Homocysteine and coronary heart disease risk in the PRIME study

Effect of cerebral small vessel disease on cognitive impairment in Parkinson's disease

OBJECTIVES

To explore the association between cerebral small vessel disease (cSVD) and cognitive impairment (CI) in Parkinson's disease (PD).

METHODS

81 PD patients were recruited into the study from September 2018 to December 2020. The demographic characteristics and radiologic and laboratory data were collected. Cognitive assessments were carried out using the Montreal Cognitive Assessment. The association between cSVD and cognitive impairment was analyzed using univariate and binary logistic regression analysis.

RESULTS

The binary logistic regression analysis showed that, after correcting for age, educational years, hyperhomocysteinemia, hypertension, and diabetes mellitus, total cSVD scores (OR 1.55, 95% CI 1.07-2.27, P = 0.02), the presence of paraventricular white matter hyperintensity (PVH) (OR 11.78, 95% CI 3.08-45.01, P < 0.001), white matter hyperintensity (WMH) (OR 7.95, 95% CI 2.28-27.79, P = 0.001), and perivascular space (PVS) (OR 6.66, 95% CI 2.08-21.40, P = 0.001) were independent risk factors for PD-CI.

CONCLUSION

The presence of cSVD was associated with cognitive dysfunction in patients with PD. It may be beneficial to manage cSVD to prevent the progression of cognitive impairment in patients with PD.

Plasma homocysteine is associated with aortic arterial stiffness but not wave reflection in Chinese hypertensive subjects

Objective

Elevated plasma total homocysteine (tHcy) acts synergistically with hypertension to exert a multiplicative effect on cardiovascular diseases risk. The aim of this study was to determine the relationship between tHcy concentration and blood pressure, and to evaluate the role of plasma tHcy in arterial stiffness and wave reflection in hypertension.

Methods

In this cross-sectional study, a community-based sample of 1680 subjects (mean age 61.6 years) was classified into four groups according to tHcy level (<21.6 vs. ≥21.6 µmol/l) and blood pressure (hypertensive vs. normotensive). Levels of plasma tHcy and other biochemical parameters (e.g., lipids, glucose) were determined. Central arterial blood pressure, reflected pressure wave, and carotid-femoral pulse wave velocity (cf-PWV) were assessed by tonometry within 2 days of obtaining the blood specimen.

Results

Neither peripheral nor central blood pressure differed according to tHcy levels in normotensive and hypertensive subjects. Differences in cf-PWV according to tHcy were observed only in hypertensive subjects; differences in cf-PWV in normotensive subjects were not significant after adjusting for confounding factors. Central augmentation index did not differ according to tHcy level in either normotensive or hypertensive subjects. Results of univariate analysis revealed significant correlations between blood pressure parameters and tHcy concentration only among normotensive subjects; however, these correlations were not significant in a partial correlation analysis. Results of multiple regression analysis showed that plasma tHcy levels were independently correlated with cf-PWV in hypertensive subjects (β = 0.713, P = 0.004). The independent relationship between tHcy and central augmentation index was not significant by further multiple analyses in normotensive or hypertensive individuals.

Conclusions

Plasma tHcy level is strongly and independently correlated with arterial stiffness measured as cf-PWV only in hypertensive subjects. Thus, hypertension is a major link between tHcy and aortic arterial stiffness.

Association of serum total bilirubin levels with the severity, extent and subtypes of coronary atherosclerotic plaques detected by coronary CT angiography

In this study, we aimed to evaluate whether serum total bilirubin was associated with the severity and morphology of coronary atherosclerotic plaques detected by computed tomography angiography (CTA). The study population consisted of 1,115 patients (55.2 % men) who underwent dual-source 64-slice CTA for the assessment of coronary artery disease (CAD). Coronary arteries were evaluated on 16 segment basis and critical coronary plaque was described as luminal narrowing >50 %, whereas plaque morphology was assessed on per segment basis. Serum bilirubin levels were determined using commercially available assay kits. The critical atherosclerotic lesions were detected in 431/1,115 (38.6 %) subjects by CTA. Serum total bilirubin levels were found to be lower in patients with any coronary plaque (0.62 ± 0.21 vs. 0.70 ± 0.25 mg/dL, p = 0.002). Also bilirubin level was lower in patients with critical stenosis compared to non-critical stenosis (0.57 ± 0.18 vs. 0.70 ± 0.24 mg/dL, p < 0.001). Subjects having primarily noncalcified plaque (NCP) and mixed plaque (MP) have lower bilirubin levels compared to calcified plaque (CP) and normal subjects (0.62 ± 0.20 for NCP and 0.60 ± 0.19 for MP, 0.65 ± 0.26 for CP and 0.71 ± 0.25 for normal subjects, p < 0.001). This independent association was remained for NCP after multinominal regression analysis (OR: 0.76; 95 % CI 0.58-0.88; p < 0.001). Our study demonstrated that serum bilirubin level was significantly associated with the presence, severity and the noncalcified morphology of atherosclerotic plaques detected by CTA. Further prospective clinical studies are needed to clarify the exact physiopathologic and prognostic role of bilirubin in CAD.

