High-resolution MRI assessed carotid atherosclerotic plaque characteristics comparing men and women with elevated ApoB levels.

Previous studies demonstrated that men were more likely to have plaque rupture and are at greater risk for myocardial infarction and stroke than women. We evaluated differences in carotid plaque characteristics by MRI between men and women with mild-moderate atherosclerosis and elevated ApoB levels. One hundred eighty-two subjects (104 men and 78 women) with CAD or carotid stenosis (≥ 15% by ultrasound), ApoB ≥ 120 mg/dL and carotid MRI scan were included. Percent wall volume (%WV) was calculated as (wall volume/total vessel volume) × 100%. Three major plaque compositions, fibrous tissue (FT), calcification (CA) and lipid rich necrotic core (LRNC), were identified and quantified using published MRI criteria. Adventitial and plaque neovascularization as fractional plasma volume (Vp) and permeability as transfer constant (Ktrans) were analyzed using kinetic modeling. These characteristics were compared between men and women. Men, compared to women, were younger (54 ± 8 vs. 58 ± 8 years, p = 0.01), had higher rate of previous MI (46 vs. 26%, p = 0.005) but lower proportions of metabolic syndrome (37 vs. 59%, p = 0.003). After adjusting for between-gender differences, men were significantly more likely to have LRNC (OR 2.22, 95% CI 1.04-4.89, p = 0.04) and showed significantly larger %LRNC than women (diff = 4.3%, 95% CI 1.6-6.9%, p = 0.002), while %WV, FT, and CA were similar between men and women. There were no statistically significant differences in adventitial and plaque Vp or Ktrans. Men were significantly more likely to have LRNC and had larger LRNC than women. However, men and women showed relatively similar levels of adventitial and plaque neovascularization and permeability.Trial registration: NCT00715273 at ClinicalTrials.gov. Registered 15 July 2008, retrospectively registered.

Types of Myocardial Infarction Among Human Immunodeficiency Virus-Infected Individuals in the United States.

Importance: The Second Universal Definition of Myocardial Infarction (MI) divides MIs into different types. Type 1 MIs result spontaneously from instability of atherosclerotic plaque, whereas type 2 MIs occur in the setting of a mismatch between oxygen demand and supply, as with severe hypotension. Type 2 MIs are uncommon in the general population, but their frequency in human immunodeficiency virus (HIV)-infected individuals is unknown. Objectives: To characterize MIs, including type; identify causes of type 2 MIs; and compare demographic and clinical characteristics among HIV-infected individuals with type 1 vs type 2 MIs. Design, Setting, and Participants: This longitudinal study identified potential MIs among patients with HIV receiving clinical care at 6 US sites from January 1, 1996, to March 1, 2014, using diagnoses and cardiac biomarkers recorded in the centralized data repository. Sites assembled deidentified packets, including physician notes and electrocardiograms, procedures, and clinical laboratory tests. Two physician experts adjudicated each event, categorizing each definite or probable MI as type 1 or type 2 and identifying the causes of type 2 MI. Main Outcomes and Measures: The number and proportion of type 1 vs type 2 MIs, demographic and clinical characteristics among those with type 1 vs type 2 MIs, and the causes of type 2 MIs. Results: Among 571 patients (median age, 49 years [interquartile range, 43-55 years]; 430 men and 141 women) with definite or probable MIs, 288 MIs (50.4%) were type 2 and 283 (49.6%) were type 1. In analyses of type 1 MIs, 79 patients who underwent cardiac interventions, such as coronary artery bypass graft surgery, were also included, totaling 362 patients. Sepsis or bacteremia (100 [34.7%]) and recent use of cocaine or other illicit drugs (39 [13.5%]) were the most common causes of type 2 MIs. A higher proportion of patients with type 2 MIs were younger than 40 years (47 of 288 [16.3%] vs 32 of 362 [8.8%]) and had lower current CD4 cell counts (median, 230 vs 383 cells/µL), lipid levels (mean [SD] total cholesterol level, 167 [63] vs 190 [54] mg/dL, and mean (SD) Framingham risk scores (8% [7%] vs 10% [8%]) than those with type 1 MIs or who underwent cardiac interventions. Conclusions and Relevance: Approximately half of all MIs among HIV-infected individuals were type 2 MIs caused by heterogeneous clinical conditions, including sepsis or bacteremia and recent use of cocaine or other illicit drugs. Demographic characteristics and cardiovascular risk factors among those with type 1 and type 2 MIs differed, suggesting the need to specifically consider type among HIV-infected individuals to further understand MI outcomes and to guide prevention and treatment.

