level determinations is largely unnecessary and unlikely to affect patient clinical risk stratification, while nonfasting measurement might improve patient compliance and safety. Copyright© the College of Family Physicians of Canada.