Heart attacks and homocysteine

Evaluation of Oxidative Stress and hsCRP in Polycystic Ovarian Syndrome in a Tertiary Care Hospital

PCOS is a heterogeneous endocrine disorder with diverse clinical presentation. Oxidative stress plays a key role in the pathophysiology of this disease. Serumhigh sensitive C-reactive protein (hsCRP), a marker of chronic low grade inflammation, is indicative of future development of cardiovascular disease. Our aim is to evaluate the oxidant status and hsCRP levels in PCOS. The study involved 61 cases and 61 controls in the age group of 18-40 years diagnosed with PCOS. Erythrocyte malondialdehyde (MDA), superoxide dismutase (SOD), serum hsCRP, gonadotrophins, thyroid stimulating hormone, prolactin, glycemic status and lipid profile were estimated. Erythrocyte MDA (p < 0.001), SOD (p = 0.007) and serum hsCRP (p < 0.001) were significantly elevated in PCOS patients than controls. Oxidative stress is present in women with PCOS along with elevated hsCRP.

Does folate therapy reduce the risk of coronary restenosis?

BACKGROUND.: A high homocysteine level is associated with an increased risk of ischaemic heart disease. Folate therapy has shown to reduce the homocysteine blood level, but does it decrease the risk of coronary restenosis in patients with coronary arterial disease? METHODS.: A systematic online literature search followed by a critical appraisal resulted in three suitable articles to provide an evidence-based evaluation of this clinical query. RESULTS.: The rate of coronary restenosis was reduced after folate therapy, except in patients who have had coronary stenting. An adverse effect of folate therapy on in-stent coronary restenosis was observed. CONCLUSION.: The effects of folate therapy on the rate of coronary restenosis after balloon angioplasty are contradicting. Until more clinical research has been preformed we recommend a conservative attitude towards folate therapy. (Neth Heart J 2007;15:12-5.).

Cobalamin status in children

Cobalamin and the metabolic markers methylmalonic acid and total homocysteine undergo marked changes during childhood. In breastfed infants a metabolic profile indicative of cobalamin deficiency is common. Symptoms of cobalamin deficiency in children differ with age, presenting a continuum from subtle developmental delay to life-threatening clinical conditions. The symptoms may be difficult to detect, particularly in infants, and there tends to be a diagnostic delay of several months in this age group. Several reports show that even moderate deficiency in children may be harmful, and long-term consequences of neurological deterioration may persist after cobalamin deficiency has been treated. Given the crucial role of cobalamin for normal growth and development, possible widespread infantile deficiency needs attention. Cobalamin deficiency should be considered a differential diagnosis in children with subtle symptoms, and strategies to prevent cobalamin deficiency in mothers and children should be addressed.

Plasma homocysteine and hematological factors in patients with venous thromboembolic diseases in Kuwait

BACKGROUND

Venous thromboembolic disease (VTE) is a common cause of morbidity in Kuwait, but the risk factors have not been studied. Hyperhomocysteinemia has been suggested as one of the risk factors. We postulate that hyperhomocysteinemia acts synergistically with hematological variables to increase VTE risk. This study evaluates the roles of hyperhomocysteinemia and hematological variables in patients with VTE.

METHODS

We measured fasting plasma total homocysteine (tHcy), activated protein C resistance, protein C (PC), protein S (PS) and antithrombin (AT) in 201 patients with VTE and 166 healthy controls. We also measured factor VIII, factor II, lupus anticoagulant, anticardiolipin, serum vitamin B12, folate, creatinine, lipid profile, glucose, full blood count and red cell folate. The glomerular filtration rate (GFR) was calculated from creatinine.

RESULTS

When patients on warfarin were excluded, 13.1% of patients (18 out of 137) had a deficiency in PC, 16.8% (23 out of 137) had a deficiency in PS, and when patients on heparin were excluded, 8.3% of patients (14 out of 168) had low AT. Spearman's rank correlation analysis showed that tHcy had significant correlations with age, creatinine and PS, and significant inverse correlations with GFR, high-density lipoprotein cholesterol and serum folate. Partial correlation analysis after correcting for age and sex showed that tHcy retained a significant correlation with creatinine, GFR and serum folate. Binary logistic regression analyses of the determinants of hyperhomocysteinemia included age, creatinine, GFR and serum folate. Multivariate logistic regression analysis showed significant association of tHcy with VTE (OR = 5.6; p < 0.0001) in the presence of known risk factors for VTE.

