• Bariatric surgery;
  • metabolism;
  • obesity;
  • pigment epithelium-derived factor;
  • weight loss

Eur J Clin Invest 2011; 41 (9): 937–942


Background  Cumulating evidence suggests that the broadly acting neurotrophic pigment epithelium-derived factor is associated with visceral adiposity, the metabolic syndrome, diabetes and exerts beneficial effects on atherosclerosis. To further elucidate the relationship between pigment epithelium-derived factor and metabolic perturbations characteristic of obesity, we examined the effect of pronounced weight loss on serum levels of pigment epithelium-derived factor.

Materials and methods  Thirty-six severely obese adults were examined before and 18 months after bariatric surgery. Abdominal fat distribution was determined by ultrasound, metabolic parameters by standard methods, pro-inflammatory biomarkers and serum pigment epithelium-derived factor levels by enzyme-linked immunosorbent assay.

Results  Bariatric surgery resulted in a mean body mass index (BMI) reduction of 9·0 ± 5·0 kg m−2 and concomitant improvements in glucose homoeostasis and lipid profile. Pigment epithelium-derived factor serum levels decreased from a median 11·0 μg mL−1 (interquartile range: 3·8) to 9·2 μg mL−1 (interquartile range: 4·5) (P < 0·0001). In univariate analysis, relative change in pigment epithelium-derived factor levels was significantly associated with change in weight, BMI, fat mass, visceral fat diameter, insulin, homoeostasis model for insulin resistance, triglyceride and leptin levels (all r > 0·370, P < 0·05). No associations were observed for C-reactive protein, interleukin-6 or tumour necrosis factor alpha. After adjustment for age, sex and smoking status, associations remained significant.

Conclusions  The beneficial effects of bariatric surgery–induced pronounced weight loss on glucose homoeostasis may partially be attributable to visceral adipose tissue reduction and concomitantly decreasing pigment epithelium-derived factor concentrations.