Adiponectin-SOGA Dissociation in Type 1 Diabetes

Area of Science:

• Endocrinology
• Metabolic Research
• Diabetes Pathophysiology

Background:

• Elevated circulating adiponectin in type 1 diabetes (T1D) and nonobese diabetic (NOD) mice is not associated with expected adiponectin action, suggesting tissue resistance.
• Adiponectin normally stimulates hepatocyte production of suppressor of glucose from autophagy (SOGA), which inhibits glucose production.

Purpose of the Study:

• To investigate if adiponectin resistance in T1D prevents the expected increase in liver SOGA, using circulating C-terminal SOGA fragment as a surrogate marker.
• To assess the relationship between adiponectin, SOGA, and insulin sensitivity in T1D and control subjects.

Main Methods:

• Measured liver and plasma SOGA in NOD mice via Western blot.
• Quantified serum adiponectin and SOGA in T1D and control participants during a three-stage insulin clamp.
• Assessed glucose turnover using stable isotope tracers (6,6[(2)H2]glucose).

Main Results:

• Diabetic NOD mice showed reduced liver and circulating SOGA, correlating with each other.
• T1D participants had higher adiponectin and insulin but lower SOGA compared to controls.
• Lower insulin infusion rates revealed negative correlations between glucose appearance/disappearance and adiponectin/SOGA in T1D and controls, with impaired insulin sensitivity in T1D.

Conclusions:

• Plasma SOGA serves as a reliable surrogate marker for liver SOGA in NOD mice.
• Reduced SOGA in diabetic models suggests adiponectin resistance.
• Dissociation of adiponectin and SOGA in T1D highlights potential therapeutic targets for improving insulin therapy outcomes.