Endothelial function in healthy younger and older hyperhomocysteinemic subjects

Abstract

Objetives: To compare endothelium-dependent vasomotor response in healthy younger and older subjects without classic cardiovascular risk factors, with high and normal fasting homocysteine (tHcy) levels. Design: We compared endothelium-dependent vasodilatation, using ultrasound, in healthy younger (aged 18-40) and older (greater than or equal to70) people with normal (<13 &mu;mol/L) and high (>15 mumol/L) tHcy levels. Exclusion criteria were smoking, personal history of cardiovascular disease, hypertension, chronic diseases, vitamin intake, obesity, abnormal serum lipids levels, and creatinine higher than 00 mumol/L. Setting: Research laboratory. Measurements: In addition to tHcy levels, serum folate and vitamin B-12 levels were measured. Results: We studied 17 younger and 12 older hyperhomocysteinemic subjects and respective aged-matched normohocysteinemic subjects. Endothelium-dependent vasodilatation was lower in the hyperhomocysteinemic older people (P <.01) than in all younger subjects and in normohomocysteinemic older people. Serum vitamin B-12 levels were higher in younger and older normal controls. Folic acid levels were higher in younger controls and in both older groups. Conclusions: This study shows an effect of high circulating tHcy on vascular reactivity in older people. Because serum levels of tHcy are associated with nutritional status of vitamin B-12 and folic acid, prospective studies are necessary to demonstrate the effects of a long-term nutritional supplementation with vitamins on vascular function and global cardiovascular risk.