Relation of coronary artery disease in women < 60 years of age to the combined elevation of serum lipoprotein (a) and total cholesterol to high-density cholesterol ratio

Association of menopause and hormone replacement therapy with large artery remodeling

OBJECTIVE

To evaluate the remodeling of large arteries according to age at menopause, duration of menopause, and use of hormone therapy (HT).

DESIGN

A cross-sectional study consisting of baseline measurements of a multicentric randomized trial were used to evaluate arterial parameters.

SETTING

The study was conducted in France, Belgium, and the Netherlands in academic hospitals and private clinics.

PATIENT(S)

Postmenopausal women (n = 538) with mild hypercholesterolemia.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Common carotid artery intima-media thickness (CCA-IMT), central pulse pressure, and aortic stiffness (carotid-femoral pulse wave velocity) were measured and centrally controlled for quality. Multivariate regression analysis was used to assess the possible covariates associated with arterial parameters.

RESULT(S)

Women were 58 ± 6 (mean ± SD) years of age with an age of 50 ± 5 at menopause and a mean duration of menopause of 8 ± 7 years. Lower age at menopause, time since menopause, and absence of HT use were independently associated with worsening of the arterial parameters. After multivariate analysis, HT was associated with a lower CCA-IMT (-40 μm [range -64 to -1]), whereas lower age at menopause and menopause duration were respectively associated with a CCA-IMT increase (25 μm/5 y and 27 μm/5 y). Similarly, values of central pulse pressure and pulse wave velocity were lower in HT users (-3.1 mm Hg [-5.1 to -0.9] and -0.31 m/s [-0.63 to -0.02], respectively) but worsened with age at menopause and menopause duration.

CONCLUSION(S)

The age at menopause, the time since menopause, and the use of HT are independently associated with the thickening and stiffening of the large arteries.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00163163.

Metabolic syndrome and cardiovascular disease in South Asians

This review discusses the prevalence of metabolic syndrome and cardiovascular disease in the South Asian population, evaluates conventional and emerging risk factors, and reinforces the need for ethnic-specific redefinition of guidelines used to diagnose metabolic syndrome. We reviewed recent and past literature using Ovid Medline and PubMed databases. South Asians represent one of the largest and fastest growing ethnic groups in the world. With this growth, a dramatic rise in the rates of acute myocardial infarction and diabetes is being seen in this population. Potential etiologies for this phenomenon include dietary westernization, poor lifestyle measures, adverse body fat patterning, and genetics. While traditional risk factors for diabetes and cardiovascular disease should not be overlooked, early metabolic syndrome has now been shown in the South Asian pediatric population, suggesting that "metabolic programming" and perinatal influences may likely play a substantial role. Health care practitioners must be aware that current guidelines used to identify individuals with metabolic syndrome are underestimating South Asian individuals at risk. New ethnic-specific guidelines and prevention strategies are discussed in this review and should be applied by clinicians to their South Asian patients.

Comparison of Lipoprotein(a) levels between elderly and middle-aged men with coronary artery disease

Lipoprotein(a) [Lp(a)] is known to be a risk factor for atherosclerotic disease in middle-aged men, but the role of Lp(a) in women and in the elderly is less clear. In most studies, excess Lp(a) is not associated with increased risk for persons >65 years of age. This study examined the strength of association of a number of risk factors to coronary artery disease (CAD) in groups of men <65 years (n = 108) and >65 of age (n = 66) with angiographically documented significant narrowing of coronary arteries. Serum Lp(a) concentrations were determined; elevated Lp(a) is positively associated with CAD for men <65 years (adjusted OR: 2.45, P <0.05) but not for men >65 of age (adjusted OR: 0.56, P = NS). For middle-aged men, elevated Lp(a) appears to be an independent risk factor for premature CAD, and the importance of Lp(a) as a risk factor appears to decrease with age. These data suggest that the utility of Lp(a) lipoprotein levels in predicting the risk of CAD in older men is limited. Factors, such as age; sex; levels of total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides; carotid-wall thickness; smoking status; the presence or absence of diabetes and systolic and diastolic hypertension; body mass index (BMI); and other traditional risk factors, must be evaluated together to determine the risk of CAD for the entire population.

Conditional risk factors for atherosclerosis

Although most patients who experience a coronary heart disease (CHD) event have one or more of the conventional risk factors for atherosclerosis, so do many people who have not yet experienced such an event. Therefore, predictive models based on conventional risk factors have a lower than desired accuracy, providing a stimulus to search for new tools to refine CHD risk prediction. In particular, there is intense interest in evaluating circulating biomarkers related to the atherosclerotic process that might add to our ability to better predict CHD risk. One such group of biomarkers was termed conditional risk factors in an American Heart Association/American College of Cardiology statement in 1999. The conditional risk factors include homocysteine, fibrinogen, lipoprotein(a), low-density lipoprotein particle size, and C-reactive protein. This review updates the conditional risk factors. The main focus is on the potential utility of these risk factors, which are currently available to clinicians, in the prediction of CHD risk in asymptomatic persons. The putative mechanisms of risk, available assays, evidence for association with CHD, and the clinical implications thereof are discussed for each of the risk factors.

Lack of association between lipoprotein(a) and coronary artery calcification in the Genetic Epidemiology Network of Arteriopathy (GENOA) study

OBJECTIVE

To investigate the relationship between lipoprotein(a) [Lp(a)] levels and the extent of coronary atherosclerosis in a cohort that consisted predominantly of hypertensive patients.

PATIENTS AND METHODS

Patients were ascertained through sibships that contained at least 2 individuals with essential hypertension diagnosed before the age of 60 years. The 10-year coronary heart disease (CHD) risk was estimated on the basis of the Framingham risk equation. Serum Lp(a) was measured by an immunoturbidimetric assay. Coronary artery calcification (CAC) was measured noninvasively by electron beam computed tomography and CAC score calculated using the Agatston score.

RESULTS

Patients included 765 non-Hispanic, white individuals (59% women) participating in the Genetic Epidemiology Network of Arteriopathy study. The mean +/- SD age of the patients was 62 +/- 8 years, and 77% had hypertension. The prevalence of detectable CAC was 87% in men and 60% in women. The CAC scores did not differ significantly across quintiles of Lp(a) levels in either men or women. In a multiple regression model that included conventional risk factors, Lp(a) levels were not related to CAC quantity in either sex. No significant interactions were noted between Lp(a) levels and the conventional risk factors in the prediction of CAC quantity. When stratified on the basis of the 10-year CHD risk, 26.5% of the patients were low risk (< 6%), 60.5% were intermediate risk (6%-20%), and 12.9% were high risk (> 20%). Lipoprotein(a) was not associated with CAC quantity within subgroups based on 10-year CHD risk.

