Homocysteine (Hcy) metabolism is crucial for regulating methionine availability, protein homeostasis, and DNA-methylation presenting, therefore, key pathways in post-genomic and epigenetic regulation mechanisms. Consequently, impaired Hcy metabolism leading to elevated concentrations of Hcy in the blood plasma (hyperhomocysteinemia) is linked to the overproduction of free radicals, induced oxidative stress, mitochondrial impairments, systemic inflammation and increased risks of eye disorders, coronary artery diseases, atherosclerosis, myocardial infarction, ischemic stroke, thrombotic events, cancer development and progression, osteoporosis, neurodegenerative disorders, pregnancy complications, delayed healing processes, and poor COVID-19 outcomes, among others. This review focuses on the homocysteine metabolism impairments relevant for various pathological conditions. Innovative strategies in the framework of 3P medicine consider Hcy metabolic pathways as the specific target for in vitro diagnostics, predictive medical approaches, cost-effective preventive measures, and optimized treatments tailored to the individualized patient profiles in primary, secondary, and tertiary care.
Keywords: Amino acids; Blood plasma; COVID-19; Cancers; Cardiovascular risk; Cellular senescence; Coronary artery disease; DNA methylation; Diagnostic and treatment targets; Dietary habits; Endothelial dysfunction; Epigenetics; Eye disorder; Folate; Genetics; Health policy; Health risk assessment; Homocysteine; Hyperhomocysteinemia (HHcy); Impaired healing; Inflammation; Ischemic stroke; Metabolism; Mitochondrial impairment; Molecular pathways; Neurological disorders; Nutrition; Oxidative stress; Predictive Preventive Personalized Medicine (PPPM/3PM); Pregnancy complications; Primary, secondary, and tertiary care; Prognosis; Proteins; Remethylation; Systemic effects; Transsulfuration; Vitamin B6 and B12.
© The Author(s) 2021.