CONCLUSION

We conclude that elevated tHcy is a significant risk factor for the development of VTE, and therefore, it should be included in the workup for patients at risk of VTE, but the determinants of tHcy should be kept in mind.

Determinants of plasma homocysteine in relation to hematological and biochemical variables in patients with acute myocardial infarction

BACKGROUND

Elevated plasma total homocysteine (tHcy) is a risk factor for coronary artery disease (CAD), but the mechanism is not known. This study evaluates the determinants and associations of tHcy in patients presenting with acute myocardial infarction (AMI).

METHODS

Plasma concentration of tHcy, protein C, protein S, and antithrombin were measured in 210 (177 males and 33 females) patients with first AMI and 167 (87 males and 80 females) controls. Serum vitamin B12, folate, creatinine, lipid profile, fasting glucose, full blood count and red cell folate were determined. Creatinine clearance was calculated using the modification of diet in renal disease formula. Univariate and multivariate analyses were used to determine the associations of tHcy.

RESULTS

Mean tHcy was higher in male than female patients. On logistic regression analysis, the most important determinants oftHcy in the patients were age, creatinine, creatinine clearance, vitamin B12 and red cell folate. When study patients were compared with the controls, tHcy, fasting glucose and serum creatinine were significantly higher, while creatinine clearance and HDL cholesterol were significantly lower in the study patients. Logistic regression analysis showed significant association of tHcy with AMI, odds ratio = 1.39, in the presence of other confounding factors.

CONCLUSIONS

Our results show that tHcy is a significant risk factor for CAD in our patient population. The determinants in the patients are age, glomerular filtration rate and the status of vitamins B12 and folate. The above determinants should be kept in mind when using tHcy as a risk factor for CAD.

Cardiovascular risk in women with polycystic ovarian syndrome (PCOS)

AIMS

Studies have suggested that polycystic ovary syndrome (PCOS) is associated with increased cardiovascular risk. The aim of this study was to examine cardiovascular risk profiles in women with PCOS compared with healthy age and weight matched control subjects using novel biochemical and biophysical markers.

METHODS

After ethics committee approval, 11 women with PCOS and 12 controls were recruited (mean age, 32; SD, 6.5 years; mean body mass index (BMI), 33.1; SD, 5.9 kg/m2). Serum was analysed for lipid and lipoprotein profile (total and high density lipoprotein cholesterol, triglycerides, apolipoprotein B-100, apolipoprotein A1, lipoprotein (a)), and sialic acid, fibrinogen, homocysteine, and C reactive protein (CRP) concentrations. Endothelial function was also assessed by a standard venous occlusion plethysmography technique to measure reactive hyperaemic forearm blood flow (RH), and expressed as per cent increase from baseline.

RESULTS

There were no significant differences in glucose, lipid, or lipoprotein concentrations between the two groups. Furthermore, sialic acid (PCOS: mean, 70.5; SD, 149 mg/litre; controls: mean, 71.3; SD, 112 mg/litre), fibrinogen (PCOS: mean, 3.1; SD, 1.0 g/litre; controls: mean, 3.3; SD, 0.7 g/litre), CRP (PCOS: mean, 4.6; SD, 4.2 mg/litre; controls: mean, 5.41 SD, 5.5 mg/litre), and RH (PCOS: mean, 158.7; SD, 135.5%; controls: mean, 200.1; SD, 114.2%) were similar.

CONCLUSIONS

There were no differences in surrogate markers of the processes linked to enhanced cardiovascular risk between patients with PCOS and weight matched controls.

Similarities in the epidemiology of neural tube defects and coronary heart disease: is homocysteine the missing link?

