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Biomedical subjects

H Campos

Publications and source records attributed to H Campos.

At least 19 recordsLinked to original sources
PubMed2006

A genetic variant at the fatty acid-binding protein aP2 locus reduces the risk for hypertriglyceridemia, type 2 diabetes, and cardiovascular disease.

Obesity and the associated pathologies including dyslipidemia, insulin resistance, type 2 diabetes, and cardiovascular disease constitute a major threat to global human health. Yet, the genetic factors that differentially predispose individuals to this cluster of pathologies are unclear. The fatty acid-binding protein aP2 is a cytoplasmic lipid chaperon expressed in adipocytes and macrophages. Mice with aP2 deficiency are partially resistant to obesity-induced insulin resistance and type 2 diabetes, have lower circulating triglycerides, and exhibit marked protection against atherosclerosis. Here, we demonstrate a functionally significant genetic variation at the aP2 locus in humans that results in decreased adipose tissue aP2 expression due to alteration of the CAAT box/enhancer-binding protein binding and reduced transcriptional activity of the aP2 promoter. In population genetic studies with 7,899 participants, individuals that carry this T-87C polymorphism had lower serum triglyceride levels and significantly reduced risk for coronary heart disease and type 2 diabetes compared with subjects homozygous for the WT allele. Taken together, our results indicate that reduction in aP2 activity in humans generate a metabolically favorable phenotype that is similar to aP2 deficiency in experimental models.

Adipose Tissue↗
PubMed2006

Dietary patterns and risk of nonfatal acute myocardial infarction in Costa Rican adults.

OBJECTIVE: To investigate the association between dietary patterns and risk of a first nonfatal acute myocardial infarction (MI) in Costa Rican adults. DESIGN: Population-based case-control study. SUBJECTS: A total of 496 incident MI cases and 518 population-based randomly selected controls matched to the cases by age (+/-5 years), gender, and county of residence. Subjects were interviewed with a validated food frequency questionnaire. Dietary patterns were identified by factor analysis. Odds ratios (OR) and 95% confidence intervals (CI) were obtained using multivariate conditional logistic regression adjusted for several recognized risk factors for MI. RESULTS: Two diet patterns were identified, 'vegetable' characterized by increased intake of vegetables and fruits, and 'staple', characterized by an increased use of palm oil for cooking, and intake of refined grains (mostly white rice and white bread), legumes, coffee, added sugar, and red meat. Compared to the lowest quintile of the staple diet pattern, the highest quintile was associated with an increased risk of MI (OR: 3.70, 95% CI: 2.30-5.97). Adjusting for potential confounders did not change the results (OR: 3.53, 95% CI: 1.98-6.31). Consistently, an increasing staple pattern score was associated with lower HDL cholesterol (P for trend <0.02) and alpha-linolenic acid in adipose tissue (P for trend <0.0001). The vegetable pattern was not associated with MI. CONCLUSIONS: The staple dietary pattern of Costa Rican adults is associated with low plasma HDL cholesterol, low alpha-linolenic acid in adipose tissue, and increased risk of MI.

Acute Disease↗
PubMed2004

Population structure and combining ability of diverse Medicago sativa germplasms.

Although unadapted germplasms have been used to improve disease and insect resistance in alfalfa, there has been little effort to use these for improving forage yield. We evaluated genetic diversity and combining ability among two unadapted germplasms ( Medicago sativa ssp. sativa Peruvian and M. sativa ssp. falcata WISFAL) and three Northern U.S. adapted alfalfa cultivars. Population structure analyses indicated that the WISFAL and Peruvian germplasms were genetically distinct from the cultivars, although Peruvian was relatively closer to the cultivars. Peruvian and WISFAL germplasms were intermated to generate a novel hybrid population. This population was crossed to the three cultivars as testers, and the testcross progenies were evaluated for forage yield along with the hybrid population, the original germplasms (Peruvian, WISFAL and cultivars), testcrosses of Peruvian and WISFAL to the three cultivars and a three-way hybrid of the cultivars. The experiment was carried out in the field in Temuco, Chile and Arlington, Wisconsin, USA, and forage was harvested during two seasons. Results from these evaluations showed that hybrids between the Peruvian x WISFAL population and the cultivar testers yielded as much as the cultivar testers. Heterosis was observed between Peruvian and WISFAL, and between these germplasms and the cultivar testers, suggesting that each germplasm may contain different favorable alleles. If Peruvian and WISFAL populations contain alleles at different loci that complement cultivar testers, then combining and enriching these alleles in a single population could result in improved combining ability with alfalfa cultivars.

