High prevalence of hyperhomocysteinemia in critically ill patients.

Objective: To test the hypothesis that the prevalence of hyperhomocysteinemia is increased in critically ill patients and correlates with disease severity and mortality in these patients.

Design: A prospective study.

Setting: Three medical intensive care units at the University of vienna Medical School serving both medical and surgical patients.

Patients: All consecutive admissions (n = 56) during a period of 4 wks. A total of 112 age- and gender-matched healthy individuals constituted the control group.

Interventions: None.

Measurements And Main Results: Blood samples were drawn within 24 hrs after admission for analysis of total homocysteine (tHcy), folate, vitamin B6 levels, and vitamin B12 levels as well as to identify the 677C-->T polymorphism in the gene coding for the enzyme 5,10-methylenetetrahydrofolate reductase. Acute Physiology and Chronic Health Evaluation III scores at admission and 24 hrs after admission as well as 30-day survival were documented in all patients. Hyperhomocysteinemia was more prevalent in critically ill patients (16.1%; 95% confidence interval, 7.6% to 28.3%) compared with age- and gender-matched healthy individuals (5.4%; 95% confidence interval, 2.0% to 11.3%; chi-square test; p = .022). There was no difference in tHcy plasma concentrations in the first 24 hrs after admission to an intensive care unit between survivors and nonsurvivors. The 5,10-methylenetetrahydrofolate reductase 677C-->T polymorphism had no influence on tHcy levels and survival of intensive care unit patients.

Conclusions: The prevalence of hyperhomocysteinemia is increased in critically ill patients compared to age- and gender-matched healthy individuals. The clinical significance of this finding remains to be determined.