A new modified gamma-%CDT method improves the detection of problem drinking: studies in alcoholics with or without liver disease

BACKGROUND: The detection of excessive alcohol consumption by laboratory methods continues to lack sensitivity and specificity. Recent studies have suggested that diagnostic improvement may be achieved by combining carbohydrate-deficient transferrin (CDT) and gamma-glutamyltransferase (GT) measurements into a marker defined as gamma-CDT. METHODS: We developed a new approach for determining gamma-CDT by using the data obtained from the Axis %CDT turbidimetric assays. Marker results were compared in the assessment of 65 alcoholics, who were either with (n=34) or without (n=31) liver disease, as analysed by clinical, laboratory, and morphological criteria. Reference individuals were 45 healthy volunteers who were either social drinkers or abstainers. RESULTS: Gamma-GT and CDT results derived from both CDTect and %CDT measurements were used to calculate marker ratios as follows 0.8 x ln(GT)+1.3 x ln(CDT). With the established cut-off of 4.0 for the gamma-%CDT, the sensitivity of this method was 94% for men and 82% for women, as compared to 61% and 46% for %CDT and 70% and 73% for GT. The gamma-%CDT method was less dependent on liver status than the various other markers and showed the highest correlation with self-reported alcohol consumption (r=0.7254). CONCLUSIONS: The data indicates that the new gamma-%CDT method yields improved diagnostic accuracy for the detection of excessive ethanol consumption.     

Combining markers of nephrotoxicity and hepatotoxicity for improved monitoring and detection of chronic alcohol abuse.

BACKGROUND: Most of the commonly used markers of chronic alcohol abuse reflect alcohol hepatotoxicity; however, such abuse is deleterious to the kidneys as well. Combined use of serum markers of liver origin and urinary markers of kidney origin may be of diagnostic advantage. METHODS: The study was performed in 73 male alcoholics undergoing detoxification and 36 male alcoholics who had maintained abstinence for > or =6 weeks. Factor analysis, discriminant analysis and receiver operating characteristic (ROC) analysis were used to assess the discriminative power of two urinary markers of alcohol nephrotoxicity, namely beta-N-acetylhexosaminidase (Hex, EC 3.2.1.52) and alanine aminopeptidase (EC 3.4.11.2), and of three serum markers of alcohol hepatotoxicity, namely aspartate aminotransferase (EC 2.6.1.1), alanine aminotransferase (EC 2.6.1.2) and gamma-glutamyltransferase (GGT, EC 2.3.2.2), and of their quantitative combinations. RESULTS: The discriminative power of the urinary markers matched that of the serum markers. Hex and GGT appeared to be the best for discriminating the study groups. Their combination given by the equation G&H=0.62 x ln(GGT)+0.72 x ln(Hex) showed excellent discriminative ability (ROC area under the curve 0.92) that was significantly higher than that of any single marker in this report, indicating superior diagnostic accuracy of the compound marker. CONCLUSIONS: Kidney-derived urinary markers, particularly Hex, can complement or replace, if necessary, serum markers of chronic alcohol abuse that relate to alcohol hepatotoxicity. The compound marker proposed seems a promising tool for the monitoring and perhaps detection of chronic alcohol abuse and warrants further studies.     

Biochemical markers of alcoholism.

Alcohol and alcohol-related diseases have become a major cause of death in Western countries. The most sensitive and specific of the commonly used biomarkers of alcohol intake are carbohydrate-deficient transferrin (CDT), and the combination of gamma-glutamyltransferase (GGT) and CDT. Other widely used laboratory markers are GGT, mean corpuscular volume of erythrocytes and the ratio of aspartate aminotransferase to alanine aminotransferase. Blood ethanol levels reveal recent alcohol use. However, more specific and sensitive biomarkers to improve the detection of excessive alcohol use at an early stage are needed. New biomarkers, not yet used in routine clinical work, include phosphatidylethanol, fatty acid ethyl esters, ethyl glucuronide, sialic acid, and acetaldehyde adducts.     

