Homocysteine, Vitamins and C-reactive Protein in the InCHIANTI Study

Abstract number: OR131

Gori¹ AM, Corsi² AM, Cellai¹ AP, Alessandrello Liotta¹ A, Falciani¹ M, Lapini¹ I, Fedi¹ S, Ferrucci³ L, Abbate¹ R, Gensini¹ GF

¹¹Department of Medical and Surgical Critical Area, Thrombosis Centre, University of Florence, Italy; Azienda Ospedaliero-Universitaria Careggi, Florence, Italy ¹¹Department of Medical and Surgical Critical Area, Thrombosis Centre, University of Florence, Italy; Azienda Ospedaliero-Universitaria Careggi, Florence, Italy ²²Laboratory of Clinical Epidemiology, Geriatric Department, National Institute of Research and Care on Aging (INRCA), Florence, Italy ³³Longitudinal Studies Section, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, USA

Elevated levels of homocysteine may reflect increasing age, male sex, renal failure, vitamin deficiencies (low folate, vitamin B12 or vitamin B6), or inherited abnormalities of enzymes involved in the methionine metabolism. Aim of this study was to determine in a large population based sample whether hyperhomocysteinemia is associated with high circulating levels of inflammatory markers. We studied 586 men and 734 women randomly selected from the people living in two sites in the surrounding of Florence, Italy. In the InCHIANTI population homocysteine, folic acid, vitamin B6 and B12 levels were 13.7 (5.4–95.9) mmol/L, 6.3 (0.7–45.3) nmol/L, 25.3 (0.4–689.2) nmol/L and 285 (25.2–1488.1) pmol/L respectively. Dietary vitamin B6 and folic acid intakes were strongly (P < 0.0001) and inversely associated with homocysteine levels, as well as serum levels of folic acid vitamin B12 and vitamin B6. Interleukin 1-receptor antagonist (IL-1ra) and interleukin-6 (IL-6) serum levels were significantly (P < 0.001) and positively associated with homocysteine plasma levels also after adjustment for creatinine levels, total energy, lipid, alcohol, and folic acid intakes, as well as serum levels of folic acid, vitamin B12, vitamin B6. At multivariate logistic regression analysis, subjects who had IL-6 serum levels in the highest tertile compared to the lowest tertile of the distribution had an increased risk of being in the highest homocysteine groups (OR = 2.53 95% CI 1.13–5.65 for homocysteine >15.6 mmol/L, P= 0.02 and OR = 1.60 95% CI 1.20–2.12 for homocysteine 12.2–15.6 mmol/L, P= 0.0013). This study provides data about the complex relationship between homocysteine, the pattern of inflammatory mediators, vitamin intakes and vitamin levels in a large population-based study, in the InChianti Study. Interleukin-6 and interleukin-1ra, but not other markers of inflammation, were found to be independent predictors of homocysteine plasma levels, in addition to the vitamins involved in methionine cycle coronary artery disease.