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Aims: To assess the effect of mandatory thiamine enrichment of wheat flour on blood thiamine levels in an alcohol-dependent population., Methods: Alcohol-dependent clients (n = 100) entering an inpatient service for the management of alcohol withdrawal had thiamine blood tests and diet interviews. Approximately half (n = 46) the alcohol-dependent participants reported taking vitamin supplements prior to admission. Standard treatment included thiamine supplementation in the form of an intramuscular injection and 100 mg tablets. If consent was gained, a second thiamine blood test was taken prior to discharge (n = 77). Control participants (n = 20) with no history of treatment for alcohol abuse had thiamine blood tests and diet interviews., Results: Control participants consumed significantly larger amounts of thiamine in their diet compared with alcohol-dependent participants (P < 0.0001). Alcohol-dependent participants who reported no use of vitamin supplements had significantly lower (P < 0.05) blood thiamine levels compared with controls, whereas controls and those who reported using vitamin supplements had no significant difference. No significant correlation was found between thiamine blood levels and reported levels of alcohol consumption., Conclusion: Reduced blood levels of thiamine in people who are alcohol dependent, compared with those with no history of alcohol abuse, are likely to be because of the poor diet. Consumption of vitamin supplements appears to bring thiamine levels closer to those seen in control participants. Supplementation of dietary intake of thiamine in people who are alcohol dependent remains an important measure for the prevention of Wernicke-Korsakoff's syndrome in this population.

In Western countries alcohol misuse is the most frequent cause of thiamine (vitamin B1) deficiency (TD) and consequent neuro-impairment. Studies have demonstrated that between 30 and 80% of alcoholics are thiamine deficient, and this puts them at risk of developing the Wernicke-Korsakoff (WK) syndrome. The relative roles of alcohol and TD in causing brain damage remain controversial and it is important to try to determine the role played by each factor. Animal studies support an additive effect of alcohol exposure and TD, and indicate the potential for interaction between alcohol and TD in human alcohol-related brain damage. Early diagnosis of alcohol-related TD is therefore an important aspect of effective intervention and treatment. Alcohol biomarkers provide a direct and indirect way of estimating the amount of alcohol being consumed, the duration of ingestion and the harmful effects that long-term alcohol use has on body functions. Appropriate use of these markers is very helpful when considering a diagnosis of alcohol-related TD.

Aims: To develop clinical guidelines to identify individuals who misuse alcohol and are at risk of developing Wernicke's Encephalopathy (WE)., Method: Non-systematic literature review of studies which includes a careful clinical record of the development of signs and symptoms of thiamine deficiency and in which the diagnosis of WE has been confirmed at autopsy., Results: The review of the clinical findings in cases of WE, diagnosed at autopsy, shows a consistent pattern of signs and symptoms. The pattern appears to be similar regardless of whether the thiamine deficiency is related to nutritional problems alone or associated with alcohol misuse., Conclusions: The assessment of the degree of thiamine deficiency and the diagnosis of WE remain a clinical evaluation, and guidelines are suggested to help the clinician. Since neurotoxicity due to the metabolism of excessive alcohol in patients with chronic and severe alcohol dependence may be an important factor in determining long-term outcome of treatment, this must form part of the overall evaluation.

Aims: To develop a Thiamine Deficiency Questionnaire (TDQ), and to assess its reliability in the identification of Thiamine deficiency, in patients with severe alcohol dependence., Methods: 58 severely alcohol dependent patients underwent socio-demographic, medical, psychiatric, and alcohol use assessment, including administration of the Thiamine Deficiency Questionnaire (TDQ). The Red Blood Cell Thiamine Pyrophosphate concentration provided the 'gold standard' to test the validity of the instrument. Univariate 2 x 2 diagnostic test tables and multivariate analysis were performed., Results: A set of eight questionnaire items had an overall predictive power of 73.7%. Two of these were highly specific: 'missed meals due to lack of funds', and the clinical co-occurrence of medical conditions potentially related to poor nutrition. The Michigan Alcohol Screening Test and serum gamma glutamyl transferase were moderately predictive., Conclusions: Screening that combines socio-demographic, clinical and biological factors, and/or standardized questionnaires, could improve early recognition of thiamine deficiency.

Thiamine deficiency may be assessed clinically by an abnormally low specific erythrocyte transketolase activity and/or by abnormally large activation by thiamine diphosphate in vitro (or 'TPP effect'). In the present investigation, we report erythrocyte transketolase activation by TPP in acute alcoholics and Wernicke-Korsakoff patients undergoing detoxification. A new age-dependent parameter was used to improve the reliability of transketolase activity as an indicator of marginal thiamine deficiency. Thus normalized transketolase activity ratio (NTKZ), primary activation ratio (PAR) and further activation ratio (FAR) were measured in 29 acute alcoholics and 12 Wernicke-Korsakoff patients upon admission, and also on 47 control subjects. It was possible to follow up 14 of the 29 acute alcoholics after 7 days of treatment. Twenty-one per cent of the acute alcoholics and 33% of the Wernicke-Korsakoff patients, on admission to the detoxification Unit, had NTKZ values beyond the defined critical conditions for thiamine deficiency, whereas 7% of the former and 25% of the latter had PAR values beyond these critical conditions. Furthermore, all three parameters were significantly different in the Wernicke-Korsakoff patients compared to the other groups. The pattern of improvement of the different parameters on follow-up varied considerably and is difficult to explain, as only the NTKZ was statistically significant. Hence, only eight out of 14 acute alcoholics showed improvement in NTKZ, seven showed improvement of PAR and six showed improvement of FAR after treatment. Five patients showed improvement of both NTKZ and PAR and none of the patients showed improvement of all three parameters. We conclude that our findings confirm previous reports and that this modified transketolase activation test improves its reliability as an indicator of marginal thiamine deficiency.