Lipoprotein (a) level in the population in Taiwan: relationship to sociodemographic and atherosclerotic risk factors

Association of sex-specific differences in lipoprotein(a) concentrations with cardiovascular mortality in individuals with type 2 diabetes mellitus

Background

Compared to individuals without type 2 diabetes mellitus, the relative increase in cardiovascular mortality is much higher in women than in men in individuals with type 2 diabetes mellitus.

Methods

We evaluated data from 7443 individuals (3792 women, 50.9%), aged 20 to 81 years, from two independent population-based investigations, SHIP-0 and MONICA/KORA S3. We analyzed the longitudinal sex-specific associations of lipoprotein(a) with cardiovascular mortality in individuals with and without type 2 diabetes mellitus using Cox regression.

Results

During a median follow-up of 20.5 years (136,802 person-years), 657 participants (404 men and 253 women) died of cardiovascular causes. Among individuals without type 2 diabetes mellitus, men had a significantly higher risk for cardiovascular mortality compared to women in unadjusted model and after adjustment. On the other hand, in participants with type 2 diabetes mellitus, the risk for cardiovascular mortality was not different between men and women in the unadjusted model and after adjustment for age, body mass index, low-density lipoprotein-cholesterol, fasting status and study sample (SHIP-0, MONICA/KORA S3). Further adjustment for lipoprotein(a) concentrations had no impact on the hazard ratio (HR) for cardiovascular mortality comparing men versus women in individuals without type 2 diabetes mellitus [HR: 1.94; 95% confidence interval (CI) 1.63 to 2.32; p < 0.001]. In individuals with type 2 diabetes mellitus, however, further adjustment for lipoprotein(a) led to an increased risk for cardiovascular mortality in men and a decreased risk in women resulting in a statistically significant difference between men and women (HR: 1.53; 95% CI 1.04 to 2.24; p = 0.029).

Conclusions

Women are described to have a stronger relative increase in cardiovascular mortality than men when comparing individuals with and without type 2 diabetes mellitus. Higher lipoprotein(a) concentrations in women with type 2 diabetes mellitus than in men with type 2 diabetes mellitus might partially explain this finding.

Lipoprotein(a) and Hyperinsulinemia in Healthy Normal-weight, Prepubertal Mexican Children

Background. Given the numerous gaps in our knowledge about the biological interactions of lipoprotein(a) [Lp(a)], we determined whether Lp(a) was associated with hyperinsulinemia in healthy normal-weight, prepubertal children.Methods. A total of 131 healthy normal-weight Mexican children aged 6 to 9 years at Tanner stage 1 who were born appropriate for gestational age were enrolled in a case-control study. Children with hyperinsulinemia were allocated into the case group (n = 32), and children with normal insulin levels were allocated into the control group (n = 99). Birth weight, age, and body mass index were matching criteria. Multivariate logistic regression analysis was used to compute the odds ratio (OR) between Lp(a) and both hyperinsulinemia and insulin resistance. Furthermore, a multivariate linear regression analysis was performed to evaluate the association between Lp(a) and both insulin levels and HOMA-IR. Both models were adjusted by sex, age, birth weight, and body mass index.Results. The median (25-75 percentile) serum levels of Lp(a) [20.0 (13.7-29.6) versus 14.6 (10.6-26.7) mg/dL, p = .003] and insulin [24.5 (6.0-30) versus 7.9 (4.3-9.0) µU/L, p < .0005] were higher in the case group than in the control group. The logistic regression analysis showed that Lp(a) was associated with hyperinsulinemia (OR 5.86; 95%CI 2.5-13.6, p < .0005) and insulin resistance (OR 2.01; 95%CI 1.1-9.9, p = .004). In addition, the linear regression analysis showed a significant association between serum Lp(a) and insulin levels (β 11.1; 95%CI 1.8-10.9, p < .0001) and the HOMA-IR index (β 2.606; 95%CI 2.3-2.9, p < .0005).Conclusion. Lp(a) was associated with hyperinsulinemia and insulin resistance in healthy normal-weight, prepubertal children.

Effects of weight change on apolipoprotein B-containing emerging atherosclerotic cardiovascular disease (ASCVD) risk factors

Background and aims

Non-high-density (HDL)-cholesterol, low-density lipoprotein (LDL)-particle number, apolipoprotein B, lipoprotein(a) (Lp(a)), and small-dense (sdLDL) and large-buoyant (lbLDL) LDL-subfractions are emerging apo B-containing atherosclerotic cardiovascular disease (ASCVD) risk factors. Current guidelines emphasize lifestyle, including weight loss, for ASCVD risk management. Whether weight change affects these emerging risk factors beyond that predicted by traditional triglyceride and LDL-cholesterol measurements remains to be determined.

Method

Regression analyses of fasting ∆apo B-containing lipoproteins vs. ∆BMI were examined in a large anonymized clinical laboratory database of 33,165 subjects who did not report use of lipid-lowering medications. Regression slopes (±SE) were estimated as: *∆mmol/L per ∆kg/m², ^†∆g/L per ∆kg/m², ^‡∆% per ∆kg/m², and ^§∆μmol/L per ∆kg/m².

