Study Objectives: To investigate the activity of brown adipose tissue (BAT) in patients with type 1 narcolepsy during cold exposure using two separate scans of sympathetic and metabolic activity of BAT to evaluate whether orexin deficiency leads to altered nonshivering thermoregulation in narcolepsy. Methods: Seven patients with type 1 narcolepsy and seven healthy controls underwent two consecutive scans after 2 hr cold exposure: 123I-meta-iodo-benzyl-guanidine (123I-MIBG) single photon emission computed tomography and18F-2-deoxy-glucose (18F-FDG) positron emission tomography and computed tomography to visualize sympathetic innervation and metabolic activity of BAT, respectively. Plasma levels of eight hormones regulating BAT activity were measured before and after 2 hr in the cold. Results: 18F-FDG-uptake and uptake of 123I-MIBG in BAT after 2 hr cold exposure were observed in all individuals, but the activity of BAT was not significantly different between patients with type 1 narcolepsy and healthy controls (p > 0.05). Plasma levels of GLP-1 were higher in patients with type 1 narcolepsy compared with controls (p < 0.05), but not altered by cold adaptation in patients and controls (p > 0.05). FGF21 concentrations decreased after 2 hr cold exposure in both patients with type 1 narcolepsy and healthy participants (p < 0.05). Conclusions: Sympathetic and metabolic activity of BAT was observed after cold exposure in patients with type 1 narcolepsy. Increased GLP-1 in narcolepsy may suggest autonomic dysfunction with metabolic changes. We conclude that BAT is functional after cold exposure in spite of the loss of orexinergic neurons in narcolepsy.
Study Objectives: To investigate the activity of brown adipose tissue (BAT) in patients with type 1 narcolepsy during cold exposure using two separate scans of sympathetic and metabolic activity of BAT to evaluate whether orexin deficiency leads to altered nonshivering thermoregulation in narcolepsy. Methods: Seven patients with type 1 narcolepsy and seven healthy controls underwent two consecutive scans after 2 hr cold exposure: 123I-meta-iodo-benzyl-guanidine (123I-MIBG) single photon emission computed tomography and18F-2-deoxy-glucose (18F-FDG) positron emission tomography and computed tomography to visualize sympathetic innervation and metabolic activity of BAT, respectively. Plasma levels of eight hormones regulating BAT activity were measured before and after 2 hr in the cold. Results: 18F-FDG-uptake and uptake of 123I-MIBG in BAT after 2 hr cold exposure were observed in all individuals, but the activity of BAT was not significantly different between patients with type 1 narcolepsy and healthy controls (p > 0.05). Plasma levels of GLP-1 were higher in patients with type 1 narcolepsy compared with controls (p < 0.05), but not altered by cold adaptation in patients and controls (p > 0.05). FGF21 concentrations decreased after 2 hr cold exposure in both patients with type 1 narcolepsy and healthy participants (p < 0.05). Conclusions: Sympathetic and metabolic activity of BAT was observed after cold exposure in patients with type 1 narcolepsy. Increased GLP-1 in narcolepsy may suggest autonomic dysfunction with metabolic changes. We conclude that BAT is functional after cold exposure in spite of the loss of orexinergic neurons in narcolepsy.
Authors: Francisco M Acosta; Guillermo Sanchez-Delgado; Borja Martinez-Tellez; Jairo H Migueles; Francisco J Amaro-Gahete; Patrick C N Rensen; Jose M Llamas-Elvira; Denis P Blondin; Jonatan R Ruiz Journal: Sleep Date: 2019-12-24 Impact factor: 5.849
Authors: Maaike E Straat; Mink S Schinkelshoek; Rolf Fronczek; Gerrit Jan Lammers; Patrick C N Rensen; Mariëtte R Boon Journal: Front Endocrinol (Lausanne) Date: 2020-04-16 Impact factor: 5.555