Distribution and reproducibility of aryl hydrocarbon hydroxylase inducibility in a prospective population study of middle-aged male smokers and nonsmokers.

Aryl hydrocarbon hydroxylase (AHH) inducibility was determined in a lymphoblast test system in 2,000 consecutive middle-aged male smokers, 304 ex-smokers, and 218 never-smokers in the same birth-year cohorts. Intraindividual, intraobserver, and interobserver, as well as temporal, reproducibility was checked in a special double-blind quadruplet sample series from 20 other consecutive middle-aged men. The results showed a three-modal phenotype distribution of AHH inducibility with high (fold induction greater than or equal to 3.6), intermediate (2.6-3.6) and low (less than or equal to 2.5) levels ranging between 7.6% to 10.5%, 38.5% to 43.0%, and 46.5% to 53.9%, respectively, in all the smoking categories. The reproducibility of the measurements was excellent, with one-way variance in the order of 0.007 to 0.033, and the applied assay method can therefore be used in large-scale prospective population investigations. Such are required in order to establish a cause-effect association between high AHH inducibility and smoking-related malignancies of the respiratory tract and oral cavity, as has been suggested from earlier retrospective studies in more limited clinical materials of cancers and precanceroses of these varieties.

Relation between aryl hydrocarbon hydroxylase inducibility, serum gamma-glutamyltransferase and serum cholesterol in middle-aged smokers and non-smokers.

Aryl hydrocarbon hydroxylase (AHH) inducibility, carbon monoxide in expired air (CO), serum gammaglutamyl-transferase (GGT), and total cholesterol were compared in equal-sized, age-matched samples of healthy middle-aged males born in 1921, 1934-1936, and 1946 attending the ongoing preventive medical population program in Malmö. AHH did not differ in various age - and smoking or non-smoking groups, and there were no correlations between AHH, GGT, and cholesterol. The findings provide evidence against the recent hypothesis that low cholesterol may mediate or reflect a carcinogenic mechanism through a state of general enzyme induction in the body.

Smoking, carboxyhaemoglobin, carbon monoxide in expired air and aryl hydrocarbon hydroxylase inducibility. A cross-sectional study and anti-smoking applications in middle-aged men.

In this cross-sectional study we report on the distributions of carboxyhaemoglobin in blood (COHb%), carbon monoxide in expired air (CO), and aryl hydrocarbon hydroxylase (AHH) inducibility in age-matched samples of males born 1934-36 and 1921, attending our ongoing preventive medical health screening program in Malmö. Both COHb% and CO showed great interindividual variations in the smokers; potentially of value as a complement to smoking history to identify smokers at high risk of tobacco-related diseases. They also provide powerful arguments for quitting smoking. Therefore, CO is now measured and discussed by the nurses as part of the screening investigation in all smokers. Neither COHb% nor CO showed correlations to the AHH induction levels. There were no associations between the latter and the smoking category, which supports that AHH inducibility is under genetic control. However, high AHH induction in smokers implies an increased risk of smoking-induced carcinogenesis. Smokers with high AHH inducibility identified in the screening have, therefore, been invited to antismoking information and counselling.