Bayes Theorem↗
PubMed2004

Genetic polymorphism of CYP1A2 increases the risk of myocardial infarction.

BACKGROUND: There is growing evidence that DNA damage caused by mutagens found in tobacco smoke may contribute to the development of coronary heart disease (CHD). In order to bind to DNA many mutagens require metabolic activation by cytochrome P450 (CYP) 1A1 or CYP1A2. The objective of this study was to determine the effects of CYP1A1 and CYP1A2 genotypes on risk of myocardial infarction (MI) and whether smoking interacts with genotype to modify risk. METHODS: Subjects (n = 873) with a first acute non-fatal MI and population based controls (n = 932) living in Costa Rica, matched for age, sex, and area of residence, were genotyped for CYP1A1*2A and CYP1A2*1F by restriction-fragment length polymorphism (RFLP)-PCR, and smoking status was determined by questionnaire. RESULTS: After adjusting for matching variables and potential confounders, no association was observed between CYP1A1 genotype and risk of MI. Compared to individuals with the high inducibility CYP1A2*1A/*1A genotype, the adjusted odds ratio and 95% confidence intervals for risk of MI were 1.19 (0.97 to 1.47) for the *1A/*1F genotype and 1.55 (1.10 to 2.18) for the *1F/*1F genotype. No significant interactions were observed between smoking and either CYP1A1 or CYP1A2 genotype. CONCLUSIONS: The low inducibility genotype for CYP1A2 was associated with an increased risk of MI. This effect was independent of smoking status and suggests that a substrate of CYP1A2 that is detoxified rather than activated may play a role in CHD.

Costa Rica↗
PubMed2003

Individual saturated fatty acids and nonfatal acute myocardial infarction in Costa Rica.

BACKGROUND: Epidemiological studies on the effect of individual saturated fatty acids (SFAs) on cardiovascular disease, especially in developing countries with different dietary patterns, are scarce. OBJECTIVE: To determine the risk of nonfatal acute myocardial infarction (MI) associated with consumption of individual SFAs and their food sources in Costa Rica. DESIGN: The cases (n=485) were survivors of a first acute MI and were matched by age, sex and area of residence to population controls (n=508). Data on anthropometrical measurements, lifestyle and diet were collected using interviewer-administered questionnaires. RESULTS: In analyses adjusted for confounders, consumption of total and individual SFAs was associated with an increased risk of MI. The odds ratio (OR) (95% confidence intervals) for 1% increase in energy from total saturated fat was 1.12 (1.03-1.21) while it was 1.51 (1.03-2.22) for lauric acid+myristic acid, 1.14 (1.01-1.30) for palmitic acid and 2.00 (1.34-3.00) for stearic acid. Although lauric and myristic acids were associated with increased risk of MI, they were consumed in small amounts and most of the saturated fat (87%) came from palmitic and stearic acids, which derived mainly from red meat and fried foods. Consumption of cheese (1-2 vs 0 servings/day) was associated with increased risk of MI (OR=3.07; 95% confidence interval: 1.74-5.39; P for trend <0.0001), while consumption of low-fat milk was not. CONCLUSION: Increased consumption of total and individual SFAs is associated with increased risk of MI. Lauric, myristic and stearic acids were more potent than palmitic acid.

Acute Disease↗
PubMed2001

Application of the method of triads to evaluate the performance of food frequency questionnaires and biomarkers as indicators of long-term dietary intake.

