To the Editor: Dr Ingelsson and colleagues1 conclude that their data do not support measurement of apo B or apo A-I in clinical practice when total cholesterol and HDL-C measurements are available. We believe their conclusions reach further than their data support.
First, the authors focus on the statistical significance of population-level models but apply their conclusions to the individual patient level. Second, the analysis was limited to low-risk, middle-aged white patients. By limiting their population to “healthy patients,”
the authors specifically excluded patients with elevated triglyceride concentration—a population known to have higher apo B levels in the setting of normal traditional lipids.2
This omission could have skewed their data toward their conclusion. Third, the predictive value of the apo B:apo A-I ratio improves as a patient's risk (as measured by traditional risk markers) increases,3
and levels of HDL-C or apo A-I may not always represent the true protective or even the proatherogenic effects of these lipoproteins.4
Remick J, Underberg JA, Shah NR. Utility of Different Lipid Measures to Predict Coronary Heart Disease. JAMA. 2008;299(1):35-36. doi:10.1001/jama.2007.4