title: Plasma total homocysteine in healthy subjects: sex-specific relation with biological traits.
abstract: Fasting plasma total homocysteine (tHcy) concentration was measured in 380 men and 204 women selected for health on the basis of clinical history, physical examination, and normal results of a biochemical profile. We sought to define tHcy reference values in healthy individuals and to determine relations between tHcy and plasma folic acid, vitamin B-12, and pyridoxal phosphate (vitamin B-6) concentrations. Men had significantly higher plasma tHcy than women (9.7 +/- 4.9 compared with 7.6 +/- 4.1 mumol/L, x +/- SD) and lower folate concentrations (8.6 +/- 5.2 compared with 9.8 +/- 6.6 nmol/L, P < 0.05). Significant correlations were found between tHcy and uric acid, creatinine, albumin, folate, and vitamin B-12 concentrations. There was no correlation with age, body mass index, blood pressure, glucose, and total and lipoprotein lipids. When divided in quartiles of vitamin concentrations, subjects with the lowest vitamin B-12 and folate values had significantly higher tHcy concentrations than those in the other three quartiles. Interestingly, after exclusion of subjects in the lowest quartiles of folate and vitamin B-12 concentration, correlations between tHcy and vitamin concentrations were no longer observed, except for vitamin B-12 in men. Stepwise-multiple-regression analyses showed that the sex-specific influence of biological variables on tHcy concentrations was twice as important in healthy women than in healthy men. This study emphasizes the significance of sex-associated differences in the biology of homocysteine and underlines the importance of considering these in the determination of threshold values.
authors.affiliation: Hyperlipidemia and Atherosclerosis Research Group, Hôtel-Dieu Hospital, Montreal, Canada. cacans@ircm.umontreal.ca
authors.forename: S
authors.initials: S
authors.lastname: Lussier-Cacan
authors.forename: M
authors.initials: M
authors.lastname: Xhignesse
authors.forename: A
authors.initials: A
authors.lastname: Piolot
authors.forename: J
authors.initials: J
authors.lastname: Selhub
authors.forename: J
authors.initials: J
authors.lastname: Davignon
authors.forename: J
authors.initials: J
authors.lastname: Genest
mesh_terms: D000328:Adult; D005260:Female; D005492:Folic Acid / Q000097:blood; D006304:Health Status; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011732:Pyridoxal Phosphate / Q000097:blood; D012016:Reference Values; D012044:Regression Analysis; D012727:Sex Characteristics; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D006710:Homocysteine; D011732:Pyridoxal Phosphate; D005492:Folic Acid; D014805:Vitamin B 12