Upper and lower body adipose tissue function: a direct comparison of fat mobilization in humans.
OBJECTIVE
Fat in the lower body is not associated with the same risk of cardiovascular disease as fat in the upper body. Is this explained by differences in the physiological functioning of the two depots? This study had two objectives: 1) to determine whether fat mobilization and blood flow differ between gluteal and abdominal adipose tissues in humans, and 2) to develop a new technique to assess gluteal adipose tissue function directly.


METHODS
We performed detailed in vivo studies of adipose tissue function involving the assessment of fat mobilization by measurement of adipose tissue blood flows, arterio-venous differences of metabolites across each depot, and gene expression in tissue biopsies in a small-scale physiological study.


RESULTS
Gluteal adipose tissue has a lower blood flow (67% lower, p < 0.05) and lower hormone-sensitive lipase rate of action (87% lower, p < 0.05) than abdominal adipose tissue. Lipoprotein lipase rate of action and mRNA expression are not different between the depots. This is the first demonstration of a novel technique to directly investigate gluteal adipose tissue metabolism.


CONCLUSIONS
Direct assessment of fasting adipose tissue metabolism in defined depots show that the buttock is metabolically "silent" in terms of fatty acid release compared with the abdomen.
Tan
Garry D
GD
Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom. garry.tan@oxlip.ox.ac.uk
Goossens
Gijs H
GH
Humphreys
Sandy M
SM
Vidal
Hubert
H
Karpe
Fredrik
F
D000005:Abdomen; D000273:Adipose Tissue / Q000098:blood supply* / Q000502:physiology*; D000328:Adult; D001158:Arteries; D001706:Biopsy; D001783:Blood Flow Velocity; D001823:Body Composition; D015992:Body Mass Index; D002081:Buttocks; D005227:Fatty Acids / Q000097:blood; D006801:Humans; D007700:Kinetics; D008071:Lipoprotein Lipase / Q000235:genetics / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000032:analysis; D002787:Sterol Esterase / Q000378:metabolism; D014280:Triglycerides / Q000097:blood; D014680:Veins
D005227:Fatty Acids; D012333:RNA, Messenger; D014280:Triglycerides; D002787:Sterol Esterase; D008071:Lipoprotein Lipase