Pegylated human recombinant leptin (PEG-OB) causes additional weight loss in severely energy-restricted, overweight men

Pegylated human recombinant leptin (PEG-OB) causes additional weight loss in severely energy-restricted, overweight men. Hukshorn CJ, Westerterp-Plantenga MS, Saris WH. Nutrition and Toxicology Research Institute Maastricht, Department of Human Biology, Maastricht University, Maastricht, Netherlands. [email protected] BACKGROUND: Increasing evidence suggests that falling leptin concentrations observed during fasting act as a peripheral signal of starvation, which serves to conserve energy in the face of limited reserves. An extension of this hypothesis is that exogenous leptin should affect energy regulation during severe energy restriction. OBJECTIVE: To explore this hypothesis, we assessed whether elevated leptin concentrations achieved with the use of long-acting pegylated human recombinant leptin [polyethylene glycol-OB protein (PEG-OB)] affected weight loss and changes in body composition, energy expenditure, appetite, and metabolic variables during semistarvation in healthy overweight men. DESIGN: A randomized, double-blind, placebo-controlled study was executed in overweight men with a mean (+/- SEM) age of 34.8 +/- 1.3 y and body mass index (in kg/m2) of 28.8 +/- 0.5. All subjects received weekly treatment with 80 mg PEG-OB (n = 12) or matching placebo (n = 10) for 46 d while their energy intake was reduced to 2.1 MJ/d by means of a very-low-energy diet. Body composition (hydrodensitometry and deuterium dilution), energy expenditure (ventilated hood), and appetite (visual analogue scales) were evaluated at the start and the end of the study. Metabolic variables were measured throughout the study period. RESULTS: Compared with placebo treatment, treatment with PEG-OB led to significant (P < 0.03) additional weight loss (14.6 +/- 0.8 compared with 11.8 +/- 0.9 kg) and a reduction in appetite (P < 0.05) after 46 d, but the 2 treatment groups did not differ significantly in changes in body composition, energy expenditure, and metabolic variables. CONCLUSION: Our observations support the hypothesis that the decrease in leptin concentrations during starvation increases appetite in human

Effects of weekly administration of pegylated recombinant human OB protein on appetite profile and energy metabolism in obese men.

Am J Clin Nutr 2001 Oct;74(4):426-34 Related Articles, Books, LinkOut Effects of weekly administration of pegylated recombinant human OB protein on appetite profile and energy metabolism in obese men. Westerterp-Plantenga MS, Saris WH, Hukshorn CJ, Campfield LA. Department of Human Biology, Maastricht University, Maastricht, Netherlands. [email protected] BACKGROUND: Results of leptin administration in mice, rats, and humans provide a rationale for therapeutic augmentation of circulating leptin (OB protein) concentrations in obese humans; this may reduce food intake, increase metabolic rate, and lower body mass. OBJECTIVE: We assessed the effects of weekly subcutaneous pegylated polyethylene glycol (PEG)-OB protein administration on appetite and energy metabolism in obese men. DESIGN: We performed a randomized, double-blind, placebo-controlled trial in 30 obese men [body mass index (in kg/m(2)): 34.2 +/- 3.6; age: 44.7 +/- 7 y]. Subjects received 20 mg PEG-OB protein/wk for 12 wk while limiting their energy intake to 2.1 MJ/d. RESULTS: During treatment, appetite and hunger before breakfast decreased and remained lower in the PEG-OB-protein group, whereas they increased and remained higher in the placebo group (P < 0.0001). During treatment, hunger decreased in the PEG-OB-protein group (P < 0.05) and cognitive restraint increased in the placebo group (P < 0.0001). Neither appetite nor food intake changed significantly during the ad libitum evening meal. Under energy balance conditions in the respiration chamber, appetite at the end of treatment was not significantly different from baseline despite similar, significant reductions in 24-h energy intake, energy expenditure, sleeping metabolic rate, body mass, fat mass, and fat-free mass (P < 0.01 for all) in both groups. CONCLUSION: Treatment with PEG-OB protein modified subjective appetite at a dosage that produced no changes in body composition, energy expenditure, or body mass loss relative to placebo treatment, suggesting that PEG-OB protein has central rather than peripheral biological activity in obese men

The effect of pegylated recombinant human leptin (PEG-OB) on weight loss and inflammatory status in obese subjects

