Objective: To investigate the association between butyrylcholinesterase (BChE) activities (total and band specific) and body mass index (BMI) in obese and nonobese individuals, considering other variables (anthropometric, biochemical and hormonal) and the leanness process.
Subjects: Obese (BMI> or =30 kg/m(2); N=181) and nonobese individuals (N=265), classified according to the CHE2 locus phenotypes, with the obese patients being followed-up when submitted to a weight-loss program.
Measurements: Anthropometric (weight, height, BMI, waist, waist/hip ratio-WHR, triceps and subscapular skinfolds, percentage of body fat and arterial pressures), hormonal (insulin, estradiol-E(2), triiodothyronine-T(3) and thyroxine-T(4)) and biochemical (glucose, total cholesterol, HDL-C, triglycerides, uric acid, urea, creatinine, sodium, potassium and BChE activities) variables.
Results: Although obese CHE2 C5- individuals presented higher mean BChE activities than their CHE2 C5- controls and diminished mean activities with leanness, similar comparisons did not show any difference in the CHE2 C5+ group. Furthermore, the mean serum potassium values of obese individuals were significantly higher in the CHE2 C5+ than in the CHE2 C5- phenotype. The BChE activities were less related to BMI in obese CHE2 C5- individuals than in their controls. In the CHE2 C5- obese group, significant regression coefficients were found between BChE activity variables and BMI (+), ethnic origin (higher in Euro-Brazilians), sex (higher in males), diastolic pressure (-), triceps skinfold (+), total cholesterol (+), T(3) (+) and E(2) (-). The main findings in the CHE2 C5+ obese group: mean insulin levels decreased with leanness and a significant correlation was detected between the C(5) complex activity and creatinine (+), insulin (-) and WHR (-); a significantly higher frequency of weight loss occurred compared to the CHE2 C5- group.
Conclusion: In the present study, different relations between obesity and some of the studied variables were found when CHE2 C5+ and CHE2 C5- individuals were compared.