Clinical Chemistry
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


Clinical Chemistry 45: 1039-1046, 1999;
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (46)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Seman, L. J.
Right arrow Articles by Schaefer, E. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Seman, L. J.
Right arrow Articles by Schaefer, E. J.
Related Collections
Right arrow Evidence Based Laboratory Medicine and Test Utilization
Right arrow Lipids, Lipoproteins, and Cardiovascular Risk Factors
(Clinical Chemistry. 1999;45:1039-1046.)
© 1999 American Association for Clinical Chemistry, Inc.


Articles

Lipoprotein(a)-Cholesterol and Coronary Heart Disease in the Framingham Heart Study

Leo J. Seman1,2,a, Carl DeLuca1,2, Jennifer L. Jenner2, L. Adrienne Cupples3, Judith R. McNamara2, Peter W.F. Wilson4, William P. Castelli4, Jose M. Ordovas2 and Ernst J. Schaefer1,2

1 Division of Endocrinology, Diabetes, Metabolism and Molecular Medicine, New England Medical Center and Tufts University School of Medicine, 750 Washington St., Boston, MA 02111.

2 Lipid Metabolism Laboratory, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111.

3 Department of Epidemiology and Biostatistics, Boston University School of Public Health, Boston, MA 02118-2394.

4 Framingham Heart Study, National Institutes of Health, National Heart, Lung, and Blood Institute, Framingham, MA 01702.
a Address correspondence to this author at: New England Medical Center, Box 216, 750 Washington St., Boston, MA 02111.


   Abstract
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
 
Background: Increased plasma lipoprotein(a) [Lp(a)] concentrations have been reported to be an independent risk factor for coronary heart disease (CHD) in some prospective studies, but not in others. These inconsistencies may relate to a lack of standardization and the failure of some immunoassays to measure all apolipoprotein(a) isoforms equally.

Methods: We measured plasma Lp(a)-cholesterol [Lp(a)-C] in a Caucasian population of offspring and spouses of the Framingham Heart Study participants, using a lectin-based assay (LipoproTM). We compared the prevalence of increased Lp(a)-C to the presence of sinking pre-ß-lipoprotein (SPB). We also related Lp(a)-C concentrations to the prevalence of CHD risk in the entire population.

Results: The mean (± SD) Lp(a)-C concentration in the Framingham population (n = 3121) was 0.186 ± 0.160 mmol/L, with no significant gender or age differences. The mean Lp(a)-C concentrations in the absence or presence of SPB were 0.158 ± 0.132 mmol/L and 0.453 ± 0.220 mmol/L, respectively (P <0.0001). The mean Lp(a)-C concentration in men with CHD (n = 156) was 0.241 ± 0.204 mmol/L, which was significantly (P <0.001) higher, by 34%, than in controls. The odds ratio for CHD risk in men with Lp(a)-C >=0.259 mmol/L (>=10 mg/dL), after adjusting for age, HDL-cholesterol, LDL-cholesterol, smoking, diabetes, blood pressure, and body mass index, was 2.293 (confidence interval, 1.55–3.94; P <0.0005). Lp(a)-C values correlated highly with a Lp(a)-mass immunoassay [ApotekTM Lp(a); r = 0.832; P <0.0001; n = 1000].

Conclusions: An increased Lp(a)-C value >=0.259 mmol/L (>=10 mg/dL) is an independent CHD risk factor in men with a relative risk of more than 2, but was inconclusive in women. Lp(a)-C measurements offer an alternative to Lp(a)-mass immunoassays and can be performed on automated analyzers.© 1999 American Association for Clinical Chemistry


   Introduction
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
 
In 1963, Kåre Berg (1) first described lipoprotein(a) [Lp(a)]1 as a lipoprotein antigen that was more prevalent in the plasma of myocardial infarction survivors than in an age-matched control group of Scandinavian men.

Apolipoprotein (a) [apo(a)] is known to be a very heterogeneous glycoprotein that shares at least 75% homology with plasminogen, including domains of plasminogen referred to as kringle 4, kringle 5, and the protease domain. There is no unique domain of the apo(a) gene that does not share homology with plasminogen (2). apo(a) is highly glycosylated (3)(4), with numerous O-glycosidic linkages in the regions between the kringle domains (5). At least 34 phenotypes are expressed, ranging from 12 to 50 kringles (6)(7), and there are potentially more phenotypes and genotypes that may exist.

Increased Lp(a) concentrations have been described in numerous case-control studies as correlating with coronary heart disease (CHD) (8)(9)(10)(11)(12)(13)(14)(15). There have been several prospective studies that have identified Lp(a) as a CHD risk factor (16)(17)(18)(19)(20)(21)(22)(23)(24)(25), although not all have been positive (26)(27)(28)(29). The measurement of Lp(a) mass has been the "standard" since the formulation of the first radioimmunoassay by Albers and Hazzard (30) in 1974. Because of variability in apo(a) isoform size, we do not believe that Lp(a) should be standardized on the basis of mass concentrations. Immunoassays may not provide an accurate measure of Lp(a) concentration if the antibodies in the assay bind to epitopes that may be present in apo(a) in multiple copies or if a single epitope within apo(a) is altered by conformational changes because of large variations in apo(a) size. Marcovina et al. (31) have reported that an isoform size bias, which misrepresents the true Lp(a) concentration, can occur with some assays, although this is less of a problem with other assays (31)(32).

Three prospective studies that measure Lp(a) as sinking pre-ß-lipoprotein (SPB) (19)(20)(21) strongly support Lp(a) as an important CHD risk factor. The method used in those studies may be reliable, in part, because of its lack of reliance on immunodetection, its dependence on lipid detection, and its measurement of fresh plasma samples, rather than frozen, archived samples. However, SPB analysis is only semiquantitative.