Little is documented about the performance of the food frequency questionnaire (FFQ) in US minority groups and in populations in developing countries. The authors applied a novel technique, the method of triads, to assess the validity and reproducibility of the FFQ among Hispanics. The subjects were men (n = 78) and women (n = 42) living in Costa Rica. Seven 24-hour dietary recalls and two FFQ interviews (12 months apart) were conducted between 1995 and 1998 to estimate dietary intake during the past year. Plasma and adipose tissue samples were collected from all subjects. Validity coefficients, which measure the correlation between observed and "true" dietary intake, were also estimated. The median validity coefficients for tocopherols and carotenoids estimated by dietary recall, the average of the two FFQs, and plasma were 0.71, 0.60, and 0.52, respectively. Compared with adipose tissue, plasma was a superior biomarker for carotenoids and tocopherols. Adipose tissue was a poor biomarker for saturated and monounsaturated fatty acids but performed well for polyunsaturated fatty acids (validity coefficients, 0.45-1.01) and lycopene (validity coefficient, 0.51). This study also showed that biomarkers did not perform better than the FFQ and that they should be used to complement the FFQ rather than substitute for it.

Adipose Tissue↗
PubMed2001

Low-density lipoprotein size, pravastatin treatment, and coronary events.

CONTEXT: Small low-density lipoprotein (LDL) particle size has been hypothesized to be a risk factor for coronary heart disease (CHD). Animal models link large LDL to atherosclerosis. However, the strong association between small LDL and other risk factors, particularly triglyceride levels, impedes determining whether LDL size independently predicts CHD in humans. OBJECTIVE: To examine whether LDL size is an independent predictor of recurrent coronary events in patients with known CHD, as opposed to a marker for other lipid abnormalities. DESIGN AND SETTING: Prospective, nested case-control study in the Cholesterol and Recurrent Events (CARE) trial, a randomized placebo-controlled trial of pravastatin conducted in 1989-1996. PARTICIPANTS: Survivors of myocardial infarction with typical LDL concentrations (416 cases and 421 controls). MAIN OUTCOME MEASURE: Subsequent myocardial infarction or coronary death during the 5-year follow-up, analyzed by quintile of LDL particle size and by treatment group. RESULTS: Overall, the mean LDL size was identical in cases and controls (25.6 nm). In patients in the placebo group, large LDL predicted coronary events in models adjusted only for age (relative risk [RR], 1.79; 95% confidence interval [CI], 1.01-3.17) and for age and lipid and nonlipid risk factors (RR, 4.00; 95% CI, 1.81-8.82), comparing those in the highest (mean, 26.6 nm) and lowest (mean, 24.5 nm) quintiles of LDL size. This increased risk was not present in those taking pravastatin (age-adjusted analysis: RR, 0.98; 95% CI, 0.47-2.04; P =.046 for interaction for a difference in the effect of LDL size on coronary events between the placebo and treatment groups; multivariable analysis: RR, 1.33; 95% CI, 0.52-3.38; P =.11 for interaction). CONCLUSIONS: Large LDL size was an independent predictor of coronary events in a typical population with myocardial infarction, but the adverse effect was not present among patients who were treated with pravastatin. Identifying patients on the basis of LDL size may not be useful clinically, since effective treatment for elevated LDL cholesterol concentrations also effectively treats risk associated with large LDL.

Anticholesteremic Agents↗
PubMed2001

Gene-diet interactions and plasma lipoproteins: role of apolipoprotein E and habitual saturated fat intake.

