Impact of the −174 G > C IL-6 Polymorphism on Bioelectrical Parameters in Obese Subjects after Laparoscopic Adjustable Gastric Banding

BACKGROUND Recent data demonstrated that the -174 G > C IL-6 polymorphism may account for differences in the therapeutic response to laparoscopic adjustable gastric banding (LAGB) surgery. OBJECTIVE We investigated the impact of -174 G > C IL-6 polymorphism on weight loss, body composition, and fluid distribution changes in obese subjects after LAGB. DESIGN AND OUTCOME MEASURES Twenty obese subjects were selected and studied at baseline and 3 months after LAGB. Genetic assessment of -174 G > C IL-6 polymorphism and anthropometric and bioelectrical impedance analysis were performed. RESULTS At baseline, C(+) carriers had a lower extracellular water (ECW) and higher intra-CW, phase angle (PA), reactance X(c), and X(c)/height. LAGB surgery determined significant reductions in weight and BMI. After LAGB, in C(-) carriers, significant decreases in weight, BMI, and ECW and increases in BCM, BCMI, ICW, PA, and X(c)/H were highlighted. In C(+) carriers, significant reductions in weight, BMI, ICW, and PA and increases in ECW, Na/K, resistance (R), and R/height were obtained. Significant higher reductions in BMI and X(c)/H were observed in C(+) with respect to C(-) carriers. CONCLUSIONS Genotyping of genetic variants, for example, the -174 G > C polymorphism of IL-6, gives the opportunity to predict therapeutic response, in terms of body composition outcomes after LAGB.