Results

When adjusted for age, ∆BMI was significantly related to ∆nonHDL-cholesterol (males: 0.0238 ± 0.0041, P = 7.9 × 10^− 9; females: 0.0330 ± 0.0037, P < 10^− 16)*, ∆LDL-particles (males: 0.0128 ± 0.0024, P = 2.1 × 10^− 7; females: 0.0114 ± 0.0022, P = 3.2 × 10^− 7)^*, ∆apo B (males: 0.0053 ± 0.0010, P = 7.9 × 10^− 8; females: 0.0073 ± 0.0009, P = 2.2 × 10^− 16)^†, ∆sdLDL (males: 0.0125 ± 0.0015, P = 2.2 × 10^− 16; females: 0.0128 ± 0.0012, P < 10^− 16)*, ∆percent LDL carried on small dense particles (%sdLDL, males: 0.296 ± 0.035, P < 10^− 16; females: 0.221 ± 0.023, P < 10^− 16)^‡, ∆triglycerides (males: 0.0358 ± 0.0049, P = 2.0 × 10^− 13; females: 0.0304 ± 0.0029, P < 10^− 16)*, and ∆LDL-cholesterol (males: 0.0128 ± 0.0034, P = 0.0002; females: 0.0232 ± 0.0031, P = 1.2 × 10^− 13)* in both males and females. Age-adjusted ∆BMI was significantly related to ∆lbLDL in females (0.0098 ± 0.0024, P = 3.9 × 10^− 5)* but not males (0.0007 ± 0.0026, P = 0.78)*. Female showed significantly greater increases in ∆LDL-cholesterol (P = 0.02) and ∆lbLDL (P = 0.008) per ∆BMI than males. ∆BMI had a greater effect on ∆LDL-cholesterol measured directly than indirect estimate of ∆LDL-cholesterol from the Friedewald equation. When sexes were combined and adjusted for age, sex, ∆triglycerides and ∆LDL-cholesterol, ∆BMI retained residual associations with ∆nonHDL-cholesterol (0.0019 ± 0.0009, P = 0.03)*, ∆LDL-particles (0.0032 ± 0.0010, P = 0.001)*, ∆apo B (0.0010 ± 0.0003, P = 0.0008)^†, ∆Lp(a) (− 0.0091 ± 0.0021, P = 1.2 × 10^− 5)^§, ∆sdLDL (0.0001 ± 0.0000, P = 1.6 × 10^− 11)^* and ∆%sdLDL (0.151 ± 0.018, P < 10^− 16) ^‡.

Conclusions

Emerging apo B-containing risk factors show associations with weight change beyond those explained by the more traditional triglyceride and LDL-cholesterol measurements.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-1094-4) contains supplementary material, which is available to authorized users.

Mini-Review of the Chin-Shan Community Cardiovascular Cohort Study in Population Health Research in Taiwan

Preventing and controlling non-communicable diseases (NCDs) is a growing global public health concern, and evidence-based data from population-based health studies are needed in order to develop appropriate public health policies for controlling NCDs. The Chin-Shan Community Cardiovascular Cohort (CCCC) study is a prospective cohort consisting of participants from one community in China in 1990-1991, and has provided substantial evidence-based data on domestic and global health issues in preventive cardiology fields. The present study is a mini-review of the CCCC study. In this review, we have described the historical background of the cardiovascular disease burden and related risk factors, especially lifestyle factors, subclinical disease markers, biomarkers and prediction models, and related international collaborative projects. In addition, this mini-review study provides a measure of insight into future plans for 21st century epidemiological research in cardiovascular diseases, suggesting possible areas of focus for future research.

Elevated lipoprotein(a) levels predict cardiovascular disease in type 2 diabetes mellitus: a 10-year prospective cohort study

BACKGROUND/AIMS

Elevated lipoprotein(a) (Lp[a]) level is known to be a risk factor for cardiovascular disease (CVD). However, the data that has been reported on the association between the Lp(a) level and CVD in type 2 diabetes has been limited and incoherent. The aim of this study was to investigate the relationship between the Lp(a) concentration and new onset CVD in type 2 diabetes.

METHODS

From March 2003 to December 2004, patients with type 2 diabetes without a prior history of CVD were consecutively enrolled. CVD was defined as the occurrence of coronary artery disease or ischemic stroke. Cox proportional hazards models were used to identify the associations between the Lp(a) and CVD after adjusting for confounding variables.

RESULTS

Of the 1,183 patients who were enrolled, 833 participants were evaluated with a median follow-up time of 11.1 years. A total of 202 participants were diagnosed with CVD (24.2%). The median Lp(a) level for 1st and 4th quartile group was 5.4 (3.5 to 7.1) and 55.7 mg/dL (43.1 to 75.3). Compared with patients without CVD, those with CVD were older, had a longer duration of diabetes and hypertension, and used more insulin and angiotensin converting enzyme inhibitors/angiotensin receptor blockers at baseline. A Cox hazard regression analysis revealed that the development of CVD was significantly associated with serum Lp(a) level (hazard ratio, 1.92; 95% confidence interval [CI], 1.26 to 2.92; p < 0.001, comparing the 4th vs. 1st quartile of Lp[a]).

CONCLUSIONS

Elevated Lp(a) level was an independent predictable risk factor for CVD in type 2 diabetes. Other cardiovascular risk factors should be treated more intensively in type 2 diabetic patients with high Lp(a) levels.

Low birthweight and elevated levels of lipoprotein(a) in prepubertal children

AIM

To evaluate whether healthy prepubertal children with low birthweight (LBW) exhibited higher serum levels of lipoprotein(a) (Lp(a)) than did those with normal birthweight (NBW).

METHODS

A total of 350 healthy children aged 6 to 9 years and in Tanner stage 1 were enrolled in a community-based cross-sectional study. Family history of hypertension, diabetes or cardiovascular disease (CVD) in parents and grandparents; active smoking; a diagnosis of acute or chronic illness; and intake of vitamins or nutritional supplements were exclusion criteria. The cut-off point for Lp(a) was 0.79 μmol/L.