Use of lipoprotein particle measures for assessing coronary heart disease risk post-American Heart Association/American College of Cardiology guidelines: the Multi-Ethnic Study of Atherosclerosis.

OBJECTIVE: The American College of Cardiology and American Heart Association have issued guidelines indicating that the contribution of apolipoprotein B-100 (ApoB) to cardiovascular risk assessment remains uncertain. The present analysis evaluates whether lipoprotein particle measures convey risk of coronary heart disease (CHD) in 4679 Multi-Ethnic Study of Atherosclerosis (MESA) participants. APPROACH AND RESULTS: Cox regression analysis was performed to determine associations between lipids or lipoproteins and primary CHD events. After adjustment for nonlipid variables, lipoprotein particle levels in fourth quartiles were found to convey significantly greater risk of incident CHD when compared to first quartile levels (hazard ratio [HR]; 95% confidence interval [CI]): ApoB (HR, 1.84; 95% CI, 1.25-2.69), ApoB/ApoA-I (HR, 1.91; 95% CI, 1.32-2.76), total low-density lipoprotein-particles (LDL-P; HR, 1.77; 95% CI, 1.21-2.58), and the LDL-P/HDL-P (high-density lipoprotein-P) ratio (HR, 2.28; 95% CI, 1.54-3.37). Associations between lipoprotein particle measures and CHD were attenuated after adjustment for standard lipid panel variables. Using the American Heart Association/American College of Cardiology risk calculator as a baseline model for CHD risk assessment, significant net reclassification improvement scores were found for ApoB/ApoA-I (0.18; P=0.007) and LDL-P/high-density lipoprotein-P (0.15; P<0.001). C-statistics revealed no significant increase in CHD event discrimination for any lipoprotein measure. CONCLUSIONS: Lipoprotein particle measures ApoB/ApoA-I and LDL-P/high-density lipoprotein-P marginally improved net reclassification improvement scores, but null findings for corresponding c-statistic are not supportive of lipoprotein testing. The attenuated associations of lipoprotein particle measures with CHD after the adjustment for lipids indicate that their measurement does not detect risk that is unaccounted for by the standard lipid panel. However, the possibility that lipoprotein measures may identify CHD risk in a subpopulation of individuals with normal cholesterol, but elevated lipoprotein particle numbers cannot be ruled out.

Age modification of the association of lipoprotein, lipid, and lipoprotein ratio with carotid intima-media thickness (from the Multi-Ethnic Study of Atherosclerosis [MESA]).

