Summary
| Direction in Gulf War Illness | ↑ Elevated — higher than in the comparison group |
|---|---|
| Category | Metabolic |
| Also described as | Sulfur amino acid metabolite |
| Compared against | HGV (healthy Gulf War veteran controls) |
| Associated symptoms | Vascular, cognitive dysfunction |
| Test type | Blood test (serum / plasma / whole blood) |
| LOINC code | 13965-9 |
| Source | Maury & Holton 2024 — doi:10.1016/j.lfs.2024.122876 |
| Condition atlas | Gulf War Illness Biomarker Atlas |
Trials, interventions and tests
In clinical-trial registrations this marker maps to the outcome term Change Methylmalonic Acid and Homocysteine (1 registered trials use a matching outcome measure).
Clinical trials using Homocysteine as an outcome
- NCT06255600: High-definition Transcranial Direct Current Stimulation and Chlorella Pyrenoidosa to Reduce Cardiovascular Risk (Unknown)
Outcome measure: Change Methylmalonic Acid and Homocysteine
Commercial test availability
Homocysteine — commercial laboratory test.
Links are for reference only; availability, specimen requirements and coverage vary by location.
Related Metabolic markers in Gulf War Illness
- Glutathione (GSH) ↓
- GSH:GSSG ratio ↓
- 8-isoprostane ↑
- Coenzyme Q10 ↓
- Acylcarnitines ↑
- Lactate ↑
- Vitamin D (25-OH) ↕
Full list: Gulf War Illness Biomarker Atlas.
Frequently asked questions
Is Homocysteine high or low in Gulf War Illness?
Elevated. Studies summarised in the OSMF atlas report higher Homocysteine in Gulf War Illness than in healthy Gulf War veteran controls. Source: Maury & Holton 2024.
What symptoms is Homocysteine associated with in Gulf War Illness?
The cited literature associates this marker with Vascular, cognitive dysfunction. These are population-level associations and do not mean the marker causes the symptoms.
Which test measures Homocysteine?
It is measured as a blood test (serum / plasma / whole blood). The standard laboratory code is LOINC 13965-9. Commercial laboratories such as Quest Diagnostics, LabCorp, Ulta Lab Tests list an orderable assay.
Is one abnormal Homocysteine result diagnostic of Gulf War Illness?
No. No single biomarker is diagnostic of Gulf War Illness. Homocysteine findings come from group comparisons, overlap considerably between patients and controls, and vary with study design, timing and comparison group. A result should be interpreted by a clinician alongside symptoms, history and other tests.
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Last reviewed: 2026-06-29 · Page generated from gulf-war-illness.json · Browse: Gulf War Illness atlas · Biomarker Index · All marker pages
Disclaimer: This page is an educational synthesis of published, peer-reviewed research and is not medical advice. Biomarker findings vary across studies with case definitions, comparison groups, timing and assay methods. Direction of change reflects the predominant finding in the cited source and does not establish a diagnostic threshold. Discuss any test result with a qualified clinician.