RESULTS

LBW was identified in 51 (14.6%) children. In total, 42 (12.0%) children had elevated Lp(a) levels, with 25 (49.0%) and 17 (5.7%) in the LBW and NBW groups, respectively (P < 0.0005). None of the children had adverse cardiovascular outcomes. Average body mass index (BMI) (17.1 ± 3.3 and 18.8 ± 3.9, P = 0.001), glucose levels (4.5 ± 0.5 and 4.8 ± 0.4 mmol/L, P = 0.007), insulin levels (67.4 ± 45.1 and 86.1 ± 54.9 pmol/L, P = 0.02), and Lp(a) levels (0.52 ± 0.21 and 1.40 ± 0.49 μmol/L, P < 0.0005) were higher in the children with LBW than in the children with NBW. A multivariate analysis adjusted by age, sex, raw BMI, BMI standard deviation score and insulin level showed a significant association between LBW and elevated levels of Lp(a) (odds ratio 8.02, 95% confidence interval 7.3-21.3; P < 0.0005).

CONCLUSIONS

LBW was shown to be strongly associated with elevated serum levels of Lp(a).

Variations of lipoprotein(a) levels in the metabolic syndrome: a report from the Maracaibo City Metabolic Syndrome Prevalence Study

BACKGROUND

Lipoprotein(a) [Lp(a)] is a known risk factor for cardiovascular disease, yet its influence on metabolic syndrome (MS) is still controversial. The purpose of this study was to assess the impact generated by this diagnosis in serum Lp(a) concentrations.

MATERIALS AND METHODS

A total of 1807 subjects of both genders (55.3% women and 44.7% men) belonging to the Maracaibo City Metabolic Syndrome Prevalence Study were evaluated. Results were expressed as Mean ± SD, determining differences through Student's t-test and One-Way ANOVA test. Multiple logistic regression models were utilized for analyzing factors associated with elevated serum Lp(a) levels and MS. Total cholesterol and LDL-C were corrected according to Lp(a)-Cholesterol when necessary.

RESULTS

No differences were found in Lp(a) values between genders; P = 0,292. The association between MS and the classification of Lp(a) was statistically significant (χ (2) = 28.33; P < 0,0001), with greater levels in subjects with this diagnosis. In the univariate analysis, subjects with each of the separate diagnostic criteria showed higher serum Lp(a) concentrations, except for hyperglycemia.

CONCLUSIONS

Lp(a) values exhibit important variations regarding MS and each of its components. Impaired fasting glucose appeared as a protecting factor against elevated Lp(a) concentrations, whereas its association with LDL-C and hs-CRP suggests a potential pro-inflammatory role.

Association between Low-Molecular Weight Apolipoprotein(a) Isoforms and Obesity in Italian Women

OBJECTIVE

Low-molecular weight (MW) apolipoprotein(a) [apo(a)] isoforms are closely associated with an increased incidence of atherothrombotic disease, prevalence of which is higher in obese individuals, particularly in women. The hypothesis of this study was to assess whether there are differences in the distribution of apo(a) phenotypes between obese patients and healthy controls.

RESEARCH METHODS AND PROCEDURES

One hundred three obese Italian women (BMI > or = 30.0 kg/m2) were enrolled in the study, and apo(a) phenotyping was performed in all subjects. The prevalence of low-MW apo(a) isoforms, detected in plasma samples of our obese women, was compared with that found in a control group of 84 normal-weight, never-obese (BMI < 25.0 kg/m(2)), age-matched women.

RESULTS

The distribution of apo(a) isoforms in the population of obese women was significantly different from that found in normal-weight female subjects. In particular, the percentage of subjects in the obese group with at least one apo(a) isoform of low MW was significantly higher than that in the control group (51.4% vs. 32.1%, p = 0.0079).

DISCUSSION

Our results seem to suggest the possibility that small-sized apo(a) isoforms may be used together with other traditional risk factors to better assess the overall predisposition to atherothrombotic disease in obese women.

Oxidized lipoprotein(a) and cardio-ankle vascular index (CAVI) in hypertensive subjects

While oxidized lipoprotein(a) (oxLp(a)) has been indicated to be involved in atherogenesis more than native lipoprotein(a) (Lp(a)), there is still a need to elucidate the associations among oxLp(a), hypertension, and atherosclerosis. The cardio-ankle vascular index (CAVI) is a recently developed index used to assess arterial stiffness that is independent of blood pressure components. The present study investigated the correlation between oxLp(a) and the CAVI among hypertensive subjects. Clinical data, including general atherosclerotic risk factors, in addition to Lp(a), oxLp(a), and the CAVI, were collected from 72 non-smoking, asymptomatic, and untreated female subjects (mean age: 64.3 years). Correlations between the CAVI and Lp(a) or oxLp(a) were examined in a hypertensive group (n = 34) and a non-hypertensive control group (n = 38). There was a significant and positive correlation between the CAVI and subject age in the control group, while there was a significant and positive correlation between the CAVI and subject age, systolic blood pressure, and oxLp(a) (r = 0.38, p < 0.05) in the hypertensive group. A stepwise multiple linear regression analysis identified the oxLp(a) to be correlated independently, significantly, and positively with the CAVI (β = 0.30, p < 0.05) in the hypertensive group, while this correlation was not significant in the control group. These findings suggest that the oxidative modification of Lp(a) may be associated with arterial stiffness in hypertensive, but not non-hypertensive, female subjects.