Multiple studies have demonstrated an age-related attenuation in risk associations of lipoproteins and lipoprotein ratios with cardiovascular disease events. We recently reported a similar age-related attenuation in risk associations of lipoproteins and lipoprotein ratios with coronary artery calcium. We assessed risk associations of lipoproteins and lipoprotein ratios with carotid intima-media thickness (CIMT), which has not been reported previously. We performed multivariable linear regression using data from the Multi-Ethnic Study of Atherosclerosis (MESA). MESA participants were community-dwelling adults 45 to 84 years of age without clinically apparent cardiovascular disease at baseline, and 4,961 met inclusion criteria for these analyses. In fully adjusted models, differences in CIMT were similar across the MESA age spectrum, with differences in internal CIMT per SD increase in low-density lipoprotein of 0.037 mm (95% confidence interval 0.018 to 0.055) for those 45 to 54 years old and 0.087 mm (95% confidence interval 0.027 to 0.146) for those 75 to 84 years old (p for interaction = 0.2). Similarly, the difference in internal CIMT per SD increase in the total/high-density lipoprotein cholesterol ratio was 0.029 mm (95% confidence interval 0.009 to 0.049) for those 45 to 54 years old and 0.101 mm (95% confidence interval 0.033, 0.169) for those 75 to 84 years old (p for interaction = 0.03). In general, risk associations of lipoproteins and lipoprotein ratios were associated with similar differences in CIMT across all age categories. In conclusion, abnormal lipoproteins and lipoprotein ratios in middle-aged and older patients are powerful risk factors for early atherosclerosis as manifested by an increased CIMT.

Plasma sterol evidence for decreased absorption and increased synthesis of cholesterol in insulin resistance and obesity.

BACKGROUND: The rise in LDL with egg feeding in lean insulin-sensitive (LIS) participants is 2- and 3-fold greater than in lean insulin-resistant (LIR) and obese insulin-resistant (OIR) participants, respectively. OBJECTIVE: We determined whether differences in cholesterol absorption, synthesis, or both could be responsible for these differences by measuring plasma sterols as indexes of cholesterol absorption and endogenous synthesis. DESIGN: Plasma sterols were measured by gas chromatography-mass spectrometry in a random subset of 34 LIS, 37 LIR, and 37 OIR participants defined by the insulin sensitivity index (S(I)) and by BMI criteria selected from a parent group of 197 participants. Cholestanol and plant sterols provide a measure of cholesterol absorption, and lathosterol provides a measure of cholesterol synthesis. RESULTS: The mean (±SD) ratio of plasma total absorption biomarker sterols to cholesterol was 4.48 ± 1.74 in LIS, 3.25 ± 1.06 in LIR, and 2.82 ± 1.08 in OIR participants. After adjustment for age and sex, the relations of the absorption sterol-cholesterol ratios were as follows: LIS > OIR (P < 0.001), LIS > LIR (P < 0.001), and LIR > OIR (P = 0.11). Lathosterol-cholesterol ratios were 0.71 ± 0.32 in the LIS participants, 0.95 ± 0.47 in the LIR participants, and 1.29 ± 0.55 in the OIR participants. After adjustment for age and sex, the relations of lathosterol-cholesterol ratios were as follows: LIS < OIR (P < 0.001), LIS < LIR (P = 0.03), and LIR < OIR (P = 0.002). Total sterol concentrations were positively associated with S(I) and negatively associated with obesity, whereas lathosterol correlations were the opposite. CONCLUSIONS: Cholesterol absorption was highest in the LIS participants, whereas cholesterol synthesis was highest in the LIR and OIR participants. Therapeutic diets for hyperlipidemia should emphasize low-cholesterol diets in LIS persons and weight loss to improve S(I) and to decrease cholesterol overproduction in LIR and OIR persons.

Carotid intima-media thickness for the practicing lipidologist.

