(575 days)
Not Found
No
The device description details a process of spectral deconvolution and calculation based on known signal characteristics and conversion factors, which is a deterministic algorithm, not AI/ML. There is no mention of training data, models, or adaptive learning.
No
Explanation: The device is a diagnostic test that measures lipoprotein particles to aid in the management of lipoprotein disorders, not a device used for therapy.
Yes
The device measures lipoprotein particles (LDL-P, HDL-C, and triglycerides) in serum and plasma to aid in the management of lipoprotein disorders associated with cardiovascular disease. This information is used for diagnosis and management decisions.
No
The device description explicitly states that the test involves the measurement of a 400 MHz proton NMR spectrum of a plasma or serum sample using an automated NMR spectrometer. This indicates the use of a physical hardware device (the NMR spectrometer) to acquire the initial data, making it a system that includes hardware, not a software-only device.
Yes, this device is an IVD (In Vitro Diagnostic).
Here's why:
- Intended Use: The intended use explicitly states that the test "measures lipoprotein particles to quantify LDL particle number (LDL-P), HDL cholesterol (HDL-C), and triglycerides in serum and plasma". It also states that these measurements are "used in conjunction with other lipid measurements and clinical evaluation to aid in the management of lipoprotein disorders associated with cardiovascular disease." This clearly indicates that the test is performed on biological samples (serum and plasma) to provide information for medical diagnosis and management.
- Device Description: The description details the process of analyzing a plasma or serum sample using NMR spectroscopy to obtain quantitative measurements of lipoprotein components. This is a characteristic of an in vitro diagnostic test.
- Performance Studies: The document includes performance studies such as analytical sensitivity, assay precision, linearity, interfering substances, and method comparisons with commercially available chemistry analyzer systems for HDL Cholesterol and Triglycerides. These are standard types of studies performed to validate the performance of an IVD.
- Predicate Devices: The mention of predicate devices (K020724, K971324, K971162) which are described as reagents for measuring LDL Cholesterol, Triglycerides, and HDL Cholesterol, further supports the classification as an IVD. These are likely other IVD devices used for similar measurements.
The fact that the test is "performed and provided as a service by LipoScience Laboratory" does not negate its classification as an IVD. Many IVD tests are performed in a laboratory setting as a service.
N/A
Intended Use / Indications for Use
The NMR LipoProfile® -2 test, used with the NMR Profiler, an automated NMR spectrometer, measures lipoprotein particles to quantify LDL particle number (LDL-P), HDL cholesterol (HDL-C), and triglycerides in serum and plasma using nuclear magnetic resonance (NMR) spectroscopy. LDL-P and these NMR-derived concentrations of triglycerides and HDL-C are used in conjunction with other lipid measurements and clinical evaluation to aid in the management of lipoprotein disorders associated with cardiovascular disease. This test is performed and provided as a service by LipoScience Laboratory.
Product codes (comma separated list FDA assigned to the subject device)
MRR, LBS, CDT, JJY, JIT
Device Description
The NMR LipoProfile Test involves measurement of the 400 MHz proton NMR spectrum of a plasma or serum sample, deconvolution of the composite signal at ~0.8 ppm to produce the signal amplitudes of the lipoprotein subclasses that contribute to the composite plasma signal, and conversion of these subclass signal amplitudes to lipoprotein subclass concentrations. The 0.8 ppm plasma NMR signal arises from the methyl group protons of the lipids carried in the VLDL, and HDL subclasses of varying diameter. The NMR signals from the various lipoprotein subclasses have unique and distinctive frequencies and lineshapes, each of which are accounted for in the deconvolution analysis model. Each subclass signal amplitude is proportional to the number of subclass particles emitting the signal, which enables subclass particle concentrations to be calculated from the subclass signal amplitudes derived from the spectral deconvolution analysis. LDL subclass particle concentrations, in units of nanomoles of particles per liter (nmol/L), are summed to give the reported total LDL particle concentration (LDL-P). By employing conversion factors that assume that the various lipoprotein subclass particles have cholesterol and triglyceride contents characteristic of normolipidemic individuals, HDL cholesterol and triglyceride concentrations are also derived.