Lipoprotein(a) in Children of Asian Indian Descendants and Their Caucasian Neighbors: The Slovak Lipid Community Study

To elucidate a higher rate of premature cardiovascular disease (CVD) in Asian Indian descendants (Roma) in Slovakia, we investigated frequency distribution, correlates and relationship of lipoprotein(a) [Lp(a)] to family CVD risk factors in Roma children and their Caucasian neighbors. The study sample consisted of 607 healthy children aged 7-18 years (55% Roma, 48% male) as part of the biracial (Roma-Caucasian) Slovak Lipid Community Study. Overall, frequency distribution data of Lp(a) were highly skewed to low concentrations, with markedly higher Lp(a) levels in Roma than in Caucasian children (median and range, mg/dL: 14.5; 0-159.2 vs 6.2; 0-112.3, P < 0.001), regardless of age and gender. Lp(a) was positively correlated with apo B (0.159, P = 0.004) in Roma, and LDL cholesterol (0.170, P = 0.005) in Caucasian children. In addition, daily income of the family was negatively related with Lp(a) in Roma (-0.134, P = 0.036) while positively in Caucasians (0.136, P = 0.047). For both race groups, no significant association was found between Lp(a) and age, body mass index, mean arterial pressure, smoking, and physical activity. Also, no significant relationships were examined between serum Lp(a) levels >30 mg/dL in children and family CVD risk factors, except for diabetes mellitus in parents of Caucasian origin (OR 4.46; 95%CI: 1.23-16.20). In a multivariate analysis, daily income, LDL cholesterol or apo B explained ~7% of the variance of Lp(a). This study suggests a significantly higher serum Lp(a) levels in Roma than in Caucasian children and a small effect, in general, of relevant CVD risk factors on the variation of Lp(a) levels in childhood.

Association between the interleukin-6 promoter polymorphism -174G/C and serum lipoprotein(a) concentrations in humans

BACKGROUND

Lipoprotein(a) [Lp(a)] is an independent risk factor for cardiovascular disease. The interleukin-6 (IL-6) receptor antagonist tocilizumab has been shown to lower serum Lp(a) concentrations. We investigated whether the IL-6 single nucleotide polymorphism -174G/C is associated with baseline serum Lp(a) concentrations.

METHODOLOGY/PRINCIPAL FINDINGS

We divided 2321 subjects from the Lipid Analytic Cologne (LIANCO) cohort into 2 groups, the ones with substantially elevated Lp(a), defined as concentrations ≥60 mg/dl (n = 510), and the ones with Lp(a) <60 mg/dl (n = 1811). The association with the genotypes GG (33.7%), GC (50.75%) and CC (15.55%) was investigated. The GC and the CC genotype were associated with a significantly increased odds ratio of having substantially elevated Lp(a) concentrations (OR = 1.3, 95% CI 1.04 to 1.63, P = 0.02 and OR = 1.44, 95% CI 1.06 to 1.93, P = 0.018). These associations remained significant after adjusting for age, sex, smoking behavior, body mass index, serum lipoproteins, hypertension and diabetes. Of these covariates, only LDL cholesterol was significantly and independently associated with elevated Lp(a) concentrations.

CONCLUSIONS/SIGNIFICANCE

The IL-6 single nucleotide polymorphism -174G/C is associated with increased odds of having elevated Lp(a). Whether this association plays a role in the Lp(a)-lowering effects of IL-6 receptor antagonists remains to be established.

Obesity, weight loss and conditional cardiovascular risk factors

Obesity is a pathological condition aggregating a substantial number of proatherogenic factors, such as insulin resistance, type 2 diabetes mellitus, dyslipidaemia and hypertension. In addition to these classic cardiometabolic risk factors, atherosclerosis may be aggravated by other non-classic factors, which are characterized as conditional, including homocysteine, fibrinogen, lipoprotein(a), LDL particle size and high-sensitivity CRP. Some of these biomarkers are disturbed in obesity because of a combination of dietary factors, hypertrophic adipose tissue, low-grade inflammation, insulin resistance and other parameters under investigation. For the reduction of these risk factors, weight loss exceeding 10-20% of the initial body weight is probably necessary, achieved through either conventional lifestyle measures or more drastic interventions such as bariatric surgery. It has been shown that certain well-balanced diets, such as the Mediterranean diet, constitute a means of improving in a concerted manner the levels of CRP, fibrinogen, homocysteine and small dense LDL particles, regardless of weight loss. The significance of considering these factors in weight management intervention is an issue that needs further investigation.

Prediction models for the risk of new-onset hypertension in ethnic Chinese in Taiwan

Prediction model for hypertension risk in Chinese is still lacking. We aimed to propose prediction models for new-onset hypertension for ethnic Chinese based on a prospective cohort design on community, which recruited 2506 individuals (50.8% women) who were not hypertensive at the baseline (1990-91). Total 1029 cases of new-onset hypertension developed during a median of 6.15 (interquartile range, 4.04-9.02) years of follow-up. In the clinical model, gender (2 points), age (8 points), body mass index (10 points), systolic blood pressure (19 points) and diastolic blood pressure (7 points) were assigned. The biochemical measures, including white blood count (3 points), fasting glucose (1 point), uric acid (3 points), additional to above clinical variables, were constructed. The areas under the receiver operative characteristic curves (AUCs) were 0.732 (95% confidence interval (CI), 0.712-0.752) for the point-based clinical model and 0.735 (95% CI, 0.715-0.755) for the point-based biochemical model. The coefficient-based models had a good performance (AUC, 0.737-0.741). The point-based clinical model had a similar net reclassification improvement as the coefficient-based clinical model (P=0.30), and had a higher improvement than the point-based biochemical model (P=0.015). We concluded that the point-based clinical model could be considered as the first step to identify high-risk populations for hypertension among Chinese.

