Depot- and ethnic-specific differences in the relationship between adipose tissue inflammation and insulin sensitivity.
OBJECTIVE
It is unclear whether there are differences in inflammatory gene expression between abdominal and gluteal subcutaneous adipose tissue (SAT), and between black and white women. We therefore tested the hypotheses that SAT inflammatory gene expression is greater in the abdominal compared to the gluteal depot, and SAT inflammatory gene expression is associated with differential insulin sensitivity (S(I) ) in black and white women.


METHODS
S(I) (frequently sampled intravenous glucose tolerance test) and abdominal SAT and gluteal SAT gene expression levels of 13 inflammatory genes were measured in normal-weight (BMI 18-25 kg/m²) and obese (BMI >30 kg/m²) black (n = 30) and white (n = 26) South African women.


RESULTS
Black women had higher abdominal and gluteal SAT expression of CCL2, CD68, TNF-α and CSF-1 compared to white women (P < 0·01). Multivariate analysis showed that inflammatory gene expression in the white women explained 56·8% of the variance in S(I) (P < 0·005), compared to 20·9% in black women (P = 0·30). Gluteal SAT had lower expression of adiponectin, but higher expression of inflammatory cytokines, macrophage markers and leptin than abdominal SAT depots (P < 0·05).


CONCLUSIONS
Black South African women had higher inflammatory gene expression levels than white women; however, the relationship between AT inflammation and S(I) was stronger in white compared to black women. Further research is required to explore other factors affecting S(I) in black populations. Contrary to our original hypothesis, gluteal SAT had a greater inflammatory gene expression profile than abdominal SAT depots. The protective nature of gluteo-femoral fat therefore requires further investigation.
Evans
Juliet
J
Department of Human Biology, the University of Cape Town, South African.
Goedecke
Julia H
JH
Söderström
Ingegerd
I
Burén
Jonas
J
Alvehus
Malin
M
Blomquist
Caroline
C
Jonsson
Fredrik
F
Hayes
Philip M
PM
Adams
Kevin
K
Dave
Joel A
JA
Levitt
Naomi S
NS
Lambert
Estelle V
EV
Olsson
Tommy
T
D000273:Adipose Tissue / Q000276:immunology* / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D044383:Black People; D018932:Chemokine CCL2 / Q000378:metabolism; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007333:Insulin Resistance / Q000502:physiology*; D016173:Macrophage Colony-Stimulating Factor / Q000378:metabolism; D008875:Middle Aged; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050151:Subcutaneous Fat / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D044465:White People; D055815:Young Adult; D000097382:CD68 Molecule
D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D018932:Chemokine CCL2; D016173:Macrophage Colony-Stimulating Factor; D014409:Tumor Necrosis Factor-alpha; C067980:CD68 antigen, human; D000097382:CD68 Molecule