Macrophage activation marker sCD163 is associated with liver injury and hepatic insulin resistance in obese patients before and after Roux‐en‐Y gastric bypass

Background Macrophages are associated with metabolic complications to obesity including fatty liver disease and impaired hepatic and muscle insulin sensitivity (IS). Bariatric surgery induces weight loss and improves IS. We investigated associations between the macrophage activation marker soluble (s)CD163, alanine‐aminotransferase (ALT), and IS before and after Roux‐en‐Y Gastric Bypass (RYGB). Methods We analyzed sCD163 from 10 type 2 diabetes (T2D) and 10 obese patients with normal glucose tolerance (NGT) undergoing RYGB for associations with hepatic, adipose tissue, and muscle IS and ALT after 1‐week, 3, and 12 months postoperatively. IS was evaluated by hyperinsulinemic‐euglycemic clamp in combination with glucose tracer technique. Results Preoperative sCD163 correlated with ALT (r = 0.58, p = 0.007) and tended to associate inversely with hepatic (r = −0.39, p = 0.1) and adipose tissue (r = −0.39, p = 0.09), but not muscle IS. Following RYGB, sCD163 decreased significantly in all patients. The decrease in sCD163 during the first 3 months correlated inversely with the improvement of hepatic IS (r = −0.65, p = 0.01) and tended to be associated with changes in muscle IS (r = −0.45, p = 0.09). After 3 months sCD163 remained associated with ALT (r = 0.75, p