A novel assay has been designed to avoid the difficulties that may arise with immunodetection of various isoforms of apo(a) by nonspecifically trapping Lp(a) with a lectin, and then measuring the cholesterol in the lectin-bound fraction using standard enzymatic cholesterol assays, standardized to a lower range of detection [0–1.297 mmol/L (0–50 mg/dL)]. This method has been described, characterized, and shown to correlate highly with an immunoassay (MacraTM; Wampole Laboratories) (33). To further evaluate Lp(a)-cholesterol [Lp(a)-C] as a CHD risk factor, we measured Lp(a)-C in plasma samples collected from participants in the Framingham Offspring Study between 1990 and 1994 and compared them to SPB results generated on the same subjects between 1970 and 1974 (19)(20). It is well documented that there are no significant changes in Lp(a) concentrations over time (34), although cross-sectional data suggest some small effect (35). In addition, we compared the results of Lp(a)-C analysis in a subset of 1000 subjects with Lp(a)-mass values generated with the ApotekTM Lp(a) Assay (Sigma).


   Materials and Methods
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
 
Plasma samples from offspring and their spouses among the Framingham Heart Study participants were routinely collected, as described previously, after an overnight fast (36). Samples collected from 3332 participants at exam 5, between 1991 and 1995, were stored at -80 °C for 2–6 years without being subjected to thawing and were then analyzed with the LipoproTM Lp(a)-cholesterol kit (Genzyme Diagnostics), according to directions contained in the package insert. In brief, 200 µL of Lipopro Lp(a) reagent was added to the top filter chamber of a microtube. Plasma (200 µL) was then added and mixed by vortex-mixing (33). The mixture was allowed to stand for 5 min at ambient room temperature before being centrifuged for 1 min at 12 000g in a microcentrifuge. Wash buffer (200 µL) was then added to the top filter chamber of each tube, vortex-mixed, and incubated for 5 min before the centrifugation step was repeated. After the second centrifugation, the lower chamber, containing unretained plasma and wash, was replaced with a new tube. Elution buffer (200 µL) was then added to the upper chamber, allowed to incubate for 5 min, and centrifuged for 3 min at 12 000g. This eluate that contained the Lp(a) was then subjected to a standard enzymatic cholesterol assay, calibrated to the range 0–1.3 mmol/L (0–50 mg/dL). Our laboratory participates in the CDC/National Heart, Lung, and Blood Institutes Cholesterol Standardization Program.

SPBs were obtained using methods described previously (19)(20). In brief, fresh plasma samples were collected from subjects, ultracentrifuged to remove VLDL (d <1.006 kg/L), and immediately blotted onto cellulose acetate strips, which were then applied to an electrophoresis apparatus containing barbital buffer. Samples were then subjected to 1.5 V/cm for 16 h. The cellulose acetate strips were then stained with oil red O. Samples were then all read at the same time, using the same reader (WPC), and classified as "positive", "trace", or "not present".

To compare Lp(a)-C results directly to Lp(a)-mass concentrations, plasma samples from a subset of 1000 Framingham Offspring Study participants were also subjected to Lp(a)-mass measurement with the Apotek Lp(a)-mass assay, an immunoassay that traps Lp(a) with a polyclonal antibody to apo(a) and detects with polyclonal antibodies to apolipoprotein B, making the assay less likely to be affected by changes in isoform size. The assay was performed according to the package insert instructions, and the results have been published elsewhere (32).

Other plasma lipoproteins were determined as described previously (36). Total cholesterol was measured on an Abbott Spectrum CCX, using the cholesterol esterase/cholesterol oxidase method (Sigma), according to the package insert. Triglycerides were also measured using this automated method, measuring glycerol after hydrolysis, according to package insert specifications (Sigma). HDL-cholesterol (HDL-C) was determined using Mg2+/dextran precipitation of lipoproteins containing apolipoprotein B, followed by cholesterol measurement of the unprecipitated HDL fraction, using a standard cholesterol esterase/cholesterol oxidase assay. LDL-cholesterol (LDL-C) was calculated using the formula developed by Friedewald et al. (37) for subjects with triglycerides <4.0 g/L (<400 mg/dL).

All prevalent CHD cases were identified at or before exam 5 (through 1995). A panel of three physicians examined the records of all potential CHD cases and confirmed the presence of CHD according to the criteria established for the analysis of the Framingham Heart Study, as described elsewhere (38). CHD includes angina pectoris, myocardial infarction, coronary insufficiency, and coronary death. No cases were prospectively identified.

The statistics were analyzed using the SAS program (SAS Institute). Subjects with prevalent CHD were compared with those with no evidence of CHD on a variety of known risk factors, including hypertension, diabetes, smoking history, LDL-C, HDL-C, and triglycerides as well as Lp(a)-C, SPB, and Lp(a) mass. A corrected LDL-C was calculated by directly subtracting Lp(a)-C from LDL-C. The Student t-test was used to compare the mean values of continuous measures. A {chi}2 test was calculated for categorical factors. We log-transformed highly skewed continuous measures to normalize the distribution before assessing them in a comparison between subjects with and without CHD. Although the untransformed means and standard deviations were reported, P values for the analyses of the transformed variables were reported. To evaluate the relationship between Lp(a)-C and SPB, different percentiles of Lp(a)-C were compared with the presence of SPB (both borderline present and present). The approximate 75th percentile for Lp(a)-C (0.259 mmol/L) was chosen as a cutoff point because this is the approach taken by the National Cholesterol Education Program for LDL-C. The sensitivity and specificity for Lp(a) were calculated using SPB as the reference; thus the sensitivity was the proportion of SPB-positive subjects who had Lp(a) >=0.259 mmol/L, and the specificity was the proportion of SPB-negative subjects who had Lp(a) <0.259 mmol/L. To adjust for known risk factors for CHD, we used logistic regression analysis for the presence or absence of prevalent CHD at exam 5. Lp(a)-C was assessed both as a continuous variable and by group analysis (less than or equal to, or greater than 0.259 mmol/L).