CONCLUSION

In this cohort enriched with hypertensive patients, the estimated 10-year CHD risk did not appear to modify the lack of an association between Lp(a) levels and CAC.

Electrophoretic measurement of lipoprotein(a) cholesterol in plasma with and without ultracentrifugation: comparison with an immunoturbidimetric lipoprotein(a) method

OBJECTIVES

Elevated plasma lipoprotein(a) [Lp(a)] is a significant risk factor for vascular disease. Standardization of Lp(a) mass measurement is complicated by the heterogeneity of apolipoprotein(a) [apo(a)]. We investigated whether Lp(a) cholesterol measurement, which is not influenced by apo(a) size, is a viable alternative to measuring Lp(a) mass.

DESIGN AND METHODS

Plasma Lp(a) cholesterol was measured electrophoretically, with and without ultracentrifugation, and results were compared to each other and to immunoturbidimetrically measured Lp(a) mass in 470 subjects.

RESULTS

Ultracentrifuged and whole plasma Lp(a) cholesterol levels demonstrated high correlation (R = 0.964). All samples with detectable (>/=2.0 mg/dl) Lp(a) cholesterol had Lp(a) mass >30 mg/dl (the clinically relevant cutpoint), while 59 samples with Lp(a) mass >30 mg/dl did not have detectable Lp(a) cholesterol.

CONCLUSIONS

Lp(a) cholesterol can be measured in whole plasma without interference from VLDL lipoproteins. The relative clinical merits of measuring Lp(a) cholesterol vs. Lp(a) mass or both in combination deserves investigation.

Predictors of 14-year changes in the total cholesterol to high-density lipoprotein cholesterol ratio in men

BACKGROUND

Although the ratio of total to high-density lipoprotein cholesterol (TC/HDL) is a powerful predictor of cardiovascular disease (CVD), few studies have investigated which factors are associated with changes in this ratio over time. We examined predictors of a change in TC/HDL ratio over a period of 14 years among 4451 men free of CVD from the Physicians' Health Study.

METHODS

Baseline and updated physician characteristics and CVD risk factors were included in multivariate linear and logistic regression models to determine factors associated with a change in the TC/HDL ratio or of having a ratio of > or =5 on follow-up.

RESULTS

After a mean follow-up of 14 years, mean total cholesterol decreased by 7 mg/dL, HDL increased by 1 mg/dL, and the ratio decreased by 0.37. In multivariate logistic analyses, physicians were more likely to have a TC/HDL ratio of > or =5 at follow-up if they maintained a weight of > or =25 kg/m2 (OR, 1.69 [1.35-2.12]), gained weight (OR, 2.01 [1.55-2.62]), or became inactive (OR, 1.43 [1.11-1.83]). However, older physicians and those who consumed alcohol or received treatment for hyperlipidemia were more likely to have a ratio of <5.

CONCLUSIONS

Although pharmacologic treatment for hyperlipidemia had the greatest favorable impact on the ratio over time, our data also show that maintaining an ideal weight and exercise have beneficial effects. We therefore advocate a renewed fervor for raising public awareness of the benefits of healthy lifestyle behaviors and pharmacologic treatments that are associated with long-term maintenance of favorable cholesterol levels.

High preprocedural non-HDL cholesterol is associated with enhanced oxidative stress and monocyte activation after coronary angioplasty: possible implications in restenosis

OBJECTIVE

To investigate whether enhanced oxidant stress in patients undergoing percutaneous transluminal coronary angioplasty (PTCA) is associated with a higher concentration of non-high density lipoprotein (HDL) cholesterol at baseline, and whether this contributes to the inflammatory reaction and luminal renarrowing after PTCA.

DESIGN

An ex vivo and in vitro study of 46 patients who underwent PTCA and who had repeat angiograms after six months. Blood samples were collected immediately before PTCA, and at 24 hours, 48 hours, and 15 days after.

SETTING

Tertiary referral centre.

SUBJECTS

46 patients (30 male, 16 female; mean (SD) age, 62 (5) years) with stable or unstable angina who underwent elective PTCA.

MAIN OUTCOME MEASURES

Continuous variable luminal loss as defined by change in minimum lumen diameter during follow up, normalised for vessel size; lag phase of low density lipoprotein to in vitro oxidation; plasma fluorescent products of lipid peroxidation (FPLP); plasma vitamin C and E; interleukin (IL) 1beta secretion from unstimulated monocytes; plasma C reactive protein (CRP).

RESULTS

Restenosis occurred in 12 patients (26%). Oxidant stress after PTCA was greater (p < 0.0001 at 15 days) in the patients with restenosis and showed a significant correlation with the preprocedural concentration of non-HDL cholesterol (p < 0.001). Inflammatory reaction (as reflected by IL-1beta production and CRP) and late lumen loss were linearly correlated (p < 0.001) with lag phase and FPLP throughout the study, and inversely (p < 0.05) with vitamin C and E measured at two and 15 days after PTCA.

CONCLUSIONS

This study provides evidence for the critical role of cholesterol dependent oxidant stress in the pathophysiology of restenosis after PTCA. The findings raise the possibility that drugs capable of modulating oxidant status might provide a novel form of adjuvant treatment in patients with hypercholesterolaemia undergoing PTCA.

Effects of Greek Orthodox Christian Church fasting on serum lipids and obesity

BACKGROUND

No study to date has focused on the impact of Greek Orthodox Christian fasting on serum lipoproteins and obesity yet.

METHODS

120 Greek adults were followed longitudinally for one year. Sixty fasted regularly in all fasting periods (fasters) and 60 did not fast at all (controls). The three major fasting periods under study were: Christmas (40 days), Lent (48 days) and Assumption (August, 15 days). A total of 6 measurements were made during one year including pre- and end-fasting blood collection, serum lipoprotein analyses and anthropometric measurements.

RESULTS

Statistically significant end-fasting total and LDL cholesterol differences were found in fasters. Fasters compared to controls presented 12.5% lower end-total cholesterol (p < 0.001), 15.9% lower end-LDL cholesterol (p < 0.001) and 1.5% lower end-BMI (p < 0.001). The end- LDL/HDL ratio was lower in fasters (6.5%, p < 0.05) while the change in end- HDL cholesterol in fasters (4.6% decline) was not significant. Similar results were found when the pre- and end-fasting values of fasters were compared. No change was found in control subjects.

CONCLUSIONS

Adherence to Greek Orthodox fasting periods contributes to a reduction in the blood lipid profile including a non-significant reduction in HDL cholesterol and possible impact on obesity.

