This 2015 trial used Womens’ Health Study data and a consideration of three alternative lipid biomarkers to demonstrate that LDL cholesterol markers significantly under- or overestimate heart disease risk in a meaningful segment of the population. Specifically, in individuals with low levels of insulin resistance — such as those following a low-carb diet alongside regular exercise — high LDL-C levels may not indicate elevated heart disease risk. Conversely, insulin-resistant individuals with low LDL-C levels may still be at a high risk of heart disease.