Association of the CHE2 locus with body mass index and butyrylcholinesterase activity

The butyrylcholinesterase (BChE; EC 3.1.1.8) activities of two electrophore tic bands of the CHE2 C5+ phenotype-C-5 and C-OF (other forms)-were quantif ied by densitometry in 100 individuals. The activity data suggested that, i n addition to determining C-5, the CHE2*C-5+ allele also increases the leve l of other BChE forms. Since the relative activity of C5 showed the highest correlation coefficient with weight when compared with the other BChE acti vity variables (total, absolute C-5, and absolute C-OF), its median activit y level was used for the classification of CHE2 C5+ phenotypes (faint and i ntense). Mean body mass index (BMI) was compared among the CHE2 locus pheno types-controlled by sex, age, and ethnic group. It was shown that the inten se CRE2 C5+ phenotype presents a significantly lower (p < 0.001) mean BMI ( 23.2) than the other phenotypes (faint CHE2 C5+ = 25.2; CHE2 C5- = 25.4). I t seems that the relative C-OF activity is positively associated with fat s torage, since CHE2 C5- and faint CHE2 C5+ phenotypes showed higher mean BMI than the intense CHE2 C5+ phenotype. Our hypothesis is that the presence o f C-5 in a relatively high proportion leads to less fat storage.