Lipoprotein (a) in childhood: correlations with family history of cardiovascular disease

The association between lipoprotein (a) [Lp(a)] and cardiovascular diseases is well known. Lp(a) is an independent risk factor for the development of atherosclerosis. Little information concerning Lp(a) during childhood is available. The aim of the present investigation was to determine the Lp(a) concentration in a cohort of children aged between 4 and 15 yr and to correlate Lp(a) with: a) overweight status; b) body fat distribution; c) family history of vascular diseases in their parents and grandparents. Six hundred and eighty-nine children (350 males, 339 females), were enrolled in the study. BMI as index of being overweight was calculated; the waist-to-hip ratio (WHR) and the waist-to-thigh ratio (WTR) were calculated to obtain two anthropometric indexes for the pattern of body fat distribution. The areas of visceral (VAT) and subcutaneous adipose tissue (SAT) were evaluated by MRI at the L4-L5 level in only 30 overweight subjects. The serum of Lp(a), total cholesterol (TC), HDL-cholesterol, LDL-cholesterol and triglycerides were evaluated in the whole population. Moreover, the same biochemical study was performed in 70 children's parents randomly chosen. A structured questionnaire was administered to the children's parents to investigate the presence of cardiovascular disease (CVD) in family stories. Our data show no Lp(a) serum differences between children according to sex, age and body composition. The strong correlation between the children's and the parents' Lp(a) concentrations and the occurrence of CVD in their grandparents suggests that Lp(a) represents an important independent early risk factor for the development of CVD in adulthood. Measurements of Lp(a) in childhood may help to evaluate this risk in subjects with family history of cardiovascular diseases.

Relation of lipoprotein(a) as coronary risk factor to type 2 diabetes mellitus and low-density lipoprotein cholesterol in patients > or =65 years of age (The Italian Longitudinal Study on Aging)

High levels of serum lipoprotein(a) [Lp(a)] have been associated with increased risk of coronary artery disease (CAD), but this association apparently is not confirmed in elderly people. We evaluated the interactions of Lp(a) with lipid and nonlipid CAD risk factors in a sample of subjects enrolled in the prevalence survey (1992 to 1993) of the Italian Longitudinal Study on Aging (ILSA). The entire population consisted of 5,632 elderly people, aged 65 to 84 years, randomly selected in 8 Italian municipalities. The present cross-sectional study included 400 free-living elderly subjects (74 +/- 6 years) from the randomized cohort of Casamassima (Bari, Southern Italy) (n = 704). The results showed that in the elderly population, high serum Lp(a) is a CAD risk factor dependent on type 2 diabetes mellitus and elevated low-density lipoprotein (LDL) cholesterol levels. In particular, the combined effect of high Lp(a) (> or =20 mg/dl) and high LDL cholesterol (> or =3.63 mmol/L [> or =140 mg/dl]), increases coronary risk by 2.75 (95% confidence interval 7.70 to 0.99); finally, the effect of Lp(a) > or =20 mg/dl and LDL cholesterol > or =3.63 mmol/L (> or =140 mg/dl), combined with type 2 diabetes mellitus, increases risk of CAD by 6.65 (95% confidence interval 35.40 to 1.25). In the elderly, elevated Lp(a) levels appear not to be an independent predictor of CAD, but this lipoprotein is a risk factor only in subjects with type 2 diabetes mellitus and elevated LDL cholesterol.

Fibrinolytic parameters and lipoprotein(a) in young women with myocardial infarction

Impaired fibrinolysis and elevated lipoprotein(a) (Lp[a]) are possible nonclassic risk factors for myocardial infarction (MI) at young age. The fibrinolytic system in young women with MI has not been evaluated yet and the role of Lp(a) is still controversial. The authors determined fibrinolytic parameters and Lp(a) in premenopausal women (mean age 42+/-3 years, n = 22) 0.5 to 6 (mean 3.5) years after MI, who were all without severe classic risk factors and had an otherwise low risk for MI. Elevated levels of tissue type plasminogen activator (t-PA) (p< 0.05) were measured in comparison to 52 age-matched controls; no difference was found in plasminogen activator inhibitor, plasminogen, fibrinogen, euglobulin clotting time and D-dimers. Significantly more MI patients had Lp(a) levels greater than 300 mg/L compared to controls (36% vs 13.5%, p< 0.05). The combination of elevated Lp(a), mild hyperlipidemia, and nonsevere smoking was found in 62.5% of MI patients who had elevated levels of Lp(a), in 23% of all women with MI, and in none of the controls. Elevated t-PA is probably only a marker of increased risk of MI, whereas elevated Lp(a) probably has a causative role. A combination of elevated Lp(a), hyperlipidemia, and nonsevere smoking seems to be a high-risk profile, relatively common in young women with MI.

Serum lipids, lipoprotein(a) level, and apolipoprotein(a) isoforms as prognostic markers in patients with coronary heart disease

OBJECTIVE

Our objective was to study prognostic factors for death in patients with coronary heart disease (CHD), focusing on serum lipids and lipoproteins.

DESIGN AND SUBJECTS

The study subjects were 964 patients with angina pectoris who underwent coronary angiography between 1985 and 1987. Follow-up, including survival and cause of death, was carried out in April 1998.

RESULTS

A total of 363 patients died. Increasing age, diabetes and low levels of HDL cholesterol and of apolipoprotein (apo) AI were associated with increased risk of total mortality and cardiac mortality. In men, low levels of LDL cholesterol and of apoB were associated with increased risk of death, but not of cardiac death only; high levels of lipoprotein(a) [Lp(a)] were not associated with increased risk. In women, however, there was a trend towards increased risk with increasing Lp(a) levels (P = 0.054); the smallest isoform of apo(a) was associated with a twofold increase in risk. In women, but not in men, risk decreased with increasing molecular weight of the apo(a) isoforms.

CONCLUSIONS

Amongst lipoprotein variables, low levels of HDL cholesterol and of apoAI and the presence of low-molecular weight isoforms of apo(a) are associated with increased risk of death in patients with CHD. Apo(a) isoforms and Lp(a) levels seem to be more important as risk factors amongst women. Low LDL cholesterol and apoB levels were associated with increased risk, but only in men. These findings demonstrate the importance of a gender-specific analysis of risk factors for CHD.