BACKGROUND: It is well known that cardiovascular disease is the number one killer of men and women in the United States and in many parts of the developed world. However, early detection of atherosclerosis remains a challenging area of research and development. Stress echo and myocardial perfusion studies were not designed to be screening tests and the majority of literature using these tests is in populations with a high probability of disease. It must be emphasized that negative stress echo and stress MPI tests only imply a lack of flow limiting disease; they do not indicate lack of atherosclerotic disease. It is important to remember that when these tests are "negative," the implication is favorable short-term prognosis rather than any implication regarding lack of disease. In contrast, carotid intima-media thickness (CIMT) scanning protocols can detect atherosclerotic disease in early and asymptomatic stages. For a number of reasons reviewed in this article, CIMT may be a more optimal screening and risk-stratifying technology: CIMT directly visualizes vasculature unlike biomarkers such as LDL cholesterol, hsCRP, or PLA2. METHODS: We performed medline searches for original articles and reviews of carotid IMT from 1985 to the present. We particularly emphasized large multi-center epidemiologic studies of the natural history of patients with carotid IMT measurements. CONCLUSION: There is substantial evidence that CIMT is a suitable surrogate for the coronary tree. CIMT is also (along with coronary calcium scoring) recognized by the American Heart Association as a surrogate marker for coronary artery disease. A recent commentary by Stein, et al reviewed the comparison of CIMT to coronary calcium scoring, with favorable findings for CIMT especially in the healthy young and middle-aged populations, as well as women and African American individuals where coronary calcification has more limited utility. Recent findings of the Multi-Ethnic Study of Atherosclerosis indicate further that increased CIMT predicted CVD events in individuals without coronary calcification.

Association of combinations of lipid parameters with carotid intima-media thickness and coronary artery calcium in the MESA (Multi-Ethnic Study of Atherosclerosis).

OBJECTIVES: The purpose of this study was to determine the association of combinations of lipid parameters with subclinical atherosclerosis. BACKGROUND: Carotid intima-media thickness (CIMT) and coronary artery calcium (CAC) are significantly associated with incident cardiovascular disease (CVD). The association between common dyslipidemias (combined hyperlipidemia, [simple] hypercholesterolemia, dyslipidemia of metabolic syndrome, isolated low high-density lipoprotein cholesterol, and isolated hypertriglyceridemia) compared with normolipemia, and CIMT and CAC has not been previously examined. METHODS: The MESA (Multi-Ethnic Study of Atherosclerosis) participants were White, Chinese, African-American, or Hispanic adults without clinical CVD. Subjects with diabetes mellitus or who were receiving lipid-lowering therapy were excluded. Every participant was classified into only 1 of 6 groups defined by specific low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, or triglyceride cut points. Multivariate linear and relative risk regressions evaluated the cross-sectional associations with CIMT and CAC after adjusting for CVD risk factors. Interactions with race, sex, and high-sensitivity C-reactive protein were evaluated for CIMT and CAC outcomes. RESULTS: Among 4,792 participants, only those with combined hyperlipidemia and hypercholesterolemia demonstrated both increased common CIMT (combined hyperlipidemia 0.048 mm thicker, 95% confidence interval [CI]: 0.016 to 0.080 mm; hypercholesterolemia 0.048 mm thicker, 95% CI: 0.029 to 0.067 mm) and internal CIMT (combined hyperlipidemia 0.120 mm thicker, 95% CI: 0.032 to 0.208 mm; and hypercholesterolemia 0.161 mm thicker, 95% CI: 0.098 to 0.223 mm) as well as increased risk for prevalent CAC (combined hyperlipidemia relative risk: 1.22, 95% CI: 1.08 to 1.38; hypercholesterolemia relative risk: 1.22, 95% CI: 1.11 to 1.34) compared with normolipemia. The interactions between lipid parameters and race, sex, or high-sensitivity C-reactive protein were not significant for any outcomes. CONCLUSIONS: Combined hyperlipidemia and simple hypercholesterolemia were associated with increased CIMT and prevalent CAC in a relatively healthy multiethnic population.

Age-modification of lipoprotein, lipid, and lipoprotein ratio-associated risk for coronary artery calcium (from the Multi-Ethnic Study of Atherosclerosis [MESA]).

