Twelve-year changes in protein profiles in patients with and without gastric bypass surgery

Gastric bypass surgery results in long-term weight loss due to re-routing of the gastro-intestinal anatomy and dietary intake alterations. Studies have examined protein change during rapid weight loss (up to 1 year post-surgery), but whether protein changes are maintained long-term after weight stabilization is unknown. To identify proteins and pathways involved with the long-term beneficial effects of weight loss, abundances of 1297 blood-circulating proteins were measured at baseline, 2 and 12 years after Roux-en-Y gastric bypass surgery. Protein changes were compared between 234 surgery and 144 non-surgery subjects with severe obesity, with discovery and replication subgroups. Seventy-one protein changes were associated with 12-year BMI changes and 58 (7 unique) with surgical status. Protein changes, including ApoM, were most strongly associated with long-term changes in lipids (HDL-C and triglycerides). Inflammation, adipogenesis, cellular signaling, and complement pathways were implicated. Short-term improvements in protein levels were maintained long-term, even after some weight regain.