   Results
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
 
Lp(a)-C values were obtained on a total of 3332 subjects. There were 149 subjects with duplicate identification numbers whose identities could not be verified and who were therefore removed from the analysis. Complete information on the CHD risk factors of an additional 62 subjects was not available. The final analysis of Lp(a)-C and CHD risk factors was performed on a total of 3121 subjects: 1488 men and 1633 women. This population was nearly all Caucasian.

The characteristics of the Framingham Offspring Subjects are shown in Table 1 and display the gender differences in this population. These data obtained from the Framingham Heart Study provide normal ranges for Lp(a)-C. There were no significant gender or age differences in Lp(a)-C concentrations. The mean Lp(a)-C values were 0.186 ± 0.160 mmol/L (7.21 ± 6.15 mg/dL) in men and 0.182 ± 0.166 mmol/L (7.06 ± 6.42 mg/dL) in women, with an overall mean of 0.185 ± 0.163 mmol/L (7.13 ± 6.29 mg/dL). As noted in the percentile distribution data in Table 2 , the Lp(a)-C values were highly skewed, with a skewness of 1.76 (1.65 in men and 1.86 in women) and a kurtosis of 3.80 (3.17 in men and 4.30 in women). The distribution patterns were consistent with the distribution of Lp(a) mass seen in the Framingham population (35) and other Caucasian populations, measured with immunoassays (39).


View this table:
[in this window]
[in a new window]
 
Table 1. Gender differences in the Framingham offspring (mean ± SD).


View this table:
[in this window]
[in a new window]
 
Table 2. Percentiles for Lp(a)-C distribution [mmol/L (mg/dL)].

Lp(a)-mass results obtained with the Apotek Lp(a) assay for a subset of 1000 Framingham Heart Study participants were similarly skewed, with a skewness of 2.34 and a kurtosis of 9.42, a mean Lp(a) mass of 0.260 ± 0.295 g/L (25.97 ± 29.49 mg/dL), and no significant gender or age differences. Lp(a)-C was highly correlated with Lp(a) mass in both men and women (P <0.0001), with Pearson correlation coefficients for the log-transformed Lp(a)-C of 0.829 and 0.835, respectively. Despite the skewed distribution, differences in measurements (cholesterol vs mass), and the wider total population variance of the Lp(a)-mass values (SD, 113% of mean) when compared with Lp(a)-C (SD, 88% of mean), comparisons of all subjects at the 75th percentile [Lp(a) mass of 0.344 g/L and Lp(a)-C of 0.259 mmol/L] were similar, with 93% specificity and 82% sensitivity in men and 93% specificity and 85% sensitivity in women.

In men, Lp(a)-C had a curvilinear relationship with age, grouped by decade (Table 3 ), but failed to attain statistical significance. In women, there was a linear relationship between Lp(a)-C and age delineated by decade, with the largest difference in the fifth decade, when most women reach menopause. Among the women, there also were differences in Lp(a)-C values that were dependent on menopausal status (Table 4 ). When pre- and postmenopausal women were compared, only 16.27% of premenopausal women had Lp(a)-C >=0.259 mmol/L, compared with 26.73% of postmenopausal women (P <0.001). Because menopause is an age-related phenomenon, it is difficult to separate the effect of age from menopause. When compared with men, women (Table 3 ) had a much larger gradation of Lp(a)-C values across increasing decades, which was sustained after the fifth decade, whereas in men, the gradation decreased dramatically after the sixth decade. Furthermore, an estrogen effect was supported by the 17.6% lower mean Lp(a)-C concentrations (P <0.01) in women without CHD and receiving hormone replacement therapy [HRT; Lp(a)-C, 0.155 ± 0.150 mmol/L (5.98 ± 5.79 mg/dL); n = 281] compared with women the same mean age (55 ± 10 years) without CHD and not receiving HRT [Lp(a)-C, 0.188 ± 0.170 mmol/L (7.26 ± 6.57 mg/dL); n = 1284].


View this table:
[in this window]
[in a new window]
 
Table 3. Differences in Lp(a)-C [mmol/L (mg/dL)] concentrations with age.


View this table:
[in this window]
[in a new window]
 
Table 4. Comparison of pre- and postmenopausal women from Framingham offspring (mean ± SD).

SBP measurements of Lp(a) were performed in this population and have been reported elsewhere to predict the risk of CHD in men <55 years (20) and in women >55 years (19). Numerous studies, reviewed by Bostom et al. (20), have demonstrated that the presence of an SPB band corresponds to Lp(a) and is highly specific for Lp(a)-mass concentrations of 0.3 g/L (30 mg/dL) or more. SPBs were reported as being "present", "borderline present", or "not present". A comparison of the mean Lp(a)-C concentrations for these three categories is shown in Table 5 and clearly shows a gradation from the absence of SPB [0.157 ± 0.131 mmol/L (6.08 ± 5.06 mg/dL)] to borderline present [0.359 ± 0.209 mmol/L (13.89 ± 8.06 mg/dL)] to present [0.453 ± 0.0.221 mmol/L (17.49 ± 8.54 mg/dL)], with very little overlap between the categories "absent" and "present". Subjects with Lp(a)-C concentrations >=0.259 mmol/L (>=10 mg/dL) are 11.6 (odds ratio) times more likely to have a SPB band (present or borderline) than subjects with Lp(a)-C concentrations <0.259 mmol/L (P <0.0002). The sensitivity and specificity with SPB as the reference are 72.1% and 81.8%, respectively.


View this table:
[in this window]
[in a new window]
 
Table 5. Relationship between Lp(a)-C and SBP.1

The mean Lp(a)-C concentrations in men and women with and without CHD are compared in Table 6 . There was a statistically significant difference between men with CHD [0.241 ± 0.166 mmol/L (9.32 ± 7.87 mg/dL)] and men without CHD [0.180 ± 0.152 mmol/L (6.96 ± 5.87 mg/dL); P < 0.001]. On the other hand, there was no significant difference between women with CHD [0.199 ± 0.158 mmol/L (7.71 ± 6.10 mg/dL)] and women without CHD [0.182 ± 0.166 mmol/L (7.03 ± 6.43)]. However, the prevalence of CHD in women was only 3.5% (68 cases out of 1633 subjects), compared with 10.4% (156 cases out of 1488 subjects) in men (see Table 1Up ) in this cohort, which was relatively young (55 ± 10 years) for assessing CHD in women.