It is hypothesised that a single aetiological pathway could explain both the strong ecological association between the birth prevalence of neural tube defects (NTD) and coronary heart disease (CHD) mortality and the potential efficacy of dietary measures, especially increased folic acid intake, in their prevention. The epidemiological similarities between NTD and CHD are strong and consistent suggesting that the relation is real rather than artefactual. It is suggested that this epidemiological association reflects a shared aetiology arising from the role of disturbed homocysteine metabolism in the pathogenesis of both conditions. Current public health measures designed to increase the intake of periconceptional folic acid in women, reinforced by a broadening of this policy to target both sexes throughout life, will (if successful) result in a reduction in both the birth prevalence of NTD and the incidence of CHD, although not necessarily contemporaneously. If disordered homocysteine metabolism is the cause of both NTD and CHD, this has implications for future research and preventive strategies for these serious and often lethal diseases.

Homocysteine and cardiovascular disease

An elevated level of total homocysteine (tHcy) in blood, denoted hyperhomocysteinemia, is emerging as a prevalent and strong risk factor for atherosclerotic vascular disease in the coronary, cerebral, and peripheral vessels, and for arterial and venous thromboembolism. The basis for these conclusions is data from about 80 clinical and epidemiological studies including more than 10,000 patients. Elevated tHcy confers a graded risk with no threshold, is independent of but may enhance the effect of the conventional risk factors, and seems to be a particularly strong predictor of cardiovascular mortality. Hyperhomocysteinemia is attributed to commonly occurring genetic and acquired factors including deficiencies of folate and vitamin B12. Supplementation with B-vitamins, in particular with folic acid, is an efficient, safe, and inexpensive means to reduce an elevated tHcy level. Studies are now in progress to establish whether such therapy will reduce cardiovascular risk.

An audit of the investigation and treatment of folic acid deficiency

On the suspicion that folate deficiency was not being thoroughly investigated we conducted a retrospective study of management in a teaching hospital. Notes from 84 consecutive patients with low red cell folates (mean age 69.5 years, range 21-95, M:F 33:51) were reviewed for haemoglobin, mean cell volume, dietary history, alcohol consumption, drug history, relevant medical history, relevant investigations, treatment, repeat measurement of red cell folate and diagnosis of deficiency. In 52 (61.9%, mean age 72.9 years, range 33-95, M:F 21:51) no diagnosis was reached. In only 32 (38.1%, mean age 63.9 years, range 21-89, M:F 12:20) was a definitive diagnosis established: 5 had coeliac disease, 1 had Crohn's disease, 9 had drug-associated deficiency (4 methotrexate, 3 phenytoin, 1 trimethoprim and 1 valproate), 1 had combined variable immunodeficiency and 16 had dietary deficiency. In most cases of folic acid deficiency no attempt was made to establish aetiology. We recommend that younger patients without an obvious cause are investigated initially by dietary assessment and measurement of anti-endomysial antibody and by duodenal biopsy with small-bowel follow-through if clinically indicated.

Homocysteine and vascular dysfunction

Elevated plasma levels of homocysteine and disulfide adducts of homocysteine (collectively termed "homocyst(e)ine") are associated with increased risk of thrombotic and atherosclerotic vascular disease. It is still not evident, however, whether moderately elevated plasma homocyst(e)ine concentration per se is a cause, or rather just a marker for an associated condition that may predispose to development of vascular disease or its complications. This distinction has important clinical consequences, since dietary intervention to lower plasma homocyst(e)ine has been proposed as a global strategy to decrease the prevalence of vascular disease. Studies of cultured cells in vitro have led to the hypothesis that homocysteine may predispose to vascular disease by altering the normally antithrombotic and vasoprotective phenotype of vascular endothelium, perhaps through a mechanism that involves generation of peroxides and other reactive oxygen species. Recent findings in animal and human models of moderate hyperhomocyst(e)inemia provide support for some aspects of this hypothesis. Endothelial dysfunction in hyperhomocyst(e)inemia may contribute to development of atherosclerosis and predispose to complications such as thrombosis and vasospasm. Important questions to be addressed in future investigations include the relative importance of homocysteine versus associated conditions (such as folate deficiency) in the etiology of vascular dysfunction, the role of homocysteine-induced oxidant stress, and the potential benefits of lowering plasma homocyst(e)ine levels through dietary supplementation with B vitamins.