CYP2D6 ultrarapid metabolizer genotype as a potential modifier of smoking behaviour.

Some 3-10% of Caucasians are deficient in CYP2D6 metabolism (poor metabolizers), due to inheritance of two defective alleles, whereas amplification of the CYP2D6 gene results in ultrarapid metabolism in 1-2% of Caucasian populations. To examine the possible association between CYP2D6 polymorphism and individual smoking behaviour, we analysed the prevalence of CYP2D6 genotypes among 292 long-term heavy smokers, 382 individuals with more variable smoking histories, and 302 never-smokers. The prevalence of ultrarapid metabolizers in heavy smokers (7.9%) was twofold compared to individuals with variable smoking habits (3.7%; odds ratio 2.3, 95% confidence interval 1.2-4.4), and fourfold compared with never-smokers (2.0%) (odds ratio 4.2, 95% confidence interval 1.8-9.8). The frequency of poor metabolizer genotype was approximately 2%, in each smoker group. However, when men and women were studied separately, the prevalence of poor metabolizer genotype was higher in male never-smokers (3.6%) than in variable smokers (2.7%) and heavy smokers (2.2%). Moreover, a trend test, adjusted by age, gender and cancer status, revealed a significant trend for the increased tobacco usage with increased metabolic capacity. Our results are in agreement with the assumption that increased CYP2D6 activity may contribute to the probability of being addicted to smoking.

A health promotion programme for oil refinery employees: changes of health promotion needs observed at three years.

The main aim of this three-year follow-up study was to evaluate the long-term effects of a workplace health promotion intervention programme offered by the Neste Oyj corporation's occupational health service. Another aim was to study factors associated with changes in health promotion needs. These were assessed using information obtained by means of questionnaires and laboratory measurements. The target areas assessed were physical activity, musculoskeletal problems, dietary habits, obesity, blood pressure, serum lipids, smoking, quality of sleep and mental well-being. Participants from one oil refinery were offered special health promotion counselling, while those from the other oil refinery studied received only their personal results, written information and instructions. Evaluation of the changes in needs was mainly based on comparison of the results of two examinations performed with an interval of three years. Effects of special health promotion counselling were observed in the target area of physical activity. Elimination of certain health promotion needs was seen in both groups in all of the target areas. The most extensive changes were seen in the target areas of musculoskeletal symptoms, dietary habits, blood pressure and mental well-being. Basic education, occupational status and age-group, as well as the value of tending health were frequent variables explaining the reduction in the need for health promotion activities. Worker participation in health promotion counselling activities provided by occupational health services can be high, as in this study in which the participation rate was 90% and the drop-out rate during the three years only 10%.

Blood vitamins, mineral elements and inflammation markers as risk factors of vascular and non-vascular disease mortality in an elderly population.

BACKGROUND: The need for protecting agents against degenerative processes of the body has been proposed to be especially high in elderly people. In order to evaluate the prognostic value of various biochemical factors in ageing the associations of blood concentrations of several vitamins, mineral elements and some other suggested risk factors with vascular and non-vascular mortality were studied in an elderly population. METHODS: A large health survey with complete clinical evaluation was carried out in the City of Turku in 1982-1983. A random sample of 344 community-living elderly individuals aged 65 years or older, stratified into four age groups, was studied. During the 13 years follow-up 225 subjects had died. Calcium, magnesium, copper, ceruloplasmin, zinc, selenium, iron, ferritin, transferrin, alpha-tocopherol, retinol, folate, vitamin B12, malondialdehyde, orosomucoid and insulin levels were analysed from the blood specimens. The relations between the compounds measured and relative mortality risks during the 13-year follow-up were analysed by Cox proportional hazards model adjusting for other known risk factors. RESULTS AND CONCLUSIONS: High concentrations of serum copper, orosomucoid and insulin were associated with increased risk of vascular mortality. The relative risks within the subjects of the highest tertile of serum concentrations were 2.2 for copper, 1.8 for orosomucoid, and 1.8 for insulin when adjusted for many confounding risk factors. Low serum vitamin B12 concentrations appeared to be significantly (P = 0.01) associated with increased vascular mortality. The associations were essentially not more significant when adjusted only for age. Contrary to earlier observations concentrations of serum magnesium, selenium, alpha-tocopherol, iron and its binding proteins or plasma and erythrocyte folate were not associated with increased mortality risk when adjusted for confounding risk factors. The authors suggest that in elderly subjects these elements and compounds are at the most weak, and probably non-independent risk factors for vascular mortality.

