Association between serum homocysteine, vitamin B12, folate and Thai coronary artery disease patients.

BACKGROUND: Homocysteine is an intermediate compound formed during metabolism of methionine. The plasma level of homocysteine is dependent on the genetically regulated level of essential enzymes and the intake of folic acid, vitamin B6 (pyridoxine), and vitamin B12 (cobalamine). Elevated serum homocysteine levels are a known risk factor for coronary artery disease (CAD). To establish the magnitude of the CAD that is associated with an increased serum homocysteine level, we compared CAD patients with normal healthy Thai controls. METHOD: In a cross-sectional study design we investigated the association between serum homocysteine, vitamin B12 and folate levels and the coronary heart disease in 178 CAD patients and 178 normal healthy controls by age and sex matching. These comprised 266 men and 90 women, mean age 58 +/- 10 years for normal controls and 60 +/- 10 years for CAD patients. Serum homocysteine, vitamin B12 and folate were measured by ELISA method and electrochemiluminescense method respectively. RESULTS: Paired t-test analysis showed that serum homocysteine concentrations were significantly higher in CAD patients (23.83 +/- 11.29 mumol/L) than in control subjects (19.69 +/- 8.51 mumol/L; p < 0.001). Homocysteine levels were also higher in males than in females. These findings were similar in healthy controls (male: 20.37 +/- 8.5 mumol/L, female: 17.77 +/- 8.2 mumol/L, p < 0.05) and in CAD patients (male: 24.91 +/- 11.8 mumol/L, female: 20.73 +/- 8.9 mumol/L, p < 0.05). Homocysteine above 17 mumol/L occurred more common in CAD patients than in control groups (OR = 1.65, 95% CI = 1.09-2.52, p = 0.0249). Low levels of vitamin B12 and folate did not reaching statistical significance when comparing controls and CAD patients. CONCLUSIONS: Serum homocysteine concentrations were significantly higher in CAD patients than in controls. Serum vitamin B12 and serum folate levels were not statistically significantly different between CAD patients and control groups. The data also demonstrated that the serum homocysteine level is almost always higher in men than in women as previously reported. Although serum vitamin B12 and serum folate levels were not below the upper limit of normal, vitamin B12 and folic acid treatment may reduce serum homocysteine concentrations in CAD patients. We hope that the reversible risk factors will be concern to clinicians for the reduction in the risk of myocardial infarction.

The prevalence of Chlamydia pneumoniae antibodies in Thai patients with coronary artery disease.

Blood samples were obtained from 243 consecutive coronary artery disease (CAD) patients (177 male, 66 female) aged 35-78 years (mean, 61 years) admitted for coronary angiography because of suspected coronary heart disease, and from 115 blood donors (91 male, 24 female) aged 25-60 years (mean, 47 years). Of the 243 CAD patients, 179 (74%) were positive by an ELISA method for Chlamydia pneumoniae antibodies IgG and 132 (54%) were positive for C. pneumoniae IgA. Among the 115 blood donors, 80 (70%) were positive for C. pneumoniae IgG and 49 (43%) were positive for C. pneumoniae IgA. When IgG antibodies were considered, there was no significant difference between CAD patients and healthy controls (OR = 1.29, 95% CI = 0.79-2.10, p > 0.05). In cases of positive IgA antibodies alone, there was a significant difference between CAD patients and healthy controls (OR = 1.58, 95% CI = 1.01-2.4, p = 0.029). If both IgG and IgA antibodies were positive, OR was increased from 1.58 to 1.80 (95% CI = 0.97-3.36, p = 0.044). In conclusion, C. pneumoniae infection is common in Thai people but chronic C. pneumoniae infection is more common in CAD patients than in middle-aged blood donors.

Carotid duplex scan; the first experience in Thailand.

To assess the clinical significance of carotid duplex scan in Thai patients, 53 healthy volunteers and 107 patients with either atherosclerotic heart/brain diseases, or associated with risk factors for atherosclerosis were examined by carotid duplex scan. The degrees of carotid stenosis were enumerated and classified as normal (0*), mild (< 40%), moderate (41 – 70%) and severe (> 70%) according to percentages of the thickest atheromatous plaque relative to the carotid diameter. There was 30 males and 23 females age ranged 33-63 years old in normal control group. The acute strike patients comprised of 37 males and 24 females with age range of 53-93 years. There were 23 patients of coronary thrombosis, 13 males and 10 females (age range 48-83 years). The asymptomatic patients with risk factors for atherosclerosis were 17 males and 10 females (between 43-63 years). There were 4 cases that had both coronary and cerebral thrombosis. The degree of carotid stenosis in the normal group was compared with the patients group. A P-value <0.05 was considered to be a significant difference. In normal volunteers, no atheromatous plaques were detected. There were significantly higher degrees of carotid stenosis in patients (p < 0.05) compared to normal subjects. Patients with cerebral thrombosis revealed the degree of 56% while in patients with the risk factors of ischemic heart-brain diseases the degree was 36% and the degree was 26% in angiographic proven coronary thrombosis. Carotid duplex scan is a new non-invasive ultrasonographic technique that can detect and monitor the progression of atherosclerosis.