Expression of tumor necrosis factor (TNF)-alpha protein in the subcutaneous and visceral adipose tissue in correlation with adipocyte cell volume, serum TNF-alpha, soluble serum TNF-receptor-2 concentrations and C-peptide level.
OBJECTIVE
The aim of the study was to evaluate the expression of tumor necrosis factor (TNF)-alpha protein in the subcutaneous and visceral adipose tIssue in correlation with adipocyte cell Volume, serum TNF-alpha, soluble TNF-receptor-2 (sTNFR-2) and indirect parameters of insulin resistance in overweight/obese and lean healthy persons.


METHODS
A cross-sectional case-control study was used.


METHODS
Twenty-eight overweight/obese probands with normal glucose tolerance (BMI>27 kg/m(2)) and 15 lean people (BMI<25 kg/m(2)), all of them undergoing planned surgical operation, participated in the study.


METHODS
Two to four grams of subcutaneous and visceral adipose tIssue were removed and studied using semi-quantitative immunohistochemical staining of the TNF-alpha protein. Serum TNF-alpha, sTNFR-2 (ELISA) and fasting C-peptide (RIA) were measured.


RESULTS
TNF-alpha protein was expressed in adipocytes of both depots. The expression was evaluated visually and found to be greater in the obese patients. Significantly higher serum TNF-alpha (5.58+/-0.87 pg/ml vs 4.21+/-0.55, mean+/-s.d., P<0.01, Mann-Whitney) and sTNFR-2 levels (7.84+/-3.56 ng/ml vs 4.59+/-1.35, P=0.005) were found in the obese subgroup in correlation with the fasting C-peptide level (r=0.49, P=0.003; and r=0.74, P=0.001) and the C-peptide/ blood glucose ratio (r=0.47, Spearman, P=0.005; and r=0.70, P=0.001). The cell Volume of both adipocyte depots was found to have a significant positive correlation with serum TNF-alpha and sTNFR-2 levels in the total group of patients (subcutaneous: r=0.52, P=0.0003; r=0.69, P<0.0001; visceral: r=0.65, P<0.0001; r=0.63, P<0.0001) and in both subgroups.


CONCLUSIONS
Adipocyte cell Volume of both the subcutaneous and visceral fat depots may be determinants of TNF-alpha, sTNFR-2 production and obesity-linked insulin resistance.
Winkler
Gábor
G
Department of Internal Medicine II, St John's Hospital, Budapest, Hungary. winkler.gabor@axelero.hu
Kiss
Sándor
S
Keszthelyi
László
L
Sápi
Zoltán
Z
Ory
Iván
I
Salamon
Ferenc
F
Kovács
Margit
M
Vargha
Péter
P
Szekeres
Orsolya
O
Speer
Gábor
G
Karádi
István
I
Sikter
Marta
M
Kaszás
Edit
E
Dworak
Otto
O
Gerö
Gábor
G
Cseh
Károly
K
D017667:Adipocytes / Q000378:metabolism* / Q000648:ultrastructure*; D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D002096:C-Peptide / Q000097:blood; D048429:Cell Size; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D018124:Receptors, Tumor Necrosis Factor / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
D002096:C-Peptide; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha