Functional brown adipose tissue and sympathetic activity after cold exposure in humans with type 1 narcolepsy

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Lotte Hahn Enevoldsen, Marie Tindborg, Nichlas Lindegaard Hovmand, Christina Christoffersen, Helga Ellingsgaard, Charlotte Suetta, Bente Merete Stallknecht, Poul Joergen Jennum, Andreas Kjær, Steen Gammeltoft

Study objectives: To investigate the activity of brown adipose tissue (BAT) in type 1 narcolepsy patients during cold exposure using two separate scans of sympathetic and metabolic activity of BAT in order to evaluate whether orexin deficiency leads to altered non-shivering thermoregulation in narcolepsy.

Methods: Seven patients with type 1 narcolepsy and seven healthy controls underwent two consecutive scans after 2 h cold exposure: 123I-meta-iodo-benzyl-guanidine (123I-MIBG) single photon emission computed tomography and 18F-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 h in the cold.

Results: 18F-FDG-uptake and uptake of 123I-MIBG in BAT after 2 h cold exposure was observed in all individuals, but the activity of BAT was not significantly different between type 1 narcolepsy patients and healthy controls (p>0.05). Plasma levels of GLP-1 were higher in type 1 narcolepsy patients compared with controls (p<0.05), but not altered by cold adaptation in patients and controls (p>0.05). FGF21 concentrations decreased after 2 h cold exposure in both type 1 narcolepsy patients and healthy subjects (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.

OriginalsprogEngelsk
Artikelnummerzsy092
TidsskriftSleep
Vol/bind41
Udgave nummer8
Sider (fra-til)1-9
ISSN0161-8105
DOI
StatusUdgivet - 2018

ID: 198408094