Relationship between ambient light and glucose metabolism in healthy subjects

Hirofumi Hirakawa,Koji Hatano,Takeshi Terao,Kentaro Kohno,Nobuyoshi Ishii

doi:10.1186/s12868-018-0444-x

Abstract

BackgroundGiven the reported inverse association between light and depressive mood, ambient light may also be associated with some of the brain regions in healthy subjects. The present study aims to investigate the effects of ambient light on glucose metabolism in the brain. We used the data of 28 healthy participants of the no intervention group from our previous randomized controlled trial and analyzed the association between ambient light and [18F]-FDG uptake in the brain.ResultsA whole brain analysis revealed a cluster of [18F]-FDG uptake that was significantly and inversely associated with log-transformed ambient light in the left culmen of the left cerebellum vermis. After adjustment for age, gender and serum melatonin levels, there remained a significant cluster of [18F]-FDG uptake with log-transformed ambient light in the left cerebellar vermis.ConclusionsThe present findings suggest that the uptake of [18F]-FDG is significantly and inversely associated with ambient light in the left cerebellar vermis in healthy subjects. The cerebellar vermis may be involved in mood suppression which may be alleviated by light exposure where glucose uptake and metabolism in this area are decreased.Trial Registration This study is a secondary analysis of the previous randomized study which wasregistered as UMIN000007537. Retrospectively registered (March 20th, 2012).

Highlights

Given the reported inverse association between light and depressive mood, ambient light may be associated with some of the brain regions in healthy subjects
Regions labeled by Talairach Daemon of the Wake Forest University Pick-Atlas *Family-Wise Error corrected p < 0.05 significantly and negatively associated with serum melatonin levels (r = − 0.38, p = 0.04), but there was no significant association between log-transformed ambient light and HDRS (r = 0.23, p = 0.23), Beck depression inventory (BDI) (r = 0.00, p = 0.97) or Young mania rating scale (YMRS) (r = 0.16, p = 0.39)
There may be other several mechanisms about light [9], the cerebellar vermis may be involved in mood suppression which may be alleviated by light exposure where glucose uptake and metabolism in this area are decreased

Summary

Introduction

Given the reported inverse association between light and depressive mood, ambient light may be associated with some of the brain regions in healthy subjects. The present study aims to investigate the effects of ambient light on glucose metabolism in the brain. Results: A whole brain analysis revealed a cluster of [18F]-FDG uptake that was significantly and inversely associated with log-transformed ambient light in the left culmen of the left cerebellum vermis. Conclusions: The present findings suggest that the uptake of [18F]-FDG is significantly and inversely associated with ambient light in the left cerebellar vermis in healthy subjects. Given the reported significant negative association between the illuminance of daylight and depressive mood in healthy subjects [3], ambient light may be associated with some of the above regions in healthy subjects.

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Results

Discussion

Conclusion