The diagnostic accuracy of carbohydrate-deficient transferrin, sialic acid and commonly used markers of alcohol abuse during abstinence

BACKGROUND: The normalization of alcohol abuse markers during the abstinence depends on the time since the last drinking. The aim of this study was to evaluate the diagnostic accuracy (area under the curve-AUC, sensitivity and specificity) of CDT, sialic acid and others biochemical and hematological markers of chronic alcohol abuse during abstinence. METHODS: We studied 75 patients admitted to the treatment of alcohol dependence. The blood samples were collected upon admission to the hospital. CDT was estimated using an immunoturbidimetric assay after anion-exchange chromatography and sialic acid by enzymatic colorimetric method. RESULTS: Mean values of all markers were significantly higher. All tests, except SA, negatively correlated with time of abstinence but not with age, duration of dependence and amounts of weekly alcohol consumption. The area under the curve (AUC) for all tested markers decreased progressively during the abstinence. The highest AUC was obtained for CDT (0.98) and the lowest for ALT (0.78) when alcohol was consumed in the last week. AUC for sialic acid was lower than of CDT but higher than of ALT. CONCLUSIONS: We conclude that the diagnostic accuracy for tested laboratory markers depends on the self-reported time of abstinence being the highest for CDT in the first week of abstinence. The accuracy of sialic acid was observed between GGT and ALT.     

Use of capillary zone electrophoresis for differentiating excessive from moderate alcohol consumption

BACKGROUND: The poorly sialylated transferrin isoforms in serum were analyzed by capillary zone electrophoresis (CZE) to differentiate moderate from heavy alcohol consumption. METHODS: We enrolled 614 volunteers, classified after interviews, self-reported drinking habits, and AUDIT scores as alcohol abusers (consuming >50 g/day ethanol for the previous 3 months or longer; n = 413) or moderate drinkers (<30 g/day ethanol; n = 201). Serum transferrin isoforms were separated at 28 kV and monitored at 214 nm on a P/ACE 5500 CZE with use of fused-silica capillaries and the related CEofix CDT reagent set. Immunosubtraction by anti-human transferrin and electrophoretic migration times identified the isoforms. Previous markers of alcohol abuse and an assay combining anion-exchange minicolumn chromatography with immunoturbidimetry (%CDT) were included in the study. Sensitivities and specificities were compared by ROC analysis. RESULTS: The asialylated isoform was missing in 95% of moderate drinkers but present in 92% of alcohol misusers. Disialotransferrin had a specificity and sensitivity of 0.75 at a cutoff of 0.7% of total transferrin, whereas the sum (asialo- + disialotransferrin) at a threshold of 1.2% had a sensitivity of 0.73 and a specificity of 0.92. Trisialotransferrin values did not distinguish between the two populations. Sensitivities and specificities of %CDT averaged 0.77 and 0.74, respectively, at a 2.6% cutoff; 0.67 and 0.83 at 2.8%; and 0.63 and 0.90 at 3%. CDT data were more sensitive and specific for males. Conventional biomarkers appeared less discriminating. CONCLUSIONS: Asialotransferrin detected by CZE in sera of alcohol abusers offers the highest discrimination between excessive and moderate drinking.     

缺糖基转铁蛋白对酒精性肝病的诊断

目的 检测酒精性肝病(ALD)患者血清中的缺糖基转铁蛋白(CDT)与总TI的比值％CDT,并与GGT、MCV、ALT、AST等指标比较,评价其对ALD的诊断价值。方法 选择健康不饮酒对照组、非酒精性肝病的其他肝病组(NALD组)、ALD组(3组均为男性),分别检测％CDT、GGT、MCV、ALT、AST等指标,各指标在不同组间的比较用F检验;各项目之间的关系研究用直线相关,计算相关系数;同时绘制各指标的ROC曲线。结果 ALD组中的％CDT显著高于对照组、NAID组。％CDT诊断ALD的ROC曲线下面积为0．857,敏感度0．75,特异度0．88,而GGT这三者分别为0．751、0．75、0．76,MCV分别为0．669、0．30、0．78,ALT分别为0．512、0．25、0．72,AST分别为0．426、0．25、0．68。％CDT、与GGT不相关,但两者联合检测敏感度提高到90％。结论 对于ALD的诊断,％CDT、GGT、MCV均具有一定的诊断价值,尤其％CDT是一个很好的辅助诊断指标。％CDT与GGT联用可提高敏感度。     

