OBJECTIVES We sought to use positron emission tomography (PET) to test the hypothesis that hyperhomocysteinemia adversely effects coronary microvascular dilator function. BACKGROUND Hyperhomocysteinemia is associated with abnormal endothelium-dependent vasodilation in peripheral human arteries. However, its effect on the coronary circulation is not known. METHODS Eighteen healthy humans, ag...

BACKGROUND Low vitamin B12 concentration in South Asian Indians is common, but the exact prevalence is not known. AIM To investigate prevalence and associations of low vitamin B12 concentration and hyperhomocysteinemia in rural and urban Indian men living in and around Pune, Maharashtra. METHOD We studied 441 middle-aged men (149 rural, 142 slum and 150 urban middle-class residents, mean ag...

In a large retrospective study of thrombophilic families, we analyzed 405 relatives of patients, hypothesizing that hyperhomocysteinemia and elevated factor VIII levels are closely related. Median factor VIII levels in hyperhomocysteinemic relatives were 169 IU/dL, compared with 136 IU/dL in normohomocysteinemic relatives (p =0.007), and were more often elevated (>150 IU/dL; p =0.006). Hyperhom...

In the last couple of decades many studies have been carried out on the association of moderately high plasma levels of total homocysteine (tHcy) with coronary artery disease, cerebrovascular disease, peripheral artery disease and venous thromboembolism. Most studies showed a positive association between tHcy and thrombosis risk. However, despite this, many investigators are still skeptical abo...

Hyperhomocysteinemia and other major cardiovascular risk factors are associated with increased vascular oxidative stress. To access the effects preoperative plasma homocysteine levels and other atherosclerotic risk factors on myocardial ischemia-reperfusion injury after conventional coronary artery bypass, 213 patients with normal renal function were enrolled prospectively. Cardiac troponin T w...

Rats were fed 25% casein (25C) diets differing in choline levels (0-0.5%) with and without 0.5% guanidinoacetic acid (GAA) or 0.75% L-methionine for 7 d to determine the effects of dietary choline level on experimental hyperhomocysteinemia. The effects of dietary choline (0.30%) and betaine (0.34%) on GAA- and methionine-induced hyperhomocysteinemia were also compared. Dietary choline suppresse...

Hyperhomocysteinemia has recently been identified as an important risk factor for atherosclerotic vascular disease. This article reviews homocysteine metabolism, causes of hyperhomocysteinemia, the pathophysiological findings of this disorder, and epidemiological studies of homocysteine and vascular disease. Screening for hyperhomocysteinemia should be considered for patients at high risk for v...

BACKGROUND AND PURPOSE Hyperhomocysteinemia and protein C deficiency are risk factors for thromboembolism. Hyperhomocysteinemia has been reported to inhibit the expression of thrombomodulin and to inactivate both thrombomodulin and protein C irreversibly, leading to decreased protein C activity. CASE DESCRIPTIONS In a 16-year-old girl, who developed a sinus sagittalis thrombosis, and in her f...

Hyperhomocysteinemia is an important risk factor for preeclampsia-eclampsia. This study established a pregnant rat model of hyperhomocysteinemia, in which blood plasma homocysteine concentrations were twice or three times greater than that of normal pregnant rats. TUNEL revealed an increase in the number of apoptotic cells in the frontal cortex of pregnant rats with hyperhomocysteinemia. In add...

Several neurodegenerative conditions, such as Alzheimer's disease and Parkinson's disease, or vascular dementia and cognitive impairment, are associated with mild hyperhomocysteinemia. Hyperhomocysteinemia is defined as an increase of the homocysteine (Hcy) level beyond 10 microM. Although the adverse effect of Hcy on neurons is well documented, knowledge about the impact of this amino acid on ...