Follow-up of asbestosis patients and predictors for radiographic progression.

OBJECTIVE: We followed a group of 85 Finnish asbestosis patients radiographically for an average of 6.5 (range 2-10) years to examine the progression of the disease and to assess possible explanations for the progression. METHODS: The examinations included full-size chest radiographs and a blood specimen analysis. The radiographs were classified according to the 1980 International Labor Office (ILO) classification. Progression was accepted if the second or third radiography was estimated (in a side-by-side comparison) to have more profusion of small opacities qualitatively than the first, even if the radiographs were classified into the same profusion category. RESULTS: In all, 38% of the patients showed progression during the follow-up period. The average progression of small opacities ranged from ILO 1/1 to ILO 2/2 (0.4 minor ILO categories/year). The asbestosis was progressive more often among the sprayers than among the insulators and asbestos factory workers [cross-tabulation, odds ratio (OR) 5.0, 95% confidence interval (95% CI) 1.2-20]. In the logistic regression model the ILO classification category at the beginning of the follow-up (OR 1.54; 95% CI 0.96-2.47), the fibronectin (OR 1.01; 95% CI 1.00-1.01) and angiotensin-converting enzyme (ACE; OR 1.10; 95% CI 1.00-1.20) levels, and the erythrocyte sedimentation rate (ESR; OR 1.05; 95% CI 1.00-1.10) were statistically associated with the radiographic progression of small opacities. Abnormalities of the pleura were found to progress more often among the patients with progressive parenchymal opacities. CONCLUSION: For the progression of small-opacity profusion the significant predictors in the logistic regression model were the ILO profusion category at the beginning of the follow-up period, the fibronectin level, the ACE value, and the ESR. The model correctly classified 94% of the patients with progression and 65% of those without progression. The differences in the mean values recorded for the biomarkers between the progressors and nonprogressors, however, were small and may therefore not be of any importance to the clinician.

Life-style related health promotion needs in oil refinery employees.

This report describes the screening procedure used in the assessment of health promotion needs in a group of oil refinery employees (n = 885). The aim of the study was to assess the life-style related health promotion needs before initiating an intervention programme study. The frequency of different health promotion needs and their distribution according to age, gender and employee group were examined, as well as the factors explaining different health promotion needs. The assessment was based on laboratory tests and questionnaires covering the target areas of physical activity and fitness, dietary habits, overweight, blood pressure, serum lipids, smoking, alcohol consumption, sleep, mental health, and musculoskeletal symptoms. Life-style related health promotion needs were frequent. Self-assessed health was strongly associated with health promotion needs in most of the ten target areas and also with the total number per person of areas with health promotion needs. Health promotion needs were also associated with such demographic variables as age, gender, basic education, and vocational training. If health promotion activities are provided to employees in a company, assessment of individual needs is necessary to find the employees with the greatest need of health promotion actions. This study presents one method of screening, although certain simplification is needed to make it fit into the daily routines. The contents of health promotion activities could also vary according to the differences related to age and gender observed in health promotion needs of the target population.

Radiographic small lung opacities and pleural abnormalities in relation to smoking, urbanization status, and occupational asbestos exposure in Finland.