View this table:
[in this window]
[in a new window]
 
Table 6. Relationship between Lp(a)-C and CHD.

Logistics regression analysis (Table 7 ) for the association of Lp(a)-C with CHD was performed, using Lp(a)-C as a continuous variable and grouping Lp(a) >=0.259 mmol/L (>=10 mg/dL), to compare the indicator that best correlated with the presence (present and borderline present) of SPB. The relative odds of CHD attributable to increased Lp(a)-C were adjusted for age, LDL-C, HDL-C, smoking, diabetes, blood pressure, and body mass index. The Lp(a)-C values were log-transformed to better normalize the distribution of this highly skewed indicator. As a continuous variable, Lp(a)-C in men had an odds ratio of 1.483 [95% confidence interval (CI), 1.186–1.854; P <0.0005] for each unit increase on a log scale, whereas the odds ratio of 1.102 was not significant (95% CI, 0.824–1.437) in women. To better isolate Lp(a)-C and LDL-C [which contains LDL and intermediate-density lipoprotein as well as Lp(a)-C], the analysis was repeated with a corrected LDL-C (LDL-C minus Lp(a)-C). Pearson correlation coefficients showed a significant correlation between LDL-C and Lp(a)-C in men (r =0.146; P = 0.0001), which disappeared when analysis was repeated with the LDL-C corrected for Lp(a)-C (r = -0.028; P = 0.2935). The logistics regression analysis with corrected LDL-C values was slightly lower than with the uncorrected LDL-C values, but with tighter confidence intervals (Table 7 ). To compare the Lp(a)-C indicators that match SPB, the same adjusted analysis for Lp(a)-C >=0.259 mmol/L (>=10 mg/dL) in men yielded an odds ratio of 2.293 (95% CI, 1.549–3.94; P <0.0001). Again, a repeat analysis with corrected LDL-C values yielded a slightly lower odds ratio, but with tighter confidence limits (Table 7 ). However, the odds ratio was not significant in women, with a value of 0.760 (95% CI, 0.390–1.481). The use Lp(a)-C values as a surrogate for SPB, a measurement of Lp(a) that confers attributable risk of CHD, yields similar results as previously published SPB prevalence data in men.


View this table:
[in this window]
[in a new window]
 
Table 7. Logistic regression analysis for association of Lp(a)-C with CHD.1


   Discussion
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
 
These analyses from the Framingham Heart Study provide normal ranges for the Lipopro Lp(a)-cholesterol assay, as well as prevalence data to generate odds ratios for CHD with various concentrations of Lp(a)-C. This is the first report of Lp(a)-C measurements within a population large enough to determine these indicators, with distribution patterns being very similar to the Lp(a)-mass values measured for this same population, using the commercially available Apotek assay. Although Lp(a)-C measurements have not been used traditionally, they provide an easy comparison to the other cholesterol-containing lipoprotein measurements, as well as a true method for correcting LDL-C concentrations for the contribution of Lp(a)-C.

The direct comparison of Lp(a)-C to SPB values provides indicators that are believed to predict the relative risk of CHD in both men and women. The odds ratio of 11.6 for Lp(a)-C >=0.259 mmol/L (10 mg/dL) to be found in subjects with the presence of SPB, with a sensitivity of 72.1% and a specificity of 81.8%, supports the similarities of these two measurements of Lp(a). Both of these methods are dependent on the detection of the lipid content of Lp(a), rather than an immunodetection method. Prevalence data support the use of Lp(a)-C >=0.259 mmol/L (>=10 mg/dL) in predicting CHD risk in men, whereas the data are less clear for women. However, the prevalence of CHD in this population of women was only 3.5% (68 cases), whereas the prevalence of CHD in men was 10.4% (152 cases). Lp(a)-C will need to be assessed prospectively in this population to determine the true relative risk of CHD in both men and women.

The results in women may be further confounded by the effect of estrogen status on Lp(a)-C concentrations. Although Jenner et al. (35) demonstrated that Lp(a)-mass values corrected for age were not different in pre- and postmenopausal women, menopause is an age-related phenomenon that cannot be clearly separated from this indicator. To support this further, our study provides evidence that when women receiving HRT are compared with women of the same age not receiving estrogen, there is a 17.6% difference in the mean Lp(a)-C between these two groups. Furthermore, a comparison of Lp(a)-C mean concentrations by decade demonstrates a continuous upward gradation that is sustained in women beyond the fifth decade, but falls in men beyond the sixth decade. The effect of estrogen status on Lp(a)-C is further supported by the work of Kim et al. (40), who reported a 23% reduction in Lp(a) mass in postmenopausal women placed on HRT (conjugated equine estrogens, 0.625 mg/day, and medroxy progesterone acetate, 2.5 mg/day); when HRT was discontinued, the concentration of Lp(a) mass returned to normal (41).

In summary, this analysis in the offspring and spouses of the Framingham Heart Study establishes normal ranges of Lp(a)-C for men and women. Our analysis confirms a similarly skewed distribution pattern of Lp(a)-C values when compared with those we reported in another publication (35), using another commercially available immunoassay (Macra). The Lp(a)-C values correlated highly with Apotek Lp(a) mass and with the presence or absence of SPB. However, in contrast to SPB, the Lp(a)-C assay provides a quantitative measure. Our data indicate that a Lp(a)-C concentration >=0.259 mmol/L (>=10 mg/dL) is a useful tool in predicting the risk of CHD in men. Regarding CHD risk, the relationship between Lp(a) and LDL-C, which was first reported by Armstrong et al. (42), is likely because of the presence of Lp(a)-C in the LDL-C value; this relationship can be directly removed from the analysis by subtracting Lp(a)-C from LDL-C when using the Lipopro Lp(a)-cholesterol assay. Lp(a)-C measurements provide useful information for CHD risk assessment. In assessing the risk of Lp(a)-C, especially in analyses that compare it with LDL-C, it may be appropriate to use a corrected LDL-C to isolate Lp(a)-C from the LDL-C value. It would be inappropriate to always correct LDL-C, because most LDL-C measurements include cholesterol from LDL, intermediate-density lipoprotein, and Lp(a). Moreover, the Lp(a)-C method may be easier to standardize, both nationally and internationally, than immunoassay methods.


