Role of dehydroepiandrosterone sulfate levels on body composition after laparoscopic adjustable gastric banding in pre-menopausal morbidly obese women.

Context. GH secretion is reduced in obese subjects and increases after body weight loss. It is still unclear if changes in the GH/IGF-I axis after laparoscopic-adjustable silicone gastric banding (LASGB) are associated with changes of body composition. Objective. To analyse the relationships between changes in the GH/IGF-I axis and those of body weight and composition before and after LASGB. Design. Observational, prospective. Setting University ‘Federico II’ of Naples (Italy). Patients. Seventy-two severely obese females (BMI: 44·9 ± 4·68; mean age: 33·1 ± 11·34 years) were studied. Main outcome measures GH peak after GHRH plus arginine test, IGF-I, IGFBP-3 and ALS levels, fat mass (FM) and free fat mass (FFM) (by Bioelectrical Impedance Analysis) at baseline and 6 months after LASGB. The change in percentage of individual variables was calculated as well as that of excess of body weight loss (EBWL%). The FM%, FFM% and EBWL% were correlated with peak GH and IGF-I levels changes. Results. At baseline, GH deficiency (GHD) (GH peak = 4·1 μg/l) was found in 22 patients (31%), 16 of them also had IGF-I deficiency (< –2SDS). IGF-I levels were inversely correlated with waist circumference (r=–0·72, P<0·001) and FM% (r=–0·75, P< 0·001). Post-LASGB the patients were classified as follows: group (1) GH and IGF-I sufficient (n= 44; 61·1%); group (2) GH and IGF-I deficient (n= 14; 19·4%) and group (3) GH sufficient and IGF-I deficient (n= 14; 19·4%). The percentage changes of EWBL (P < 0·05, P= 0·051, respectively) and FM (P <0·001, P< 0·01, respectively) were lower in groups (2) and (3) than in group (1). At the stepwise linear regression analysis, postoperative IGF-I levels were the strongest eterminant of percent changes of FM (P<0·0001), of FFM (P = 0·009) and of EBWL (P < 0·0001). Conclusions. IGF-I levels is the most sensitive to unfavourable changes in body composition 6 months after LASGB making investigation of the comatotropic axis useful in the evaluation of bariatric surgery outcomes.