CIRCULATING TNF ALPHA RECEPTOR LEVELS IDENTIFY OLDER ADULTS WHO FAIL TO REGAIN WEIGHT AFTER ACUTE WEIGHT LOSS

Objective: Some healthy older adults have difficulty regaining weight after acute weight loss, and the reason for this failure to regain weight is unknown. The objective of this study was to determine if elevated leptin or pro-inflammatory cytokine levels are associated with failure to regain weight over two years after an acute weight loss intervention. Design: Two year prospective study after an acute weight loss intervention. Setting: University of Washington Medical Center from 2001-2006. Participants: Nineteen older (≥ 70 years old) men and women. Measurements: Body weights, health status questionnaire, body composition data, serum leptin, glucose, insulin, C- reactive protein and pro-inflammatory cytokine levels were measured every six months for two years. Results: Five subjects out of 19 failed to regain weight after two years. The subjects who failed to regain weight after 2 years had higher circulating levels of tumor necrosis factor receptor particle 55 (TNFRp55) at baseline and at 6, 12, 18 and 24 months of follow up compared to subjects who regained weight after 2 years (P = 0.02 ). Conclusion: Five out of 19 older subjects had difficulty regaining weight for up to 2 years following an acute weight loss intervention, and their TNFRp55 levels were persistently higher than in subjects who regained weight. Greater TNF action, as reflected by higher circulating levels of TNFRp55, could be contributing towards inability of some older persons to regain weight after acute weight loss