   Acknowledgments
 
L.J. Seman was supported in part by a CAP Award from General Clinical Research (Grant M01-RR00054). J.L. Jenner was supported by US Department of Agriculture Training Grant T32AG00209.


   Footnotes
 
1 Nonstandard abbreviations: Lp(a), lipoprotein(a); apo(a), apolipoprotein(a); CHD, coronary heart disease; SPB, sinking pre-ß-lipoprotein; Lp(a)-C, lipoprotein(a)-cholesterol; HDL-C, HDL-cholesterol; LDL-C, LDL-cholesterol; HRT, hormone replacement therapy; and CI, confidence interval.


   References
Top
Abstract
Introduction
Materials and Methods
Results
Discussion
References
 

  1. Berg K. A new serum type system in man: the Lp system. Acta Pathol Microbiol Scand 1963;59:362-382.
  2. McLean JW, Tomlinson JE, Kuang W, Eaton DL, Chen EY, Fless GM, et al. cDNA sequence of human apolipoprotein(a) is homologous to plasminogen. Nature 1987;33:132-137.
  3. Enholm C, Garoff H, Simons K, Aro H. Purification and quantification of the plasma lipoprotein carrying the Lp(a) antigen. Biochim Biophys Acta 1971;236:431-439. [Medline] [Order article via Infotrieve]
  4. Seman LJ, Breckenridge WC. Isolation and characterization of apolipoprotein (a). J Biochem Cell Biol 1986;64:999-1009.
  5. Kratzin H, Armstrong VW, Niehaus M, Hilschmann N, Seidel D. Structural relationship of an apolipoprotein (a) phenotype (570 kDa) to plasminogen: homologous kringle domains are linked by carbohydrate rich regions. Biol Chem Hoppe-Seyler 1987;368:1533-1544. [Web of Science][Medline] [Order article via Infotrieve]
  6. Lackner C, Cohen JC, Hobbs HH. Molecular definition of the extreme size polymorphism in apolipoprotein (a). Hum Mol Genet 1993;2:933-940. [Abstract/Free Full Text]
  7. Marcovina SM, Zhang ZH, Guar VP, Albers JJ. Identification of 34 apolipoprotein (a) isoforms: differential expression of apolipoprotein (a) alleles between American Blacks and Whites. Biochem Biophys Res Commun 1994;191:1192-1196.
  8. Dahlen G, Ramberg UB. Pre-beta-1 lipoprotein and early detection of risk factors for coronary heart disease. Acta Med Scand 1974;195:341-344. [Web of Science][Medline] [Order article via Infotrieve]
  9. Dahlen G, Frick MH, Berg K, Valle M, Wiijasalo M. Further studies of Lp(a) lipoprotein/pre-beta-1 lipoprotein in patients with coronary heart disease. Clin Genet 1975;8:183-189. [Web of Science][Medline] [Order article via Infotrieve]
  10. Rhoads G, Morton NE, Gulbrandsen CL, Kagan A. Sinking prebeta lipoprotein and coronary heart disease in Japanese American men in Hawaii. Am J Epidemiol 1978;108:350-356. [Abstract/Free Full Text]
  11. Avogaro G, Cazzolato G. "Sinking" prebeta lipoprotein in normal, hyperlipoproteinemic, and atherosclerotic patients. Clin Chim Acta 1978;61:239-246.
  12. Genest JJ, Jr, Martin-Munley SS, McNamara JR, Ordovas JM, Jenner J, Myers RH, et al. Familial lipoprotein disorders in patients with premature coronary artery disease. Circulation 1992;85:2025-2033. [Abstract/Free Full Text]
  13. Genest J, Jr, McNamara JR, Ordovas JM, Jenner JL, Silberman SR, Anderson KM, et al. Lipoprotein cholesterol, apolipoproteins AI and B, and lipoprotein (a) abnormalities in men with premature coronary heart disease. J Am Coll Cardiol 1992;19:792-802. [Abstract]
  14. Utermann G. The mysteries of lipoprotein (a). Science 1989;246:904-910. [Abstract/Free Full Text]
  15. Maher VMG, Brown BG. Lipoprotein (a), coronary heart disease. Curr Opin Lipidol 1995;6:229-235. [Web of Science][Medline] [Order article via Infotrieve]
  16. Sandkamp M, Funke H, Schulte H, Kohler E, Assmann G. Lipoprotein (a) is an independent risk factor for myocardial infarction at a young age. Clin Chem 1990;26:20-23.
  17. Rhoads GG, Dahlen G, Berg K, Morton N, Dannenberg AL. Lp(a) lipoprotein as a risk factor for myocardial infarction. JAMA 1986;256:2540-2544. [Abstract/Free Full Text]
  18. Rosengren A, Wilhelmsen L, Eriksson E, Risberg B, Wedel H. Lipoprotein(a), coronary heart disease: a prospective case-control study in a general population sample of middle aged men. Br Med J 1990;301:1248-1251.
  19. Bostom AG, Gagnon DR, Cupples LA, Wilson PWF, Jenner JL, Ordovas JM, et al. A prospective investigation of elevated lipoprotein(a) detected by electrophoresis and cardiovascular disease in women: the Framingham Heart Study. Circulation 1994;90:1688-1695. [Abstract/Free Full Text]
  20. Bostom AG, Cupples LA, Jenner JL, Ordovas JM, Seman LJ, Wilson PWF, et al. Elevated plasma lipoprotein(a) and premature coronary heart disease in Framingham men: a prospective study. JAMA 1996;276:544-548. [Abstract/Free Full Text]
  21. Nguyen TT, Ellefson RD, Hodge DO, Bailey KR, Kottke TE, Abu-Lebdeh HS. Predictive value of electrophoretically detected lipoprotein (a) for coronary heart disease and cerebrovascular disease in a community-based cohort of 9936 men and women. Circulation 1997;96:1390-1397. [Abstract/Free Full Text]
  22. Schaefer EJ, Lamon-Fava S, Jenner JL, McNamara JR, Ordovas JM, Davis E, et al. Lipoprotein(a) levels and risk of coronary heart disease in men: the Lipid Research Clinics Coronary Primary Prevention Trial. JAMA 1994;271:999-1003. [Abstract/Free Full Text]