To test whether plasma lipoprotein levels and low density lipoprotein (LDL) particle size are modulated by an interaction between habitual saturated fat intake and apolipoprotein E (APOE) genotype, we studied 420 randomly selected free-living Costa Ricans. The APOE allele frequencies were 0.03 for APOE2, 0.91 for APOE3, and 0.06 for APOE4. The median saturated fat intake, 11% of energy, was used to divide the population into two groups, LOW-SAT (mean intake 8.6% energy) represents those below median intake, and HIGH-SAT (mean intake 13.5%) represents those above median intake. Significant interactions between APOE genotype and diet were found for VLDL (P = 0.03) and HDL cholesterol (P = 0.02). Higher saturated fat intake was associated with higher VLDL cholesterol (+29%) and lower HDL cholesterol (-22%) in APOE2 carriers, while the opposite association was observed in APOE4 carriers (-31% for VLDL cholesterol and +10% for HDL cholesterol). Higher saturated fat intake was associated with smaller LDL particles (-2%, P < 0.05) in APOE2 carriers, and larger LDL particles (+2%, P < 0.05) in APOE4 carriers, but the gene-diet interaction was not statistically significant (P = 0.09). Higher saturated fat intake was associated with higher LDL cholesterol in all genotypes (mean +/- SEM, LOW-SAT 2.61 +/- 0.05 vs. HIGH-SAT 2.84 +/- 0.05 mmol/L, P = 0.009). These data suggest that the APOE2 allele could modulate the effect of habitual saturated fat on VLDL cholesterol and HDL cholesterol in a population with an average habitual total fat intake of less than 30%.

Adult↗
PubMed2001

Population-based study of alpha- and gamma-tocopherol in plasma and adipose tissue as biomarkers of intake in Costa Rican adults.

BACKGROUND: gamma-Tocopherol is the most abundant form of vitamin E in the US diet, but alpha-tocopherol concentrations are the highest in plasma and tissues. Although plasma and adipose tissue concentrations of alpha-tocopherol have been used as biomarkers of intake, the relation between gamma-tocopherol intake and concentrations in plasma and adipose tissue is unknown. OBJECTIVE: Our goal was to investigate in a randomly selected population from Costa Rica whether plasma or adipose tissue concentrations of alpha- and gamma-tocopherol are suitable biomarkers of intake. DESIGN: A total of 361 men (x +/- SD age: 55 +/- 11 y) and 121 women (aged 59 +/- 10 y) completed a 135-item food-frequency questionnaire and provided a fasting blood sample and adipose tissue biopsy sample. RESULTS: Dietary gamma-tocopherol correlated with adipose tissue (r = 0.37, P < 0.001) and plasma (r = 0.42, P < 0.001) concentrations, regardless of supplement use. Dietary alpha-tocopherol correlated poorly with adipose tissue (r = 0.15, P < 0.01) and plasma (r = 0.16, P < 0.001) concentrations, and these correlations were even lower when users of vitamin supplements (n = 24) were excluded (adipose tissue: r = 0.10, P < 0.05; plasma: r = 0.09, P < 0.05). Compared with subjects who reported palm shortening (36%) as the major type of fat used for cooking, subjects using soybean oil (52%) had higher amounts of both alpha- and gamma-tocopherol in their diets. However, only gamma-tocopherol concentrations were higher in the plasma and adipose tissue of soybean oil users. CONCLUSIONS: Plasma and adipose tissue concentrations of gamma-tocopherol are equally good biomarkers of intake. The weak associations between alpha-tocopherol intake and plasma or adipose tissue concentrations suggest that these biomarkers are influenced more by factors other than alpha-tocopherol intake.

Adipose Tissue↗
PubMed2001

Distinct patterns of lipoproteins with apoB defined by presence of apoE or apoC-III in hypercholesterolemia and hypertriglyceridemia.