Although abnormal lipoproteins and lipoprotein ratios are powerful risk factors for clinical cardiovascular events, these associations are stronger in younger than in older subjects. Whether age modifies the relation of lipoproteins and lipoprotein ratios to the relative risk of subclinical cardiovascular disease (CVD), as assessed by coronary artery calcium (CAC) scores, has not been examined in a contemporary, multiethnic cohort. We performed multivariate relative risk regression analyses to determine the relative risks for associations of lipoproteins and lipoprotein ratios with prevalent CAC in participants in Multi-Ethnic Study of Atherosclerosis (MESA). The participants were community-dwelling adults aged 45 to 84 years without clinically apparent CVD at baseline. We excluded those taking lipid-lowering therapy (15%) and stratified the results by decades of age. A total of 5,092 participants met the inclusion criteria. In the fully adjusted models, per SD of low-density lipoprotein, the age-stratified, adjusted relative risk for CAC was 1.17 (95% confidence interval [CI] 1.07 to 1.28) for those aged 45 to 84 years but was 1.05 (95% CI 1.01 to 1.10) for those aged 75 to 84 years (p-interaction = 0.12). The relative risk per SD of total/high-density lipoprotein cholesterol ratio was 1.20 (95% CI 1.12 to 1.29) for those aged 45 to 54 years but only 1.04 (95% CI 1.00 to 1.09) for those aged 75 to 84 years (p-interaction <0.001). The lipoproteins levels and lipoprotein ratios were associated with increased relative risks for CAC across all age categories. However, these associations were markedly attenuated by age. In conclusion, abnormal lipoprotein levels in middle age are a powerful risk factor for early atherosclerosis, as manifested by prevalent CAC.

Interpregnancy weight gain and cesarean delivery risk in women with a history of gestational diabetes.

OBJECTIVE: Along with the rising prevalence of obesity, rates of gestational diabetes mellitus (GDM) and associated adverse outcomes also have increased. We conducted a population-based, retrospective cohort study to assess the association of weight gain between pregnancies with cesarean delivery for the subsequent pregnancy among women with a history of GDM. METHODS: Using linked birth-certificate data for women with at least two singleton births in Washington State during the period from 1992-2005, we identified 2,753 women with GDM who delivered vaginally at the baseline pregnancy (first pregnancy on record). The interpregnancy weight change (subsequent-baseline prepregnancy weight) for each woman was calculated and assigned to one of three categories: weight loss (more than 10 lb), weight stable (+/-10 lb), or weight gain (more than 10 lb). Multiple logistic regression was used to calculate the risk (odds ratio [OR]) of cesarean delivery at the subsequent pregnancy among the weight-gain and weight-loss groups relative to the weight-stable category. RESULTS: Among 2,581 eligible women, 10.9% lost more than 10 lb between pregnancies, 54.0% were weight-stable, and 35.1% gained more than 10 lb. Women who gained more than 10 lb had an adjusted OR for subsequent cesarean delivery of 1.70 (95% confidence interval [CI] 1.16-2.49, 9.7% of women who gained weight), whereas the adjusted OR for women who lost weight was 0.55 (95% CI 0.28-1.10, 4.7% of women who lost weight). CONCLUSION: Women with a history of GDM who gained more than 10 lb between pregnancies are at increased risk of future cesarean delivery. Appropriate weight management among women with a history of GDM may result in decreased cesarean delivery rates along with decreases in associated excess risks and costs. LEVEL OF EVIDENCE: II.

Combined hyperlipidemia in relation to race/ethnicity, obesity, and insulin resistance in the Multi-Ethnic Study of Atherosclerosis.