长期饮酒者戒酒前后血清指标检测结果分析

目的 探讨长期问题饮酒患者戒酒前后血清生化指标变化趋势.方法 对53例长期饮酒并成功戒酒的患者戒酒前和戒酒3、6、12周时血清铁蛋白(FER)、糖缺失转铁蛋白(CDT)、转铁蛋白(Tf)、γ-谷氨酰转肽酶(GGT)、丙氨酸氨基转移酶(ALT)和天冬氨酸氨基转移酶(AST)水平,并计算CDT在Tf中所占百分比(CDT%).对结果 进行统计学分析.结果 随着患者戒酒时间的延长,血清CDT、CDT%、GGT水平下降(P＜0.05).与戒酒前相比,戒酒6周和戒酒12周血清FER水平降低(P<0.05).结论 长期饮酒者血清GGT、CDT、CDT%、FER水平随戒酒时间延长降低,但FER水平下降速度缓慢,GGT水平易受其他因素影响.因此,血清CDT及CDT%水平可以用于问题饮酒患者戒酒情况的长期监控.     

Biomarkers of alcohol consumption in patients classified according to the degree of liver disease severity

OBJECTIVE: In the search for optimal biomarkers of excessive drinking, only a few studies have been conducted to compare the relationships between ethanol consumption, liver status, and various laboratory markers of ethanol-induced diseases. MATERIAL AND METHODS: Concentrations of carbohydrate-deficient transferrin (%CDT and CDTect methods), serum sialic acid (SA), gamma-glutamyl transferase (gamma-GT), aspartate aminotransferase (ASAT), mean corpuscular volume (MCV), and a marker of fibrogenesis (PIIINP) were studied in 102 alcoholics with (n=59) or without (n=43) alcoholic liver disease. Controls were 34 healthy volunteers who were either social drinkers or abstainers. RESULTS: Although concentrations of all markers were significantly higher in the alcoholic patients than in the healthy controls, their diagnostic characteristics showed a considerable degree of variation. The %CDT, SA, and MCV showed the strongest correlations with the amount of recent alcohol intake. The presence of liver pathology notably influenced the results of CDTect, GT, ASAT, and PIIINP. In ROC analyses, the highest rates of diagnostic accuracy for detecting hazardous drinking were reached with GT (0.94), CDT (0.86), and SA (0.85), followed by MCV (0.79) and ASAT (0.77). Upon abstinence, the estimated times for normalization varied between 10 days (CDTect) and 25 days (GT). CONCLUSIONS: Our data suggest distinct differences in the clinical characteristics of biological markers of ethanol consumption. While the overall accuracy of CDT and GT appear to be highest in the detection of problem drinking, serum SA and PIIINP measurements are of further value when the effects of liver pathology and ethanol drinking need to be differentiated.     

Beverage-specific effects of ethanol consumption on its biological markers

BACKGROUND: Serum gamma-glutamyltransferase (GGT) and erythrocyte mean corpuscular volume (MCV) are well-known biological markers of excessive ethanol consumption. METHODS: The beverage-specific effects of ethanol consumption on GGT level and MCV value were analyzed cross-sectionally and retrospectively among middle-aged Japanese men who underwent a retirement health checkup (n = 974). RESULTS: Both the consumption of distilled alcohol and that of fermented alcohol positively correlated with the logarithm of GGT [standard regression coefficient (beta) 0.261 and 0.174, respectively]. The prevalence rate of elevated GGT levels > or = 70 IU/L) was higher among heavy drinkers of distilled alcohol than among heavy drinkers of fermented alcohol (38.8% vs. 27.6%, p = 0.013). The MCV value correlated with distilled alcohol consumption (beta: 0.212, p < 0.0001) but not with fermented alcohol consumption (beta: 0.043, not significant). The prevalence rate of an elevated MCV (> or = 97 fL) was higher among heavy drinkers of distilled alcohol than among heavy drinkers of fermented alcohol (35.3% vs. 16.8%, p < 0.001). CONCLUSIONS: These results suggest that MCV is less sensitive for detecting heavy consumption of fermented alcohol than for detecting that of distilled alcohol in apparently healthy middle-aged men.     