Apolipoprotein (apo) E and apoC-III concentrations in VLDL and LDL are associated with coronary heart disease. We studied the relationship between apoE and apoC-III and the abnormal concentrations and distribution of apoB lipoproteins in 10 hypercholesterolemic and 13 hypertriglyceridemic patients compared with 12 normolipidemic subjects (mean age, 45 years). Sixteen distinct types of apoB lipoprotein particles were separated by first using anti-apoE and anti-apoC-III immunoaffinity chromatography in sequence and then ultracentrifugation [light VLDL, dense VLDL, IDL, and LDL, with apoE with or without apoC-III (E(+)C-III(+), E(+)C-III(-)) or without apoE with or without apoC-III (E(-)C-III(+), E(-)C-III(-))]. The concentrations of VLDL particles with apoC-III (E(+)C-III(+), E(-)C-III(+)) were increased in the hypertriglyceridemic group compared with the hypercholesterolemic and normolipidemic groups. These particles were the most triglyceride rich of the particle types, and their triglyceride content was twice as high in hypertriglyceridemics compared with the other two groups. Hypertriglyceridemics had a similar concentration of total E(-)C-III(-) particles compared with normolipidemics, but the E(-)C-III(-) particles were distributed more to VLDL and IDL than to LDL. Hypercholesterolemics, in contrast, were distinguished from the normolipidemic group by 2-fold higher concentrations of apoB lipoproteins without apoE or apoC-III (E(-)C-III(-)), mainly LDL, which had high cholesterol content. Nonetheless, both normolipidemics and hypercholesterolemics had apoC-III-containing VLDL, which comprised 68% and 43% of their total VLDL particles. E(+)C-III(-) particles were a minor type, comprising <10% of particles in all lipoproteins and patient groups. Therefore, VLDL particles with apoC-III may play a central role in identifying the high risk of coronary heart disease in hypertriglyceridemia, but their substantial prevalence in normolipidemics may be of clinical significance as well.

Apolipoprotein C-III↗
PubMed2000

Quantitative radioligand assays using de novo-synthesized recombinant autoantigens in connective tissue diseases: new tools to approach the pathogenic significance of anti-RNP antibodies in rheumatic diseases.

OBJECTIVE: To describe new assays for the detection and quantification of antibodies to RNPs in rheumatic diseases, using soluble nuclear antigens synthesized de novo in reticulocyte lysates. METHODS: Sera from 381 patients with various rheumatic diseases, including 212 patients with systemic lupus erythematosus (SLE), were analyzed in order to evaluate the sensitivity and specificity of serum autoantibody reactivities to several recombinant soluble autoantigens: U1-A RNP, Sm-B, SSA/Ro 52 and SSA/Ro 60, SSB/La, and Ku. Radioligand assays (RLAs) were performed following the in vitro transcription and translation of each autoantigen from the corresponding complementary DNA, labeled with 35S-methionine. The radiolabeled protein was then bound by the specific serum autoantibody, forming immune complexes that were captured by protein A-Sepharose beads and quantified by counting the radioactivity. RESULTS: Among the SLE patients, 44% were positive for anti-U1-A RNP activity, 34% for anti-Sm-B, 44% for anti-SSA (32% for Ro 52 and 46% for Ro 60), 32% for anti-SSB/La, and 11% for anti-Ku reactivities. SSA antibodies had a high frequency in patients with mixed connective tissue disease (MCTD) (80%); 65% of these patient sera reacted with Ro 52, 45% with Ro 60, and 45% with U1-A RNP. Twenty percent of the MCTD patients also exhibited antibodies to Sm-B and Ku. In patients with Sjögren's syndrome, anti-SSA was the main anti-RNP antibody (63%), together with SSB/La antibodies (44%). Among patients with inflammatory myopathy, only antibodies against Ro 52 (36%) and Ro 60 (36%) were present. These new RLA allowed observation of a strong correlation (P < 0.0001) between Sm-B antibody levels and the severity of SLE (as measured by the SLE Disease Activity Index), and establishment of a correlation between anti-U1-A RNP antibodies and the occurrence of SLE nephritis (P < 0.02). All RLAs were highly specific for the antigen tested and displayed, in the disease groups studied, a higher sensitivity than conventional immunodiffusion assays. CONCLUSION: These highly sensitive, specific, and quantitative RLAs represent new tools for the detection of autoantibodies to RNP antigens in rheumatic diseases, and may be useful for (differential) diagnosis in clinical practice.

Autoantibodies↗
PubMed2000

Tobacco smoking modifies association between Gln-Arg192 polymorphism of human paraoxonase gene and risk of myocardial infarction.