We have asked whether the prevalence of combined hyperlipidemia (CHL) differs by race/ethnicity, obesity, and insulin resistance in a contemporary, multiethnic, US cohort. We determined the prevalence and adjusted odds of CHL in a cohort of 5923 men and women free of clinically recognized cardiovascular disease and diabetes according to race/ethnicity (white, Chinese, African American, and Hispanic), obesity, and insulin resistance. Untreated lipid values were imputed for those on lipid-lowering therapy. Combined hyperlipidemia was defined using age- and sex-specific greater than or equal to 75th percentile cut points for low-density lipoprotein cholesterol and triglycerides obtained from a predominantly white North American population study. Compared with whites, adjusted odds ratios for CHL were 0.48 in African Americans (95% confidence interval [CI], 0.30-0.75), 1.33 in Hispanics (95% CI, 0.93-1.91), and 1.06 in Asians (95% CI, 0.62-1.82). Within the entire population, the adjusted odds of CHL were over 2-fold higher in overweight and obese participants compared with normal-weight participants and more than 4-fold higher in quartiles 2 through 4 of insulin resistance compared with quartile 1. African Americans had lower odds for CHL than whites despite higher body mass index and abdominal adiposity. Hispanics had a nonsignificantly higher trend, and Asians had no significantly different odds than whites. Modest increases in weight and insulin resistance were associated with significantly higher odds of CHL in a multiethnic US population. Further research is needed to determine the most efficacious diet, exercise, and drug management to decrease the risk of CHL and coronary heart disease among racial/ethnic groups in the United States.

The SLIM Study: Slo-Niacin® and Atorvastatin Treatment of Lipoproteins and Inflammatory Markers in Combined Hyperlipidemia.

BACKGROUND: The combination of niacin and statin has proven value in hyperlipidemia management and heart disease prevention. However, the efficacy of the non-prescription time-release niacin, Slo-Niacin®, is little studied alone and not at all with atorvastatin. We gave Slo-Niacin® and atorvastatin, singly and together to determine efficacy on the combined abnormalities of triglyceride, LDL and HDL. METHODS: 42 men and women with LDL-C>130mg/dL HDL-C <45 (men or 55mg/dL (women) were randomized to 3 months of atorvastatin 10 mg/day or incremental doses of Slo-Niacin® to 1500 mg/day. The alternate drug was added in the next 3-month segment. Lipid profiles and transaminases were measured monthly and other measures at baseline and the end of each treatment sequence. RESULTS: Mean entry lipids (mg/dL) were: TG 187, LDL-C 171, and HDL-C 39. Mean BMI was 32.6 Kg/m(2). Monotherapy with Slo-Niacin® decreased median triglyceride 15%, mean LDL-C 12% and non-HDL-C 15% and increased HDL-C 8%. Atorvastatin decreased median triglyceride 26%, and mean LDL-C 36%, non-HDL-C 36% and increased HDL-C 6%. Combined therapy decreased median triglyceride 33% and mean LDL-C and non-HDL-C each 43%. HDL-C increased 10% (all p<0.001). Median remnant-like lipoprotein-C decreased 55%, mean apo-B 40%, median hsCRP 23% (all p<0.05), TNFa 12% and no change in IL-6. Mean LDL buoyancy increased 15%, apo-A-I 5% and median HDL(2)-C 20% (all p<0.05). ALT declined with Slo-Niacin® treatment alone compared to atorvastatin and also decreased when Slo-Niacin® was added to atorvastatin. Six subjects dropped out, 3 for niacin related symptoms. CONCLUSIONS: Slo-Niacin® 1.5g/day with atorvastatin 10 mg/day improved lipoprotein lipids, apoproteins and inflammation markers without hepatotoxicity. Slo-Niacin® deserves further study as a cost-effective treatment of hyperlipidemia.

Comprehensive lipid management versus aggressive low-density lipoprotein lowering to reduce cardiovascular risk.