  23. Wald NJ, Law M, Watt HC, Wu T, Bailey A, Johnson AM, et al. Apolipoproteins and ischaemic heart disease: implications for screening. Lancet 1994;343:75-79. [Web of Science][Medline] [Order article via Infotrieve]
  24. Cremer P, Nagel D, Labrot B, Mann H, Muche R, Elster H, Seidel D. Lipoprotein Lp(a) as predictor of myocardial infarction in comparison to fibrinogen, LDL cholesterol and other risk factors: results from the prospective Gottingen Risk Incidence and Prevalence Study (GRIPS). Eur J Clin Investig 1994;24:444-453. [Web of Science][Medline] [Order article via Infotrieve]
  25. Wild SH, Fortmann SP, Marcovina SM. A prospective case-control study of lipoprotein (a) levels and apo(a) size and risk of coronary heart disease in Stanford Five-City Project participants. Arterioscler Thromb Vasc Biol 1997;17:239-245. [Abstract/Free Full Text]
  26. Jauhiainen M, Koskinen P, Enholm C, Frick MH, Manttan M, Manninen V, Huttunen JK. Lipoprotein (a) and coronary heart disease risk: a nested case-control study of the Helsinki Heart Disease Study participants. Atherosclerosis 1991;89:59-67. [Web of Science][Medline] [Order article via Infotrieve]
  27. Ridker PM, Hennekens CH, Stampfer MJ. A prospective study of lipoprotein (a) and the risk of myocardial infarction. JAMA 1993;270:2195-2199. [Abstract/Free Full Text]
  28. Alfthan G, Pekannen J, Jauhiainen M, Pitkaniemi J, Karvonen M, Tuomilehto J, et al. Relation of serum homocysteine and lipoprotein (a) to atherosclerotic disease in a prospective Finnish population-based study. Atherosclerosis 1994;106:9-19. [Web of Science][Medline] [Order article via Infotrieve]
  29. Cantin B, Gagnon F, Moorjani S, DesPres JP, LaMarche B, Lupien PJ, Dagenais GR. Is lipoprotein (a) an independent risk factor for ischemic heart disease in men? The Quebec Cardiovascular Study. J Am Coll Cardiol 1998;31:519-525. [Abstract/Free Full Text]
  30. Albers JJ, Hazzard WR. Immunochemical quantification of human plasma Lp(a) lipoprotein. Lipids 1974;9:15-26. [Web of Science][Medline] [Order article via Infotrieve]
  31. Marcovina SM, Albers JJ, Gamble B, Koschinsky ML, Gaur VP. The effect of the number of apolipoprotein (a) kringle 4 domains on the immunochemical measurement of lipoprotein (a). Clin Chem 1995;41:246-255. [Abstract/Free Full Text]
  32. Taddei-Peters WC, Butman BT, Jones GR, Venetta TM, Macomber PF, Ransom H. Quantification of lipoprotein (a) particles containing various apolipoprotein (a) isoforms by a monoclonal anti-apo(a) capture antibody and a polyclonal anti-apolipoprotein B detection antibody sandwich enzyme immunoassay. Clin Chem 1993;39:1382-1389. [Abstract]
  33. Seman LJ, Jenner JL, McNamara JR, Schaefer EJ. Quantification of lipoprotein (a) in plasma by assaying cholesterol in lectin-bound plasma fraction. Clin Chem 1994;40:400-403. [Abstract/Free Full Text]
  34. Pagan A, Kostner G, Braggion N, Ziron L. Relationship between sinking pre-beta lipoprotein [Lp(a) lipoprotein] and age in a family kindred. Gerontology 1982;28:381-385. [Web of Science][Medline] [Order article via Infotrieve]
  35. Jenner JL, Ordovas JM, Lamon-Fava S, Schaefer MM, Wilson PWF, Castelli WP, Schaefer EJ. Effects of age, sex, and menopausal status on plasma lipoprotein(a) levels: the Framingham Offspring Study. Circulation 1993;87:1135-1141. [Abstract/Free Full Text]
  36. Feinleib M, Kannel WB, McNamara PM, Garrison RJ, Castelli WP. The Framingham Offspring Study. Prev Med 1975;4:518-525. [Web of Science][Medline] [Order article via Infotrieve]
  37. Friedewald WT, Levy RI, Fredrickson DS. Estimation of the concentration of low-density lipoprotein cholesterol in plasma, without use of the preparative ultracentrifuge. Clin Chem 1972;18:499-502. [Abstract]
  38. Cupples LA, D'Agostino RB. Some risk factors related to the annual incidence of cardiovascular disease and death using pooled repeated biennial measurements. Kannel WB Wolf PA Garrison RJ eds. The Framingham Heart Study: an epidemiological investigation of cardiovascular disease. National Institutes of Health Publication no. 87-2703, Section 34 1987 National Heart, Lung, and Blood Institute Bethesda, MD. .
  39. Marcovina SM, Albers JJ, Jacobs DR, Jr, Perkins LL, Lewis CE, Howard BV, Savage P. Lipoprotein (a) concentrations and apolipoprotein (a) phenotypes in Caucasians and African Americans: the CARDIA Study. Arterioscler Thromb 1993;13:1037-1045. [Abstract/Free Full Text]
  40. Kim CJ, Jang HC, Cho DH, Min YK. Effects of hormonal replacement therapy on lipoprotein (a) and lipids in postmenopausal women. Arterioscler Thromb 1994;14:275-281. [Abstract/Free Full Text]
  41. Kim CJ, Ryu WS, Kwak JW, Park CT, Ryoo UH. Changes in Lp(a) lipoprotein and lipid levels after cessation of female sex hormone production and estrogen replacement therapy. Arch Intern Med 1996;156:500-504. [Abstract/Free Full Text]
  42. Armstrong VW, Cremer P, Eberle E, Manke A, Schulze F, Wieland H, et al. The association between serum Lp(a) concentration and angiographically assessed atherosclerosis. Dependence on serum LDL levels. Atherosclerosis 1986;62:249-257. [Web of Science][Medline] [Order article via Infotrieve]