Paraoxonase, a high density lipoprotein-associated human serum enzyme, plays a role in atherosclerosis by protecting against lipid peroxidation. Its activity is modulated by 2 common amino acid polymorphisms at positions 192 (Gln-->Arg) and 55 (Met-->Leu) in the paraoxonase gene (P:ON1). We studied the association of P:ON1 polymorphisms and myocardial infarction (MI) in a population-based study consisting of 492 cases and 518 controls matched for age, sex, and area of residence, all living in Costa Rica. The allele frequency of P:ON1(192Arg) was higher in cases (0.27) than in controls (0.24, P:=0.008), whereas that of P:ON1(55Leu) was identical (0.26). Compared with P:ON1(192Gln-Gln), the P:ON1(192Arg) allele was associated with an increased risk of MI (odds ratio [OR] 1.36, CI 1.06 to 1.75), and this association was independent of the P:ON1(55) polymorphism, which was not associated with MI (OR 1.10, CI 0.82 to 1.48). Adjustment for lipid and nonlipid risk factors strengthened the association between P:ON1(192Arg) and the risk of MI (OR 1.51, CI 1.13 to 2.03). Interestingly, this association was evident only among nonsmokers (OR 1.90, CI 1.29 to 2.79): there was no evidence of an association in smokers (OR 0.95, CI 0.57 to 1.79). The interaction between P:ON1(192) and smoking status was statistically significant (P:=0.04). Thus, the PON1(192) but not the PON1(55) gene polymorphism is associated with an increased risk of MI. This association is not evident among smokers.

Aged↗
PubMed2000

Plasma lipids and other cardiovascular risk factors in Costa Rican adolescents.

This study assessed plasma lipids and other cardiovascular risk factors in adolescents in a developing Latin American country and compared those risk factors to those of adolescents in the United States of America, where the risk of heart disease is high. In a cross-sectional study, data were collected from September 1998 to April 1999 on 161 Costa Rican adolescents between the ages of 12 and 20. A general questionnaire was used to collect demographic, smoking, socioeconomic, and women's health data. Anthropometric measurements, blood pressure, and a fasting blood sample were taken. The Costa Rican males had lower levels of total cholesterol than did the Costa Rican females (mean +/- standard error of the mean (SEM), 149 +/- 6.5 mg/dL vs. 158 +/- 6.3 mg/dL). This was mainly due to lower high-density lipoprotein (HDL) cholesterol in males than in females (mean +/- SEM, 38 +/- 2.0 mg/dL vs. 44 +/- 2.4 mg/dL). As compared to the United States, adolescents in this study had lower levels of total cholesterol, largely due to lower HDL cholesterol. Both genders of Costa Ricans had levels of low-density lipoprotein (LDL) cholesterol that were similar to those of counterpart groups in the United States. Costa Rican male and female adolescents had higher LDL/HDL ratios than did their United States counterparts. Therefore, as compared to the United States, Costa Rican adolescents have an adverse lipid profile as demonstrated by a higher LDL/HDL ratio. Overweight prevalence in Costa Rica was 13%, approaching the 15% overall level of the United States.

Adolescent↗
PubMed2000

Siesta and the risk of coronary heart disease: results from a population-based, case-control study in Costa Rica.

BACKGROUND: The siesta (afternoon nap or rest), a common traditional behaviour in tropical areas, may increase the risk of myocardial infarction (MI) since the post siesta cardiovascular response very closely resembles the period soon after waking up in the morning when the onset of acute cardiovascular events is high. METHODS: We studied 505 MI survivors and 522 randomly selected controls, matched for age, gender, and area of residence, in a population-based case-control study in Costa Rica. Participation rates were 97% for cases and 90% for controls. All subjects completed a physical activity questionnaire that included occupational and leisure time components with specific questions on siesta. Five siesta frequency categories (<1/wk, 1-4/wk, 5-6/wk, daily [> or =1 h and <2 h], and daily [> or =2 h and <3:30 h]) were used to calculate the odds ratio (OR) by multiple logistic regression. RESULTS: Compared to controls, cases were more likely to take daily siestas (44 versus 35%, P = 0. 01), and spend more time per siesta (1:07 +/- 0:04 versus 0:54 +/- 0:04 h:min, P = 0.002). As compared to subjects with the lowest siesta frequency (<1/wk), the OR for MI among those in the highest category was 1.51 (95% CI : 1.02-2.25, P for trend = 0.006). After adjusting for risk factors, lifestyle, and health history the OR across the siesta categories were 1.0, 0.77, 1.28. 1.66, and 1.40 (P for trend = 0.02). CONCLUSIONS: Our data suggest that the practice of daily siesta is associated with increased risk of MI.