Mentions image processing
Not Found
Mentions AI, DNN, or ML
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Input Imaging Modality
Nuclear Magnetic Resonance (NMR) spectroscopy
Anatomical Site
Not Found
Indicated Patient Age Range
Not Found
Intended User / Care Setting
This test is performed and provided as a service by LipoScience Laboratory.
Description of the training set, sample size, data source, and annotation protocol
Not Found
Description of the test set, sample size, data source, and annotation protocol
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Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)
Analytical Sensitivity:
The analytical sensitivity was determined by serially diluting serum specimens with low initial concentrations of LDL-P, HDL-C, and triglycerides. 20 replicates of each were analyzed. CVs and % bias between observed and target values were determined with acceptance criteria based on total error ≤20%.
Limits of quantification (LOQ) are 300 nmol/L for LDL-P, 10 mg/dL for HDL-C, and 25 mg/dL for triglycerides.
Assay Precision:
Intra-assay and inter-assay variability were determined by testing 20 replicates of two patient serum pools in the same run (intra-assay) and in 20 different runs over 4 days (inter-assay).
Intra-assay Precision (Pool 1, Pool 2 respectively):
LDL-P (nmol/L): Mean 2222, SD 49.1, %CV 2.2; Mean 1042, SD 47.7, %CV 4.6
HDL-C (mg/dL): Mean 41, SD 0.54, %CV 1.3; Mean 57, SD 0.42, %CV 0.7
Trig (mg/dL): Mean 189, SD 2.0, %CV 1.1; Mean 75, SD 1.2, %CV 1.5
Inter-assay Precision (Pool 1, Pool 2 respectively):
LDL-P (nmol/L): Mean 1925, SD 66.7, %CV 3.5; Mean 1053, SD 68.4, %CV 6.5
HDL-C (mg/dL): Mean 42, SD 1.17, %CV 2.8; Mean 56, SD 0.83, %CV 1.5
Trig (mg/dL): Mean 219, SD 2.9, %CV 1.3; Mean 80, SD 1.7, %CV 2.1
Linearity:
Two serum pools with high or low values of LDL-P, HDL-C, and triglycerides were mixed and diluted to produce 12 different samples. Mean values from analysis of 6 replicates were compared to expected target values.
Linear ranges: LDL-P: 300-6000 nmol/L; HDL-C: 7-160 mg/dL; Triglycerides: 5-2700 mg/dL.
Reportable Range:
LDL-P: 300 - 3500 nmol/L
HDL-C: 7 - 140 mg/dL
Triglycerides: 5 - 1100 mg/dL
Interfering Substances:
Evaluation of endogenous and exogenous substances showed no appreciable interference at tested levels representative of highest blood concentrations.
Clinical Performance:
Method Comparison - HDL Cholesterol:
Study Type: Split-sample comparison
Sample Size: 5,362 plasma samples
Data Source: Multi-Ethnic Study of Atherosclerosis (MESA)
Key Results: HDL-C concentrations ranged from 15 to approximately 140 mg/dL. Mean values observed for the predicate and the NMR LipoProfile test were 51.3 and 50.7 mg/dL, respectively. R-squared value = 0.897.
Method Comparison - Triglycerides:
Study Type: Split-sample comparison
Sample Size: 5,362 plasma samples
Data Source: Multi-Ethnic Study of Athero-sclerosis (MESA)
Key Results: Triglyceride concentrations ranged from 21 to 400 mg/dL. Mean values observed for the predicate and the NMR LipoProfile test were 123.9 and 128.7 mg/dL, respectively. R-squared value = 0.929.
