Serum homocysteine does not associate with uncomplicated coronary heart disease

Elevated plasma homocysteine level is associated with ischemic stroke in Chinese hypertensive patients

BACKGROUND

Accumulating data suggest that hyperhomocysteinemia is associated with the risk of ischemic stroke (IS) and coronary heart disease (CHD) in the general population, but the relationship remains unclear in hypertensive patients. We examined the association of total homocysteine (tHcy) with IS and CHD in hypertensive patients.

METHODS

A total of 5935 Chinese hypertensive patients were recruited in a community-based cross-sectional study from 60 communities in Shenzhen, China. Plasma tHcy was quantitatively measured using the enzyme cycle method. Conventional risk factors for IS and CHD were obtained through questionnaire interviews and physical examinations. We included cerebral infarction, embolism and small-vessel disease as IS; and myocardial infarction, angina pectoris, coronary revascularization, and cardiac arrest as CHD. IS and CHD were retrospectively adjudicated by specialists via interviews, hospital records or relevant tests.

RESULTS

Significantly higher values of tHcy were observed in IS patients than in non-IS controls among both men and women. Greater tHcy level was dose dependently associated with an increased risk of IS presence in women, men and them combined (p-trend: 0.002, 3.8×10(-4) and 0.001). The odds ratios (95% CI) of IS for tHcy ≥30 (vs. <15) μmol/L were 2.84 (1.73-4.34) in men, 4.41 (1.62-9.15) in women, and 2.86 (1.72-4.75) in their combination after adjusting for other main risk factors of IS. We did not find any significant association between tHcy and presence of CHD after the adjustment for covariates.

CONCLUSIONS

Plasma homocysteine level is positively associated with the presence of IS, but not CHD, in Chinese hypertensive patients.

Dietary patterns are associated with hyperhomocysteinemia in an urban Pakistani population

Little attention has been given to the association of dietary patterns with plasma homocysteine. Our objective in this study was to identify major dietary patterns and investigate their association with plasma homocysteine. In a cross-sectional survey, 872 healthy adults (355 males, 517 females; aged 18-60 y) were enrolled from an urban population in Karachi. Dietary intake was assessed by a FFQ. We used factor analysis to define major dietary patterns. Fasting concentrations of plasma or serum homocysteine, folate, pyridoxal-phosphate (PLP; coenzyme form of vitamin B-6), and vitamin B-12 were measured. Three major dietary patterns were identified and labeled as "prudent diet," "high animal-protein diet," and "high plant-protein diet." We observed a protective effect of the prudent dietary pattern for the highest quartile of intake compared with the lowest quartile of hyperhomocysteinemia when the model was adjusted for age, gender, household income, BMI, tobacco chewing, and smoking [OR = 0.52 (95% CI = 0.30-0.90); P = 0.01]. The high plant-protein diet pattern was inversely related to hyperhomocysteinemia, with a higher intake being protective. Compared with the 1st quartile, the adjusted OR was 0.42 (95% CI = 0.25-0.69; P = 0.001) for the 4th quartile. The high animal-protein diet was positively associated with hyperhomocysteinemia, with participants in the highest quartile of intake having the greatest increase in risk [OR = 2.10 (95% CI = 1.22-3.60); P = 0.007]. Plasma homocysteine concentrations appeared to be correlated more with circulating folate (r = -0.25; P < 0.001) than with PLP (r = -0.02; P = 0.663) or vitamin B-12 (r = -0.16; P < 0.001). A diet rich in fruits and uncooked vegetables decreased the risk of hyperhomocysteinemia, whereas diets rich in red meat, chicken, and tea with milk were positively associated with hyperhomocysteinemia.

Ubiquinol-10/lipids ratios in consecutive patients with different angiographic findings

OBJECTIVE

Information concerning un-supplemented plasma concentrations of ubiquinol-10 in coronary artery disease patients is still controversial. The aim of this study is to determine the levels of plasma ubiquinol-10 and ratios of ubiquinol-10 to plasma lipids in consecutive patients with different angiographic findings.

SUBJECTS AND METHODS

Thirty-six consecutive patients who underwent coronary angiography were split in two groups with different atherosclerotic changes. These patients were un-supplemented with antioxidants and were not treated by lipid-lowering medication. We have measured a plasma level of ubiquinol-10 using high-performance liquid chromatography with coulometric detection. Conventional plasma lipids, markers of oxidative stress and other widely accepted risk factors of atherosclerosis have been determined too.

RESULTS

Plasma ubiquinol-10 to low-density lipoprotein cholesterol (LDL-C) ratios in patients with different angiographic findings have been found as 180+/-69 and 132+/-43, respectively (p=0.020). The ubiquinol-10/LDL-C ratio was significantly lower in angiographically positive patients. There were also significant differences in ubiquinol-10 per total cholesterol (109+/-47 and 80+/-26, respectively; p=0.031), per triglycerides (426+/-191 and 237+/-86, respectively; p=0.002) and per the sum of triglycerides and total cholesterol (86+/-35 and 61+/-20, respectively; p=0.013).

CONCLUSIONS

There have not been found any significant differences between levels of widely accepted risk factors for genesis and progress of atherosclerotic changes in these two groups of patients. Only the level of triglycerides and the total cholesterol minus high-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio were significantly higher in patients with stenosis. This ratio correlated with the ubiquinol-10/LDL-C ratio, which was significantly lower in patients with stenosis. Our results indicate that the ratio of ubiquinol-10/LDL-C is likely to be a risk factor for atherogenesis.

Serum Homocysteine and Long-Term Risk of Myocardial Infarction and Sudden Death in Patients with Coronary Heart Disease

We have prospectively evaluated the risk of incident coronary events in association with serum total homocysteine in patients with preexisting chronic coronary heart disease. A nested case-control design was used. Total homocysteine concentration was measured in baseline fasting serum samples from patients with chronic coronary heart disease enrolled in the Bezafibrate Infarction Prevention Study (n = 3,090) who developed coronary events during 6.2 years of follow-up (n = 69). They were matched for age and gender with controls without subsequent cardiovascular events. Elevated homocysteine levels were associated with 2.5 times higher risk of subsequent coronary events and each 5 mumol/l increment was associated with a 25% higher risk.