Correlates of plasma total homocysteine in patients with hyperlipidaemia

The study sought to define the relation of plasma total homocysteine to biological and clinical variables and to serum vitamin concentrations in patients with primary hyperlipidaemia. Fasting plasma total homocysteine was measured in 219 men and 159 women; vitamin concentrations were available for about 60% of the sample. Men had significantly higher plasma total homocysteine than women [median (25th, 75th percentiles) 9.4 (8.2, 11.5) mumol L-1 vs. 8.5 (7.0, 10.2) mumol L-1; P = 0.0001]. Plasma total homocysteine was lower in women taking lipid-lowering drugs than in women who were not taking drugs. Serum folate and vitamin B12 concentrations were normal for all but one and four subjects respectively. Correlations (P < or = 0.06) were found between plasma total homocysteine and age, triglyceride concentration in women, uric acid concentration in men, serum folate, vitamin B12 and creatinine concentrations. In multiple regression analysis, the association between plasma total homocysteine and sex and between plasma total homocysteine and use of lipid-lowering drugs disappeared when creatinine concentration was entered into the analysis. This study shows that plasma total homocysteine is related to vitamin concentrations within the normal range, suggesting that plasma total homocysteine may be modifiable by diet in hyperlipidaemic subjects with normal vitamin nutrition. Sex-related differences appear to be related to men's higher creatinine concentration. Whether lipid-lowering drugs interact with total homocysteine concentration requires further study.