Limb fat to trunk fat ratio in elderly persons is a strong determinant of insulin resistance and adiponectin levels.
BACKGROUND
Similar to lipodystrophy syndromes, aging results in increased visceral adiposity with loss of subcutaneous adipose tissue in the extremities. The hypothesis of this study is that the distribution of limb fat to trunk fat (LF/TF) ratio in elderly persons has a stronger correlation than trunk fat alone to insulin resistance and adiponectin levels.


METHODS
Thirty-eight elderly participants were divided into an insulin-resistant (IR) group and an insulin-sensitive (IS) group. Limb fat and trunk fat were measured by dual-energy x-ray absorptiometry. Insulin resistance was measured by a hyperinsulinemic-euglycemic clamp.


RESULTS
There was no significant difference between the IS and IR groups with respect to body mass index, body fat index, absolute amount of trunk fat, or percent body fat. However, the difference in LF/TF ratio between the IS (1.02 +/- 0.05) and the IR groups (0.77 +/- 0.05) was highly significantly different (p <.001). Insulin resistance had a stronger correlation to the LF/TF ratio (r = 0.61, p <.001) than to absolute trunk fat (r = -0.32, p =.051). Adiponectin levels had a strong association with the LF/TF ratio (r = 0.63, p <.001), but did not correlate to absolute trunk fat (r = -0.24, p =.18).


CONCLUSIONS
The distribution of body fat (LF/TF ratio) in elderly persons is a stronger determinant of insulin resistance and adiponectin levels than is trunk fat alone. The LF/TF ratio can be a useful tool to assess insulin sensitivity in the elderly population.
Gavi
Shai
S
Department of Medicine, Division of General Medicine and Geriatrics, School of Medicine, Health Sciences Center, State University of New York at Stony Brook, Stony Brook, NY 11794-8154, USA. sgavi@notes.cc.sunysb.edu
Feiner
Joshua J
JJ
Melendez
Mark M
MM
Mynarcik
Dennis C
DC
Gelato
Marie C
MC
McNurlan
Margaret A
MA
D000005:Abdomen; D015502:Absorptiometry, Photon; D052242:Adiponectin / Q000097:blood; D050154:Adiposity / Q000502:physiology*; D000368:Aged; D000375:Aging / Q000097:blood / Q000473:pathology* / Q000502:physiology*; D050218:Body Fat Distribution; D005121:Extremities; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D013909:Thorax
C499918:ADIPOQ protein, human; D052242:Adiponectin