1.
[Significance of Homocysteine in Glaucoma].
Jünemann, A, Rejdak, R, Hohberger, B
Klinische Monatsblatter fur Augenheilkunde. 2018;(2):163-174
Abstract
Endothelial dysfunction and vascular dysregulation play a role in the multifactorial pathogenesis of glaucomatous optic nerve atrophy. Hyperhomocysteinemia is a risk factor for endothelial dysfunction and is associated with primary open-angle glaucoma as well as secondary open-angle glaucoma in the pseudoexfoliation syndrome. This paper reviews the literature on the association between homocysteine metabolism and glaucomatous disease and explains the possible role of hyperhomocysteinemia in the pathogenesis and progression of glaucoma. We discuss the role of exogenous modifiable risk factors for the prevention and therapy of glaucoma, as well as modification of these factors by changes in life style, such as weight reduction, changes in nutrition and physical activity. The roles of homocysteine in regulating the extracellular matrix, vasotoxicity, neurodegeneration, and epigenetics are explained. Prevention and therapy of glaucoma by regulation of homocysteine levels are discussed.
2.
[Hyperhomocysteinemia and kidney diseases].
Zhou, YF, Guan, YF
Sheng li xue bao : [Acta physiologica Sinica]. 2018;(6):607-611
Abstract
Homocysteine (Hcy) is an intermediate metabolite of methionine metabolism. Hyperhomocysteinemia (HHcy) is defined as a condition characterized by plasma Hcy level above 16 μmol/L which can result from abnormal Hcy metabolism. HHcy has been confirmed to be related to cardio-cerebrovascular disease, peripheral vascular disorders, neurodegenerative diseases, diabetes, pregnancy-induced hypertension syndrome, liver cirrhosis and kidney diseases. In this review, we summarize the correlation between HHcy and kidney diseases. Elucidating the role of HHcy in kidney diseases may provide a new strategy to prevent and treat kidney diseases.
3.
[Consequences of moderate hyperhomocysteinemia in internal medicine].
Zák, A, Zeman, M
Casopis lekaru ceskych. 2004;(6):367-74
Abstract
Homocysteine is an intermediate product in the methionine metabolism, which is catalysed by several enzymes with B2, B6, B12 vitamins and folic acid as cofactors. Moderate hyperhomocysteinemia, defined as total homocysteine concentration between 12 to 30 micromol/l, represents an independent risk factor for heart disease, vascular brain disease, phlebothrombosis and thromboembolic complications. It is related to placental abruptions, spina bifida and some neuropsychiatric disorders. Hyperhomocysteinemia is a metabolic syndrome based on interaction between genetic factors (most frequently 677C/T polymorphism of methylentetrahydrofolate reductase), diseases and demographic factors (smoking, aging, hormonal and nutritional factors). Moderate hyperhomocysteinemia occurs in about 20 to 30% of patients with clinical complications of atherosclerosis. Prospective and genetic studies have shown, that moderate hyperhomocysteinemia in healthy persons is only a weak predictor of cardiovascular diseases. Contrary to it, in patients with ischaemic heart disease, renal failure or diabetes mellitus and in thromboembolic disease, hyperhomocysteinemia represents a strong predictor of vascular morbidity and mortality. Toxic effects of hyperhomocysteinemia on the vascular wall can be explained by a chemical modification of lipoproteins and vascular structure, oxidative stress, endothelial dysfunction, inadequate endothelial cell regeneration, smooth muscle cell proliferation or by an accumulation of functionally non sufficient connective tissue. Also thrombogenic effects or an increased expression of cholesterol level controlling proteins and fatty acids in the liver can be considered. Treatment of hyperhomocysteinemia is based on the administration of pharmacological doses of folic acid, B6 and B12 vitamins, which can decrease total homocysteine concentration by 25 to 30%. Such decrease, which is in average 3 micromol/l, results in the decrease of relative risk of ischaemic heart disease by 11 to 16%, phlebothrombose by 25% and vascular brain diseases by 19 to 24%.