Introduction and objectives: We have already proved that basal and after load homocysteinemia are risk factors for vascular disease and it is also known that premenopausal women are relatively protected against this disease. The objective of this paper was the assess whether there are any differences in the plasma levels of homocystein which might contribute to explain the differences in the incidence of vascular diseases found in both sexes.
Patients and methods: Two hundred and four patients (153 males) without previous vascular disease were enrolled in the study. These patients were participating in a screening program for cardiovascular risk factors in a central hospital in Lisbon. We evaluated the basal homocysteinemia and homocysteinemia 6 hours after an oral load with methionine (0.1 g/kg body weight). Basal and after load homocysteinemia in men and women, as well as in women before and after menopause, was compared. Because homocysteinemia does not have a normal distribution, we used non-parametric statistical tests, namely the Mann-Whitney test.
Results: Men had higher values for basal homocysteinemia than women (mean and standard deviation)--9.64 +/- 3.15 versus 8.56 +/- 2.82 mumol/l, (p = 0.0018)--as well as for after load homocysteinemia--24.40 +/- 7.84 versus 23.71 +/- 10.16 mumol/L, non significant difference. Premenopausal women (n = 42) had lower basal homocysteinemia values than post menopausal women (n = 9)--8.41 +/- 3.02 versus 9.23 +/- 1.38 mumol/L, p < 0.05--and similarly after load homocysteinemia values--23.86 +/- 10.65 versus 23.01 +/- 7.47 mumol/L.
Conclusions: Basal homocysteinemia is significantly higher in men than in women. After menopause, basal homocysteinemia levels increase significantly in women, approaching those in men. The levels of after load homocystein are not dependent on sex or pre- or postmenopausal condition. Homocysteinemia might explain, at least partly, the differences in the incidence of vascular disease in both sexes and the increased vascular risk in postmenopausal women.