Contribution of dietary intakes of antioxidants to homocysteine-induced low density lipoprotein (LDL) oxidation in atherosclerotic patients

PURPOSE

Elevated circulating oxidized low density lipoprotein (Ox-LDL) levels are associated with increased risk of atherosclerosis, which may be due to high plasma homocysteine (Hcy) and low intakes of antioxidants. We investigated the contribution of dietary intakes of antioxidants to Hcy-induced LDL oxidation in atherosclerotic patients (AP) and controls.

MATERIALS AND METHODS

Male AP (n = 101) who were confirmed by coronary angiography and 91 controls were evaluated by blood biochemistry and dietary intakes. To determine whether homocysteine is an independent risk factor for atherosclerosis, subjects were divided into three groups; low- (<or= 6.9 uM/L), normal- (7 uM-12 uM/L) and high- (>or= 12.1 uM/L) Hcy.

RESULTS

Plasma levels of homocysteine and LDL were higher, but plasma apo A-I in HDL and folate were lower in the AP group. The odds ratio (OR) for the risk of atherosclerosis was 3.002 [95% confidence interval (CI), 1.27-7.09] for patients in the highest tertile with homocysteine >or= 12.1 uM/L. AP having high homocysteine levels had low intakes of vitamin A, beta-carotene and vitamin C. By logistic regression analysis, age, body mass index (BMI), plasma LDL, plasma folate, and low intakes of vitamin A and beta-carotene were found to be risk factors for atherosclerosis in patients with high-Hcy, but dietary B vitamins including folate were not.

CONCLUSION

A high-Hcy level was a risk factor for atherosclerosis in patients with high Ox-LDL levels. High intakes of antioxidants appeared to be a protective factor for atherosclerosis, perhaps exerting a pro-oxidative effect on LDL when combined with high levels of Hcy and LDL. However, more evidence for the benefits of B vitamins as a homocysteine-lowering therapy is needed.

Siglec-1 on monocytes is a potential risk marker for monitoring disease severity in coronary artery disease

OBJECTIVES

Siglec-1 has long been considered as an important biomarker of the activation of monocyte/macrophage and a type I interferon-specific imprint, but its role in atherosclerosis has not been elucidated.

METHODS

We examined the expression of Siglec-1 by flow cytometry and RT-PCR in 83 CAD patients and 38 healthy controls. In addition, the levels of serum lipids, Gensini score, hs-CRP and homocysteine were determined.

RESULTS

The transcriptional and protein levels of Siglec-1 on monocytes in CAD patients were significantly increased compared with healthy controls [3.17 versus 1.0, P<0.01; (11.5+/-3.9)% versus (1.8+/-2.0)%, P<0.01], but the increased Siglec-1 had no correlation with the level of native serum lipids. Interestingly, the expression of Siglec-1 was positively correlated with Gensini score (r=0.338, P=0.015), hs-CRP (r=0.316, P=0.016) and homocysteine level (r=0.224, P=0.042).

CONCLUSION

Siglec-1 may be considered as a potential non-invasive indicator for monitoring disease severity and a biomarker for predicting the relative risk of cardiovascular events.

Practical management of dyslipidemia with elevated lipoprotein(a)

OBJECTIVE

To report a case and describe a practical approach to treating dyslipidemia in a very-high-risk patient with elevated lipoprotein(a) [Lp(a)].

SETTING

Pharmacist-managed lipid clinic, from November 2006 to July 2007.

PATIENT DESCRIPTION

A 50-year-old white woman with a recent history of multiple myocardial infarctions presented for management of dyslipidemia.

CASE SUMMARY

At baseline, the patient had elevated low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), total cholesterol (TC), and Lp(a) (306 nmol/L) levels and low high-density lipoprotein cholesterol (HDL-C) levels. Early initiation of combination therapy with a statin and niacin extended release (ER) titration was started. After 3 months, despite progressive weight gain caused by dietary indiscretion, LDL-C decreased by 24% and TG and TC levels reached goal. Lp(a) levels did not change. Niacin ER titration continued, pravastatin was maximized, and ezetimibe 10 mg daily was started. Despite dramatic 9-month weight gain (68 lb total), LDL-C and HDL-C reached goal and Lp(a) levels decreased by 33% (204 nmol/L) after niacin ER maximization.

RESULTS

Lp(a) is an emerging risk factor in cardiovascular disease (CVD). Elevated Lp(a) (>30 mg/dL) has been implicated as both an independent and an additive risk factor for CVD and stroke, particularly in women. In this case, the patient did not reach the optimal goal (<30 mg/dL) but did experience more than 30% reduction in Lp(a) levels. Although multiple factors, including subclinical hypothyroidism, hormonal changes, and renal disease, increase Lp(a) levels, few beneficial treatment options exist (i.e., estrogen and niacin). Although the exact mechanism of action is unknown, niacin ER has been documented to reduce Lp(a) by 36% to 38%. Some effect of ezetimibe on Lp(a) in this patient cannot be ruled out.