Comparison of Bio-Rad %CDT TIA and CDTect as laboratory markers of heavy alcohol use and their relationships with gamma-glutamyltransferase

BACKGROUND: Carbohydrate-deficient transferrin (CDT) is used as a serum marker for heavy drinking. We compared a new Bio-Rad %CDT TIA assay with the CDTect assay; we also compared both to gamma-glutamyltransferase (GGT) as markers of heavy drinking. METHODS: Serum samples of well-defined alcoholics (n = 404) and matched (age, race, and gender) social drinkers (204) from 10 clinical centers were assayed with both CDT assays. Both assays use microcolumn separation after iron saturation, followed by enzyme immunoassay (CDTect) or turbidimetric immunoassay (Bio-Rad %CDT). In the latter, CDT is expressed as a percentage of total transferrin. RESULTS: The slope and intercept [95% confidence intervals (CIs)] for linear regression of results obtained by the %CDT-TIA (as percentage) and CDTect (units/L) assays were 0.091 (0.088-0.097) and 0.70% (0.54-0.86%), respectively (S(y/x) =1.30%; r = 0.848). The areas under the ROC curves (95% CIs) for CDTect and Bio-Rad %CDT TIA were 0.89 (0.86-0.92) and 0.88 (0.85-0.91), respectively, for men (P, not significant) and 0.76 (0.72-0.80) and 0.72 (0.68-0.76) for women (P, not significant). When CDT (CDTect or Bio-Rad %CDT) was combined with GGT (either one positive), the clinical sensitivity in men was 90% for both assays, and specificities were 81% and 84%, respectively; sensitivities in women were 75% and 76%, respectively, and specificities were 87% and 91%. CONCLUSION: The new Bio-Rad %CDT TIA assay compares favorably to the widely studied CDTect assay in the detection of alcohol-use disorders.     

Carbohydrate-deficient transferrin isoforms measured by capillary zone electrophoresis for detection of alcohol abuse

BACKGROUND: Measurements of carbohydrate-deficient transferrin (CDT) are used as markers of alcohol abuse. We developed a capillary zone electrophoresis (CZE) method aimed at improving accuracy of CDT testing. METHODS: We studied 111 alcohol abusers with Alcohol Use Disorders Identification Test scores >11 and 50 teetotalers. CZE was performed with a P/ACE 5500, fused-silica capillaries, and a CEofix CDT reagent set. After iron saturation, sera were loaded by low-pressure injection, separated at 28 kV, and monitored at 214 nm. We identified the transferrin isoforms by migration times, treatment with 100 U/L neuraminidase, and immunosubtraction with anti-human transferrin and anti-C-reactive protein antibodies. We compared CZE results with current biological markers of alcohol abuse, including the %CDT turbidimetric immunoassay. RESULTS: Migration times of the isoforms were identical in both populations. Asialotransferrin was missing in teetotalers but present in 92% of alcohol abusers. Disialotransferrin was higher in those who consumed excessive amounts of alcohol, whereas mean trisialotransferrin concentration was not affected by alcohol abuse. At cutoffs to maximize sensitivity and specificity, these values were 0.92 and 1 [mean ROC area (MRa), 0.96; 95% confidence interval (CI), 0.93-0.99] for asialotransferrin; 0.84 and 0.94 for the sum of asialo- + disialotransferrin (MRa, 0.94; 95% CI, 0.91-0.98); 0.79 and 0.94 for disialotransferrin (MRa, 0.89; 95% CI, 0.84-0.94); 0.62 and 0.53 for trisialotransferrin (MRa, 0.58; 95% CI, 0.49-0.68); 0.79 and 0.82 for a 3% %CDT; and 0.83 and 0.69 for a 2.6% cutoff (MRa, 0.87; 95% CI, 0.81-0.92). Current markers lack sensitivity (<0.65). Transferrins were not significantly correlated with serum enzymes and mean erythrocyte volume. CONCLUSIONS: CZE-isolated desialylated transferrin isoforms allowed differentiation between chronic alcohol abusers and teetotalers.     

Should we use carbohydrate-deficient transferrin instead of gamma-glutamyltransferase for detecting problem drinkers? A systematic review and metaanalysis

BACKGROUND: Carbohydrate-deficient transferrin (CDT) has been used as a test for excessive alcohol consumption in research, clinical, and medico-legal settings, but there remain conflicting data on its accuracy, with sensitivities ranging from <20% to 100%. We examined evidence of its benefit over a conventional and less expensive test, gamma-glutamyltransferase (GGT), and compared the accuracy of different CDT assay methods. METHODS: We performed a systematic review using summary ROC analysis of 110 studies prior to June 1998 on the use of CDT in the detection of alcohol dependence or hazardous/harmful alcohol use. RESULTS: We identified several potential sources of bias in studies. In studies examining CDT and GGT in the same subjects, subject characteristics were less likely to influence the comparison. In such paired studies, the original Pharmacia CDT assay was significantly more accurate than GGT, but the modified CDTect assay did not perform as well as the original and was not significantly better than GGT. The accuracy of the AXIS %CDT assay was statistically indistinguishable from modified CDTect. Several CDT assay methods appeared promising, in particular, liquid chromatography (chromatofocusing, HPLC, fast protein liquid chromatography) and isoelectric focusing, but there were insufficient paired studies from which to draw firm conclusions. CONCLUSIONS: In studies published before June 1998, the results obtained with commercially available CDT assays were not significantly better than GGT as markers of excessive alcohol use in paired studies. Further high-quality studies comparing CDTect (modified) and other CDT assays with GGT in the same subjects are needed.     

