Body composition and adipose tissue cellularity before and after jejuno-ileostomy in severely obese subjects.

In severe obesity with adipose tissue hyperplasia it is difficult to achieve and sustain weight decrease by conventional therapy. Fifteen severely obese patients (mean body weight 135 kg) with hyperplastic obesity had a jejuno-ileostomy according to Payne to induce weight reduction by controlled malabsorption. Body composition, adipose tissue cellularity, and glucose tolerance were studied before and after the operation when the patients had reached a new stable weight (WS) a mean 21 months after surgery. Preoperative fat cell number was unchanged at follow-up in contrast to all other variables of body composition. Reductions in fat cell size were evenly distributed in different major subcutaneous regions. Body potassium was determined immediately after operation and at 6 months intervals until WS. The postoperative decrease stopped at 6 months, thus differing from the decrease in body weight. Significant positive correlations between the postoperative decrease in body weight or body fat, and preoperative body weight, body fat and body cell mass were analysed by multiple stepwise regression. Preoperative body weight and body fat were shown to predict postoperative weight loss at a leve of P less than 0.005. A positive correlation between body fat decrease and fat cell number could be explained hypothetically by an increased caloric demand in hyperplastic obesity.