Lipoprotein(a) changes during natural menstrual cycle and ovarian stimulation with recombinant and highly purified urinary FSH

This prospective, randomized, controlled study compared the effects of recombinant human FSH (r-hFSH) and highly purified urinary FSH (u-hFSH HP) on lipoprotein(a) [Lp(a)] concentrations in women undergoing ovarian stimulation. Fifty infertile women were randomly allocated into two equally sized treatment groups (n = 25 per group). Thirty normal ovulation women were recruited as controls. The infertile women received u-hFSH or r-hFSH 150 IU/day starting on cycle day 2. From cycle day 6 the dose was adjusted according to ovarian response. Human chorionic gonadotrophin 10,000 IU was administered once there was at least one follicle > or =18 mm in diameter. The luteal phase was supported with progesterone 50 mg/day for at least 15 days. Repeated measurements of Lp(a) concentrations were performed during both stimulated and natural cycles. A significant increase in luteal phase Lp(a) concentrations was detected in the stimulated cycles, whereas no significant changes in serum Lp(a) concentrations were observed during natural cycles. There were no significant differences between the urinary and recombinant FSH effects on serum Lp(a). The luteal Lp(a) increase was transitory because after 1 month Lp(a) concentrations returned to baseline values if pregnancy failed to occur; in pregnant women persistent increased Lp(a) concentrations were found at the 8th week. The percentage changes in serum Lp(a) were positively correlated with the luteal progesterone increase (r = 0.40, P < 0.05), but not with follicular or luteal oestradiol increase. The women with low baseline Lp(a) (< or =5 mg/dl) had a greater increase of the Lp(a) concentrations at midluteal phase than women with baseline Lp(a) >5 mg/dl. In conclusion, the recombinant or urinary hFSH administration does not directly influence Lp(a) concentrations. The luteal Lp(a) increase in stimulated cycles is not related to gonadotrophin treatment per se, but appears to be related to the high luteal progesterone concentrations, physiologically or pharmacologically determined. Our results also suggest that the sensitivity to the progesterone changes could be related to apolipoprotein(a) phenotype.

Lipoprotein(a) associated with coronary artery disease in older women: age and gender analysis

BACKGROUND

Lipoprotein (a) has been associated with increased coronary artery disease (CAD) risk in men, but relatively little data exists in women. While age influences the cardiovascular risk associated with Lp(a) in men, little is known about this phenomenon in women. The impact of gender on Lp(a) has not been fully studied in an ongoing clinical practice.

METHODS AND RESULTS

Baseline Lp(a) values were measured in 918 CAD and 829 non-CAD patients (603 females, 1144 males) entering an outpatient prevention clinic. The age-specific association of elevated Lp(a) (> 30 mg/dl) with CAD was examined after adjustment for traditional risk factors. Lp(a) was a significant risk factor (OR = 1.9, CI, 1.4-2.6) in men and women (OR = 1.9, CI 1.3-2.9). In men age < or = 55 years the odds ratio for increased cardiovascular risk in high vs low Lp(a) was 2.5 (CI 1.6-3.9). In men < or = 55, CAD increased from 32 to 61% as Lp(a) progressively rose from < or = 5 to > or = 45 mg/dl (P value for trend < 0.001). No significant increase was observed in men > 55 years (OR = 1.3, CI 0.9-2.1). In women < or = 55 years, the risk of CAD increased from 22 to 35% (OR 1.6, CI 0.8-3.2), and increased from 38 to 63% in women > 55 (OR 2.1, CI 1.3-3.5). Further, of high-risk patients (men < or = 55 and women > 55 years) with an Lp(a) in the range of 20-44 mg/dl (third quartile), younger men showed a greater incidence of CAD (51%) than older women (43%). Both genders revealed substantial risk when the Lp(a) values were above 45 mg/dl. (OR = 3.7, CI = 2.0-6.8 in younger men; OR = 3.3, CI = 1.6-6.6 in older women).

CONCLUSIONS

In this cross sectional study of both men and women, elevated Lp(a) was associated with a significantly increased risk of CAD in men and women. While we corroborate previous reports on the lack of association in older men, the determination of an enhanced Lp(a)-related risk in older women was new and unanticipated. Further, in this population of high risk patients, substantial cardiovascular risk appeared to be represented by higher concentrations of Lp(a) in women than observed in men.

Effects of menopause and obesity on lipid profiles in middle-aged Taiwanese women: the Chin-Shan Community Cardiovascular Cohort Study

In this cross-sectional study, we examined the associations between lipid profiles and menopausal status, age, and obesity in Taiwanese women. The study population, established in 1990-91, consisted of 671 premenopausal and 872 postmenopausal women from the Chin-Shan Community Cardiovascular Cohort (CCCC). The associations of age, body mass index (BMI), and menopausal status with serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), apoproteins (Apo) A-1 and B, and lipoprotein (a) [Lp (a)] were evaluated. The results showed that menopause was associated with significant increases in TC, LDL-C, TG, and Apo B levels (all P < 0.001). Total cholesterol, LDL-C, TG, and Apo B levels increased consistently with BMI in middle-aged women, regardless of menopausal status. Among women aged 45-49, menopausal women had significantly higher levels of TC and LDL-C than premenopausal women (P < 0.01). However, TG and Apo B levels were higher in postmenopausal than in premenopausal women aged 50-54 years (P < 0.05). Standardized regression analyses showed all lipid variables, except those of Apo A1 and Lp (a) before menopause and TC, LDL-C, and Lp (a) after menopause, were significantly associated with BMI (all P < 0.01). We conclude serum lipid levels in Taiwanese women are no more strongly associated with menopause and BMI than with age.

Novel risk factors for atherosclerosis

In the past several years, evidence has accumulated that factors other than conventional risk factors may contribute to the development of atherosclerosis. Conventional risk factors predict less than one half of future cardiovascular events. Furthermore, conventional risk factors may not have the same causal effect in different ethnic groups in whom novel risk factors may have a role. These newer risk factors for atherosclerosis include homocysteine, fibrinogen, impaired fibrinolysis, increased platelet reactivity, hypercoagulability, lipoprotein(a), small dense low-density lipoprotein cholesterol, and inflammatory-infectious markers. Identification of other markers associated with an increased risk of atherosclerotic vascular disease may allow better insight into the pathobiology of atherosclerosis and facilitate the development of preventive and therapeutic measures. In this review, we discuss the evidence associating these factors in the pathogenesis of atherosclerosis, the mechanism of risk, and the clinical implications of this knowledge.

Lack of association of lipoprotein(a) levels with coronary calcium deposits in asymptomatic postmenopausal women

OBJECTIVES

This study sought to determine the relationship of lipoprotein(a) (Lp(a)) and other cardiac risk factors to coronary atherosclerosis as measured by calcification of coronary arteries in asymptomatic postmenopausal women.

BACKGROUND

Lipoprotein(a) is considered a risk factor for coronary heart disease. Coronary calcium deposition is believed to be a useful noninvasive marker of coronary atherosclerosis in women. However, to our knowledge, there are no reports of the relationship of Lp(a) to coronary calcium in postmenopausal women.

