Blood cholesterol trends 2001-2011 in the United States: analysis of 105 million patient records.

OBJECTIVES: 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. BACKGROUND: 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. METHODS AND RESULTS: 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. CONCLUSIONS: 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.

Vitamin D may not improve lipid levels: a serial clinical laboratory data study.

BACKGROUND: Vitamin D deficiency is highly prevalent and is associated with dyslipidemia and cardiovascular disease. The impact of correcting vitamin D deficiency on blood lipids, strong cardiovascular disease prognostic factors, is unknown. METHODS AND RESULTS: To determine relationships between 25-hydroxyvitamin D levels and lipids, we analyzed 4.06 million deidentified patient laboratory test results from September 2009 through February 2011. We performed a cross-sectional study of this population to determine associations between 25-hydroxyvitamin D levels and lipids across clinically defined strata. We also conducted a retrospective cohort study of vitamin D deficient patients to investigate how changes in 25-hydroxyvitamin D levels relate to changes in lipid levels. After exclusions, 107 811 patients with serial testing were selected for cross-sectional analysis. Compared with vitamin D deficient patients (<20 ng/mL), those with optimal levels (≥30 ng/mL) had lower mean total cholesterol (-1.9 mg/dL; 95% confidence interval [95% CI], -1.2 to -2.7; P<0.0001), lower low-density lipoprotein cholesterol (-5.2 mg/dL; 95% CI, -4.5 to -5.8; P<0.0001), higher high-density lipoprotein cholesterol (4.8 mg/dL; 95% CI, 4.5-5.0; P<0.0001), and lower triglycerides (-7.5 mg/dL; 95% CI, -6.2 to -8.7; P<0.0001). For the retrospective cohort analysis, raising vitamin D levels from <20 to ≥30 ng/mL (n=6260), compared with remaining at <20 ng/mL (n=2332), was associated with a mean increase in total cholesterol (0.77 mg/dL; 95% CI, 0.18-1.36; P=0.01) and high-density lipoprotein cholesterol (0.42 mg/dL; 95% CI, 0.08-0.76; P=0.02) but nonsignificant changes in low-density lipoprotein cholesterol (0.32 mg/dL; 95% CI, -0.01 to 0.66; P=0.06) and triglycerides (0.04 mg/dL; 95% CI, -2.16 to 2.23 mg/dL; P=0.97). CONCLUSIONS: Although vitamin D deficiency is associated with an unfavorable lipid profile in cross-sectional analyses, correcting for a deficiency might not translate into clinically meaningful changes in lipid concentrations; however, data from intervention trials are required to confirm these findings.

Value of laboratory tests in employer-sponsored health risk assessments for newly identifying health conditions: analysis of 52,270 participants.

BACKGROUND: Employer-sponsored health risk assessments (HRA) may include laboratory tests to provide evidence of disease and disease risks for common medical conditions. We evaluated the ability of HRA-laboratory testing to provide new disease-risk information to participants. METHODOLOGY/PRINCIPAL FINDINGS: We performed a cross-sectional analysis of HRA-laboratory results for participating adult employees and their eligible spouses or their domestic partners, focusing on three common health conditions: hyperlipidemia, diabetes mellitus, and chronic kidney disease. HRA with laboratory results of 52,270 first-time participants were analyzed. Nearly all participants had access to health insurance coverage. Twenty-four percent (12,392) self-reported one or more of these medical conditions: 21.1% (11,017) self-identified as having hyperlipidemia, 4.7% (2,479) self-identified as having diabetes, and 0.7% (352) self-identified as having chronic kidney disease. Overall, 36% (n = 18,540) of participants had laboratory evidence of at least one medical condition newly identified: 30.7% (16,032) had laboratory evidence of hyperlipidemia identified, 1.9% (984) had laboratory evidence of diabetes identified, and 5.5% (2,866) had laboratory evidence of chronic kidney disease identified. Of all participants with evidence of hyperlipidemia 59% (16,030 of 27,047), were newly identified through the HRA. Among those with evidence of diabetes 28% (984 of 3,463) were newly identified. The highest rate of newly identified disease risk was for chronic kidney disease: 89% (2,866 of 3,218) of participants with evidence of this condition had not self-reported it. Men (39%) were more likely than women (33%) to have at least one newly identified condition (p<0.0001). Among men, lower levels of educational achievement were associated with modestly higher rates of newly identified disease risk (p<0.0001); the association with educational achievement among women was unclear. Even among the youngest age range (20 to 29 year olds), nearly 1 in 4 participants (24%) had a newly identified risk for disease. CONCLUSIONS/SIGNIFICANCE: These results support the important role of employer-sponsored laboratory testing as an integral element of HRA for identifying evidence of previously undiagnosed common medical conditions in individuals of all working age ranges, regardless of educational level and gender.