Clinical performance of NMR LipoProfile test for LDL-P Measurement:
Three external clinical outcome studies were conducted to evaluate the clinical performance. Results indicated that LDL-P was statistically significantly related to CVD risk.
Veterans Affairs HDL Intervention Trial (VA-HIT):
Study Type: Prospective, nested case-control study
Sample Size: 1061 plasma samples (364 cases, 697 controls)
Data Source: Randomized placebo-controlled Veterans Affairs HDL Intervention Trial (VA-HIT)
Key Results: Baseline levels of LDL-P were statistically significantly associated with incident CHD events (odds ratio 1.31 (95% CI, 1.09-1.57, p=0.004)). On-trial LDL-P values had a somewhat weaker association (odds ratio 1.19 (95% CI, 0.99-1.43, p=0.054)).
EPIC -Norfolk study:
Study Type: Nested case-control study
Sample Size: 2,888 (1,003 cases, 1,885 controls)
Data Source: Prospective EPIC (European Prospective Investigation into Cancer and Nutrition)-Norfolk study
Key Results: LDL-P values ranged from 485-4156 nmol/L. Conditional logistic regression showed LDL-P was statistically significantly associated with incident CAD events in both univariable analyses and multivariable analyses.
Univariable Odds Ratio (95% CI) for Q1-Q4: 1.00, 1.23 (0.97-1.56), 1.48 (1.17-1.87), 2.00 (1.58-2.59), p
§ 862.1475 Lipoprotein test system.
(a)
Identification. A lipoprotein test system is a device intended to measure lipoprotein in serum and plasma. Lipoprotein measurements are used in the diagnosis and treatment of lipid disorders (such as diabetes mellitus), atherosclerosis, and various liver and renal diseases.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 862.9.
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LIPOSCIENCE
JUL 2 8 2008
2500 Sumner Boulevard Raleigh, NC 27616
Main Number: 919.212.1999 Customer Service: 877.547.6837
510(k) Summary
LipoScience NMR LipoProfile-2 Assay and NMR Profiler Instrument Test System
This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92.
Assigned 510(k) Number: K063841
Submitter's Name, Address, Telephone Number, Contact Person, and Date Prepared
Submitter: LipoScience, Incorporated 2500 Sumner Boulevard Raleigh, NC 27616
919-256-1236 Phone: Facsimile: 919-256-1039
Contact Person: E. Duffy McDonald, SPHR Vice President, Operations LipoScience, Incorporated Phone: 919-256-1236 Facsimile: 919-256-1039
Date Prepared: September 18, 2006 (summary revised July 17, 2008)
Name of Device and Name/Address of Sponsor
Name of Device NMR LipoProfile-2 Assay and NMR Profiler Test System
Sponsor:
LipoScience, Incorporated 2500 Sumner Boulevard Raleigh, NC 27616
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Common or Usual Name
NMR LipoProfile test
Classification Name (s)
Lipoprotein test system (21CFR 862.1475, product codes MRR and LBS) Triglyceride test system (21CFR 862.1705, product code CDT) Quality control material (21 CFR 862.1660, product code JJY) Calibrator (21 CFR 862.1150, JIT)
Predicate Device(s)
| Device Name: | Dimension Automated LDL Cholesterol Flex Reagent |
|---|---|
| Manufacturer: | Dade Behring, Inc. |
| 510(k) Number: | K020724 |
| Device Name: | Triglycerides Reagent |
| Manufacturer: | Carolina Liquid Chemistries |
| 510(k) Number: | K971324 |
| Device Name: | Liquid N-geneous HDL Cholesterol Kit |
| Manufacturer: | Genzyme Corporation |
| 510(k) Number: | K971162 |
Intended Use / Indications for Use
The NMR LipoProfile® -2 test, used with the NMR Profiler, an automated NMR spectrometer, measures lipoprotein particles to quantify LDL particle number (LDL-P), HDL cholesterol (HDL-C), and triglycerides in serum and plasma using nuclear magnetic resonance (NMR) spectroscopy. LDL-P and these NMR-derived concentrations of triglycerides and HDL-C are used in conjunction with other lipid measurements and clinical evaluation to aid in the management of lipoprotein disorders associated with cardiovascular disease. This test is performed and provided as a service by LipoScience Laboratory.
