Long-Term Improvement in Insulin Sensitivity After RYGB
Despite weight regain, long-term improvement seen in insulin sensitivity and adipose phenotypes
WEDNESDAY, Nov. 23, 2016 (HealthDay News) -- Despite weight regain, Roux-en-Y gastric bypass (RYGB) is associated with long-term improvement in insulin sensitivity and adipose phenotypes, according to a study published online Nov. 16 in Diabetes Care.
Johan Hoffstedt, M.D., Ph.D., from Karolinska University Hospital in Stockholm, and colleagues examined 49 obese women before and at two and five years after RYGB. Thirty subjects were pairwise matched for body mass index (BMI) and age to 30 control women at the five-year follow-up.
The researchers found that BMI decreased from 43 to 29 kg/m² after two years, which correlated with improvements in insulin sensitivity (homeostatic model assessment of insulin resistance [HOMA-IR]), increased circulating and adipose secreted adiponectin, and decreased adipose lipolysis and fat cell size; there was no change in adipocyte number. BMI increased to 31 kg/m² between two and five years after surgery, correlating with slightly increased HOMA-IR and unaltered circulating or adipose secreted adiponectin but higher secretion of tumor necrosis factor-α and increased lipolysis and fat cell number; there was no change in adipocyte size. Except lipolysis, all parameters were more favorable compared with those in matching controls. Compared with controls, the relationship between HOMA-IR and circulating adiponectin was less steep.
"RYGB improves long-term insulin sensitivity and adipose phenotypes beyond the control state despite weight regain," the authors write. "Postoperative beneficial alterations in adipose function may be involved in the diabetes-protective effect of bariatric surgery."