Aortic root dimension as an independent predictor for all-cause death in adults <65 years of age (from the Chin-Shan Community Cardiovascular Cohort Study)

BACKGROUND

Evidence on aortic root dimension for predicting cardiovascular morbidity and mortality is inconclusive. This cohort study sought to characterize the predictive power of aortic root dimension on cardiovascular morbidity and mortality in an ethnic Chinese population.

METHODS

We recruited 1,851 participants in the Chin-Shan Community Cardiovascular Cohort (CCCC) study who had received echocardiography without previous cardiovascular events. Aortic root dimension was measured by M-mode echocardiography and indexed by body surface area to obtain aortic root dimension index (AOI). The end points were all-cause death and incident cardiovascular events including coronary heart disease and stroke over a median follow-up of 11.9 years.

RESULTS

Although tertiles of AOI was associated with an increased risk of cardiovascular events and all-cause death in univariate analysis, the significance diminished after adjusting for age variable (P for trend = 0.11 for cardiovascular events; P for trend = 0.23 for all-cause death). In subgroup analysis, we found a significant association between tertiles of AOI and risk of all-cause death in the final multivariate Cox regression model in adults <65 years. The adjusted relative risk was 1.88 (95% CI, 1.04 to 3.40) in participants in the upper tertile of AOI compared with participants in the lower tertile (P for trend = 0.037). In adults > or = 65 years, tertile of AOI was not associated with all-cause death (P for trend = 0.14). Tertiles of AOI was not associated with cardiovascular events throughout this study.

CONCLUSION

Our study showed a significant association between AOI and all-cause death in adults <65 years in an ethnic Chinese population. (Echocardiography 2010;27:487-495).

Left ventricular mass and risk of cardiovascular events and all-cause death among ethnic Chinese--the Chin-Shan Community Cardiovascular Cohort study

BACKGROUND

We conducted this cohort study involving ethnic Chinese population to explore the association between left ventricular mass and cardiovascular events and all-cause death, and to define the cutoff value of left ventricular mass for risk stratification.

METHODS

We evaluated 2604 participants aged ≥35years in the Chin-Shan Community Cardiovascular Cohort (CCCC) study who had received echocardiography without previous cardiovascular events. Left ventricular mass was divided by body surface area to obtain left ventricular mass index (LVMI). The end-points were all-cause death and incident cardiovascular events including coronary heart disease and stroke over a median follow-up of 14.4years.

RESULTS

By multivariate Cox regression analyses, a linear relationship between LVMI and cardiovascular events was found (adjusted hazard ratio 2.01, 95% CI, 1.11 to 3.63, for the highest quintile of LVMI compared with the lowest quintile, p for trend=0.001). A J-shape relationship between LVMI and all-cause death was observed, with the test for a linear relationship being rejected (p=0.003). The adjusted hazard ratios of all-cause death were significantly lower in the second quintile (0.58, 95% CI, 0.40 to 0.84) and in the third quintile (0.68, 95% CI, 0.47 to 0.96) of LVMI compared with the lowest quintile. The proposed cut-off value of LVMI was 105g/m(2) for prediction of cardiovascular events.

CONCLUSION

A linear relationship between LVMI and cardiovascular events, and a J-shape relationship between LVMI and all-cause death were found. The cut-off value derived from our Chinese population was lower than the frequently applied value derived from Caucasian population.

Carotid artery intima-media thickness, carotid plaque and coronary heart disease and stroke in Chinese

Background

Our aim was to prospectively investigate the association between carotid artery intima-media thickness (IMT) as well as carotid plaque and incidence of coronary heart disease (CHD) and stroke in Chinese, among whom data are limited.

Methods and Findings

We conducted a community-based cohort study composed of 2190 participants free of cardiovascular disease at baseline in one community. During a median 10.5-year follow up, we documented 68 new cases of coronary heart disease and 94 cases of stroke. The multivariate relative risks (RRs) associated with a change of 1 standard deviation of maximal common carotid IMT were 1.38 (95% confidence interval [CI], 1.12–1.70) for CHD and 1.47 (95% CI, 1.28–1.69) for stroke. The corresponding RRs with internal carotid IMT were 1.47 (95% CI, 1.21–1.79) for CHD and 1.52 (95% CI, 1.31–1.76) for stroke. Carotid plaque measured by the degree of diameter stenosis was also significantly associated with increased risk of CHD (p for trend<0.0001) and stroke (p for trend<0.0001). However, these associations were largely attenuated when adjusting for IMT measurements.

Conclusions

This prospective study indicates a significant association between carotid IMT and incidence of CHD and stroke in Chinese adults. These measurements may be useful for cardiovascular risk assessment and stratification in Chinese.

Lipoprotein(a) is associated with coronary heart disease independent of metabolic syndrome

AIM

To assess (i) the association between lipoprotein(a) [Lp(a)] with the likelihood of coronary heart disease and metabolic syndrome (MS) and (ii) its covariates in Turkish adults.

METHODS

Cross-sectional evaluation of 1309 adults, who had serum Lp(a) determinations by Behring nephelometry, and followed for a mean 1.0 year. MS was defined by ATPIII criteria modified for male abdominal obesity.