Aged↗
PubMed1999

Effects of estrogenic oral contraceptives on the lipoprotein B particle system defined by apolipoproteins E and C-III content.

Apolipoproteins E and C-III are modulators of lipoprotein metabolism that could affect development of atherosclerosis. The prevalence in plasma of apoB-containing particles (LpB) that contain either apoE or apoC-III, both or neither, and the effect of estrogen on these lipoproteins are unknown. The LpB particle system, defined by the presence or absence of apoE or C-III, was studied in 13 normolipidemic women, 7 nonusers and 6 users of oral contraceptives. Fasting plasma was separated by anti-apoE and C-III affinity chromatography and ultracentrifugation into four types of VLDL, IDL, and LDL particles: with apoE but not apoC-III (E+C-), apoC-III but not apoE (E-C+), both (E+C+) or neither (E-C-). The predominant VLDL particles were E-C- (42% in nonusers, 56% in users) and E+C+ (39% in nonusers, 24% in users), suggesting that apoE and apoC-III mainly exist together in VLDL. In IDL, E-C- was the major fraction (74% nonusers, 81% users), and in LDL, it was 99% in both groups. The triglycerides in VLDL and IDL were mainly contained in C+ particles (79% and 66% of the total VLDL and IDL triglycerides, respectively). Within VLDL, IDL, and LDL, E-C- particles had the smallest size and E+C+ or E-C+ the largest. Users had higher concentrations of VLDL E-C- (280%) and IDL E-C- (90%) particles than nonusers. They also had higher free cholesterol and cholesteryl ester concentrations associated with these fractions and with VLDL E-C+. The triglyceride contents of VLDL E-C- particles were lower in users of oral contraceptives than in nonusers. This study demonstrates that the elevated VLDL TG concentrations in users of estrogen-dominant oral contraceptives is mainly caused by an increased concentration of small VLDL particles that have reduced TG content, and that do not have apoE and C-III. These particles may have lower atherogenicity than particles enriched with apoE and C-III.-Khoo, C., H. Campos, H. Judge, and F. M. Sacks. Effects of estrogenic oral contraceptives on the lipoprotein B particle system defined by apolipoproteins E and C-III content.

Adult↗
PubMed1998

Change in dietary saturated fat intake is correlated with change in mass of large low-density-lipoprotein particles in men.

We tested whether nutrient intakes estimated from 4-d diet records were associated with plasma lipoprotein subclasses in 103 men who were randomly assigned to a low-fat (24% fat) and a high-fat (46% fat) diet for 6 wk each in a crossover design. Postheparin plasma lipoprotein lipase (LPL) and hepatic lipase (HL) activities were also determined in a subset of 43 men. Changes in intake (ie, high fat minus low fat) of total saturated fatty acids, as well as myristic (14:0) and palmitic (16:0) acids, were positively correlated (P < 0.01) with increases in mass of large LDL particles [measured by analytic ultra-centrifugation as mass of lipoproteins of flotation rate (Sf) 7-12] and with LDL peak particle diameter and flotation rate, but not with changes in LDL-cholesterol concentration. Changes in total saturated fatty acids as well as myristic and palmitic acids were also inversely associated with changes in HL activity (P < 0.05). With the high-fat diet only, variation in dietary total saturated fatty acid intake was inversely correlated (P < 0.01) with concentrations of small, dense LDL of Sf 0-5. This correlation was significant specifically for myristic acid (P < 0.001). Stearic acid (18:0), monounsaturates, and polyunsaturates showed no significant associations with lipoprotein concentrations. These data indicate that a high saturated fat intake (especially 14:0 and 16:0) is associated with increased concentrations of larger, cholesterol-enriched LDL and this occurs in association with decreased HL activity.

Adult↗