Device Description
Principle of Operation
The NMR LipoProfile Test involves measurement of the 400 MHz proton NMR spectrum of a plasma or serum sample, deconvolution of the composite signal at ~0.8 ppm to produce the signal amplitudes of the lipoprotein subclasses that contribute to the composite plasma signal, and conversion of these subclass signal amplitudes to lipoprotein subclass concentrations. The 0.8 ppm plasma NMR signal arises from the methyl group protons of the lipids carried in the VLDL, and HDL subclasses of varying diameter. The NMR signals from the various lipoprotein subclasses have unique and distinctive frequencies and lineshapes, each of which are accounted for in the deconvolution analysis model. Each subclass signal amplitude is proportional to the number of subclass particles emitting the signal, which enables subclass particle
2
concentrations to be calculated from the subclass signal amplitudes derived from the spectral deconvolution analysis. LDL subclass particle concentrations, in units of nanomoles of particles per liter (nmol/L), are summed to give the reported total LDL particle concentration (LDL-P). By employing conversion factors that assume that the various lipoprotein subclass particles have cholesterol and triglyceride contents characteristic of normolipidemic individuals, HDL cholesterol and triglyceride concentrations are also derived.
Types of Specimen
Freshly drawn serum collected in an NMR LipoTube is the preferred specimen. Freshly drawn serum collected in plain red-top blood collection tubes and EDTA or heparin plasma are also acceptable specimens. The optimum volume is ≥0.5 mL. Patient fasting is not necessary prior to the blood draw, except for determination of fasting triglyceride concentrations.
Testing Procedure
Each patient specimen is diluted 2-fold using the NMR Diluent, mixed thoroughly, and placed in separate specimen vials in predefined locations of the bar-coded measurement racks. Automated testing is then initiated according to the operating instructions.
Result Calculation
The NMR Profiler test system performs all calculations necessary to produce the final reported results. These calculations include the linear least squares spectral deconvolution analysis which gives the NMR signal amplitudes of each lipoprotein subclass, the conversion of these signal amplitudes to subclass particle concentrations and calculated subclass cholesterol and triglyceride concentrations, and summation of the appropriate subclass concentrations to give the reported values of LDL-P. HDL-C. and triglycerides.
Software and Hardware
The NMR Profiler test system contains a Rack Reader, a Nuclear Magnetic Resonance (NMR) system, and a LipoProfile Analysis Server. These three core systems manage information through databases and file systems. The algorithm resident on the LipoProfile Analysis Server is the foundation of the LipoProfile assay. The NMR system and Rack reader are configured off-the-shelf components. The remaining software serves to transmit data, store data, and report the results of the LipoProfile analysis. The LipoProfiler System may be configured as a stand alone system or integrated into a Laboratory Information System (LIS).
Technological Characteristics and Substantial Equivalence
The NMR LipoProfile test, when used with the NMR Profiler, is as safe and effective as the Dade Dimension Automated LDL Cholesterol Flex Reagent, Carolina Liquid Chemistries Triglycerides Reagent, and Genzyme Liquid N-geneous HDL Cholesterol
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test. The NMR LipoProfile test has the same intended uses and similar indications and principles of operation as its predicate devices. The minor technological differences between the NMR LipoProfile test and its predicate devices raise no new issues of safety or effectiveness. Performance data further demonstrate that the NMR LipoProfile test is as safe and effective as its predicate devices. Thus, the NMR LipoProfile test is substantially equivalent.