The role of smoking and an urban living environment in the etiology of radiographic pleural and pulmonary abnormalities was studied in a population sample that was representative of the Finnish adult population. A total of 7095 full-size chest radiographs were classified according to the International Labor Organization's 1980 classification of radiographs of pneumoconioses, with some modifications. The risk of bilateral pleural plaques was significantly higher among urban men (RR, 2.0) and women (RR, 3.8), even when adjusted for age and probability of occupational asbestos exposure and smoking. The risks of small lung opacities and abnormalities of the visceral pleura were not higher in urban areas. Risks of small lung opacities and thickening of the visceral pleura were positively associated with smoking, and the risk of small lung opacities was also higher among smokers than never-smokers in the population fraction with unlikely occupational asbestos exposure.

CA 125 as a screening test for ovarian cancer.

BACKGROUND - Screening for ovarian cancer is based on ultrasound, colour Doppler, and tumour markers. There is only limited evidence on their discriminatory performance and no evidence on their effectiveness in reducing mortality. OBJECTIVE - To investigate the discriminatory performance of CA 125 as a screening test for ovarian cancer. METHODS - A registry of 15 093 serum samples drawn in 1968-72 was linked to the cancer registry. During follow up between 1968 and 1980 24 ovarian cancers were identified. One or two matched case-control design nested within the sample bank was applied and the concentrations of CA 125 were assessed. RESULTS - Case-control differences (relative risk 4-0, 95% confidence interval 1.0 to 15.5 at 20 kU/1) were found. Detection rate of the CA 125 test was 21-33% and the true negative rate was 75-98% depending on the cut off level and interval between drawing of the blood sample and diagnosis of the cancer. CONCLUSION - CA 125 is not a valid screening test if used alone. Case-control differences of borderline significance were found in CA 125 before diagnosis of ovarian cancer, but they were not large enough to provide a sufficient detection rate.

Serum concentrations of apolipoprotein A-I, apolipoprotein B, and lipoprotein(a) in a population sample.

Serum concentrations of apolipoprotein (apo) A-I, apo B, and lipoprotein(a) [Lp(a)] were studied with respect to age and sex in a Finnish population sample of 575 subjects (286 men and 289 women), ages 27-67 years. Apo A-I and apo B were measured with an immunoturbidimetric method calibrated against WHO International Reference Materials. Lp(a) was measured by RIA. Apo A-I and apo B concentrations were almost normally distributed (apo A-I: mean 1.38 g/L vs median 1.34 g/L for men, and 1.58 g/L vs 1.55 g/L for women; apo B: mean 1.21 g/L vs median 1.20 g/L for men and 1.09 g/L vs 1.05 g/L for women). The distribution of Lp(a) was remarkably skewed (mean 190 mg/L vs median 86 mg/L for men, and 169 mg/L vs 85 mg/L for women). The 95% intervals for apo A-I were 1.09-1.84 g/L for men and 1.06-2.28 g/L for women; for apo B, they were 0.63-1.88 g/L and 0.56-1.82 g/L, respectively. Apo A-I concentrations appeared to be unrelated to age, whereas apo B and Lp(a) concentrations were age-dependent. Cutoff values based on the 90th percentile for apo B and the 10th percentile for apo A-I are proposed for identifying subjects at increased risk of coronary heart disease.

Poor applicability of the Friedewald formula in the assessment of serum LDL cholesterol for clinical purposes.

OBJECTIVE: To determine the accuracy of the estimation of serum low-density lipoprotein (LDL) cholesterol concentration by the Friedewald formula. METHODS: Modifications of the calculation formula are presented on the basis of ultracentrifugal separation of serum high-density lipoprotein and LDL cholesterol in the specimens collected (n = 1215) in a nationwide health survey. RESULTS: The formulas obtained from different subject groups differed relatively little from each other. The accuracy of the original Friedewald formula was poor; in about 36% of the subjects the error was more than 5% compared with ultracentrifugally obtained results. By applying the currently recommended coronary heart disease (CHD) risk categorizations, high proportions (5%-28%) of the subjects were classified into wrong CHD risk categories when LDL cholesterol was calculated with any of the formulas. At high serum triglyceride levels, misclassifications were especially common. CONCLUSIONS: We conclude that even the most accurate LDL cholesterol calculation methods should be used with caution while classifying subjects into categories of CHD risk. In hypertriglyceridemic subjects, the calculation formulas probably should not be used at all.