METHODS

In 178 asymptomatic postmenopausal women (64 +/- 8 years), we measured Lp(a) and other cardiac risk factors: age, hypertension, diabetes, low-density lipoprotein cholesterol, smoking status, body mass index, physical activity level and duration of hormone replacement therapy. Electron-beam computed tomography was done to measure coronary calcium (calcium score). We analyzed the relationship between calcium score and cardiac risk factors using multivariate analysis.

RESULTS

Although calcium score correlated with traditional risk factors of age, diabetes, hypertension and smoking, it did not correlate with Lp(a) in the asymptomatic postmenopausal women. Similar multivariate analyses were done in the subjects age >60 years and in the subjects with significant coronary calcium deposit (calcium score > or =50). These analyses also have failed to show an association of levels of Lp(a) with coronary calcium deposits.

CONCLUSIONS

We conclude that in asymptomatic postmenopausal women, Lp(a) levels do not correlate with coronary atherosclerosis as measured by coronary calcium deposits.

A randomised comparison of the effects of oral versus transdermal 17beta-oestradiol, each combined with sequential oral norethisterone acetate, on serum lipoprotein levels

OBJECTIVE

To investigate the effects of oral versus transdermal 17beta-oestradiol, given in both cases with sequential addition of oral norethisterone acetate, on serum lipid and lipoprotein levels in postmenopausal women.

DESIGN

Open, randomised, parallel groups study.

SETTING

University Clinical Research Group.

POPULATION

Sixty-four postmenopausal women with climacteric complaints who were otherwise healthy were screened. Of these, 58 fulfilled the entry criteria.

METHODS

Fifty-eight postmenopausal women were randomised to receive either oral 17beta-oestradiol/oestriol (Trisequens) or transdermal 17beta-oestradiol (Estrapak) together with cyclical addition of norethisterone acetate for 48 weeks.

MAIN OUTCOME MEASURES

Serum levels of total cholesterol, triglycerides, high density lipoproteins (HDL), low density lipoproteins (LDL), very low density lipoproteins (VLDL), apolipoproteins, and lipoprotein(a) at baseline, and after 46 weeks (oestrogen-alone phase), and 48 weeks (oestrogen-progestogen phase) of treatment.

RESULTS

Oral oestradiol therapy did not affect serum total cholesterol levels during the oestrogen-alone phase, but during the combined phase there was a 5% fall (P < 0.05) due to a 7% decrease in LDL cholesterol levels (P < 0.01). Oral therapy also increased serum triglyceride levels by 9.4% during the oestrogen-alone phase (P < 0.05). During the combined phase of transdermal therapy, there was a 19% fall in serum triglyceride levels (P < 0.05) and a 6% fall in HDL levels (P < 0.05). Oral oestradiol reduced lipoprotein(a) levels by 31% during the oestrogen-alone phase and by 37% with norethisterone acetate addition (P < 0.05). Transdermal therapy had no significant effect on lipoprotein(a).

CONCLUSIONS

Other than a minor fall in HDL3 in women receiving transdermal 17beta-oestradiol, coadministration of oral progestogen in general improved, rather than worsened, this serum lipoprotein profile.

Lipoprotein(a) interactions with lipid and non-lipid risk factors in patients with early onset coronary artery disease: results from the NHLBI Family Heart Study

BACKGROUND

A positive interaction between high plasma lipoprotein(a) [Lp(a)] and unfavorable plasma lipid levels has been reported to result in very high risk for premature coronary artery disease (CAD). We further examined this issue for men and women with early onset CAD. We also examined potential interactions between Lp(a) and non-lipid risk factors.

METHODS AND RESULTS

In 338 men and women with early onset CAD (most with a positive family history of early CAD) and 480 general population controls, we measured Lp(a), lipids and other risk factors. In univariate analysis, relative odds for CAD was 1.7 (P = 0.002) for plasma Lp(a) >50 mg/dl. Elevated Lp(a) level was found to interact with adjusted plasma total/high density lipoprotein (HDL) cholesterol such that when Lp(a) was over 50 mg/dl and adjusted plasma total/HDL cholesterol >5.8, relative odds for CAD were 8.0-9.6 (P<0.0001) in multiple logistic regression. Non-lipid risk factors were generally found to multiply the risk associated with Lp(a) (as predicted by logistic regression) without evidence for interaction.

CONCLUSIONS

We find evidence that Lp(a) does interact positively with adjusted plasma total/HDL cholesterol ratio. Aggressive risk factor intervention, especially for lipids, in those with elevated Lp(a) therefore appears indicated.

Did grandma give you heart disease? The new battle against coronary artery disease

Atherosclerosis/coronary artery disease (CAD) is largely a result of genetically linked dyslipidemias that can often be identified in clinical practice. Expression of these genetic traits is highly individual and can be affected by environmental factors such as diet and exercise. By understanding the heterogeneity of CAD, it becomes clear that all patients cannot be optimally managed with the same therapeutic regimen. Whereas elevated low-density lipoprotein (LDL) cholesterol is strongly correlated with CAD risk, reduction of LDL cholesterol alone is not an adequate strategy in many cases. Patients with the small, dense LDL of the atherogenic lipoprotein profile (pattern B) experience a 3-fold increased risk of CAD, and pattern B is also correlated with the development of type 2 diabetes. Likewise, elevated lipoprotein(a) increases atherosclerotic risk, particularly in the presence of other risk factors, and is predictive of CAD risk in both women and men. Recent data show that the routine lipid profile--total cholesterol, triglycerides, LDL cholesterol, and high-density lipoprotein (HDL) cholesterol--does not detect the most common inherited dyslipidemias. Newer, more sophisticated tests, such as gradient gel electrophoresis, can detect disease-relevant lipidemic details, e.g., LDL subclass pattern, LDL particle diameter, and LDL subregions. Although these testing procedures are more expensive, their cost must be weighed against the potential lifelong cost of sometimes expensive drug treatment that may be avoided based on the results of such tests. Thus, by attending to the implications of family history, the interactions of genetic, metabolic, and environmental factors, and utilizing more targeted testing procedures, physicians can match the patient's disorder with specifically effective therapy while maintaining a cost-effective approach to disease management.

Effect of risk factors on the mechanism of acute thrombosis and sudden coronary death in women

BACKGROUND

Traditional risk factors have been linked to atherosclerotic heart disease in women. However, the effect of risk factors and menopausal status on the mechanism of sudden coronary death is unknown.