Obesity and the clinical use of serum GGT activity as a marker of heavy drinking

OBJECTIVE: Gamma-glutamyl transferase (GGT) is a widely used clinical marker of alcohol abuse. However, although obesity may also elevate serum GGT activities, the effects of overweight on the interpretation of GGT testing have remained poorly defined. MATERIAL AND METHODS: GGT activities from 1147 moderate drinkers and 449 abstainers who were classified according to body mass index (BMI) were compared with those of 208 heavy drinkers admitted for detoxification. RESULTS: GGT upper normal limits, defined based on normal weight abstainers (men 53 U/L; women 45 U/L) were lower than those based on moderate drinkers (men 68 U/L; women 50 U/L). The relative increases in GGT activities in male moderate drinkers with overweight (54%) or obesity (125%) exceeded the corresponding changes found in women (25% and 75%, respectively). The BMI-dependent variation on the sensitivity of GGT for correctly classifying heavy drinkers ranged from 29% to 67%. The rates of false-positive values in the subgroups from low to high BMI varied from 0% to 27%, respectively. CONCLUSIONS: The data indicate that the diagnostic value of serum GGT testing could be improved by using reference data derived from databases of abstainers with normal weight or BMI-based categorization of reference ranges.     

Changes in serum enzymes in moderate drinkers after an alcohol challenge

When 14 "moderate" drinkers abstained from alcohol for four weeks, the activity of gamma-glutamyltransferase (GGT; EC 2.3.2.2) in their serum showed a large decrease. Immediately after the period of abstention, an orally given ethanol challenge of 1 g/kg produced a marked increase in serum GGT at 24 h, followed by a slow decline thereafter. Aspartate amino-transferase activity in serum was significantly increased at 24 h; however, alkaline phosphate, alanine aminotransferase, and lactate dehydrogenase showed much smaller or no changes. An abnormal increase in lactate dehydrogenase isoenzyme 5 was observed in seven subjects. In some of the moderate drinkers, liver biopsies showed mild chronic hepatitis or nonspecific changes. Eight nondrinking controls showed only slight increases in serum GGT following the same alcohol challenge; results for the other enzyme tests were unchanged. We consider it probable that pre-existing liver disease affects the response to ethanol, so that greater amounts of GGT are released from hepatic tissue; alternatively, drinkers may have a higher GGT activity in this tissue as a result of enzyme induction by ethanol. The alcohol challenge test was an effective discriminator between moderate drinkers and abstainers.     

Biomarkers in alcoholism

Alcoholism ranks as one of the main current threats to the health and safety of people in most Western countries. Therefore, a high priority should be given to aims at reducing its prevalence through more effective diagnosis and early intervention. The need for objective methods for revealing alcohol abuse in its early phase has also been widely acknowledged. It is postulated here that the diagnosis of alcohol use disorders could be markedly improved by a more systematic use of specific questionnaires and laboratory tests, including blood ethanol, serum gamma-glutamyltransferase (GGT), carbohydrate-deficient transferrin (CDT), and mean corpuscular volume of erythrocytes (MCV). Recent research has provided new insights into the relationships between ethanol intake, biomarkers, and factors affecting their diagnostic validation, including gender, age, and the effects of moderate drinking and obesity. It appears that the concept of reference intervals for several ethanol-sensitive parameters in laboratory medicine needs to be revisited. CDT is currently the most specific marker of alcohol abuse, and when combined with GGT using a mathematically formulated equation a high sensitivity is reached without loss of assay specificity. Possible new biomarkers include minor ethanol metabolites (protein-acetaldehyde condensates and associated autoimmune responses, ethylglucuronide, and phosphatidylethanolamine), 5-hydroxytryptophol, and genetic markers although so far their routine applications have been limited.     

