Reply to Letters Regarding Article, “Prognostic Value of Fasting Versus Nonfasting Low-Density Lipoprotein Cholesterol Levels on Long-Term Mortality: Insight From the National Health and Nutrition Examination Survey III (NHANES-III)”
Authors: Bethany Doran, Yu Guo, Jinfeng Xu, Howard Weintraub, Samia Mora, David J. Maron, Sripal Bangalore
Journal: Circulation (2015)

We appreciate the letters by Aldasouqi et al and Horne et al about our article. 1Their thought-provoking comments further strengthen the call to abandon fasting lipid panels in the majority of patients.Aldasouqi et al outline the potential dangers of the fasting requirement in patients with diabetes mellitus.Obtaining fasting lipid panels in diabetics poses risks because they may experience significant hypoglycemia if required to fast; additionally, there is the inconvenience of a second visit.Hypoglycemic episodes may lead to a number of complications, including confusion and loss of consciousness, road traffic accidents, seizures, and even death.Two major trials examining intensive glucose lowering in patients, Action to Control Cardiovascular Risk in Diabetes (ACCORD) and Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE), demonstrated that those with ≥1 severe hypoglycemic episodes had a higher risk of death than those without hypoglycemic episodes. 2n addition, Horne et al outline a transient increase in low-density lipoprotein cholesterol (LDL-C) levels after 12 to 24 hours of fasting, which is supported by data from other clinical studies, although the exact mechanism of this finding is not fully known.These findings highlight the uncertain gains of obtaining fasting lipid profiles and the complexity of the association of fasting status with LDL-C levels and cardiovascular risk prediction.Further complicating the issue of obtaining fasting lipid profiles is the variability of recommendations from national and international agencies on the need for fasting and the duration of fasting.The American College of Cardiology/ American Heart Association guidelines recommend fasting but do not specify an optimal duration to define fasting time, whereas European guidelines specifically recommend 12 hours of fasting. 3,4he American College of Cardiology/American Heart Association guidelines also note that although fasting lipid panels for obtaining triglyceride levels and LDL-C is "preferred," nonfasting panels may have some utility in diagnosing genetic hypercholesterolemia in individuals with non-high-density lipoprotein cholesterol >220 mg/ dL.Nonfasting lipid profiles have been shown to have utility in the assessment of non-high-density lipoprotein cholesterol and triglycerides in predicting cardiovascular events and have been shown to be superior in prediction to obtaining fasting lipid profiles in some studies.The National Institute for Health Care Excellence in the United Kingdom does not recommend fasting panels unless triglycerides are between 10 and 20 mmol/L (roughly 885-1770 mg/dL). 5urther research is needed to explore the societal risk to diabetics required to fast before lipid panels and the impact of transient increases in LDL-C levels after fasting.Few studies support the use of obtaining fasting LDL-C levels, and these letters to the editor raise important additional points, suggesting that relying on convention not supported by data must be re-examined.