Health-based reference intervals for ALAT, ASAT and GT in serum, measured according to the recommendations of the European Committee for Clinical Laboratory Standards (ECCLS).

The reference intervals for the activities of L-alanine aminotransferase (EC 2.6.1.2, ALAT), L-aspartate aminotransferase (EC 2.6.1.1, ASAT) and gamma-glutamyltransferase (EC 2.3.2.2, GT) in serum were determined according to the recommendations of the European Committee for Clinical Laboratory Standards (ECCLS). Serum specimens from 954 subjects were analysed for ALAT and ASAT and from 794 subjects for GT. The subjects, aged 27-67 years, were participants in general health surveys. The reference population was formed by excluding subjects with any disease, or on any medication, affecting the liver, and also those consuming excessive amounts of alcohol. The 95% inner reference intervals for ALAT and ASAT were 9-50 (n = 189) and 15-36 U l-1 (n = 192) in men and 8-38 (n = 270) and 13-33 U l-1 (n = 270) in women. For GT the reference interval was 11-58 in men (n = 165) and 8-42 U l-1 in women (n = 220). Serum GT levels correlated clearly with alcohol consumption. Serum ALAT and ASAT were only slightly associated with alcohol consumption at levels less than 280 g per week in men and 190 g per week in women. There were modest positive associations between the three enzyme levels and body mass index. None of the enzymes correlated significantly with age.

Ovarian hormone status, life-style factors, and markers of bone metabolism in women aged 50 years.

Fifty-year-old women (n = 519) attending a health examination were divided by their ovarian hormone status into four groups: premenopausal, perimenopausal, postmenopausal without ovarian hormone replacement therapy (HRT), and postmenopausal with HRT. Information on lifestyle factors was obtained with interviews and questionnaires. Bone mineral density at the calcaneus was assessed with single-photon absorptiometry, and several serum and urine markers of bone metabolism were measured. Postmenopausal women without HRT had significantly higher levels of fasting serum alkaline phosphatase, osteocalcin, total and ionized calcium, phosphate, and fasting urinary hydroxyproline than those in the three other study groups. No difference was found in bone mineral density between the premenopausal and postmenopausal groups. Postmenopausal women without HRT showed a marked correlation between serum osteocalcin and urine hydroxyproline. Both markers showed significant correlations with serum calcium, phosphate, and alkaline phosphatase. Multivariate analyses showed a statistically significant association of ovarian hormone status and body mass index with most measured markers of bone metabolism. The association between alcohol consumption and serum osteocalcin was highly significant. Cigarette smoking was associated with levels of serum alkaline phosphatase and total and ionized calcium. A weak association was found between coffee drinking and serum alkaline phosphatase.

Health-based reference values of the Mini-Finland Health Survey: 2. Cholesterol in total serum and in different lipoprotein fractions.

The reference values for cholesterol concentrations in the whole serum and in its VLDL, LDL and HDL fractions have been produced based on the data obtained in the Mini-Finland Health Survey. The lipoprotein fractions were separated with ultracentrifugation. The aim was to obtain reference values for the apparently healthy, ambulatory population. Two health-derived criteria were used to select subjects for reference populations: those based on the literature available and those based on the recommendations published by the Committee on Reference Values of the Scandinavian Society for Clinical Chemistry and Clinical Physiology, with slight modifications. The 95% inner reference intervals of total serum cholesterol in all the subjects and in the two selection groups were 4.2-9.0, 4.2-8.4, and 4.2-8.5 mmol l-1 for men, and 4.2-9.4, 4.1-8.6, and 4.2-9.0 mmol l-1 for women, respectively. The corresponding medians were 6.3, 6.2 and 6.2 mmol l-1 in men, and 6.4, 6.0 and 6.1 mmol l-1 in women, respectively. Frequency distribution curves showed clear skewness to the right in VLDL cholesterol and slight skewness in LDL and HDL cholesterol. In women there was a clear rise in total, VLDL and LDL cholesterol after the early middle age, whereas HDL cholesterol was lower in the older age groups. In men the age dependency was not as prominent; total cholesterol levels showed lower levels in older men. Of the background lifestyle factors alcohol consumption, smoking, obesity and physical exercise had negligible associations with total, VLDL, LDL and HDL cholesterol reference intervals.

