Jason Bini1,2, Shivani Bhatt3, Ansel T Hillmer4,3, Jean-Dominique Gallezot4, Nabeel Nabulsi4, Richard Pracitto4, David Labaree4, Michael Kapinos4, Jim Ropchan4, David Matuskey4,3,5, Robert S Sherwin6, Ania M Jastreboff6,7, Richard E Carson4, Kelly Cosgrove4,3, Yiyun Huang4. 1. Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA. jason.bini@yale.edu. 2. Yale University PET Center, 801 Howard Ave, PO Box 208048, New Haven, CT, 06520-8048, USA. jason.bini@yale.edu. 3. Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA. 4. Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA. 5. Department of Neurology, Yale University School of Medicine, New Haven, CT, USA. 6. Department of Internal Medicine, Endocrinology, Yale University School of Medicine, New Haven, CT, USA. 7. Department of Pediatrics, Pediatric Endocrinology, Yale University School of Medicine, New Haven, CT, USA.
Abstract
CONTEXT: Cortisol, a glucocorticoid steroid stress hormone, is primarily responsible for stimulating gluconeogenesis in the liver and promoting adipocyte differentiation and maturation. Prolonged excess cortisol leads to visceral adiposity, insulin resistance, hyperglycemia, memory dysfunction, cognitive impairment, and more severe Alzheimer's disease phenotypes. The intracellular enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyzes the conversion of inactive cortisone to active cortisol; yet the amount of 11β-HSD1 in the brain has not been quantified directly in vivo. OBJECTIVE: We analyzed positron emission tomography (PET) scans with an 11β-HSD1 inhibitor radioligand in twenty-eight individuals (23 M/5F): 10 lean, 13 overweight, and 5 obese individuals. Each individual underwent PET imaging on the high-resolution research tomograph PET scanner after injection of 11C-AS2471907 (n = 17) or 18F-AS2471907 (n = 11). Injected activity and mass doses were 246 ± 130 MBq and 0.036 ± 0.039 μg, respectively, for 11C-AS2471907, and 92 ± 15 MBq and 0.001 ± 0.001 μg for 18F-AS2471907. Correlations of mean whole brain and regional distribution volume (VT) with body mass index (BMI) and age were performed with a linear regression model. RESULTS: Significant correlations of whole brain mean VT with BMI and age (VT = 15.23-0.63 × BMI + 0.27 × Age, p = 0.001) were revealed. Age-adjusted mean whole brain VT values were significantly lower in obese individuals. Post hoc region specific analyses revealed significantly reduced mean VT values in the thalamus (lean vs. overweight and lean vs. obese individuals). Caudate, hypothalamus, parietal lobe, and putamen also showed lower VT value in obese vs. lean individuals. A significant age-associated increase of 2.7 mL/cm3 per decade was seen in BMI-corrected mean whole brain VT values. CONCLUSIONS: In vivo PET imaging demonstrated, for the first time, correlation of higher BMI (obesity) with lower levels of the enzyme 11β-HSD1 in the brain and correlation of increased 11β-HSD1 levels in the brain with advancing age.
CONTEXT: Cortisol, a glucocorticoid steroid stress hormone, is primarily responsible for stimulating gluconeogenesis in the liver and promoting adipocyte differentiation and maturation. Prolonged excess cortisol leads to visceral adiposity, insulin resistance, hyperglycemia, memory dysfunction, cognitive impairment, and more severe Alzheimer's disease phenotypes. The intracellular enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyzes the conversion of inactive cortisone to active cortisol; yet the amount of 11β-HSD1 in the brain has not been quantified directly in vivo. OBJECTIVE: We analyzed positron emission tomography (PET) scans with an 11β-HSD1 inhibitor radioligand in twenty-eight individuals (23 M/5F): 10 lean, 13 overweight, and 5 obese individuals. Each individual underwent PET imaging on the high-resolution research tomograph PET scanner after injection of 11C-AS2471907 (n = 17) or 18F-AS2471907 (n = 11). Injected activity and mass doses were 246 ± 130 MBq and 0.036 ± 0.039 μg, respectively, for 11C-AS2471907, and 92 ± 15 MBq and 0.001 ± 0.001 μg for 18F-AS2471907. Correlations of mean whole brain and regional distribution volume (VT) with body mass index (BMI) and age were performed with a linear regression model. RESULTS: Significant correlations of whole brain mean VT with BMI and age (VT = 15.23-0.63 × BMI + 0.27 × Age, p = 0.001) were revealed. Age-adjusted mean whole brain VT values were significantly lower in obese individuals. Post hoc region specific analyses revealed significantly reduced mean VT values in the thalamus (lean vs. overweight and lean vs. obese individuals). Caudate, hypothalamus, parietal lobe, and putamen also showed lower VT value in obese vs. lean individuals. A significant age-associated increase of 2.7 mL/cm3 per decade was seen in BMI-corrected mean whole brain VT values. CONCLUSIONS: In vivo PET imaging demonstrated, for the first time, correlation of higher BMI (obesity) with lower levels of the enzyme 11β-HSD1 in the brain and correlation of increased 11β-HSD1 levels in the brain with advancing age.
Entities:
Keywords:
11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1); Aging; Body mass index (BMI); Brain imaging; Neuroendocrinology; Obesity; PET imaging
Authors: Eva Rask; Brian R Walker; Stefan Söderberg; Dawn E W Livingstone; Mats Eliasson; Owe Johnson; Ruth Andrew; Tommy Olsson Journal: J Clin Endocrinol Metab Date: 2002-07 Impact factor: 5.958