Hyperhomocysteinemia: a new risk factor for degenerative diseases

Area of Science:

• Biochemistry
• Cardiovascular Medicine
• Neurology

Background:

• Hyperhomocysteinemia (HHCY) arises from disrupted methionine metabolism, often due to enzyme or vitamin deficiencies.
• Elevated homocysteine (HCY) levels are independently linked to atherosclerotic cardiovascular diseases, stroke, peripheral arterial occlusive disease, and venous thrombosis.
• HHCY is also associated with neurodegenerative conditions like cognitive impairment, dementia, Alzheimer's disease, and depression.

Purpose of the Study:

• To review the established role of HHCY as a risk factor for various diseases.
• To highlight the prevalence of HHCY, particularly vitamin B12 deficiency, in specific populations.
• To emphasize the importance of early diagnosis and potential therapeutic interventions.

Main Methods:

• Review of epidemiological and clinical studies.
• Discussion of diagnostic markers for vitamin B12 deficiency, including serum methylmalonic acid and holotranscobalamin II.
• Identification of patient groups with a high prevalence of HHCY.

Main Results:

• HHCY is a confirmed independent risk factor for cardiovascular and cerebrovascular diseases.
• A high prevalence of HHCY, linked to vitamin B12 deficiency, is observed in the elderly and strict vegetarians.
• More reliable diagnosis of vitamin B12 deficiency is achieved through methylmalonic acid and holotranscobalamin II measurements compared to total vitamin B12.

Conclusions:

• HHCY is a significant risk factor for cardiovascular and neurodegenerative diseases, as well as adverse pregnancy outcomes.
• Early detection of vitamin B12 deficiency is critical for preventing neurological damage, especially in vulnerable groups.
• Measuring HCY is recommended for patients with a history of atherothrombotic diseases, diabetes, hyperlipidemia, renal disease, obesity, and in elderly individuals, vegetarians, postmenopausal women, and during early pregnancy.