METHODS AND RESULTS

We examined 51 cases of sudden coronary death and 15 hearts from women who died of trauma. Coronary deaths were divided into four mechanisms of death: ruptured plaque with acute thrombus (n = 8), eroded plaque with acute thrombus (n = 18), stable plaque with healed infarct (n = 18), and stable plaque without infarction (n = 7). Vulnerable plaques prone to rupture were defined as those with a thin, fibrous cap infiltrated by macrophages and were quantitated in coronary deaths and control subjects. Total cholesterol (TC), HDL cholesterol, glycosylated hemoglobin, cigarette smoking, and hypertension were determined in each case. Compared with control subjects, women with plaque ruptures had elevated TC (270 +/- 55 versus 194 +/- 44 mg/dL, P = 0.002), and those with erosions were more likely to be smokers (78% versus 33%, P = 0.01). Women with stable plaque and healed infarct had elevated glycosylated hemoglobin (10.2 +/- 5.0% versus 6.4 +/- 0.4% in control subjects, P = 0.001) and were more likely to be hypertensive (50% versus 15% in control subjects, P = 0.03). By multivariate analysis, cigarette smoking was associated with plaque erosion (P = 0.03, odds ratio [OR] 21), glycoslyated hemoglobin with stable plaque and healed infarct (P = 0.03, OR 41), TC with plaque rupture (P = 0.02, OR 7), and hypertension with stable plaque with healed infarct (P = 0.02, OR 15). Seven of 8 plaque ruptures occurred in women > 50 years of age versus 3 of 18 erosions (P = 0.001). In cases of coronary death, vulnerable plaques were associated with elevated cholesterol (P = 0.002) and age > 50 years (P = 0.002), independent of other risk factors.

CONCLUSIONS

In women, traditional risk factors have distinct effects on the mechanisms of sudden coronary death, which vary by menopausal status. Effective risk factor modification may therefore differ between younger and older women and may be targeting different mechanisms of plaque instability.

Elevated plasma lipoprotein(a) is associated with coronary artery disease in patients with chronic stable angina pectoris

OBJECTIVES

We sought to assess the relation between plasma lipoprotein(a) [Lp(a)] levels, clinical variables and angiographic coronary artery disease (CAD) in patients with chronic stable angina.

BACKGROUND

The relation between plasma Lp(a) levels and the severity and extent of angiographic CAD has not been studied in well characterized patients with stable angina pectoris.

METHODS

We investigated clinical variables, lipid variables and angiographic scores in 129 consecutive white patients (43 women) undergoing coronary angiography for chronic stable angina.

RESULTS

Plasma Lp(a) levels were significantly higher in patients with than in those without significant angiographic stenoses (> or =70%) (372 mg/liter [interquartile range 87 to 884] vs. 105 mg/liter [interquartile range 56 to 366], respectively, p=0.002). This difference remained significant when patients with mild or severe angiographic disease were compared with those with completely normal coronary arteries (312 mg/liter [interquartile range 64 to 864] vs. 116 mg/liter [interquartile range 63 to 366], respectively, p=0.02). However, subset analysis indicated that this difference achieved statistical significance only in women. Multiple logistic regression analysis indicated that Lp(a) concentration was independently predictive of significant angiographic stenoses (adjusted odds ratio [OR] 9.1, 95% confidence interval [CI] 2.0 to 42.1, p=0.006) and remained true even after exclusion of patients receiving lipid-lowering treatment (n=27) (OR 10.4, 95% CI 1.1 to 102.9, p=0.05). Lp(a) also had independent predictive value in a similar analysis using mild or severe angiographic disease as the outcome variable (OR 11.8, 95% CI 1.5 to 90.8, p=0.02).

CONCLUSIONS

Our results indicate that elevated plasma Lp(a) is an independent risk factor for angiographic CAD in chronic stable angina and may have particular significance in women.

Short-term effects of transdermal estrogen replacement therapy on coronary vascular reactivity in postmenopausal women with angina pectoris and normal results on coronary angiograms

OBJECTIVES

This study sought to analyze the effect of short-term transdermal estradiol treatment on in vivo coronary endothelial function in postmenopausal women with angina and normal results on coronary arteriograms.

BACKGROUND

The incidence of coronary heart disease increases in women after menopause. Estrogen replacement therapy has been associated with a global reduction in cardiovascular disease incidence and mortality. In addition, coronary endothelial dysfunction has been demonstrated in a group of postmenopausal women. It has been shown that intravenous or intracoronary estrogens improve endothelial function in postmenopausal women with coronary atherosclerosis. However, the efficacy of this treatment is unknown in patients with angina and normal coronary arteries.

METHODS

Endothelium-dependent coronary reactivity was analyzed in 15 postmenopausal women with angina and normal coronary arteries at baseline and after 24 h of estradiol transdermal administration (100 microg).

RESULTS

Estradiol concentration increased from 22 +/- 8 pg/ml (mean +/- SEM) at baseline to 76 +/- 13 pg/ml (p < 0.01) at 24 h. At baseline, acetylcholine induced vasoconstriction, with a mean diameter reduction of -23 +/- 6% (p = 0.002). After estrogen treatment, there was no vasoconstriction with acetylcholine, with a mean diameter change of 0 +/- 4%, significantly different from the pretreatment diameter reduction observed (p = 0.003). Similarly, estimated coronary blood flow significantly increased in response to acetylcholine after estrogen treatment, with a mean change of 50 +/- 30% compared with 5 +/- 24% before estradiol administration (p = 0.04).

CONCLUSIONS

Early after transdermal estrogen administration, endothelium-dependent coronary vasomotion is improved in postmenopausal women with angina and normal coronary arteries.

Lipoprotein(a) interactions with lipid and nonlipid risk factors in early familial coronary artery disease

An interaction between high plasma lipoprotein(a) [Lp(a)], unfavorable plasma lipids, and other risk factors may lead to very high risk for premature CAD. Plasma Lp(a), lipids, and other coronary risk factors were examined in 170 cases with early familial CAD and 165 control subjects to test this hypothesis. In univariate analysis, relative odds for CAD were 2.95 (P < .001) for plasma Lp(a) above 40 mg/dL. Nearly all the risk associated with elevated Lp(a) was found to be restricted to persons with historically elevated plasma total cholesterol (6.72 mmol/L [260 mg/dL] or higher) or with a total/HDL cholesterol ratio > 5.8. Nonlipid risk factors were also found to at least multiply the risk associated with Lp(a). When Lp(a) was over 40 mg/dL and plasma total/HDL cholesterol > 5.8, relative odds for CAD were 25 (P = .0001) in multiple logistic regression. If two or more nonlipid risk factors were also present (including hypertension, diabetes, cigarette smoking, high total homocysteine, or low serum bilirubin), relative odds were 122 (P < 1 x 10(-12)). The ability of nonlipid risk factors to increase risk associated with Lp(a) was dependent on at least a mildly elevated total/HDL cholesterol ratio. In conclusion, high Lp(a) was found to greatly increase risk only if the total/HDL cholesterol ratio was at least mildly elevated, an effect exaggerated by other risk factors. Aggressive lipid lowering in those with elevated Lp(a) therefore appears indicated.

