Long-term changes in adipose tissue gene expression following bariatric surgery.

OBJECTIVE: Patients undergoing bariatric surgery present long-term metabolic improvements and reduced type 2 diabetes risk, despite long-term weight regain. We hypothesized that part of these protective effects could be linked to altered gene expression in white adipose tissue (WAT).

METHODS: Transcriptomic profiling by gene microarray was performed in abdominal subcutaneous WAT from women before (n = 50) and two (n = 49) and five (n = 38) years after Roux-en-Y gastric bypass (RYGB) surgery as well as in 28 age-matched nonoperated women.

RESULTS: In the obese women, the average body weight decrease was 38 kg 2 years postsurgery followed by an 8 kg weight regain between 2 and 5 years. Most of the long-term changes in WAT gene expression occurred during the first 2 years. However, a subset of genes encoding proteins involved in inflammation displayed a continued decrease between baseline, 2 and 5 years, respectively; that is an expression pattern independent of body weight regain. Expression of 71 of these genes correlated with measurements of adipocyte morphology or serum adipokine levels.

CONCLUSION: The continuous improvement in WAT inflammatory gene expression, despite body weight relapse, may contribute to the sustained effects on adipose morphology after bariatric surgery.