Disturbed ratio of erythrocyte and plasma S-adenosylmethionine/S-adenosylhomocysteine in peripheral arterial occlusive disease

Altered homocysteine metabolism associated with peripheral arterial occlusi ve disease (PAOD) may lead to impairment of vital methylation reactions thr ough accumulation of S-adenosylhomocysteine (AdoHcy) as well as through alt eration of the ratio S-adenosylmethionine (AdoMet)/AdoHcy. We determined Ad oMet, AdoHcy, their ratio, and homocysteine in plasma as well as AdoMet, Ad oHcy, and their ratio in erythrocytes of 61 patients with PAOD (age 49-93) and 50 healthy controls (age 41-87). Geometric mean values of plasma homocy steine, AdoMet, and AdoHcy were significantly increased in patients compare d with controls (15.5 vs. 10.4 mu mol/l**; 107 vs. 52.3* nmol/l; 55.0 vs. 2 3.1** nmol/l, respectively; *P < 0.01, **P < 0.001), while the ratio of Ado Met/AdoHcy was decreased in patients (1.92 vs. 2.52*). In erythrocytes pati ents exhibited increased levels of AdoHcy compared with controls (309 vs. 2 05 nmol/l**) whereas AdoMet (3351 vs. 3732 nmol/l*) and the ratio of AdoMet /AdoHcy (11.8 vs. 19.1**) were decreased. The odds ratio (OR) for developin g PAOD with decreased AdoMet/AdoHcy ratio after adjustment for kidney funct ion was significant for erythrocyte levels less than or equal to 14.2 (OR, 7.1 (6.9-7.2, 95% CI). Tn addition, hematocrit levels were found to be sign ificantly decreased in patients versus controls (0.35 vs. 0.42 l/l**) and w ere significantly correlated with the ratio of AdoMet/AdoHcy in erythrocyte s of the patients. Since the ratio of AdoMet/AdoHcy is closely linked with the activity of numerous enzymatic methylation reactions, these results sug gest that methylation may be impaired in these patients. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.