Aging per se does not influence glucose homeostasis: in vivo and in vitro evidence.
OBJECTIVE
To assess the effect of age on glucose metabolism by examining 1) glucose metabolism in young and middle-aged subjects when total or regional adiposity is taken into account and 2) in vitro glucose transport in adipose tissue explants from young and middle-aged women paired for total and abdominal adiposity.


METHODS
Study 1: body composition, subcutaneous abdominal and visceral adipose tissue areas, and fasting and oral glucose-stimulated glucose and insulin were measured in 84 young and 81 middle-aged men and in 110 young and 91 middle-aged women. Study 2: glucose uptake in subcutaneous abdominal and visceral adipose tissue explants were measured in eight young and eight middle-aged women.


RESULTS
Study 1: young and middle-aged men showed similar subcutaneous abdominal tissue area, whereas fat mass and visceral adipose tissue were greater in middle-aged than in young men (P < 0.01). Fat mass and subcutaneous and visceral adipose tissue areas were greater in middle-aged as compared with young women (P < 0.01). Fasting plasma glucose and the glucose response to an oral glucose tolerance test were significantly higher in middle-aged than in young men and women (P < 0.001). Statistical control for visceral adipose tissue area eliminated the difference seen in glucose response in men and women. Study 2: glucose transport in subcutaneous and omental adipose tissue did not differ between young and middle-aged women.


CONCLUSIONS
1) Visceral obesity, more than age per se, correlates with glucose intolerance in middle-aged subjects; 2) aging does not influence in vitro adipose tissue glucose uptake.
Imbeault
Pascal
P
School of Human Kinetics, University of Ottawa, Ontario, Canada. imbeault@uottawa.ca
Prins
Johannes B
JB
Stolic
Manuela
M
Russell
Anthony W
AW
O'Moore-Sullivan
Trisha
T
Després
Jean-Pierre
JP
Bouchard
Claude
C
Tremblay
Angelo
A
D000005:Abdomen; D000273:Adipose Tissue / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D001786:Blood Glucose / Q000032:analysis; D005215:Fasting / Q000097:blood; D005260:Female; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D006706:Homeostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism* / Q000473:pathology; D009852:Omentum; D040521:Subcutaneous Tissue / Q000378:metabolism; D014781:Viscera
D001786:Blood Glucose; D005947:Glucose