Health-based reference values of the Mini-Finland Health Survey: 3. Triglycerides in total serum and in different lipoprotein fractions.

The reference values for triglyceride concentrations in total serum and in its VLDL, LDL and HDL fractions have been produced based on the data obtained in the Mini-Finland Health Survey. The lipoprotein fractions were separated with ultracentrifugation. Efforts were made to obtain reference values for the healthy ambulatory population. Two health-derived selection criteria were used for inclusion of persons into the reference population: those based on the literature available and those based on the recommendations published by the Committee on Reference Values of the Scandinavian Society for Clinical Chemistry and Clinical Physiology, with minor modifications. The frequency distributions of triglycerides especially in total serum and in VLDL fraction were very skewed. Because of that the data were transformed before the calculation of the reference ranges according to the method of Box and Cox [1]. This transformation method appeared to be the best one of many tested methods in obtaining the distributions closer to the normal ones. The 95% inner reference intervals of total serum triglycerides in all subjects and in the two selection groups were 0.5-4.0, 0.5-2.8, and 0.5-3.2 mmol l-1 for men and 0.5-3.4, 0.5-2.3, and 0.5-2.4 mmol l-1 for women, respectively. The age dependence of triglyceride level was prominent in women after the early middle age. The distribution and age dependence of VLDL triglycerides resembled those of total triglycerides. In LDL and HDL fractions the skewness was not as clear as in the whole serum or in VLDL fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Tumour markers and screening for gastrointestinal cancer: a follow up study in Finland.

BACKGROUND: Screening for gastrointestinal cancer is based mainly on a barium contrast x ray method and on identification of occult blood in stools. The methods are relatively expensive, not always acceptable to the participants, and there is only limited evidence of their effectiveness in reducing the mortality from gastrointestinal cancer. OBJECTIVE: To investigate the validity of several tumour markers as a screening test for stomach cancer and for colorectal cancer. METHODS: A registry of 36,265 serum samples drawn during 1968-72 was linked to the cancer registry. Follow up was during 1968-80 when 94 stomach cancers and 95 colorectal cancers were identified. One to two matched case-control design was applied, and the concentrations of CEA, CA 19-9, CA 50, and TATI were assessed. RESULTS: The mean values of the markers between the cases and the controls were almost the same for the total material. Case-control differences were found between the 11 sets with an interval of less than one year between drawing the sample and diagnosis of the cancer. The highest validity was found in CEA for colorectal cancer (specificity 91%; sensitivity 64%) and in CA 19-9 for stomach cancer (specificity 74%; sensitivity 73%). CONCLUSION: CEA, CA 19-9, CA 50, or TATI are not valid screening tests. Case-control differences were found with a potential one year screening interval, but they were not large enough for sufficient validity.

Serum tumor markers CEA, CA 50, TATI, and NSE in lung cancer screening.

