Association of Adipose Tissue and Liver Fibrosis With Tissue Stiffness in Morbid Obesity: Links With Diabetes and BMI Loss After Gastric Bypass

Liver and white adipose tissue (WAT) develop inflammation and fibrosis.The aim of the study was to evaluate the bioclinical relevance of WAT fibrosis in morbid obesity and diabetes and the relationships with tissue stiffness measured using a novel device.Observational and longitudinal studies were conducted in a hospital nutrition department.Biopsies of liver and subcutaneous WAT (scWAT) and omental adipose tissue were collected from 404 obese bariatric surgery candidates, of whom 243 were clinically characterized before surgery and 3, 6, and 12 months after surgery. In 123 subjects, liver and scWAT stiffness was assessed noninvasively using vibration-controlled transient elastography (VCTE).Bariatric surgery was performed for some patients.Adipose tissue fibrosis and stiffness and their link to obesity phenotypes were measured.scWAT fibrosis was positively associated with liver fibrosis (fibrosis score ≥2) (ϱ= 0.14; P = .01). VCTE-evaluated liver and scWAT stiffness was positively correlated with immunohistochemistry-determined liver (ϱ= 0.46; P = .0009) and scWAT fibrosis (ϱ= 0.48; P = .0001). VCTE-evaluated scWAT stiffness measures negatively associated with dual-energy x-ray absorptiometry-evaluated body fat mass (R = -0.25; P = .009) and were correlated with metabolic variables. Diabetic subjects showed increased scWAT stiffness. Participants less responsive to gastric bypass were older and more frequently diabetic, and they had increased body mass index, serum IL-6, and scWAT and liver fibrosis. Subjects with no diabetes and normal liver had higher fat mass and lower tissue fibrosis and stiffness.scWAT stiffness was associated with tissue fibrosis, obesity, and diabetes-related traits. Noninvasive evaluation of scWAT stiffness might be useful in clinical practice.