The Very Large Database of Lipids (VLDL)
Closer examination of granular lipid data in a large population offers numerous opportunities to generate new knowledge, ranging from studies examining concordance between commonly used lipid parameters to phenotypic characterization of rare or extreme disorders of lipid metabolism, opening possibilities to better personalize future treatment of abnormal blood lipids.
The Very Large Database of Lipids (VLDL) includes adults and children who were clinically referred for a Vertical Auto Profile (VAP).
The VAP test (Atherotech, Birmingham, Alabama, USA) directly measures cholesterol concentrations of low density lipoprotein, very low density lipoprotein, intermediate density lipoprotein, high density lipoprotein, their subfractions, and lipoprotein(a). Triglycerides in the database are directly measured using the Abbott ARCHITECT C‐8000 system (Abbott Park, Illinois, USA). Lipid distributions in the database closely match those from the population-representative National Health and Nutrition Examination Survey (NHANES) 2007-2008.
This database was investigator-initiated. Only de-identified data reach the investigational site. The first data harvest was in 2011, and encompassed 1,350,908 samples. The second harvest is underway; thus far, an updated database suited to assess seasonal variation has been established with 2,859,333 samples. The master database is housed at The Johns Hopkins Hospital in Baltimore, Maryland, and maintained by Drs. Jones and Martin. Only electronic data, and not biospecimens, are sent to Hopkins. The academic investigators have unrestricted access to study data, take responsibility for the accuracy of analyses, and have authority over manuscript preparation and submission.
The variables currently in the VLDL database are testing date, age, sex, low density lipoprotein, very low density lipoprotein, intermediate density lipoprotein, high density lipoprotein, their subfractions, lipoprotein(a), and LDL pattern. From these primary variables, many additional variables were derived for inclusion in the master database (e.g., non-HDL-C, Friedewald LDL-C, TC/HDL-C, etc.). Other analytes measured by validated assays in subsets of the VLDL database include apoB, apoA1, hsCRP, homocysteine, uric acid, insulin, hemoglobin A1c, 25-hydroxy vitamin D, cystatin C, Lp-PLA2, TSH, free T3 and T4, pro-BNP, direct bilirubin, CPK, creatinine and other components of the comprehensive metabolic panel, magnesium, and phosphate.
In the current database, each record represents a unique patient. The 1st available VAP test for each patient is included. To meet the needs of a variety of research questions, we are prospectively planning to organize harvest 2 data into 3-year interval datasets (i.e., VLDL 2006-2008, 2009-2011, VLDL 2012-2014, etc), a summation dataset (first VAP test for each patient), serial lab dataset (patients who have had repeated testing), and ancillary datasets (subsets of patients with coexisting data on other measures such as apolipoproteins, vitamin D, hs-CRP, TSH/T4, etc).
Individual VLDL studies will be based on a priori hypotheses or aims with statistical analysis plans (SAPs) peer-reviewed prior to execution. In the expandable "Detailed Description" section below, the VLDL investigators will periodically register individual studies and update their status on clinicaltrials.gov.
Lipid Disorders and Lipid Measurement
|Study Design:||Time Perspective: Cross-Sectional|
- all-cause mortality [ Time Frame: up to 9 years from time of baseline lipid profile ] [ Designated as safety issue: No ]
|Study Start Date:||April 2011|
|Primary Completion Date:||April 2013 (Final data collection date for primary outcome measure)|
REGISTRATION & STATUS OF VLDL STUDIES:
- VLDL-1A: Friedewald Estimated versus Directly Measured Low-Density Lipoprotein Cholesterol and Treatment Implications (abstract presented; manuscript published; citation provided below)
- VLDL-1B: Derivation and Validation of a Novel Method for More Accurate Estimation of Low-Density Lipoprotein Cholesterol from the Standard Lipid Profile (manuscript under review)
- VLDL-2: Non-HDL-C, TC/HDL-C, and LDL-C Population Percentiles and Discordance (abstract presented; manuscript published; citation provided below)
- VLDL-3: Vitamin D Levels and Lipids (abstract presented; manuscript in preparation)
- VLDL-4: Correlates of the TG/HDL-C Ratio (abstract submitted; manuscript in preparation)
- VLDL-5: Ratio of Dense to Buoyant LDL Subclass and LDL Density Phenotype (abstract presented; manuscript published; citation provided below)
- VLDL-6: Characterization of Fredrickson-Levy Dyslipidemia Classes without Chylomicrons (IIa, IIb, III,IV) (abstract presented; manuscript in preparation)
- VLDL-7: Characterization of Fredrickson-Levy Dyslipidemia Classes with Chylomicrons (I,V) (abstract presented; manuscript in preparation)
- VLDL-8: Continuum of Non-Chylomicron Dyslipidemia Phenotype not Classifiable by Fredrickson-Levy Criteria (abstract presented; manuscript in preparation)
- VLDL-9: Characterization of Those with Extremely Low or High HDL-C Concentrations (abstract submitted; manuscript in preparation)
- VLDL-10A: Atherogenic Lipid Levels in 662,711 Elderly Persons: The Very Large Database of Lipids 10A (abstract submitted; manuscript in preparation)
- VLDL-10B: Narrowing Sex Differences in Lipoprotein Cholesterol Subclasses Following Menopause: Insights from the Very Large Database of Lipids (abstract submitted; manuscript in preparation)
- VLDL-11: Triglyceride-Rich Remnant Lipoprotein Cholesterol Concentrations in AIM-HIGH-Like Patients (abstract submitted; manuscript in preparation)
- VLDL-12: Complementary Information in Common Lipid Classifications (abstract in preparation)
- VLDL-13: The Relationship between Thyroid dysfunction and Advanced Lipoprotein Cholesterol Subfractions in a Contemporary Sample of US Adults (abstract submitted; manuscript in preparation)
- VLDL-14: Seasonal Differences in Lipid Profiles of 2.8 Million Consecutive, Unique US Adults: The Very Large Database of Lipids Seasonal Substudy (abstract submitted; manuscript in preparation)
Please refer to this study by its ClinicalTrials.gov identifier: NCT01698489
|United States, Maryland|
|Johns Hopkins University|
|Baltimore, Maryland, United States|
|Study Director:||Steven R Jones, MD||Johns Hopkins University|