Blood Cholesterol Trends 2001–2011 in the United States: Analysis of 105 Million Patient Records

Abstract

We report annual trends in low density lipoprotein cholesterol (LDL-C) from an in-care patient population of nearly 105 million adults across the United States (U.S.), from 2001 through 2011. Average blood cholesterol values have declined in the U.S. since at least 1960. The National Health and Nutrition Examination Survey (NHANES) reported declining blood cholesterol values from 1999 through 2010. In the absence of more recent published data, we examined LDL-C values from a single clinical laboratory database to determine whether these values continued to decline through 2011. We extracted almost 247 million LDL-C results from nearly 105 million adults who received diagnostic testing from a single national clinical laboratory. Annual age-adjusted mean LDL-C values were calculated, and analyzed by gender. Piecewise regression analysis of the total study population indicates a breakpoint, or change in slope, in the years following 2008 (F = 163.13; p<0.05). Between 2001 and 2008, the average rate of annual decline was −2.05 mg/dL (95% CI [−2.35, −1.75]). After 2008, mean LDL-C levels flattened out, with a slope not statistically different from zero (slope = −0.10 mg/dL/year; 95% CI [−1.46, 1.26]). This stabilization was observed in both genders and all age ranges, and was also reflected in the percentage of results in low- and high-risk categories. The trends reported suggest historical progress in decreasing LDL-C levels, observed from 2001–2008, may have stalled in recent years. Further research is needed to determine the cause of the observed trends and develop new strategies to reduce lipid-based cardiovascular risk further.