Similarity to Predicates
As with the predicate assays, the NMR LipoProfile test is intended for the separation and quantitation of LDL, HDL, and triglycerides in serum and plasma, measurements of which are used in conjunction with other lipid measurements and clinical evaluation to aid in the management of lipoprotein disorders associated with cardiovascular disease.
Therefore, substantial equivalence of the NMR LipoProfile Test to the claimed predicate devices is based upon the following:
- substantially similar intended use and indications for use, .
- use of the same clinical specimen (serum and plasma)
- substantial similar safety and effectiveness; i.e.; no new questions of safety � and effectiveness are raised when the tests are used as intended
Differences from Predicate
The NMR LipoProfile Test differs from its predicates in three ways, related to the primary technological characteristic difference of the NMR LipoProfile Test, which uses nuclear magnetic resonance (NMR) spectroscopy as compared to chemistry-based spectrophotometric detection.
- NMR uses a different energy source magnetic resonance versus . photometric,
- . NMR directly measures lipoprotein particles - direct measure of particle number concentration versus chemistry-based lipid assay, and
- NMR does not require chemical or enzymatic reactions to measure lipoprotein . concentrations.
Therefore, fundamentally the NMR LipoProfile Test and predicates are intended to measure substantially similar information by way of different methods, by evaluating the quality and quantity of lipoproteins in biological specimens using proprietary algorithms. physical measurements, and calculations. Although the NMR LipoProfile Test differs in technological characteristics, the performance of this assays has been shown to be equivalent through the testing of clinical specimens. For LDL-P, substantial equivalence and clinical utility was demonstrated in the target population utilizing appropriate clinical outcome measures and for the measurement of triglycerides and HDL-C, comparing the NMR test results to standard chemical methods for TRIG and HDL-C determination.
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Performance Data - Non-Clinical
Analytical Sensitivity
The analytical sensitivity of the NMR LipoProfile test measurements of LDL-P. HDL-C. and triglycerides was determined as the lowest concentration measurable with acceptable precision and accuracy. Serum specimens with low initial concentrations LDL-P, HDL-C, and triglycerides were serially diluted and 20 replicates of each were analyzed. CVs and % bias between observed and target values were determined and acceptance criteria are based on total error ≤20%. Limits of quantification (LOQ) are 300 nmol/L for LDL-P, 10 mg/dL for HDL-C, and 25 mg/dL for triglycerides.
Assay Precision
Intra-assay and inter-assay variability were determined by testing 20 replicates of two patient serum pools in the same run (intra-assay) and in 20 different runs over 4 days (inter-assay). The results of this testing are summarized below:
| Intra-assay Precision | Inter-assay Precision | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pool 1 | Pool 2 | Pool 1 | Pool 2 | |||||||||
| Mean | SD | % CV | Mean | SD | % CV | Mean | SD | % CV | Mean | SD | % CV | |
| LDL-P (nmol/L) | 2222 | 49.1 | 2.2 | 1042 | 47.7 | 4.6 | 1925 | 66.7 | 3.5 | 1053 | 68.4 | 6.5 |
| HDL-C (mg/dL) | 41 | 0.54 | 1.3 | 57 | 0.42 | 0.7 | 42 | 1.17 | 2.8 | 56 | 0.83 | 1.5 |
| Trig (mg/dL) | 189 | 2.0 | 1.1 | 75 | 1.2 | 1.5 | 219 | 2.9 | 1.3 | 80 | 1.7 | 2.1 |
Linearity
Two serum pools were prepared from patient specimens with high or low values of LDL-P, HDL-C, and triglycerides as determined by NMR LipoProfile analysis. Each were mixed and diluted in different proportions to produce 12 different samples with widely varying target concentrations. Mean values from analysis of 6 replicates were compared to the expected target values to determine the percent bias for each sample. Linear ranges were determined as follows:
| LDL-P | 300-6000 nmol/L |
|---|---|
| HDL-C | 7-160 mg/dL |
| Triglycerides | 5-2700 mg/dL |
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Reportable Range
The following are the reportable ranges for LDL-P, HDL-C and triglycerides.
