The Effect Of Alcohol Toxicology In The Form Of Different Alcohol Drinking Patterns On A Biomarker Of Cardiovascular Disease Risk

Abstract

Introduction The amino acid homocysteine has been identified as a risk factor for cardiovascular disease (CVD), as elevated levels induce atherosclerosis, through a direct effect on arterial tissue. In alcohol dependent individuals an association between plasma homocysteine levels and alcohol consumption has been found (Bleich et al. 2000d). However this link has not been explored in individuals who have a range of nondependent alcohol drinking patterns. This fact has informed the design of the present work. Material and Methods A convenience sample of abstainers (N=7), non-dependent drinkers (N=28) and alcohol dependent individuals (N=18) was recruited. Alcohol consumption was recorded using questionnaires and diaries. All study participants’ biological samples were analysed for the following biomarkers: plasma homocysteine (HPLC); serum folate and vitamin B12 (competitive immunoassay); serum Carbohydrate Deficient Transferrin (N-Latex immunoassay); urinary creatinine (colorimetric assay) and the methylenetetrahydrofolate (MTHFRC677T) polymorphism (Real-Time Polymerase Chain Reaction (PCR)). Results There was no association between alcohol consumption during drinking days and plasma homocysteine levels in non-dependent drinkers. However when this group was categorised according to pattern of consumption, plasma homocysteine levels were found to be lower in abstainers (median 5.60 μmol/l), but higher in sessional drinkers (median 7.15 μmol/l) and alcohol-dependent individuals (median 7.89 μmol/). The mutant MTHFR(C677T) polymorphism when present was associated with an increase in plasma homocysteine levels, which correlated with alcohol consumption (R=0.975). CDT levels were found to be elevated in both sessional and alcohol-dependent individuals at baseline (median 2.68% and 5.95% respectively) compared with abstainers (2.16%). Additionally there was a linear relationship between the number of drinking days in a week and a positive CDT result, in a sample of sessional drinkers (R=0.98). Discussion The work undertaken has shown that sessional drinking and alcohol dependence does increase homocysteine levels in comparison to abstainers. This may have important implications in relation to CVD risk. Additionally new evidence of the utility of CDT as a biomarker of alcohol consumption within a sample of sessional drinkers, has been identified.