The effect of pegylated recombinant human leptin (PEG-OB) on weight loss and inflammatory status in obese subjects. Hukshorn CJ, van Dielen FM, Buurman WA, Westerterp-Plantenga MS, Campfield LA, Saris WH. Nutrition and Toxicology Research Institute Maastricht, Department of Human Biology, Maastricht University, The Netherlands. [email protected] OBJECTIVE: To investigate whether weekly subcutaneous administration of 60 mg of long-acting pegylated human leptin (PEG-OB) for 8 weeks was able to influence weight loss, metabolic profile and inflammatory status of obese subjects on a mildly hypoenergetic diet (deficit: 3.2 MJ/day). DESIGN: A prospective, randomized, double-blind and placebo-controlled single-center trial. SUBJECTS: Twenty-eight healthy, obese subjects (16 women, 12 men; age 22-65 y; body mass index 27.7-38.7 kg/m2). MEASUREMENTS: Bodyweight, metabolic profile (including lipids), C-reactive protein (CRP) and soluble TNF alpha-receptor (sTNF-R) 55 and 75 levels. RESULTS: At the end of the study no significant differences in the delta or percentage weight loss between the placebo (n = 14) and PEG-OB (n = 14) groups was observed. Also the changes in metabolic profile, CRP, sTNF-R55 and R75 concentrations between the two groups after 8 weeks of treatment did not differ. CONCLUSION: Weekly injection of 60 mg PEG-OB did not lead to additional weight loss after 8 weeks of treatment. Furthermore, PEG-OB administration did not affect the changes in metabolic profile and the inflammatory status of obese subjects

The polycystic kidney disease 1 gene encodes a 14 kb transcript and lies within a duplicated region on chromosome 16

Autosomal dominant polycystic kidney disease (ADPKD) is a common genetic disorder that frequently results in renal fallure due to progressive cyst development. The major locus, PKD1, maps to 16p13.3. We identified a chromosome translocation associated with ADPKD that disrupts a gene (PBP) encoding a 14 kb transcript in the PKD1 candidate region. Further mutations of the PBP gene were found in PKD1 patients, two deletions (one a de novo event) and a splicing defect, confirming that PBP is the PKD1 gene. This gene is located adjacent to the TSC2 locus in a genomic region that is reiterated more proximally on 16p. The duplicate area encodes three transcripts substantially homologous to the PKD1 transcript. Partial sequence analysis of the PKD1 transcript shows that it encodes a novel protein whose function is at present unknown

Leptin and energy expenditure

PURPOSE OF REVIEW: A fundamental advance in our understanding of endocrine control of energy balance and body weight came with the discovery of the adipocyte-derived hormone leptin. The leptin pathway appeared to be the long-sought peripheral signal pathway from the adipose tissue to the brain involved in the regulation of feeding and energy balance. RECENT FINDINGS: Initially, leptin was considered to function as the long-sought antiobesity hormone. According to this hypothesis, rising concentrations of leptin with increasing adiposity would generate a signal to reduce food intake and increase energy expenditure in order to limit further weight gain. However, widespread resistance to the proposed antiobesity action of leptin is observed in humans, which might reflect the fact that the inability to store energy efficiently at times of abundance is evolutionarily disadvantageous. According to this alternative view, falling leptin concentrations observed during fasting act as a peripheral signal of starvation, which serves to conserve energy in the face of limited reserves. However, leptin administration failed to blunt the changes in energy expenditure during severe energy restrictions in several clinical studies. In addition, leptin therapy in several different human low-leptin states failed to affect energy expenditure in recent studies. SUMMARY: Increasing evidence from human studies suggests that leptin predominantly influences the human energy balance through appetite but appears not to be involved in regulating energy expenditure. None of the expected factors such as resting metabolic rate, total diurnal energy expenditure or dietary induced thermogenesis was related to blood leptin concentrations

Effects of very low calorie diet induced body weight loss with or without human pegylated recombinant leptin treatment on changes in ghrelin and adiponectin concentrations

The aim of the study was to investigate the effects of energy restriction with or without pegylated recombinant leptin (PEG-leptin) treatment on ghrelin, adiponectin, insulin and glucose concentrations. A randomized double-blind placebo-controlled trial was performed in 24 moderately overweight/obese men. PEG-leptin or placebo was administered weekly for 6 weeks, combined with a restricted energy intake of 2.1 MJ/d. At days 1, 25, and 46 a blood sample was taken and body-weight (BW) was measured. Days 1-25 was named phase 1, and days 25-46 phase 2. During phase 1 the rate of BW loss was significantly higher in the PEG-leptin compared to the placebo group (0.38+/-0.07 vs 0.32+/-0.06 kg/d, p<0.05). The rate of BW loss during phase 2 was 0.24+/-0.08 and 0.18+/-0.09 kg/d, respectively (p=0.07). In both groups the rate of BW loss during phase 1 was significantly higher than during phase 2 (p<0.001). Energy balance (EB) was significantly more negative during phase 1 than during phase 2 in both groups (p<0.0005). During phase 1 insulin, glucose and adiponectin decreased significantly in both groups. Adiponectin and ghrelin concentrations changed in the opposite direction between phase 1 and phase 2 (p<0.05). Initial BW loss due to a considerable negative EB induced decreased ghrelin, adiponectin, insulin and glucose levels. However, when EB became less negative and the rate of BW loss decreased, these changes were reversed for adiponectin and ghrelin. The PEG-leptin injections did not have an effect on the changes in insulin, glucose and adiponectin, but had an effect on the changes in ghrelin concentrations. AD - Department of Human Biology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands