Radiologic evidence that hypothalamic gliosis is associated with obesity and insulin resistance in humans. (November 2015)

• Record Type: Journal Article
• Authors: Schur, Ellen A.; Melhorn, Susan J.; Oh, Seok‐Kyun; Lacy, J. Matthew; Berkseth, Kathryn E.; Guyenet, Stephan J.; Sonnen, Joshua A.; Tyagi, Vidhi; Rosalynn, Mary; De Leon, B.; Webb, Mary F.; Gonsalves, Zenobia T.; Fligner, Corinne L.; Schwartz, Michael W.; Maravilla, Kenneth R.
• Is Part Of: Obesity. Volume 23:Number 11(2015:Nov.)
• Page Start: 2142
• Page End: 2148
• Publication Date: 2015-11
• Subjects: Obesity -- Periodicals; 616.398005
• DOI: 10.1002/oby.21248
• Languages: English
• ISSNs: 1930-7381

Abstract

Abstract : Objective: To use quantitative magnetic resonance imaging (MRI) to test whether mediobasal hypothalamic (MBH) gliosis is associated with obesity and insulin resistance in humans. Methods: Sixty‐seven participants underwent a fasting blood draw and MRI. Cases with radiologic evidence of MBH gliosis ( N = 22) were identified as the upper tertile of left MBH T2 relaxation time and were compared to controls ( N = 23) from the lowest tertile. In a separate postmortem study, brain slices ( N = 10) through the MBH were imaged by MRI and stained for glial fibrillary acidic protein (GFAP). Results: In all participants, longer T2 relaxation time in the left MBH was associated with higher BMI ( P = 0.01). Compared with controls, cases had longer T2 relaxation times in the right MBH ( P < 0.05), as well as higher BMI ( P < 0.05), fasting insulin concentrations ( P < 0.01), and HOMA‐IR values ( P < 0.01), adjusted for sex and age. Elevations in insulin and HOMA‐IR were also independent of BMI. In the postmortem study, GFAP staining intensity was positively associated with MBH T2 relaxation time ( P < 0.05), validating an MRI‐based method for the detection of MBH gliosis in humans. Conclusions: These findings link hypothalamic gliosis to insulin resistance in humans and suggest that the link is independent of the level of adiposity.