Plasma homocysteine before and after methionine loading with regard to age, gender, and menopausal status

Abstract

Homocysteine is a probably atherogenic amino acid, the fasting and post-methionine load serum concentrations of which have been reported to be much lower in premenopausal women than in men and postmenopausal women. This difference has been proposed to explain the reduced proneness of premenopausal women to vascular disease. We measured both free and total plasma homocysteine concentrations both fasting and post-methionine load, in 169 healthy subjects. Twelve subjects (7%) had distinctly abnormal plasma homocysteine values. Among the remaining 157 subjects, neither fasting nor post-load values of free or total homocysteine were lower in premenopausal women (n = 46) than in men of similar age (n = 41) or postmenopausal women (n = 37). Fasting but not post-load values were lower in postmenopausal women than in men of similar age (n = 33), and lower among the women as a whole (n = 83) than among the men (n = 74). In men, fasting values increased with age, and paralleled age-related decreases in the concentrations of homocysteine metabolism cofactors (serum vitamin B12, blood folate, and plasma pyridoxal 5-phosphate). Both in men and in women, fasting total plasma homocysteine values were significantly and negatively correlated to serum vitamin B12 and blood folate concentrations. Whether the small differences in plasma homocysteine values between the present men and women may be a contributory factor vis-à-vis their different proneness to vascular disease has yet to be settled.

Tamoxifen reduces plasma homocysteine levels in healthy women

“…This difference may be due not only to the higher dose used (30 mg day-') but also to the abnormal baseline tHcy levels observed in most breast British Journal of Cancer (1998) 77(12), [2264][2265][2266] cancer patients (mean 12.4 gmol 1-') in comparison with normal women (8-9 ,tmol 1-') (Andersson et al, 1992;Nyg'ard et al, 1995). As the high tHcy levels found in breast cancer women might also reflect the activity of tumour cells, the possibility that the inhibitory effect induced by tamoxifen on tHcy was secondary to its antitumoral activity cannot be convincingly ruled out.…”

Elevated Plasma Homocysteine Concentrations Six Months after Gastroplasty in Morbidly Obese Subjects.

“…In a case-control study, Lolin et al (30) showed that the prevalence of hyperhomocysteinemia in Hong Kong Chinese patients with premature coronary artery disease wassimilar to that found in Caucasians. Although we did not follow a control group during this oneyear period, it is unlikely that their homocysteine concentrations would change (31). Wefailed to find a decline in serum folic acid in association with the elevation of homocysteine levels probably because the number of study subjects was relatively limited.…”

Impaired Homocysteine Metabolism and Atherothrombotic Disease

“…This might be partially explained by gender differences in the transsulfuration and remethylation of homocysteine, with a more efficient remethylation in women than in men (Fukagawa et al, 2000), who may have a more efficient transsulfuration (Silberberg et al, 1997). Hormone replacement therapy attenuates the increase in plasma homocysteine observed after menopause (Andersson et al, 1992;Mijatovic et al, 1998;van der Mooren et al, 1994). Black South Africans have lower homocysteine levels than white South Africans consuming the same diet, this resistance may be genetic in origin (Ubbink et al, 1995).…”