Clinical relevance of hyperhomocysteinaemia in atherothrombotic disease

Area of Science:

• Cardiovascular Medicine
• Clinical Biochemistry
• Nutritional Science

Background:

• Elevated fasting plasma homocysteine levels (> 12-15 mumol/L) are prevalent and linked to increased atherothrombotic disease risk.
• High post-methionine loading homocysteine levels (> 40-50 mumol/L) are also common, though less studied in relation to atherothrombotic disease.
• Folic acid and pyridoxine are established treatments for normalizing homocysteine levels.

Purpose of the Study:

• To review the association between elevated homocysteine levels and atherothrombotic disease.
• To discuss the efficacy of homocysteine-lowering therapies.
• To provide guidance on clinical management strategies pending further research.

Main Methods:

• Literature review of studies on plasma homocysteine levels and atherothrombotic disease.
• Analysis of evidence regarding the effectiveness of folic acid and pyridoxine treatments.
• Evaluation of current clinical practice guidelines for managing hyperhomocysteinemia.

Main Results:

• Strong, though not definitive, evidence suggests a causal link between high homocysteine and atherothrombotic disease.
• Folic acid (1-5 mg/day) and pyridoxine (50-250 mg/day) are effective in reducing plasma homocysteine.
• Randomized trials on clinical outcomes are expected in 4-6 years.

Conclusions:

• Consider homocysteine-lowering therapy for very high-risk patients (e.g., early-onset atherothrombotic disease, end-stage renal disease, strong family history).
• Current recommendations should be re-evaluated as trial results become available.
• Further research is needed to definitively establish the causal role of homocysteine in atherothrombotic disease.