| LDL-P | 300 - 3500 nmol/L |
|---|---|
| HDL-C | 7 - 140 mg/dL |
| Triglycerides | 5 - 1100 mg/dL |
Interfering Substances
Endogenous substances normally found in blood and exogenous substances (common and prescription drugs) were evaluated for potential interference with the NMR LipoProfile test. Six plasma pools with LDL-P, HDL-C, and triglyceride values spanning the clinically-relevant range were spiked with potential interferents. No appreciable interference was produced by the substances at the spiked levels tested, which were representative of the highest blood concentrations expected for the highest therapeutic doses of these compounds.
| Potential Interferent | Test Concentration |
|---|---|
| Endogenous | |
| Bilirubin | 20 mg/dL |
| Creatinine | 20 mg/dL |
| Hemoglobin | 500 mg/dL |
| Urea | 300 mg/dL |
| Uric acid | 40 mg/dL |
| Exogenous | |
| Acetaminophen | 1050 µmol/L |
| Aspirin | 880 µmol/L |
| Clopidogrel | 28 µmol/L |
| Enalapril | 13 µmol/L |
| Fenofibrate | 70 µmol/L |
| Furosemide | 38 µmol/L |
| Glipizide | 7 µmol/L |
| Hydralazine | 60 µmol/L |
| Hydrochlorothiazide | 27 µmol/L |
| Ibuprofen | 550 µmol/L |
| Isosorbide dinitrate | 80 µmol/L |
| Metformin | 960 µmol/L |
| Metoprolol | 23 µmol/L |
| Naproxen | 470 µmol/L |
| Niacin | 2200 µmol/L |
| Nifedipine | 37 µmol/L |
| Piroxicam | 10 µmol/L |
| Simvastatin | 30 µmol/L |
| Thiazolidinedione | 61 µmol/L |
| Triamterene | 31 µmol/L |
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Performance Data - Clinical
Method Comparison - HDL Cholesterol
Method comparison was evaluated by split-sample comparison of HDL-C values measured by the NMR LipoProfile test with those analyzed on a commercially available chemistry analyzer system. The data below summarize the results of analyses performed on 5,362 plasma samples from individuals who were part of the Multi-Ethnic Study of Atherosclerosis (MESA). HDL-C concentrations ranged from 15 to approximately 140 mg/dL and the mean values observed for the predicate and the NMR LipoProfile test were 51.3 and 50.7 mg/dL, respectively.
Image /page/6/Figure/3 description: This image is a scatter plot that compares NMR LipoProfile HDL-C to Predicate HDL-C, both measured in mg/dL. The x-axis represents Predicate HDL-C, ranging from 0 to 160 mg/dL, while the y-axis represents NMR LipoProfile HDL-C, also ranging from 0 to 160 mg/dL. A diagonal line runs through the plot, and the data points are clustered closely around this line. The R-squared value, indicating the goodness of fit, is given as 0.897.
Method Comparison - Triglycerides
Method comparison was evaluated by split-sample comparison of triglyceride values measured by the NMR LipoProfile test with those analyzed on a commercially available chemistry analyzer system. The data below summarize the results of analyses performed on 5,362 plasma samples from individuals who were part of the Multi-Ethnic Study of Atherosclerosis (MESA). Triglyceride concentrations ranged from 21 to 400 mg/dL and the mean values observed for the predicate and the NMR LipoProfile test were 123.9 and 128.7 mg/dL, respectively ..
Image /page/6/Figure/6 description: This image is a scatter plot that compares NMR LipoProfile Triglycerides to Predicate Triglycerides, both measured in mg/dL. The data points are clustered tightly around a diagonal line, indicating a strong positive correlation between the two variables. The R-squared value is 0.929, which suggests that the model explains 92.9% of the variance in the data. The x and y axis range from 0 to 500 mg/dL.