CONCLUSION

This case illustrates a practical use of currently available therapy options to address Lp(a) as a secondary cardiovascular risk factor. Niacin is a preferred option for Lp(a) lowering in very-high-risk patients with coronary heart disease and dyslipidemia. The importance of moderate reductions in Lp(a) is not known.

Homocysteine predicts adverse clinical outcomes in unstable angina and non-ST elevation myocardial infarction: implications from the folate intervention in non-ST elevation myocardial infarction and unstable angina study

BACKGROUND

Unstable angina and non-ST elevation myocardial infarction (NSTEMI) are common acute coronary events. Homocysteine is a novel risk factor for coronary heart diseases. Together with the conventional risk factors, they may affect the outcome of non-ST coronary events.

OBJECTIVE

This study aims to determine the effect of clinical risk factors that are responsible for the occurrence of mortality, and the composite outcome of mortality, nonfatal myocardial infarction and serious rehospitalization within 6 months after the onset of non-ST acute coronary syndromes.

METHODS

A total of 124 Filipino patients were interviewed and tested for blood homocysteine levels and lipid profiles. Outcomes were assessed after 6 months.

RESULTS

Homocysteinemia (>16 micromol/l) is associated with increased mortality and composite outcomes (mortality, nonfatal reinfarction, and serious rehospitalization), even if adjusted for conventional risk factors. No association was detected for the conventional risk factors. Earlier acute coronary syndrome was found to be positively associated with mortality and the composite outcomes. Early stroke is associated with increased composite outcomes, whereas greater mortality and adverse outcomes were observed in NSTEMI compared with intermediate-risk unstable angina.

CONCLUSION

Increased homocysteine level is associated with mortality and serious nonfatal outcomes in patients with unstable angina and NSTEMI.

Homocysteine induces connective tissue growth factor expression in vascular smooth muscle cells

BACKGROUND

Increased homocysteine levels in blood might be an important risk factor for the development of cardiovascular diseases. Connective tissue growth factor (CTGF) was found to be involved in atherosclerotic plaque progression. So far, the possible connection between homocysteine and CTGF has not been studied.

OBJECTIVE

This study was designed to test whether homocysteine could induce CTGF expression in vascular smooth muscle cells (VSMC).

METHODS AND RESULTS

Hyperhomocysteinemia was induced in Sprague-Dawley rats after 4 weeks of a high-methionine diet. CTGF mRNA and protein expression was detected in the aortas isolated from hyperhomocysteinemic rats, but not in the controls. The underlying mechanism of homocysteine-induced CTGF expression was investigated in cultured human umbilical vein smooth muscle cells (HUVSMC). CTGF mRNA expression was induced after treatment with dl-homocysteine (50 micromol L(-1)) for 1 h, which remained at the elevated level for up to 8 h. CTGF protein level increased after homocysteine treatment for 8 h, and the elevated status was maintained for up to 48 h. Several intracellular signals elicited by homocysteine are involved in CTGF synthesis, including protein kinase C (PKC) activation and reactive oxygen species (ROS). Transfection HUVSMCs with a CTGF small interference RNA (siRNA) plasmid, which specifically inhibited the expression of CTGF, decreased extracellular matrix (ECM) accumulation caused by homocysteine.

CONCLUSION

Our results demonstrate that homocysteine could increase the expression of CTGF in VSMC both in vivo and in vitro. The novel findings suggest that homocysteine might contribute to accelerated progression of atherosclerotic lesions by inducing CTGF expression.

Relationship between two sequence variations in the gene for peroxisome proliferator-activated receptor-gamma and plasma homocysteine concentration. Health in men study

The concentration of circulating homocysteine has been associated with a variety of diseases, including myocardial infarction, stroke, venous thrombosis and cognitive decline. Genetic variation has been demonstrated to play an important role in determining plasma homocysteine, however, the genes involved are incompletely understood. Ligation of the transcription factor peroxisome proliferator-activated gamma (PPARG) has been demonstrated to lower plasma homocysteine. We examined the association of two sequence variations in PPARG with plasma concentrations of homocysteine in a population-based study of 3,875 elderly men. PPARG c.34G > C and PPARG c.1347C > T sequence variations were determined by real-time quantitative PCR and related to logarithm transformed homocysteine concentrations using linear regression, adjusting for the co-variants age, renal function, smoking, coronary heart disease, waist to hip ratio, diabetes, hypertension and MTHFR g.677C > T sequence variation. Median plasma homocysteine concentration was 10% higher in men who were homozygous for the rare allelic variation in PPARG c.34G > C and PPARG c.1347C > T by comparison to those who had wild type sequence variation. PPARG c.1347C > T (beta = 0.038, P = 0.01 recessive model; beta = 0.036, P = 0.02 dominant model) sequence variation was positively associated with homocysteine concentration after adjusting for co-variants. The two PPARG sequence variations were in linkage disequilibrium and the common haplotype was associated with lower plasma homocysteine (P = 0.005). Our findings demonstrate a new genotypic association with plasma homocysteine. Replication will be required in other cohorts.