Der Alkoholkranke als Patient

Chronic alcohol abuse is of significant clinical and economic relevance. A major part of internal medical pathology is associated with chronic alcoholism. 50% of all accidents with subsequent traumatic injuries are related to alcohol intake. Patients who are chronic alcohol abusers have prolonged hospital stays and substantial increases in postoperative morbidity. A sophisticated diagnosis of alcoholism within standard clinical routine is often difficult, and in most cases the treatment of alcohol-related diseases and complications is protracted and requires increased energy expenditure by the treating physicians. In surgical patients, chronic alcohol abuse is associated with a 3- to 4-fold risk of infections, sepsis, cardiac and bleeding complications. Therefore, the patients themselves, along with the general practitioner and an in-hospital interdisciplinary team should cooperate in medical and operative treatment in order to attain better clinical outcome. Each patient history should include a detailed assessment of the quantity of daily alcohol intake. Alcoholic diagnostic regimens including questionnaires (i.e. CAGE, AUDIT) in combination with specific laboratory markers (CDT, GGT, MCV), if implemented, could prove valuable, especially in cases where major surgical procedures are considered. Strict abstinence by alcoholic patients with organ pathology in medical and elective surgical settings as well as the prophylactic treatment of pre-operative alcohol withdrawal appear to be useful strategies to reduce the risk of complications. Short-term interventions are associated with reduced alcohol intake and decreased incidence of re-trauma. Considering the clinical relevance of alcohol abuse, sufficient screening, interventions, and open approaches to address alcohol problems should be important components of the daily clinical routine in outpatient clinics, emergency rooms, in GPs' offices and in general hospitals.     

Analytical evaluation of a new capillary electrophoresis method for carbohydrate-deficient transferrin measurement

BACKGROUND: Carbohydrate-deficient transferrin (CDT), the sum of a- and disialotransferrin, is considered the most efficient routine biological marker of alcohol abuse. In recent years, methods based on capillary zone electrophoresis (CZE) have been developed using specialized monocapillary systems. These are characterized by a high analytical detection level, counterbalanced by a poor productivity. We evaluated a new CZE method for CDT measurement on the Sebia Capillarys, an eight-capillary system developed for routine serum capillary electrophoresis. METHODS: Precision and possible biases due to abnormal (low or high) transferrin levels or lipemic samples were assessed. Exactitude and precision were tested by comparison with a HPLC procedure acknowledged to be the most reliable to date. The validity of the manufacturer's cut-off was checked by measuring CDT in a population comprising abstaining patients, moderate alcohol consumers and alcohol abusers. Lastly, the method was compared to the routine %CDT TIA and N Latex CDT methods. RESULTS: The imprecision was 18.5% at the minimum detection level and decreased to 6.1% for high CDT values. No significant shift in the CDT results was observed in relation to abnormally low or high serum transferrin, or in lipemic samples. A high level of concordance was observed with the HPLC method used as reference. The results were strongly correlated with both other routine methods (r>0.90). The diagnostic values were comparable to the literature data, even if differences in the studied populations make difficult a direct comparison of the results. Our data suggested that the cut-off could be raised from 1.3% to 1.4% to reduce the number of false positive values without loss of diagnostic efficiency. CONCLUSIONS: This Capillarys method from Sebia showed good precision as compared to those published using other CZE methods. Capillarys method correlated well with HPLC and two routine methods. However, we noticed significant bias at low CDT concentrations. Therefore, with the advantage of high throughput and full automation, these results indicate that the new method is a consistent alternative to the other methods proposed for routine CDT measurement.     

Liver enzymes, the metabolic syndrome, and incident diabetes: the Mexico City diabetes study

