Pancreatic fat and β-cell function in overweight/obesechildren with nonalcoholic fatty liver disease

AIM: To analyze the associations of pancreatic fat with other fat depots and β-cell function in pediatric nonalcoholic fatty liver disease(NAFLD).METHODS: We examined 158 overweight/obese children and adolescents, 80 with NAFLD [hepatic fat fraction(HFF) ≥ 5%] and 78 without fatty liver. Visceral adipose tissue(VAT), pancreatic fat fraction(PFF) and HFF were determined by magnetic resonance imaging. Estimates of insulin sensitivity were calculated using the homeostasis model assessment of insulin resistance(HOMA-IR), defined by fasting insulin and fasting glucose and whole-body insulin sensitivity index(WBISI), based on mean values of insulin and glucose obtained from oral glucose tolerance test and the corresponding fasting values. Patients were considered to have prediabetes if they had either:(1) impaired fasting glucose, defined as a fasting glucose level ≥ 100 mg/d L to < 126 mg/d L;(2) impaired glucose tolerance, defined as a 2 h glucose concentration between ≥ 140 mg/d L and < 200 mg/d L; or(3) hemoglobin A1 c value of ≥ 5.7% to < 6.5%.RESULTS: PFF was significantly higher in NAFLD patients compared with subjects without liver involvement. PFF was significantly associated with HFF and VAT, as well as fasting insulin, C peptide, HOMA-IR, and WBISI. The association between PFF and HFF was no longer significant after adjusting for age, gender, Tanner stage, body mass index(BMI)-SD score, and VAT. In multiple regression analysis withWBISI or HOMA-IR as the dependent variables, against the covariates age, gender, Tanner stage, BMI-SD score, VAT, PFF, and HFF, the only variable significantly associated with WBISI(standardized coefficient B,-0.398; P = 0.001) as well as HOMA-IR(0.353; P = 0.003) was HFF. Children with prediabetes had higher PFF and HFF than those without. PFF and HFF were significantly associated with prediabetes after adjustment for clinical variables. When all fat depots where included in the same model, only HFF remained significantly associated with prediabetes(OR = 3.38; 95%CI: 1.10-10.4; P = 0.034).CONCLUSION: In overweight/obese children with NAFLD, pancreatic fat is increased compared with those without liver involvement. However, only liver fat is independently related to prediabetes.

Pancreatic fat in type 2 diabetes:Causal or coincidental?

Type 2 diabetes(T2D)is a multifactorial metabolic disorder affecting more than 450 million people across the globe.With the increasing prevalence of T2D and obesity,the role of fat accumulation at sites other than subcutaneous adipose tissue has received significant attention in the pathophysiology of T2D.Over the past decade and a half,a pressing concern has emerged on investigating the association of pancreatic fat accumulation or pancreatic steatosis with the development of disease.While a few reports have suggested a possible association between pancreatic fat and T2D and/or impaired glucose metabolism,a few reports suggest a lack of such association.Pancreatic fat has also been linked with genetic risk of developing T2D,prediabetes,reduced insulin secretion,and beta cell dysfunction albeit some confounding factors such as age and ethnicity may affect the outcome.With the technological advancements in clinical imaging and progress in assessment of pancreatic beta cell function,our understanding of the role of pancreatic fat in causing insulin resistance and development of various etiologies of T2D has significantly improved.This review summarizes various findings on the possible association of pancreatic fat accumulation with the pathophysiology of T2D.

Diabetes remission and nonalcoholic fatty pancreas disease

This editorial focuses on the relationship between nonalcoholic fatty pancreas disease(NAFPD)and the development and remission of type 2 diabetes(T2D).NAFPD is characterized by intrapancreatic fatty deposition associated with obesity and not associated with alcohol abuse,viral infections,and other factors.Ectopic fat deposition in the pancreas is associated with the development of T2D,and the underlying mechanism is lipotoxicβ-cell dysfunction.However,the results on the relationship between intrapancreatic fat deposition(IPFD)andβ-cell function are conflicting.Regardless of the therapeutic approach,weight loss improves IPFD,glycemia,andβ-cell function.Pancreatic imaging is valuable for clinically monitoring and evaluating the management of T2D.