RESULTS

Mean age of the sample was 56.8+/-11.3 years. After adjustment for sex, age, and smoking status, log-transformed Lp(a) levels were associated significantly with coronary heart disease likelihood in both sexes combined [odds ratio: 1.53 (95% confidence interval: 1.06; 2.20)]. This association persisted after additional adjustment for MS [odds ratio: 1.57 (95% confidence interval: 1.09; 2.26)]. The Lp(a) mid-tertile (5-17 mg/dl), accompanied by significantly lower serum triglycerides than the two remaining tertiles, was inversely associated significantly with MS in either sex; in women, this association was independent of waist circumference. In a linear regression comprising seven variables, excepting total cholesterol, only gamma-glutamyltransferase in women (P=0.002) and waist circumference (P=0.057) in men were inverse covariates of modest magnitude of Lp(a).

CONCLUSION

Coronary heart disease likelihood, significantly associated with Lp(a) concentrations, is independent of MS and insulin resistance. Suggestive evidence was provided that intermediary Lp(a) concentrations, when accompanied by the presence of MS, could accelerate progression of vascular disease, especially in women.

Lipoprotein(a) and cardiovascular disease in ethnic Chinese: the Chin-Shan Community Cardiovascular Cohort Study

BACKGROUND

Little is known about lipoprotein(a) [Lp(a)] as a predictor of vascular events among ethnic Chinese. We prospectively investigated the association of Lp(a) with cardiovascular disease and all-cause death in a community-based cohort.

METHODS

We conducted a community-based prospective cohort study of 3484 participants (53% women; age range, 35-97 years) who had complete lipid measurements and were free of a cardiovascular disease history at the time of recruitment. Over a median follow-up of 13.8-years, we documented 210 cases of stroke, 122 cases of coronary heart disease (CHD), and 781 deaths.

RESULTS

The incidences for each event increased appreciably with Lp(a) quartile for stroke and all-cause death, but not for CHD. Baseline Lp(a) concentration by quartile was not significantly associated with stroke, all-cause death, and CHD in multivariate analyses. The multivariate relative risk was significant for stroke at the 90th and 95th percentiles and for total death at the 95th and 99th percentiles.

CONCLUSIONS

Our findings suggest a threshold relationship with little gradient of risk across lower Lp(a) values for stroke and all-cause death in Chinese adults.

Lipoprotein(a) as a risk factor associated with ischemic heart disease: Ouro Preto Study

Evidences suggest that lipoprotein(a) [Lp(a)] is an important risk factor for cardiovascular disease. However, literature has been controversial in confirming its role as an independent risk factor for cardiovascular disease. The objective of the present study is to evaluate the association between serum levels of Lp(a) and ischemic heart disease as well as other cardiovascular risk factors in a population-based study conducted on a local cohort of the Brazilian population. Lp(a) serum levels were measured in 400 individuals selected from a larger sample of a populational survey carried out in Ouro Preto, a city in the southeast of Brazil. Lipid profile, fasting blood glucose, anthropometric and clinical parameters were analyzed. Lp(a) levels were significantly associated with the presence of ischemic heart disease. In relation to other cardiovascular risk factors, it was verified that Lp(a) levels were statistically associated with age, total cholesterol, LDL-cholesterol and percentage of body fat determined by bioelectric impedance. Lp(a) was also highly associated with the Framingham risk score (p=0.003). In a multivariate analysis two significant interactions were revealed; one involving ischemic heart disease, sex and age and other associating ischemic heart disease, age and total cholesterol. In summary, in the present analysis Lp(a) serum levels were correlated with the occurrence of ischemic heart disease and other cardiovascular risk factors.

Impact of heart failure and left ventricular function on long-term survival--report of a community-based cohort study in Taiwan

BACKGROUND

There is little community-based information on heart failure (HF) prognosis in ethnic Chinese populations, in whom there is a low prevalence of coronary heart disease.

AIMS

To study the impact of HF and left ventricular function on long-term all-cause mortality.

METHODS AND RESULTS

This community-based prospective cohort study included 2660 subjects (1215 men, 1445 women, mean age 54.4+/-11.9 years) over a 10 year follow-up period. The prevalence of HF was 5.5%. Hypertension was the most common factor related to HF. The five and ten year all-cause mortality was higher in the HF/preserved LVEF group (14.1% and 24.4%) and the HF/impaired LVEF group (29.2% and 48.2%) than in the HF-free group (6.0% and 14.6%, p<0.0001 for both). In multivariable Cox analyses, controlling for sex, LV mass, atrial fibrillation, hypertension, coronary heart disease, HF/preserved LVEF and HF/impaired LVEF were important predictors of all-cause mortality (p=0.007).

CONCLUSIONS

Hypertension is a major heart failure related disease. HF and LV systolic dysfunction are associated with a significant increase in all-cause mortality in an ethnic Chinese population.

The relationship of TFPI, Lp(a), and oxidized LDL antibody levels in patients with coronary artery disease

OBJECTIVES

The aim of the present study was to determine and correlate tissue factor pathway inhibitor (TFPI), lipoprotein (a) (Lp(a)), oxidized low-density lipoprotein (LDL) antibody (oLAB), and thiobarbituric acid reactive substances (TBARS; as a marker of lipid peroxidation) levels in patients with coronary artery disease (CAD) and in a control group.

DESIGN AND METHODS

Peripheral blood samples from patients with coronary heart disease were provided by the Department of Cardiology. Serum oLAB, Lp(a), plasma total TFPI, and plasma-free TFPI levels were determined by ELISA. Serum TBARS levels were determined by a spectrophotometric method using thiobarbituric acid.