The following articles in journals at HighWire Press have cited this article:


Home page
JAMAHome page
S. R. Jones and R. S. Blumenthal
Lipoprotein(a) Measurement and Determining Risk of Myocardial Infarction
JAMA, October 21, 2009; 302(15): 1645 - 1645.
[Full Text] [PDF]


Home page
Ann Rheum DisHome page
C A Wijbrandts, S I van Leuven, H D Boom, D M Gerlag, E G S Stroes, J J P Kastelein, and P P Tak
Sustained changes in lipid profile and macrophage migration inhibitory factor levels after anti-tumour necrosis factor therapy in rheumatoid arthritis
Ann Rheum Dis, August 1, 2009; 68(8): 1316 - 1321.
[Abstract] [Full Text] [PDF]


Home page
J. Nutr.Home page
E. J. Schaefer, J. A. Gleason, and M. L. Dansinger
Dietary Fructose and Glucose Differentially Affect Lipid and Glucose Homeostasis
J. Nutr., June 1, 2009; 139(6): 1257S - 1262S.
[Abstract] [Full Text] [PDF]


Home page
J. Lipid Res.Home page
Y.-T. Wang, A. von Zychlinski, and S. P. A. McCormick
Dimyristoylphosphotidylcholine induces conformational changes in apoB that lowers lipoprotein(a)
J. Lipid Res., May 1, 2009; 50(5): 846 - 853.
[Abstract] [Full Text] [PDF]


Home page
Arch Intern MedHome page
A. Bennet, E. Di Angelantonio, S. Erqou, G. Eiriksdottir, G. Sigurdsson, M. Woodward, A. Rumley, G. D. O. Lowe, J. Danesh, and V. Gudnason
Lipoprotein(a) Levels and Risk of Future Coronary Heart Disease: Large-Scale Prospective Data
Arch Intern Med, March 24, 2008; 168(6): 598 - 608.
[Abstract] [Full Text] [PDF]


Home page
Clin. Chem.Home page
G. T. Jones, A. M. van Rij, J. Cole, M. J.A. Williams, E. H. Bateman, S. M. Marcovina, M. Deng, and S. P.A. McCormick
Plasma Lipoprotein(a) Indicates Risk for 4 Distinct Forms of Vascular Disease
Clin. Chem., April 1, 2007; 53(4): 679 - 685.
[Abstract] [Full Text] [PDF]


Home page
JAMAHome page
J. Suk Danik, N. Rifai, J. E. Buring, and P. M Ridker
Lipoprotein(a), measured with an assay independent of apolipoprotein(a) isoform size, and risk of future cardiovascular events among initially healthy women.
JAMA, September 20, 2006; 296(11): 1363 - 1370.
[Abstract] [Full Text] [PDF]


Home page
J. Nutr.Home page
S. S. AbuMweis, C. A. Vanstone, N. Ebine, A. Kassis, L. M. Ausman, P. J. H. Jones, and A. H. Lichtenstein
Intake of a Single Morning Dose of Standard and Novel Plant Sterol Preparations for 4 Weeks Does Not Dramatically Affect Plasma Lipid Concentrations in Humans
J. Nutr., April 1, 2006; 136(4): 1012 - 1016.
[Abstract] [Full Text] [PDF]


Home page
Mayo Clin Proc.Home page
I. J. Kullo and C. M. Ballantyne
Conditional Risk Factors for Atherosclerosis
Mayo Clin. Proc., February 1, 2005; 80(2): 219 - 230.
[Abstract] [PDF]


Home page
J. Lipid Res.Home page
R. J. Sharp, M. A. Perugini, S. M. Marcovina, and S. P. A. McCormick
Structural features of apolipoprotein B synthetic peptides that inhibit lipoprotein(a) assembly
J. Lipid Res., December 1, 2004; 45(12): 2227 - 2234.
[Abstract] [Full Text] [PDF]


Home page
CirculationHome page
R. Carmena, P. Duriez, and J.-C. Fruchart
Atherogenic Lipoprotein Particles in Atherosclerosis
Circulation, June 15, 2004; 109(23_suppl_1): III-2 - III-7.
[Abstract] [Full Text]


Home page
Arch Intern MedHome page
J. McKenney
New Perspectives on the Use of Niacin in the Treatment of Lipid Disorders
Arch Intern Med, April 12, 2004; 164(7): 697 - 705.
[Abstract] [Full Text] [PDF]


Home page
J CARDIOVASC PHARMACOL THERHome page
V. Tsimihodimos, A. Kostoula, A. Kakafika, E. Bairaktari, A. D. Tselepis, D. P. Mikhailidis, and M. Elisaf
Effect of Fenofibrate on Serum Inflammatory Markers in Patients With High Triglyceride Values
Journal of Cardiovascular Pharmacology and Therapeutics, March 1, 2004; 9(1): 27 - 33.
[Abstract] [PDF]