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Clinical performance of NMR LipoProfile test for LDL-P Measurement
Three external clinical outcome studies were conducted to evaluate the clinical performance of the NMR Lipoprofile measurement of LDL-P. The studies estimated the prediction of future (incident) cardiovascular disease (CVD) events by previously measured values of LDL-P. Results of all three studies indicated that LDL-P was statistically significantly related to CVD risk
Veterans Affairs HDL Intervention Trial (VA-HIT)
A prospective, nested case-control study was conducted using 1061 plasma samples collected from male patients enrolled in the randomized placebocontrolled Veterans Affairs HDL Intervention Trial (VA-HIT), a secondary prevention trial examining the efficacy of gemfibrozil for prevention of new CHD events among men with known CHD and low levels of both HDL and LDL cholesterol. Fasting EDTA plasma samples were collected at baseline and after 7 months from 2,531 men. Case subjects (n=364) were men who experienced a CHD event (cardiac death or nonfatal myocardial infarction) during the mean 5,1 year follow-up period. Control subjects (n=697) were men matched for age who remained free of CHD events during follow-up.
Table 1 shows the odds ratios (OR) for a new CHD event associated with a 1- SD increment of LDL-P in the subjects treated with placebo (n=546). Baseline levels of LDL-P were statistically significantly associated with incident CHD events (odds ratio 1.31 (95% CI, 1.09-1.57, p=0.004), while on-trial LDL-P values had a somewhat weaker association .
| Baseline | On-Trial | |
|---|---|---|
| LDL-P | ||
| Odds Ratio (95% CI) | 1.31 (1.09-1.57) | 1.19 (0.99-1.43) |
| p value | 0.004 | 0.054 |
Table 1: Prediction of CHD Events by LDL-P in the Placebo Group
EPIC -Norfolk study
A nested case-control study was performed in the prospective EPIC (European Prospective Investigation into Cancer and Nutrition)-Norfolk study, which was carried out between 1993 and 1997 to investigate dietary and other determinants of cancer. Additional data were obtained to enable the assessment of determinants of other diseases, including coronary artery disease (CAD). The study population comprised 25,663 men and women inhabitants of Norfolk, United Kingdom, aged 45 to 79 years, who completed a baseline questionnaire survey and attended a clinic visit. At this baseline visit, non-fasting serum samples were obtained from participants and stored at -80℃ before NMR LipoProfile testing. Participants were followed for six years for the development of CAD, defined as CAD death, myocardial infarction, and angina. Samples
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tested (n=2,888; 36% women; average age 65 years) were from cases (n=1,003) who developed CAD during the 6-year follow-up period and controls (n=1,885) who did not develop CAD, matched for age, gender, and enrollment time. None of the cases or controls were taking any lipid altering medications.
LDL-P values measured in this study spanned the range of 485-4156 nmol/L. Conditional logistic regression was used to calculate odds ratios for future (incident) CAD, adjusted for smoking and blood pressure plus matching for age, gender, and enrollment time. Table 2 shows the odds ratios for development of CAD by increasing quartiles of LDL-P. LDL-P was statistically significantly associated with an incident CAD events in both univariable analyses and multivariable analyses adjusted for HDL-C and triglycerides.
| Quartiles | |||||
|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | p§ | |
| Range (nmol/L) | 1812 | ||||
| Univariable | |||||
| Odds Ratio (95% CI) | 1.00 | 1.23 | |||
| (0.97-1.56) | 1.48 | ||||
| (1.17-1.87) | 2.00 | ||||
| (1.58-2.59) | 1703 | ||||
| HR | |||||
| (95% CI) | 1.00 | 1.37 | |||
| (1.01-1.85) | 1.35 | ||||
| (1.01-1.81) | 1.80 | ||||
| (1.36-2.38) | 2.51 | ||||
| (1.91-3.30) |