RESULTS

The CAD and the control group were matched for age and sex. Serum Lp(a), oLAB, and plasma total TFPI levels in patients with coronary heart disease were found to be significantly higher than in the control group (P < 0.001). But there was no difference in plasma-free TFPI levels between patients with CAD and the control group (P > 0.05). In patients with single (P < 0.05), double, and triple vessel (P < 0.01) disease, the mean serum Lp(a) levels were significantly higher than in the control group. On the other hand, in patients with single vessel disease (P < 0.05), double vessel disease (P < 0.05), and triple vessel disease (P < 0.001), plasma total TFPI levels were found to be significantly higher than in the control group. We also found a significant positive correlation (r = 0.28, P < 0.05) between serum Lp(a) and plasma total TFPI levels in CAD. In the patient group, TBARS, total cholesterol, triglyceride (TRG), and LDL cholesterol levels were found to be significantly higher than those in the control group. In addition, high-density lipoprotein (HDL) cholesterol levels were found to be significantly lower than the control group.

CONCLUSIONS

These results suggest that elevated plasma levels of total TFPI, Lp(a), and oLAB may be useful diagnostic and monitoring markers in patients with CAD.

Effects of Fat-Modified Dairy Products on Blood Lipids in Humans in Comparison with Other Fats

BACKGROUND/AIM

Due to its high content of LDL-raising saturated fatty acids (SFA), milk fat has been considered to be hypercholesterolaemic, but it also contains fatty acids and other constituents which seem to have a hypocholesterolaemic effect. Milk fat was modified by feeding cows rapeseed cake, resulting in a reduced content of SFA and an increased content of unsaturated fatty acids. The objective of this study was to investigate the effects of modified milk fat (ModFat) on serum cholesterol fractions, triacylglycerides (TAG) and lipoprotein(a) [LP(a)], compared with regular milk fat (RegFat) and with soft margarine (Marg).

METHOD

Fifteen women and 16 men were enrolled in the intervention study. Nine of the participants were hypercholesterolaemic. Nutrient intake parameters, serum lipids and LP(a) were determined.

RESULTS

The serum concentration of HDL cholesterol increased in the ModFat period, leading to a decreased LDL/HDL ratio in this period. The lowest LP(a) concentrations were measured at the end of the control phase and at the end of the ModFat period. A decreasing tendency of serum TAG concentration was observed in the ModFat period.

CONCLUSION

The fat-modified milk seems to have positive effects on the LDL/HDL ratio and the LP(a) concentrations, both of which have been established as risk factors for coronary heart disease.

Lipoprotein(a) is an independent risk factor for peripheral arterial disease in Chinese type 2 diabetic patients in Taiwan

OBJECTIVE

To examine the association between lipoprotein(a) [Lp(a)] and peripheral arterial disease (PAD) and determine the optimal cutoff in Chinese type 2 diabetic patients in Taiwan.

RESEARCH DESIGN AND METHODS

Serum Lp(a) was determined in 557 type 2 diabetic patients (243 men and 314 women) recruited consecutively from a diabetes clinic at the National Taiwan University Hospital. Ankle-brachial index (ABI) <0.9 was diagnosed as PAD (n = 45) and <0.8 as severe PAD (n = 20). Potential confounders included age, sex, BMI, waist-to-hip ratio (WHR), diabetes duration, insulin usage, smoking, hypertension, systolic and diastolic blood pressure, fasting plasma glucose (FPG), total cholesterol, triglycerides, and HDL and LDL cholesterol.

RESULTS

The distribution of Lp(a) was right skewed and no significant differences for sex, WHR, insulin usage, smoking, hypertension, and systolic and diastolic blood pressure were observed. In men, log[Lp(a)] was correlated positively with age, duration, and total and LDL cholesterol (borderline significant, P < 0.1) and negatively with BMI, triglycerides, and FPG (P < 0.1). In women, log[Lp(a)] was correlated positively with total and LDL cholesterol and negatively with triglycerides and BMI (P < 0.1). ABI was significantly correlated with log[Lp(a)], especially in men or in patients with PAD. The optimal cutoff determined by discriminant analysis was 13.3 mg/dl. Patients with Lp(a) above this value had a 2.7-fold higher risk of PAD after multivariate adjustment. Lp(a) also significantly increased from no PAD to mild and severe PAD (17.1 +/- 14.4, 23.7 +/- 20.3, and 36.9 +/- 22.8 mg/dl, respectively, P < 0.001).

CONCLUSIONS

Lp(a) is an independent risk factor for PAD in type 2 diabetic patients in Taiwan. The optimal cutoff is 13.3 mg/dl.

[Effect of weight reduction on lipids and lipoprotein (a) serum levels]

BACKGROUND AND OBJECTIVE

A quasi-experimental study to determine the effects of a body weight reduction treatment on lipids and lipoprotein (a) serum levels.

PATIENTS AND METHOD

Ponderal and lipidogram values were determined in 69 premenopausic obese women before and after treatment. Differences were determined at a given time and at intervals.

RESULTS

Apart from a high fasting HDLc, a reduction of the lipid values was observed.

CONCLUSIONS

Our results suggest that weight reduction modifies favourably the lipid profile in premenopausic obese women.

Apolipoprotein A-I and B and stroke events in a community-based cohort in Taiwan: report of the Chin-Shan Community Cardiovascular Study

BACKGROUND AND PURPOSE

There are limited prospective cohort studies of the well-known association between stroke events and serum lipids for the Taiwanese population, in whom stroke is the second most common cause of death.

METHODS

This report describes the effect of dyslipidemia on the risk of stroke in a community-based cohort consisting of 3602 adults aged > or =35 years, established in 1990 in the Chin-Shan community in Taipei County, Taiwan.