Is there a menopausal metabolic syndrome?

Estradiol-17 beta has beneficial effects on a range of metabolic risk factors for coronary heart disease and the decline in estrogen concentrations at the menopause would be expected to have adverse effects. Review of the literature on effects of the menopause and of estradiol-17 beta provides evidence for the following changes occurring at or after the menopause: increased total cholesterol and triglycerides; decreased high density lipoprotein (HDL) and HDL subfraction 2; increased low density lipoprotein, particularly in the small, dense subfraction; increased lipoprotein (a); increased insulin resistance; decreased insulin secretion; decreased insulin elimination; increased android fat distribution; impaired vascular function; increased factor VII and fibrinogen, and reduced sex-hormone binding globulin. Many of these changes will themselves have adverse effects on other metabolic risk factors. This complex of inter-correlated adverse changes in metabolic risk factors justifies identification of a distinct menopausal metabolic syndrome which originates in estrogen deficiency and which could contribute to the increased risk of coronary heart disease seen in postmenopausal women. Estrogen replacement can diminish the expression of this syndrome.

Lipoprotein(a) as a determinant of coronary heart disease in young women

BACKGROUND

Lipoprotein(a) [Lp(a)] appears to be a risk factor for coronary heart disease (CHD) in men. The role of Lp(a) in women, however, is less clear.

METHODS AND RESULTS

We examined the ability of Lp(a) to predict CHD in a population-based case-control study of women 65 years of age or younger who lived in the greater Stockholm area. Subjects were all patients hospitalized for an acute CHD event between February 1991 and February 1994. Control subjects were randomly selected from the city census and were matched to patients by age and catchment area. Lp(a) was measured 3 months after hospitalization by use of an immunoturbidometric method (Incstar) calibrated to the Northwest Lipid Research Laboratories (coefficient of variation was < 9%). Of the 292 consecutive patients, 110 (37%) were hospitalized for an acute myocardial infarction, and 182 were hospitalized (63%) for angina pectoris. The mean age for both patients and control subjects was 56 +/- 7 years. Of participants, 74 patients (25%) and 84 control subjects (29%) were premenopausal. The distributions of Lp(a) were highly skewed in both patients and control subjects, with a range from 0.001 to 1.14 g/L. Age-adjusted odds ratio for CHD in the highest versus the lowest quartile of Lp(a) was 2.3 (95% confidence interval [CI], 1.4 to 3.7). After adjustment for age, smoking, education, body mass index, systolic blood pressure, total cholesterol, triglycerides, and HDL, the odds ratio was 2.9 (95% CI, 1.6 to 5.0). The odds ratios were similar when myocardial infarction and angina patients were compared with their respective control subjects. The odds ratios were 5.1 (95% CI, 1.4 to 18.4) and 2.4 (95% CI, 1.3 to 4.5) in premenopausal and postmenopausal women, respectively.

CONCLUSIONS

These results suggest that Lp(a) is a determinant of CHD in both premenopausal and postmenopausal women.

Correlation of lipoprotein (a) to angiographically defined coronary artery disease in Indians

Lipoprotein (a) [Lp(a)] levels have been correlated with angiographically defined coronary artery disease (CAD). Pattern of Lp(a) distribution in various racial groups is different. To study this relationship in Indian patients, plasma levels of Lp(a) and other lipid values were assessed in 101 patients undergoing coronary arteriography. Lp(a) concentration was higher in CAD group (n = 77) compared to normal coronary artery group (n = 24) (26.83 +/- 22.09 mg/dl vs. 15.07 +/- 14.61 mg/dl, P < 0.05). Lp(a) values had graded association with CAD. In Lp(a) quartile of < 5 mg/dl, 66.7% patients had CAD; in Lp(a) quartile of 5-25 mg/dl, 69.0% had CAD; Lp(a) quartile of 26-75 mg/dl, 87.5% had CAD; and in Lp(a) quartile of > or = 76 mg/dl, all patients had CAD. High density lipoprotein (HDL) cholesterol was higher in the normal coronary artery group as compared to CAD group (45.25 +/- 8.26 mg/dl vs. 41.83 +/- 16.47 mg/dl; NS). In HDL quartile of < 35 mg/l, 88.9% patients had angiographically defined CAD. Plasma values of total cholesterol, triglycerides (TG), apolipoprotein-A1 (Apo-A1), apolipoprotein-B (Apo-B), low density lipoprotein (LDL) cholesterol, LDL/HDL cholesterol ratio and Apo A1/B ratio were not significantly different in the groups with normal coronary arteries and CAD. Our results indicate that the measurement of Lp(a) provides a better marker for predicting the presence of angiographically defined CAD as compared to traditional measures.

Effects of apo B and apo E gene polymorphisms on lipid and apolipoprotein concentrations after a test meal

The role of apo B signal peptide and apo E polymorphisms, and individual factors (age, sex, etc.) have been investigated on the interindividual variability of the postprandial response of 274 subjects ingesting a 1.260-KJ milkshake. The mean postprandial response, observed during 4 h, is significantly positive for total cholesterol (P < 0.005), LDL-cholesterol (P < 0.0001), triglycerides (P < 0.001), apo E (P < 0.0001) and glucose (P < 0.0001), whereas HDL-cholesterol, apo A-I and apo B do not present mean postprandial variation. Independently of the mean response, some parameters present a large interindividual variability of response, which is significantly influenced by cofactors, such as weight or BMI, for total and LDL-cholesterol, apo B and apo E or tobacco use for HDL-cholesterol. Sex has no effect on any lipid levels. Total, LDL-cholesterol and apo E responses are correlated with their corresponding fasting values. ApoB signal peptide polymorphism is not involved in the postprandial responses, whereas apo E polymorphism explains a significant part of the variability of HDL-cholesterol and apo A-I responses.

Lack of increased coronary atherosclerotic risk due to elevated lipoprotein(a) in women > or = 55 years of age

BACKGROUND

Numerous studies have indicated that there is an association between lipoprotein(a) [Lp(a)] and coronary artery disease (CAD) in middle-aged men; however, few studies have addressed this issue in women or the elderly.

