TY - JOUR
T1 - Functional brown adipose tissue and sympathetic activity after cold exposure in humans with type 1 narcolepsy
AU - Enevoldsen, Lotte Hahn
AU - Tindborg, Marie
AU - Hovmand, Nichlas Lindegaard
AU - Christoffersen, Christina
AU - Ellingsgaard, Helga
AU - Suetta, Charlotte
AU - Stallknecht, Bente Merete
AU - Jennum, Poul Joergen
AU - Kjær, Andreas
AU - Gammeltoft, Steen
PY - 2018/8/1
Y1 - 2018/8/1
N2 - 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.
AB - 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.
U2 - 10.1093/sleep/zsy092
DO - 10.1093/sleep/zsy092
M3 - Journal article
C2 - 29771387
SN - 0161-8105
VL - 41
SP - 1
EP - 9
JO - Sleep
JF - Sleep
IS - 8
M1 - zsy092
ER -