Pancreatic steatosis is not associated with impaired insulin secretion among individuals with diabetes

Aims We aimed to assess pancreatic and hepatic steatosis (PS/HS) association with residual insulin secretion and insulin resistance in individuals with diabetes. Methods Pancreatic/liver fat fractions (PFF/LFF) in magnetic resonance imaging (MRI) were used as a proxy for PS and HS in 170 participants. Insulin secretion was estimated by HOMA2-B, C-peptide response 6 minutes after an i.v. bolus of 0.5 mg glucagon (ΔC-Pe), and fasting proinsulin to C-peptide ratio (PI:C). Insulin resistance was estimated by HOMA2-IR, Adipo-IR and i.v. insulin (0.05 IU/kg) tolerance test. Results PFF did not correlate with measures of insulin secretion but it correlated with fasting indices of insulin resistance among women (HOMA2-IR, R = 0.26, p = 0.017; Adipo-IR, R = 0.29, p = 0.007). Both LFF and PFF correlated with BMI (R = 0.43 & R = 0.34, respectively, p < 0.001) but not with each other (R = 0.10, p = 0.215). Unlike PS, HS was associated with higher HOMA2-IR, Adipo-IR, HOMA2-B, PI:C and glucagon, after adjustment with confounders. Participants with PS without HS had lower fasting C-peptide, HOMA2-IR, HOMA2-B, Adipo-IR, glucagon and triglycerides (p < 0.05) compared to those having HS without PS. Cluster-based subgroups of diabetes did not differ in PF (p = 0.071). Conclusions Within this cohort, pancreatic fat was more strongly associated with adiposity than with the investigated measures of β-cell function or insulin resistance.