OBJECTIVE: To test the hypothesis that enzymes conventionally associated with liver dysfunction (aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase [GGT], and alkaline phosphatase) may predict diabetes. RESEARCH DESIGN AND METHODS: From a population-based diabetes survey, we selected 1,441 men and women in whom serum enzyme levels were < or =3 SDs of the mean population value, alcohol intake was <250 g/week, and hepatitis B and C virus testing was negative. At follow-up (7 years), 94 subjects developed diabetes and 93 impaired glucose tolerance (IGT). RESULTS: At baseline, all four enzymes were related to most of the features of the metabolic syndrome. After controlling for sex, age, adiposity/fat distribution, alcohol intake, serum lipids, and blood pressure, higher alanine aminotransferase and GGT values were significantly (P < 0.01) associated with both IGT and diabetes, whereas alkaline phosphatase was associated with diabetes only (P = 0.0004) and aspartate aminotransferase with IGT only (P = 0.0001). Raised GGT alone was associated with all the features of the metabolic syndrome. Raised GGT was a significant predictor of either IGT or diabetes (odds ratio 1.62 [95% CI 1.08-2.42] top quartile vs. lower quartiles, P < 0.02) after controlling for sex, age, adiposity/fat distribution, alcohol consumption, fasting plasma insulin and proinsulin levels, and 2-h postglucose plasma glucose concentrations. CONCLUSIONS: Although mild elevations in liver enzymes are associated with features of the metabolic syndrome, only raised GGT is an independent predictor of deterioration of glucose tolerance to IGT or diabetes. As GGT signals oxidative stress, the association with diabetes may reflect both hepatic steatosis and enhanced oxidative stress.     

Obesity and the clinical use of serum GGT activity as a marker of heavy drinking

Objective. Gamma‐glutamyl transferase (GGT) is a widely used clinical marker of alcohol abuse. However, although obesity may also elevate serum GGT activities, the effects of overweight on the interpretation of GGT testing have remained poorly defined. Material and methods. GGT activities from 1147 moderate drinkers and 449 abstainers who were classified according to body mass index (BMI) were compared with those of 208 heavy drinkers admitted for detoxification. Results. GGT upper normal limits, defined based on normal weight abstainers (men 53?U/L; women 45?U/L) were lower than those based on moderate drinkers (men 68?U/L; women 50?U/L). The relative increases in GGT activities in male moderate drinkers with overweight (54%) or obesity (125%) exceeded the corresponding changes found in women (25% and 75%, respectively). The BMI‐dependent variation on the sensitivity of GGT for correctly classifying heavy drinkers ranged from 29% to 67%. The rates of false‐positive values in the subgroups from low to high BMI varied from 0% to 27%, respectively. Conclusions. The data indicate that the diagnostic value of serum GGT testing could be improved by using reference data derived from databases of abstainers with normal weight or BMI‐based categorization of reference ranges.     

Detection and exclusion of alcoholism in men on the basis of clinical laboratory findings

Alcoholism is a common disease; it is found in 10% to 15% of all patients admitted to general hospitals. There is no single characteristic finding, but on the other hand, changes as compared with normal values have been reported in the literature for more than 30 frequently assayed clinical chemical and haematological parameters. In the project reported here all 24 clinical chemical parameters and all 8 haematological parameters frequently assayed were studied in each of 82 hospitalized men with a confirmed diagnosis of alcoholism. The diagnosis of alcoholism was made on the basis of the Munich Alcoholism Test (MALT) together with the following standardized assessments and examinations: past history, an alcohol questionnaire, general physical examination and neurological examination. All forms were filled in completely. All steps in the clinical laboratory investigations were standardized, and all were subject to ongoing reliability control. The clinical problem is usually not to differentiate alcohol abusers or alcoholics from healthy persons but rather to identify the alcoholics among a population of patients with a variety of illnesses. For this reason 70 patients from two hospitals who were clearly neither alcohol abusers nor alcoholics were studied in exactly the same manner as the alcoholics. In this combined group of 152 hospitalized patients significant differences were found in the distribution of the values for the alcoholics and the non-alcoholics for the following clinical chemical and haematological parameters: at the 0.1% level gamma-glutamyltransferase, aspartate aminotransferase, urea, creatinine and mean corpuscular volume (MCV), and at the 1% level glutamate dehydrogenase, alanine aminotransferase and alkaline phosphatase. From these eight parameters those combinations of between two and six parameters were selected that discriminated best between the alcoholics and the non-alcoholics. Using conventional decision limits the following was found: For the alcoholics two or more of the results for the following five parameters were outside the decision limits given in parentheses: gamma-glutamyltransferase (greater than or equal to 28 U/l), aspartate aminotransferase (greater than or equal to 18 U/l), alanine aminotransferase (greater than or equal to 22 U/l), MCV (greater than or equal to 96 fl), creatinine (less than or equal to 66.3 mumol/l). The diagnostic sensitivity (alcoholics) is 85%, the diagnostic specificity (non-alcoholics) is 64%.(ABSTRACT TRUNCATED AT 400 WORDS)