BACKGROUND: There are no effective means for screening for lung cancer, so the authors assessed the utility of four lung cancer tumor makers for screening. METHODS: A case-control study, nested in a cohort study based on the linkage of records of health survey examinees with Finnish Cancer Registry records, was used to test the validity of tumor markers carcinoembryonic antigen (CEA), tumor-associated trypsin inhibitor (TATI), neuron-specific enolase (NSE), and CA 50 in lung cancer screening. Ten years after health examinations, record linkage indicated that 187 men had lung cancer; 344 control subjects, matched for age, sex, and municipality were drawn from the same records. RESULTS: The data allowed assessment of the sensitivity of the marker assays at a 95% specificity level, which was highest for CEA (17% at a concentration level of 5.3 micrograms/l). Logistic discrimination analysis indicated that of the other markers, only TATI, when used in combination, improved the discriminatory power of CEA. CEA and TATI levels correlated significantly with smoking. They also showed a significant gradient toward increasing risk of lung cancer from the lowest to the highest quintiles of marker levels (for CEA, crude relative risk between the highest and lowest quintiles, 8.6). The gradient also was evident in the subgroup whose cancer had been diagnosed more than 5 years after serum specimen collection. The trend persisted, although relative risk was halved after adjustment for smoking. CONCLUSIONS: The markers do not seem to be useful tools for lung cancer screening. However, CEA and TATI levels seem to give information on cancer risk long before the clinical cancer stage, as the quintile-based analyses of marker levels indicate.

Urinary and blood manganese in occupationally nonexposed populations and in manual metal arc welders of mild steel.

To obtain reference values for blood and serum manganese levels, blood specimens were collected from 29 men and 36 women. Mn in blood showed a normal distribution; its upper 97.5% limit in blood was 0.38 mumol/l. Mn in serum showed a skewed distribution, which did not differ from the normal one after logarithmic transformation. The respective reference limit was 19 nmol/l. In both specimens, the levels of Mn were significantly lower in men than in women. To obtain reference values for Mn in urine, midday urine specimens were collected from 58 men and 96 women. Mn in urine also showed a skewed distribution, and the upper 97.5% limit was 38 nmol/l. The levels of Mn in blood and urine were statistically significantly higher in manual metal arc (MMA) welders of mild steel (MS) than in the reference populations. Five MMA/MS welders were subjected to a further study in which the ambient intramask Mn levels and urinary Mn excretion were monitored throughout a full working week. For two welders the correlation of Mn in urine specimens voided in the afternoon was good with the before noon Mn concentrations in the hygienic measurements; for the rest the correlation was minimal. Mn in diurnal urine specimens collected in six portions showed fluctuation if specific gravity or creatinine in urine was used to standardize for the urinary flow, but it was less evident for urinary Mn excretion rate. Our results seem to indicate that the measurement of Mn in urine or blood may be used for monitoring Mn exposure in MMA/MS welders only at the group level.

Assessment of exposure to polychlorinated biphenyls: analysis of selected isomers in blood and adipose tissue.

Concentrations of 12 selected polychlorinated biphenyl (PCB) congeners and isomers in human serum and adipose tissue after environmental and short- and long-term occupational exposures were determined. The individual congener concentrations in adipose tissue varied between less than 0.01 and 420 micrograms/kg (tri-, tetra-, penta-, hexa-, and heptachlorobiphenyls); the dominating isomers were 2,2',4,4',5,5'- and 2,2',3,4,4',5'-hexaCB, which represented approximately 90% of all PCBs in adipose tissue. Those isomers were also the most abundant in serum specimens after environmental exposure, their contribution together with the 2,2',3,4,4',5',6-heptaCB was approximately 90%. After short-term as well as long-term occupational exposure, the most remarkable changes were observed in the concentrations of the tri- and tetrachlorobiphenyls. In long-term occupational exposure 2,4,4'-triCB (mean 3.15 micrograms/liter) and 2,4,4',5-tetraCB (mean, 9.4 micrograms/liter) showed the highest concentrations, whereas after short-term exposure 2,2',5-tri- (mean 2.04 micrograms/liter) and 2,3',4,4'-tetraCB (mean 1.5 micrograms/liter) were most abundant. In people with only environmental exposure, the concentrations in adipose tissue of some PCB isomers were interrelated. The concentrations of the isomers 2,4,4'5-tetraCB (IUPAC 74), 2,2',4,4',5,5'-hexaCB (IUPAC 153), 2,2',3,4,4'5'-hexaCB (IUPAC 138), 2,3,3',4,4',5-hexaCB (IUPAC 156), 2,2',3,4,4',5',6-heptaCB (IUPAC 183), and 2,2',3,3',4,4',5-heptaCB (IUPAC 171) showed close correlation, the coefficients varied from 0.42 to 0.98. The correlation between the concentrations of individual PCB isomers in adipose tissue was highest for 2,4-substituted highly chlorinated isomers, i.e., isomers with longest half-times in the body.

