Subscribe to RSS
DOI: 10.1055/s-0034-1374964
Pancreatic lipids and insulin secretion in humans with or without type 2 diabetes
Objective: This study compared the effects of obesity and pancreas fat on β-cell function, while non-invasively distinguishing between peripancreatic, interlobular, and parenchymal fat.
Methods: Forty-eight participants (lean, overweight/obese, type 2 diabetes, 16 per group), underwent a frequent-sampling oral glucose tolerance test (OGTT), magnetic resonance imaging (MRI; whole-body and pancreas) and magnetic resonance spectroscopy (1H-MRS; liver and pancreas). Pancreas fat measurements consisted of standard 2-cm3 1H-MRS, 1-cm3 1H-MRS with localization that aimed to measure parenchymal fat, and a MRI method to test for uniform steatosis.
Results: Comparison of 1H-MRS techniques found that pancreas fat consists of an inhomogeneous distribution of interlobular and intralobular adipose tissue. MRI measurements revealed regions of parenchymal tissue void of lipid accumulation in all participants, providing evidence against uniform pancreatic steatosis. Lipid content increased with age (P < 0.05) and obesity (P < 0.05), with evidence of parenchymal fat being a better indicator than interlobular fat of decreased insulin sensitivity and β-cell function. However, body mass and visceral fat were more tightly associated with β-cell function, as well as early and late phase insulin and C-peptide secretion, in both healthy and glucose intolerant or diabetes patients.
Conclusion: Obesity and hyperglycemia have a greater influence on β-cell function than pancreas fat content.