METHODS AND RESULTS

Serum Lp(a) concentrations were determined in 354 women and 706 men with or without angiographically defined CAD (one or more coronary arteries with narrowing of > or = 75%). The age-specific impact of elevated Lp(a) (> or = 30 mg/dL) on CAD was examined in each sex. In the younger age group (< 55 years old), elevated Lp(a) was independently associated with CAD in both sexes (adjusted odds ratio [OR]: women, 6.90, P < .01; men, 2.63, P < .05). The age-specific ORs declined with age, and elevated Lp(a) no longer conferred an increased CAD risk in either elderly men or women > or = 65 years old. In the age group of 55 to 64 years, elevated Lp(a) was positively associated with CAD for men (adjusted OR: 2.45, P < .05) but not for women (adjusted OR: 0.56, P = NS).

CONCLUSIONS

For both sexes, elevated Lp(a) appears to be an independent risk factor for premature CAD and the importance of Lp(a) appears to decrease with age. However, for women, the risk estimate of Lp(a) began to decline at an age approximately 10 years younger than for men. These data suggest that not only age- but also sex-specific factors such as menstrual status may interact with the association between Lp(a) and CAD.

How often has Lp(a) evolved?

The lipoprotein Lp(a) is associated with increased risk of atherosclerosis and myocardial infarction in humans. Lp(a) is mostly confined to primate species, due to the limited phylogenetic distribution of its distinguishing protein component, apolipoprotein(a) which is a close homolog of plasminogen. The known properties of Lp(a) are reviewed here. Many of these derive from the ability of Lp(a) to bind to the same substrates as plasminogen. A possible new animal model of Lp(a) is the hedgehog, which contains an Lp(a)-like particle that is the apparent product of independent evolution of a multi-kringle, apolipoprotein(a)-like protein by duplication and modification of portions of the hedgehog plasminogen gene.

Correlation of toddlers' serum lipoprotein(a) concentration with parental values and grandparents' coronary heart disease: the STRIP baby study

The correlation between lipoprotein(a) (Lp(a)) concentrations in children aged 7-24 months and their family members was determined and the association between the Lp(a) values of the children and a family history of coronary heart disease (CHD) was assessed. The Lp(a) values of the children correlated strongly with midparent Lp(a) values as early as at 7 months of age (r = 0.54 to 0.59, p < 0.0001). This correlation was stronger than the correlation of serum total cholesterol and total cholesterol corrected for Lp(a)-cholesterol between children and parents. None of the parents had CHD. The median Lp(a) concentration of the parents with a family history of CHD was significantly higher than that of parents with no such history (111 vs 87 mg/1, p = 0.024). However, the children's Lp(a) levels were not associated with CHD in their grandparents. The genetic dependence of the Lp(a) concentration is already evident in infancy. The Lp(a) concentration in young parents, but not in their 24-month-old children, is associated with CHD in grandparents. This may be explained by a dilution of the genetic influence on Lp(a) over two generations.

Determination of 17 alpha-dihydroequilenin in rat, rabbit and monkey plasma by high-performance liquid chromatography with fluorimetric detection

A high-performance liquid chromatographic (HPLC) method with fluorescence detection for the determination of total (unconjugated and conjugated) 17 alpha-dihydroequilenin in male and female rat, female rabbit and male and female rhesus monkey plasma is described here. Plasma sample preparation involved hydrolysis with enzyme (Glusulase), addition of internal standard (14 beta-equilenin) and solvent extraction. The extracts were chromatographed on a C6, 5-microns reversed-phase HPLC column and detection was accomplished with a fluorescence detector operated at an excitation wavelength of 210 nm and an emission wavelength of 370 nm. The assay was linear over a range of 2.5 to 100 ng/ml in male and female rat plasma, and 5 to 500 ng/ml in female rabbit and male and female monkey plasma. The method was specific, accurate and reproducible (percent differences < 14.5; coefficients of variation < 9.5%) in all matrices examined. The applicability of this method was successfully tested by quantifying total plasma concentrations of 17 alpha-dihydroequilenin in ovariectomized female rats, ovariectomized female rabbits and a normal female rhesus monkey receiving 2.0, 8.3 and 0.1 mg/kg, respectively, of 17 alpha-dihydroequilenin sulfate intragastrically.

Long-term (5-year) changes in HDL cholesterol in cardiac rehabilitation patients. Do sex differences exist?

BACKGROUND

It is unknown whether the benefits of a cardiac rehabilitation program on HDL cholesterol (HDL-C) are equally achieved in men and women. To study this, we compared changes in HDL-C and other lipids in a large group of men and women participating in a cardiac rehabilitation program for up to 5 years.

METHODS AND RESULTS

We compared changes in HDL-C and other fasting lipids in 553 men and 166 women participating in a cardiac rehabilitation program at baseline and then annually for up to 5 years. Patients exercised 3 days a week at 70% to 85% of their maximum heart rate predetermined by a symptom-limited treadmill test. Aerobic capacity was estimated in metabolic equivalents (METs), and percent body fat was determined by skin-fold measurements. Baseline HDL-C, LDL cholesterol (LDL-C), and total cholesterol were significantly higher in women, whereas the ratio of total cholesterol to HDL-C was lower. Although both men and women showed an increase in HDL-C after 1 year (10% and 7%, respectively), only the women's level continued to increase over 5 years (20% versus 5% for men, P = .03). The sex difference in change in HDL-C remained after adjustment for age and smoking. A nonsignificant trend toward a greater change in HDL-C in women existed after adjustment for baseline percent body fat and estimated METs. The change in the ratio of total cholesterol to HDL-C was also more favorable in women, with a 38% decrease over 5 years compared with a 14% decrease in men (P = .01). Total cholesterol decreased by 20% in women and 8% in men (P = .001), whereas LDL-C dropped by 34% in women and 15% in men (P = .0001). There was no sex difference in change in triglycerides.

CONCLUSIONS

Women with heart disease who participate in a cardiac rehabilitation program may achieve greater lipid benefits over longer periods of time than previously demonstrated in men.

Malignant coronary artery disease in young Asian Indians: thoughts on pathogenesis, prevention, and therapy. Coronary Artery Disease in Asian Indians (CADI) Study

Asian Indians have the highest rates of coronary artery disease (CAD) of any ethnic group studied, despite the fact that nearly half of this group are life-long vegetarians. CAD occurs early in age and generally follows a malignant course. Although the incidence of classic risk factors is low, high triglyceride and low high-density lipoprotein cholesterol levels, high lipoprotein(a) levels, hyperinsulinemia, and apple-type obesity all show a substantial prevalence in this population. Aggressive modification of life style beginning before adolescence seems justified in view of the malignant nature of CAD in this population. Pharmacologic intervention similar to that of secondary prevention of CAD seems justified as primary prevention in high-risk Asian Indians.