Urinary excretion of chlorinated phenols in saw-mill workers.

The excretion and conjugation of chlorophenols were studied in workers exposed to 2,4,6-tri-, 2,3,4,6-tetra-, and pentachlorophenolates, the main components of the chlorophenolate product manufactured by direct chlorination of phenol. The workers were exposed in two different saw mills in which sodium chlorophenolate was used for treatment of lumber during the warm season. Urine specimens were collected at the end of the treatment season as well as at the start of a new treatment period in the spring. Serum specimens were collected towards the end of the treatment period. Total and unconjugated chlorophenols were analyzed with a gas chromatographic method. The maximal concentrations of urinary 2,4,6-tri-, 2,3,4,6-tetra- and pentachlorophenol at the end of the lumber-treatment period were 1-11.8, 3.4-17.3, and 0.2-0.9 mumol/l, respectively, and the average apparent half-times calculated using a one-compartment model were 18 h, 4.3 days and 16 days, respectively. For 2,3,4,6-tetrachlorophenol, the data of some subjects showed a better fit with a two-compartment model; the corresponding half-times were 5.3 and 26 days. During the continuous-exposure period the average serum levels of tetra- and pentachlorophenol were rather similar before and after the working day: 2.79 +/- 1.78 mumol/l for tetrachlorophenol and 0.85 +/- 0.4 mumol/l for pentachlorophenol. Renal clearance values for tetra- and pentachlorophenol were related to urine flow and indicated tubular reabsorption. At low concentrations, sulfate conjugation was dominant. With increasing chlorophenol concentrations the proportion of glucuronide conjugation was increased, especially for pentachlorophenol.

Health-based reference values of the Mini-Finland Health Survey: 1. Serum gamma-glutamyltransferase, aspartate aminotransferase and alkaline phosphatase.

The reference values for gamma-glutamyltransferase (GT), aspartate aminotransferase (ASAT) and alkaline phosphatase (AFOS) activities in serum have been produced on the basis of measurements done in the Mini-Finland Health Survey. A representative sample of all Finns aged 30 years or over comprised 8000 persons, of whom 99.2% participated in the actual health survey. Every effort was made to obtain reference values for the healthy ambulatory population. Three separate health-derived selection criteria were used to obtain such reference values for the above-mentioned enzymes: those based on the available literature, with minor modifications, the recommendations published by the Committee on Reference Values of the Scandinavian Society for Clinical Chemistry and Clinical Physiology, criteria that were obtained after subgroup comparisons of the obtained data, where all the factors affecting the enzyme levels were identified. The recommendations of the Expert Panel on Theory of Reference Values (1987) were strictly adhered to in the statistical analyses. The distribution of the serum activity of GT was very skewed. The overall intervals for men and women were 5.1-1460 and 4.7-748 U/l, respectively. The frequency distributions could be transformed to the normal ones logarithmically. The 95% inner reference intervals for GT in the three groups were 7-76, 7-65, and 8-57 U/l for men and 6-35, 6-30 and 6-32 U/l for women, respectively. For ASAT the full intervals of the enzyme levels in serum were 2.6-770 U/l for men and 8.3-172 U/l for women. After logarithmic transformation the respective reference intervals in the three selection groups were 14-42, 14-40 and 13-39 U/l for men and 13-33, 12-31 and 13-33 U/l for women. The full intervals of AFOS were 47.5-2755 and 5.4-816 U/l for men and women, respectively; after the logarithmic transformation the reference intervals of the three selection groups were 98-267, 97-254 and 97-264 U/l for men and 77-265, 75-231 and 75-250 U/l for women, respectively.