Home page
BloodHome page
N. S. Haque, J. T. Fallon, J. J. Pan, M. B. Taubman, and P. C. Harpel
Chemokine receptor-8 (CCR8) mediates human vascular smooth muscle cell chemotaxis and metalloproteinase-2 secretion
Blood, February 15, 2004; 103(4): 1296 - 1304.
[Abstract] [Full Text] [PDF]


Home page
J. Lipid Res.Home page
C. Y. Y. Liu, R. Broadhurst, S. M. Marcovina, and S. P. A. McCormick
Mutation of lysine residues in apolipoprotein B-100 causes defective lipoprotein[a] formation
J. Lipid Res., January 1, 2004; 45(1): 63 - 70.
[Abstract] [Full Text] [PDF]


Home page
Arterioscler. Thromb. Vasc. Bio.Home page
R. J. Sharp, M. A. Perugini, S. M. Marcovina, and S. P.A. McCormick
A Synthetic Peptide That Inhibits Lipoprotein(a) Assembly
Arterioscler Thromb Vasc Biol, March 1, 2003; 23(3): 502 - 507.
[Abstract] [Full Text] [PDF]


Home page
CirculationHome page
References
Circulation, December 17, 2002; 106(25): 3373 - 3421.
[Full Text]


Home page
Am. J. Clin. Nutr.Home page
O. I Bermudez, W. Velez-Carrasco, E. J Schaefer, and K. L Tucker
Dietary and plasma lipid, lipoprotein, and apolipoprotein profiles among elderly Hispanics and non-Hispanics and their association with diabetes
Am. J. Clinical Nutrition, December 1, 2002; 76(6): 1214 - 1221.
[Abstract] [Full Text] [PDF]


Home page
Eur Heart JHome page
M.B. Andresdottir, G. Sigurdsson, H. Sigvaldason, and V. Gudnason
Fifteen percent of myocardial infarctions and coronary revascularizations explained by family history unrelated to conventional risk factors. The Reykjavik Cohort Study
Eur. Heart J., November 1, 2002; 23(21): 1655 - 1663.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Clin. Nutr.Home page
E. J Schaefer
Lipoproteins, nutrition, and heart disease
Am. J. Clinical Nutrition, February 1, 2002; 75(2): 191 - 212.
[Abstract] [Full Text] [PDF]


Home page
J Am Coll CardiolHome page
A. von Eckardstein, P. Cullen, and G. Assmann
Problems in the measurement of Lp(a) (millimoles per liter versus milligrams percent): Reply
J. Am. Coll. Cardiol., November 1, 2001; 38(5): 1584 - 1585.
[Full Text] [PDF]


Home page
CirculationHome page
A. R. Sharrett, C. M. Ballantyne, S. A. Coady, G. Heiss, P. D. Sorlie, D. Catellier, and W. Patsch
Coronary Heart Disease Prediction From Lipoprotein Cholesterol Levels, Triglycerides, Lipoprotein(a), Apolipoproteins A-I and B, and HDL Density Subfractions: The Atherosclerosis Risk in Communities (ARIC) Study
Circulation, September 4, 2001; 104(10): 1108 - 1113.
[Abstract] [Full Text] [PDF]


Home page
Arch Intern MedHome page
Y. Cui, R. S. Blumenthal, J. A. Flaws, M. K. Whiteman, P. Langenberg, P. S. Bachorik, and T. L. Bush
Non-High-Density Lipoprotein Cholesterol Level as a Predictor of Cardiovascular Disease Mortality
Arch Intern Med, June 11, 2001; 161(11): 1413 - 1419.
[Abstract] [Full Text] [PDF]


Home page
Clin. Chem.Home page
J. Ordonez-Llanos, A. M. Wagner, R. Bonet-Marques, J. L. Sanchez-Quesada, F. Blanco-Vaca, and F. Gonzalez-Sastre
Which Cholesterol Are We Measuring with the Roche Direct, Homogeneous LDL-C Plus Assay?
Clin. Chem., January 1, 2001; 47(1): 124 - 126.
[Full Text] [PDF]


Home page
BloodHome page
N. S. Haque, J. T. Fallon, M. B. Taubman, and P. C. Harpel
The chemokine receptor CCR8 mediates human endothelial cell chemotaxis induced by I-309 and Kaposi sarcoma herpesvirus-encoded vMIP-I and by lipoprotein(a)-stimulated endothelial cell conditioned medium
Blood, January 1, 2001; 97(1): 39 - 45.
[Abstract] [Full Text] [PDF]


Home page
BloodHome page
M. von Depka, U. Nowak-Gottl, R. Eisert, C. Dieterich, M. Barthels, I. Scharrer, A. Ganser, and S. Ehrenforth
Increased lipoprotein (a) levels as an independent risk factor for venous thromboembolism
Blood, November 15, 2000; 96(10): 3364 - 3368.
[Abstract] [Full Text] [PDF]


Home page
CirculationHome page
N. S. Haque, X. Zhang, D. L. French, J. Li, M. Poon, J. T. Fallon, B. R. Gabel, M. B. Taubman, M. Koschinsky, and P. C. Harpel
CC Chemokine I-309 Is the Principal Monocyte Chemoattractant Induced by Apolipoprotein(a) in Human Vascular Endothelial Cells
Circulation, August 15, 2000; 102(7): 786 - 792.
[Abstract] [Full Text] [PDF]


Home page
Clin. Chem.Home page
M. Nauck, W. Marz, and H. Wieland
Is Lipoprotein(a) Cholesterol a Significant Indicator of Cardiovascular Risk?
Clin. Chem., March 1, 2000; 46(3): 436 - 437.
[Full Text] [PDF]


This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (46)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Seman, L. J.
Right arrow Articles by Schaefer, E. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Seman, L. J.
Right arrow Articles by Schaefer, E. J.
Related Collections
Right arrow Evidence Based Laboratory Medicine and Test Utilization
Right arrow Lipids, Lipoproteins, and Cardiovascular Risk Factors


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS