Morphology and function: MR pineal volume and melatonin level in human saliva are correlated.
OBJECTIVE
To investigate the relation between circadian saliva melatonin levels and pineal volume as determined by MRI. Plasma melatonin levels follow a circadian rhythm with a high interindividual variability.


METHODS
In 103 healthy individuals saliva melatonin levels were determined at four time points within 24 h and MRI was performed once (3.0 Tesla, including three-dimensional T2 turbo spin echo [3D-T2-TSE], susceptibility-weighted imaging [SWI]). Pineal volume as well as cyst volume were assessed from multiplanar reconstructed 3D-T2-TSE images. Pineal calcification volume tissue was determined on SWI. To correct for hormonal inactive pineal tissue, cystic and calcified areas were excluded. Sleep quality was assessed with the Landeck Inventory for sleep quality disturbance.


RESULTS
Solid and uncalcified pineal volume correlated to melatonin maximum (r = 0.28; P < 0.05) and area under the curve (r = 0.29; P < 0.05). Of interest, solid and uncalcified pineal volume correlated negatively with the sleep rhythm disturbances subscore (r = -0.17; P < 0.05) despite a very homogenous population.


CONCLUSIONS
Uncalcified solid pineal tissue measured by 3D-T2-TSE and SWI is related to human saliva melatonin levels. The analysis of the sleep quality and pineal volume suggests a linkage between better sleep quality and hormonal active pineal tissue.
Department of Neuroradiology, Medical Faculty Mannheim, University of Heidelberg, Germany.
Luisa-Sophie
LS
Liebrich
Michael
M
Schredl
Peter
P
Findeisen
Christoph
C
Groden
Jan Malte
JM
Bumb
Ingo S
IS
Nölte
D000293:Adolescent; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D009929:Organ Size / Q000502:physiology; D010870:Pineal Gland / Q000033:anatomy & histology* / Q000502:physiology*; D015203:Reproducibility of Results; D012463:Saliva / Q000378:metabolism*; D012680:Sensitivity and Specificity; D012894:Sleep Stages / Q000502:physiology*; D013223:Statistics as Topic; D055815:Young Adult
D008550:Melatonin
magnetic resonance imaging (MRI); melatonin; pineal gland volume; saliva; sleep; volume