RESULTS

As of the end of 1998, 97 stroke incidence cases were identified from medical records and death certificates (53 in men and 44 in women). The female-to-male stroke event rates increased from 0.42 in the youngest group (aged 35 to 44 years) to 1.38 in the oldest (aged > or =75 years). Multiple Cox proportional hazard regression models controlling for age and sex revealed that individuals with serum apolipoprotein A-I (apoA-I) at the highest quartile were more likely to have a stroke event than those at the lowest quartile level (relative risk [RR]=2.02, P for trend=0.010). The corresponding risk of stroke predicted by apolipoprotein B (apoB) was also significant (RR=1.88, P for trend=0.020). After adjustment for age, sex, hypertension, and diabetes status, the interaction between hypertension and apoA-I level remained significant in predicting stroke events in men but not in women (RR=1.71, P=0.033 in men; RR=2.29, P=0.071 in women).

CONCLUSIONS

We conclude that apoA-I but not apoB levels may serve as an effect modifier of hypertension for the risk of stroke events.

Hypertension Status Is the Major Determinant of Carotid Atherosclerosis

Background and Purpose — Extracranial carotid artery (ECCA) atherosclerosis has been associated with hypertension-related stroke. The present study was aimed at investigating the determinants of ECCA atherosclerosis in patients with hypertension in Taiwan.

Methods — The extent and severity of ECCA atherosclerosis were measured by high-resolution B-mode ultrasonography and expressed as maximal intima-media thickness (IMT) of the common carotid artery, ECCA plaque score, and carotid stenosis ≥50%. From July through December 1996, 263 hypertensive patients (146 with hypertension and 117 with borderline hypertension) and 270 normotensive adults from the Chin-Shan Community Cardiovascular Cohort participated in this study. Risk factors and ECCA atherosclerosis were stratified by the blood pressure status.

Results — A significant dose-response relationship was found between the status of hypertension and the severity of carotid atherosclerosis. Multivariate logistic regression models revealed that hypertension (including borderline), male gender, smoking, and age ≥65 years significantly increased the risk of thicker IMT. The risk of ECCA plaque score >6 increased significantly in conjunction with hypertension, age ≥65 years, left ventricular hypertrophy on ECG, and smoking. However, hypertension and smoking were the 2 evident determinants of carotid stenosis ≥50% after adjustment for other covariates. Compared with the normotensive subjects, the ORs (and 95% CIs) for the hypertensive patients to develop carotid atherosclerosis were 5.0 (3.0 to 8.4) indexed by maximal common carotid artery IMT ≥75th percentile, 3.7 (1.8 to 7.9) by ECCA score >6, and 4.8 (1.4 to 16.5) by carotid stenosis ≥50%.

Conclusions — Hypertension strongly influence carotid atherosclerosis. Our findings reinforce the hypothesis that hypertension has a major role in the pathogenesis of atherosclerosis.

Left ventricular mass and correlated atherosclerotic risk factors in young adolescents: report from Chin-Shan community cardiovascular study in Taiwan

Various subclinical disease indicators can be used as an early stage marker of atherosclerosis. Left ventricular (LV) mass has been related to cardiovascular morbidity and mortality. The distribution of LV mass in Chinese is rarely studied and nothing is known about its relationships with various atherosclerotic risk factors in young teenagers, in particular, aspects of lipid profiles. We performed a community-based survey of 523 males and 555 females, aged 12-15, in Chin-Shan, a suburb area near Taipei, Taiwan. LV mass was calculated from the Penn convention. Normalized LV mass by height with power of 2.7 was defined. LV mass and normalized LV mass were significantly greater in males than in females. There were significant positive correlation coefficients between LV mass and age, blood pressure, body mass index, low density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) B, fasting insulin levels and significant negative correlation coefficients between LV mass and high density lipoprotein cholesterol (HDL-C) and Apo A1 level in both genders. Multiple linear regression models showed gender and body mass index (BMI) were important factors associated with LV mass or normalized values for adolescents. Age and systolic blood pressure were also significant predictors of LV mass, but not of normalized LV mass values. LV mass values were found to be negatively associated with HDL-C values at marginal statistically significant level. Age and BMI are the most significant factors of echocardiographic LV mass distributions in young adolescent in Taiwan. LV mass may also be associated with atherosclerotic risk factors.

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.

Comparison of risk factors of macrovascular complications. Peripheral vascular disease, cerebral vascular disease, and coronary heart disease in Japanese type 2 diabetes mellitus patients

Although macroangiopathies such as peripheral vascular disease (PVD), cerebral vascular disease (CVD), and coronary heart disease (CHD) can often be observed in patients with diabetes mellitus, they are not specific for diabetes mellitus. Moreover, it is unclear whether their progressive mechanism is different. In the present study, we compared the risk factors among the diabetic macrovascular complications. Univariate analyses showed that in all patients, age at examination, duration of diabetes, thrombin-antithrombin III complex (TAT) level, fibrinogen level, lipoprotein (a) (Lp(a)) level, total cholesterol (T-Chol) level, and existence of microagiopathy were risk factors for PVD. Age, duration of diabetes, insulin level, TAT level, fibrinogen level, HDL cholesterol (HDL-Chol) level, hypertension, and nephropathy were risk factors for CVD. Only fibrinogen level was a risk factor for CHD. Moreover, Lp(a) level was a risk factor for PVD and CVD in male patients, but not in females. On the other hand, insulin level was a risk factor for CVD in female patients, but not in males. Multivariate analyses showed that TAT level, T-Chol level, and neuropathy were independent variables for PVD and that age, TAT level, and HDL-Chol level were independent variables for CVD. On the other hand, only fibrinogen level was the independent variable for CHD in males. Our results suggest that the progressive mechanism of PVD and CVD might be different from that of CHD and might differ according to gender in Japanese diabetic patients.