Cigarette smoking affects the differences between male and female phenotypes.

BACKGROUND Sex-gender medicine focuses on differences and similarities in health and disease between men and women. The present study focused on the existence of male and female phenotypes when routine demographic, biochemical and haematological data are considered and aimed to determine the influence of smoking on phenotypes and evaluate the role of body weight on sex-gender differences in view of the fact that some of them can be utilized as biomarkers of diagnosis, diseases and therapeutic response. METHODS Eighty-five healthy young adult men (27 smokers and 58 non-smokers) and 85 women (32 smokers and 53 non-smokers) well matched for age were enrolled. 31 haematochemical parameters were measured and data were analysed before and after normalization for body weight applying the two-way analysis of variance and principal component analysis (PCA). RESULTS In non-smoking cohorts, there were numerous sex-gender differences and PCA analysis distinguished two different phenotypes: males and females. Body weight normalization induced qualitatively and quantitatively changes, but male and female phenotypes were still well evident. Smoking influenced numerous parameters and PCA analysis evidenced that these changes led to the abolition of male and female phenotypes. CONCLUSIONS Personalized medicine has the goals to study modification of markers profile in the single individual, which is strongly influenced by sex-gender and smoking habit. In non-smokers, male and female phenotypes are present independently from the quantitation method used. In smokers only one phenotype is present. These results suggest that smoking and sex-gender should be considered as an independent variable in clinical research.