Five lines of evidence justify comprehensive lipoprotein management over aggressive low-density lipoprotein (LDL) lowering alone in most cases of cardiovascular disease (CVD) prevention. First, lipoprotein lipid transport consists of a single, recycling system involving very-low-density lipoprotein, LDL, and high-density lipoprotein (HDL). Single lipid interventions affect all lipoprotein classes to varying degrees. These effects can be expanded by using different drug classes in combination. Second, observational studies support the unitary nature of lipoprotein risk. A family of curves describes increasing CVD risk from increasing LDL as other risk factors are present. Conversely, a family of curves describes increasing CVD risk from decreasing levels of HDL in mirror image to LDL. The LDL and HDL risks are additive. Third, clinical trials that raise HDL and lower triglyceride ameliorate CVD, as does lowering LDL. Lowering LDL prevents heart disease, but by only 22%-36% with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor therapy. Studies indicate that better CVD prevention is obtained when drugs for triglyceride and HDL reduction are combined with LDL reduction. Fourth, HDL and its apolipoprotein (apo), apo A-I, as well as apo A-I analogues, decrease atherosclerosis. Each modality decreases atherosclerosis in animal models, and apo A-I Milano acutely decreases human coronary luminal stenosis. Apo A-I analogues have similar promise. Fifth, combined hyperlipidemia is the most common lipid disorder, has the strongest risk for CVD, and combines elevated LDL, hypertriglyceridemia, and low HDL. This condition requires the comprehensive treatment approach described above. In conclusion, 5 lines of evidence justify comprehensive diet and drug treatment for combined hyperlipidemia and, at lesser LDL elevations, the atherogenic dyslipidemias of obesity, diabetes mellitus, and the metabolic syndrome.

Sex differences in lipoprotein metabolism and dietary response: basis in hormonal differences and implications for cardiovascular disease.

The transport of fat in the blood stream is approximately twice as fast in women as men. Disease states such as obesity and diabetes are associated with greater lipoprotein abnormalities in women compared with men. A greater increment in cardiovascular disease risk in women is linked to these abnormalities. A greater change in triglyceride level and a lesser change in low-density lipoprotein are observed in women than men with high-carbohydrate or high-fat feeding. Most consistent are greater changes in high-density lipoprotein (HDL), HDL(2), and apolipoprotein A-I levels in women compared with men with high-carbohydrate or high-fat feeding. Dietary fat restriction in women appears to have a less beneficial lipoprotein effect than in men. Dietary fat restriction for heart disease prevention may be less ideal in women than in men.

A moderate-fat diet for combined hyperlipidemia and metabolic syndrome.

A low-fat diet is recommended for hyperlipidemia. However, low-density lipoprotein (LDL) responses depend on the type of hyperlipidemia (ie, simple hypercholesterolemia or combined hyperlipidemia). In combined hyperlipidemia, which is typical of patients with metabolic syndrome, LDL levels are only one third as responsive to fat and cholesterol as simple hypercholesterolemia. The diminished dietary sensitivity of combined hyperlipidemia is explained by diminished intestinal absorption of cholesterol, a feature of metabolic syndrome. In turn, combined hyperlipidemia is caused by heightened lipid secretion by the liver. A moderate-fat, moderate-carbohydrate diet employing allowable fats has the promise of reducing endogenous lipoprotein production in combined hyperlipidemia. Triglyceride, LDL, and small-dense LDL should be lower, and high-density lipoprotein, apoprotein A-I, and buoyant LDL should be higher. A test of this dietary strategy on lipoproteins and downstream benefits on inflammatory mediators, oxidative stress, and vascular reactivity is now underway.

Gender differences in lipoprotein metabolism and dietary response: basis in hormonal differences and implications for cardiovascular disease.

The transport of fat in the blood stream is approximately twice as fast in women as men. Disease states such as obesity and diabetes are associated with greater lipoprotein abnormalities in women compared with men. A greater increment in cardiovascular disease risk in women is linked to these abnormalities. A greater change in triglyceride level and a lesser change in low-density lipoprotein are observed in women than men with high-carbohydrate or high-fat feeding. Most consistent are greater changes in high-density lipoprotein (HDL), HDL2, and apolipoprotein A-I levels in women compared with men with high-carbohydrate or high-fat feeding. Dietary fat restriction in women appears to have a less beneficial lipoprotein effect than in men. Dietary fat restriction for heart disease prevention may be less ideal in women than in men.